/* ==========================================================================
   PORTFOLIO DESIGN SYSTEM — COMPLETE REFINED EDITION
   Candidate: Bhamidipati, Shiridi Prasad Revanth
   Architecture: Unified CSS Variables, Dual Themes, Responsive Layouts, Motion
   ========================================================================== */

/* --- CSS RESET & BASE STYLES --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root, html[data-theme="dark"], body[data-theme="dark"] {
  --theme: "dark";
  
  /* Canvas & Background Surfaces */
  --bg-base: #07090E;
  --bg-surface: #0E1320;
  --bg-card: #131A2C;
  --bg-card-hover: #182238;
  --bg-elevated: #1D2944;
  --bg-subtle: rgba(255, 255, 255, 0.03);
  --bg-overlay: rgba(7, 9, 14, 0.85);

  /* Borders & Dividers */
  --border-subtle: #1D263B;
  --border-medium: #2B3754;
  --border-bright: #3E4E75;
  --border-glow: rgba(56, 189, 248, 0.35);

  /* Typography Colors */
  --text-pure: #F8FAFC;
  --text-main: #E2E8F0;
  --text-sub: #94A3B8;
  --text-dim: #64748B;
  --text-inverse: #07090E;

  /* Domain Palette */
  --brand-cyan: #38BDF8;
  --brand-blue: #0284C7;
  --brand-indigo: #818CF8;
  --brand-emerald: #10B981;
  --brand-amber: #F59E0B;
  --brand-rose: #FB7185;
  --brand-purple: #C084FC;

  /* Ambient Glows */
  --glow-cyan: rgba(56, 189, 248, 0.15);
  --glow-emerald: rgba(16, 185, 129, 0.15);
  --glow-amber: rgba(245, 158, 11, 0.15);
  --glow-indigo: rgba(129, 140, 248, 0.15);

  /* Elevation Shadows */
  --shadow-sm: 0 2px 6px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.65);

  /* Typography Stacks */
  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, 'Liberation Mono', monospace;
  --font-hand: 'Caveat', 'Nanum Pen Script', 'Segoe Print', 'Bradley Hand', 'Comic Sans MS', cursive;
}

/* Light Theme Variables */
html[data-theme="light"], body[data-theme="light"] {
  --theme: "light";

  --bg-base: #F8FAFC;
  --bg-surface: #FFFFFF;
  --bg-card: #FFFFFF;
  --bg-card-hover: #F1F5F9;
  --bg-elevated: #E2E8F0;
  --bg-subtle: rgba(0, 0, 0, 0.03);
  --bg-overlay: rgba(248, 250, 252, 0.9);

  --border-subtle: #E2E8F0;
  --border-medium: #CBD5E1;
  --border-bright: #94A3B8;
  --border-glow: rgba(2, 132, 199, 0.35);

  --text-pure: #0F172A;
  --text-main: #1E293B;
  --text-sub: #475569;
  --text-dim: #64748B;
  --text-inverse: #FFFFFF;

  --brand-cyan: #0284C7;
  --brand-blue: #0369A1;
  --brand-indigo: #4F46E5;
  --brand-emerald: #059669;
  --brand-amber: #D97706;
  --brand-rose: #E11D48;
  --brand-purple: #9333EA;

  --glow-cyan: rgba(2, 132, 199, 0.1);
  --glow-emerald: rgba(5, 150, 105, 0.1);
  --glow-amber: rgba(217, 119, 6, 0.1);
  --glow-indigo: rgba(79, 70, 229, 0.1);

  --shadow-sm: 0 2px 4px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 16px 40px rgba(15, 23, 42, 0.12);
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-base);
html {
  scroll-behavior: smooth;
  color-scheme: dark light;
  overflow-x: clip;
}

body {
  background-color: var(--bg-base);
  color: var(--text-main);
  font-family: var(--font-sans);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: clip;
  transition: background-color 0.25s ease, color 0.25s ease;
}

/* Container Utility */
.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Typography Utilities */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-pure);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

section[id], header[id] {
  scroll-margin-top: 80px;
}

a {
  color: var(--brand-cyan);
  text-decoration: none;
  transition: all 0.2s ease;
}

a:hover {
  color: var(--brand-indigo);
}

/* Tag & Chip Badges */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 4px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.badge-cyan {
  background: var(--glow-cyan);
  border: 1px solid var(--border-glow);
  color: var(--brand-cyan);
}

.badge-emerald {
  background: var(--glow-emerald);
  border: 1px solid rgba(16, 185, 129, 0.35);
  color: var(--brand-emerald);
}

.badge-indigo {
  background: var(--glow-indigo);
  border: 1px solid rgba(129, 140, 248, 0.35);
  color: var(--brand-indigo);
}

.badge-amber {
  background: var(--glow-amber);
  border: 1px solid rgba(245, 158, 11, 0.35);
  color: var(--brand-amber);
}

/* ==========================================================================
   FLOATING CAPSULE NAVIGATION BAR
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--bg-overlay);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--border-subtle);
  transition: all 0.25s ease;
  padding: 10px 0;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text-pure);
  font-weight: 800;
  font-size: 15px;
  letter-spacing: -0.02em;
  white-space: nowrap;
  flex-shrink: 0;
  text-decoration: none;
}

.brand-symbol {
  width: 38px;
  height: 38px;
  border-radius: 9999px;
  background: linear-gradient(135deg, var(--brand-cyan), var(--brand-indigo));
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 15px;
  box-shadow: 0 4px 14px var(--glow-cyan);
  flex-shrink: 0;
}

/* Floating Navigation Capsule Container */
.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: 9999px;
  padding: 4px 6px;
  box-shadow: var(--shadow-sm);
  transition: all 0.2s ease;
}

/* Capsule Nav Link Item */
.nav-link {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-sub);
  padding: 6px 14px;
  border-radius: 9999px;
  text-decoration: none;
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  border: 1px solid transparent;
}

.nav-link:hover {
  color: var(--text-pure);
  background: var(--bg-card-hover);
}

/* Active Pill Tab */
.nav-link.active {
  background: var(--bg-card-hover);
  color: var(--brand-accent, var(--brand-cyan));
  border-color: var(--accent-border, var(--border-bright));
  font-weight: 700;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.nav-link.active::after {
  display: none;
}

/* Whiteboard Dedicated Badge Pill */
.nav-link.nav-link-whiteboard {
  background: rgba(129, 140, 248, 0.12);
  border: 1px solid rgba(129, 140, 248, 0.3);
  color: var(--brand-indigo) !important;
  font-weight: 700;
  border-radius: 9999px;
  padding: 6px 14px;
  box-shadow: 0 0 10px rgba(129, 140, 248, 0.15);
}

.nav-link.nav-link-whiteboard:hover {
  background: rgba(129, 140, 248, 0.22);
  border-color: var(--brand-indigo);
  transform: translateY(-1px);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

/* Theme Toggle Button - Circular Capsule */
.btn-theme-toggle {
  background: var(--bg-card);
  border: 1px solid var(--border-medium);
  color: var(--text-sub);
  width: 38px;
  height: 38px;
  border-radius: 9999px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 15px;
}

.btn-theme-toggle:hover {
  border-color: var(--brand-cyan);
  color: var(--brand-cyan);
  background: var(--bg-card-hover);
  transform: rotate(15deg);
}

/* Primary Resume Download Button */
.btn-primary {
  background: linear-gradient(135deg, var(--brand-cyan), var(--brand-indigo));
  color: #fff;
  font-size: 13px;
  font-weight: 700;
  padding: 9px 18px;
  border-radius: 8px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 16px var(--glow-cyan);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  white-space: nowrap;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(56, 189, 248, 0.35);
  color: #fff;
}

.btn-secondary {
  background: var(--bg-card);
  border: 1px solid var(--border-medium);
  color: var(--text-pure);
  font-size: 13px;
  font-weight: 600;
  padding: 9px 18px;
  border-radius: 8px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  transition: all 0.15s ease;
}

.btn-secondary:hover {
  border-color: var(--brand-cyan);
  color: var(--brand-cyan);
  background: var(--bg-card-hover);
  transform: translateY(-2px);
}

.btn-whiteboard-jump {
  background: linear-gradient(135deg, rgba(129, 140, 248, 0.15), rgba(56, 189, 248, 0.15));
  border: 1.5px solid var(--brand-indigo);
  color: var(--brand-indigo);
  font-size: 13px;
  font-weight: 700;
  padding: 9px 18px;
  border-radius: 8px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-whiteboard-jump:hover {
  background: linear-gradient(135deg, var(--brand-indigo), var(--brand-cyan));
  color: #fff;
  box-shadow: 0 6px 20px var(--glow-indigo);
  transform: translateY(-2px);
}

/* ==========================================================================
   HERO SECTION
   ========================================================================== */
.hero-section {
  padding: 80px 0 60px 0;
  position: relative;
  overflow: hidden;
}

.hero-content {
  display: grid;
  grid-template-columns: 1.35fr 1fr;
  gap: 48px;
  align-items: center;
}

.hero-eyebrow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: 20px;
}

.pulse-pip {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--brand-emerald);
  box-shadow: 0 0 10px var(--brand-emerald);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.2); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

.hero-title {
  font-size: 46px;
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 20px;
  letter-spacing: -0.03em;
}

.hero-title .gradient-text {
  background: linear-gradient(135deg, var(--brand-cyan), var(--brand-indigo));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-lead {
  font-size: 17px;
  line-height: 1.6;
  color: var(--text-sub);
  margin-bottom: 28px;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 36px;
}

/* Verified Metrics Highlight Bar */
.metrics-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  padding: 20px;
  box-shadow: var(--shadow-sm);
}

.metric-item {
  display: flex;
  flex-direction: column;
}

.metric-number {
  font-size: 26px;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--text-pure);
  line-height: 1.2;
}

.metric-label {
  font-size: 11.5px;
  color: var(--text-sub);
  margin-top: 4px;
}

/* Hero Right: Live Architecture Node Hologram */
.hero-visual-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: 16px;
  padding: 24px;
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

.visual-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 16px;
}

.visual-title {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--brand-cyan);
}

/* Mini Architecture Topology Flow in Hero */
.hero-topology-preview {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.topo-node {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  padding: 12px 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: all 0.2s ease;
}

.topo-node:hover {
  border-color: var(--brand-cyan);
  background: var(--bg-card-hover);
  transform: translateX(4px);
}

.topo-name {
  font-weight: 700;
  font-size: 13px;
  color: var(--text-pure);
}

.topo-tech {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-sub);
}

.topo-flow-arrow {
  text-align: center;
  color: var(--text-dim);
  font-size: 12px;
  font-family: var(--font-mono);
}

/* ==========================================================================
   SECTION COMMON STYLES
   ========================================================================== */
.section {
  padding: 80px 0;
  border-top: 1px solid var(--border-subtle);
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 48px auto;
}

.section-eyebrow {
  display: inline-block;
  margin-bottom: 10px;
}

.section-title {
  font-size: 34px;
  font-weight: 800;
  margin-bottom: 14px;
  letter-spacing: -0.02em;
}

.section-desc {
  font-size: 16px;
  color: var(--text-sub);
  line-height: 1.6;
}

/* ==========================================================================
   WORKFLOWS INTERACTIVE ENGINES (STEP 3 PROTOTYPE CORE)
   ========================================================================== */
.workflow-deck {
  display: flex;
  flex-direction: column;
  gap: 36px;
}

.workflow-card {
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.08), rgba(129, 140, 248, 0.08));
  background-color: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: 20px;
  overflow: hidden;
  box-shadow: 0 8px 32px -6px rgba(0, 0, 0, 0.45);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), border-color 0.25s ease, box-shadow 0.25s ease;
  position: relative;
}

html[data-theme="light"] .workflow-card {
  background: linear-gradient(135deg, rgba(2, 132, 199, 0.06), rgba(99, 102, 241, 0.06));
  background-color: #FFFFFF;
  box-shadow: 0 6px 24px -4px rgba(0, 0, 0, 0.10);
}

.workflow-card:hover {
  border-color: var(--brand-accent);
  box-shadow: 0 16px 40px -8px var(--accent-glow), 0 0 24px rgba(56, 189, 248, 0.25);
}

.workflow-card-header {
  padding: 24px 28px;
  background: rgba(19, 26, 44, 0.70);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(56, 189, 248, 0.18);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

html[data-theme="light"] .workflow-card-header {
  background: rgba(241, 245, 249, 0.85);
  border-bottom-color: rgba(2, 132, 199, 0.18);
}

.wf-title-block h3 {
  font-size: 20px;
  font-weight: 800;
  color: var(--text-pure);
  margin-bottom: 4px;
}

.wf-meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-sub);
}

.wf-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}

.wf-btn {
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  color: var(--text-main);
  padding: 6px 12px;
  border-radius: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.15s ease;
}

.wf-btn:hover:not(:disabled) {
  border-color: var(--brand-cyan);
  color: var(--brand-cyan);
}

.wf-btn:disabled {
  opacity: 0.38 !important;
  cursor: not-allowed !important;
  pointer-events: none !important;
  filter: grayscale(60%) !important;
}

.wf-btn.active {
  background: var(--brand-cyan);
  color: #07090E;
  border-color: var(--brand-cyan);
  font-weight: 700;
}

/* Workflow Stage Visualizer */
.wf-visualizer {
  padding: 28px;
  background: #0B0E17;
  border-top: 1.5px solid #28344E;
  background-image: radial-gradient(#1A2234 1.5px, transparent 1.5px);
  background-size: 20px 20px;
}

html[data-theme="light"] .wf-visualizer {
  background: #F8FAFC;
  border-top-color: #CBD5E1;
  background-image: radial-gradient(#E2E8F0 1.5px, transparent 1.5px);
}

/* Stage Stepper Navigation Track */
.wf-steps-track {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px;
  margin-bottom: 24px;
  position: relative;
}

.wf-step-node {
  background: #141B2A;
  border: 1.5px solid #28344E;
  border-radius: 10px;
  padding: 14px;
  cursor: pointer;
  transition: all 0.2s ease;
  position: relative;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

html[data-theme="light"] .wf-step-node {
  background: #FFFFFF;
  border-color: #CBD5E1;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.wf-step-node:hover {
  border-color: var(--border-bright);
}

.wf-step-node.active {
  border-color: var(--brand-cyan);
  background: var(--bg-card-hover);
  box-shadow: 0 0 20px var(--glow-cyan);
}

.wf-step-node.completed {
  border-color: var(--brand-emerald);
}

.step-num {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  color: var(--text-dim);
  text-transform: uppercase;
  margin-bottom: 4px;
}

.wf-step-node.active .step-num {
  color: var(--brand-cyan);
}

.step-label {
  font-weight: 700;
  font-size: 13px;
  color: var(--text-pure);
  line-height: 1.3;
}

/* Explanation & Contract Panel */
.wf-explanation-panel {
  background: rgba(20, 27, 42, 0.85);
  border: 1px solid rgba(56, 189, 248, 0.25);
  border-radius: 12px;
  padding: 20px 24px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
}

html[data-theme="light"] .wf-explanation-panel {
  background: #FFFFFF;
  border-color: #E2E8F0;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.wf-explain-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 10px;
}

.wf-explain-title {
  font-weight: 700;
  font-size: 15px;
  color: var(--text-pure);
}

.wf-explain-text {
  font-size: 14px;
  color: var(--text-main);
  line-height: 1.6;
  margin-bottom: 16px;
}

.wf-contract-code {
  background: var(--bg-base);
  border: 1px solid var(--border-medium);
  border-radius: 6px;
  padding: 14px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--brand-cyan);
  overflow-x: auto;
  line-height: 1.5;
  display: none;
}

.wf-contract-code.show {
  display: block;
}

.wf-verified-banner {
  margin-top: 16px;
  background: var(--glow-emerald);
  border: 1px solid rgba(16, 185, 129, 0.35);
  border-radius: 6px;
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--brand-emerald);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* ==========================================================================
   PROJECT SHOWCASE & 4-PART MATRIX CARDS
   ========================================================================== */
.project-filter-tabs {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 36px;
}

.filter-tab {
  background: var(--bg-card);
  border: 1px solid var(--border-medium);
  color: var(--text-sub);
  font-family: var(--font-mono);
  font-size: 12px;
  padding: 7px 16px;
  border-radius: 20px;
  cursor: pointer;
  transition: all 0.15s ease;
}

.filter-tab:hover, .filter-tab.active {
  background: var(--brand-cyan);
  color: #07090E;
  border-color: var(--brand-cyan);
  font-weight: 700;
}

#projects .container {
  max-width: 1440px;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 1400px;
  margin: 0 auto;
  width: 100%;
}

.project-card {
  width: 100%;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.08), rgba(129, 140, 248, 0.08));
  background-color: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: 20px;
  padding: 24px 22px;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 24px -4px rgba(0, 0, 0, 0.35);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), border-color 0.25s ease, box-shadow 0.25s ease;
}

html[data-theme="light"] .project-card {
  background: linear-gradient(135deg, rgba(2, 132, 199, 0.06), rgba(99, 102, 241, 0.06));
  background-color: #FFFFFF;
  box-shadow: 0 4px 20px -4px rgba(0, 0, 0, 0.08);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-bottom: 32px;
}

.about-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: 14px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

@media (max-width: 1280px) and (min-width: 861px) {
  .projects-grid {
    grid-template-columns: repeat(2, 1fr);
    max-width: 900px;
    gap: 20px;
  }
}

@media (max-width: 860px) and (min-width: 601px) {
  .projects-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    width: 100%;
  }
}

@media (max-width: 600px) {
  .projects-grid {
    grid-template-columns: 1fr;
    gap: 16px;
    width: 100%;
  }
}

.project-card:hover, .about-card:hover {
  transform: translateY(-4px);
  border-color: var(--brand-accent);
  box-shadow: var(--shadow-md);
}

.project-topline {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.project-title {
  font-size: 20px;
  font-weight: 800;
  color: var(--text-pure);
  margin-bottom: 8px;
  line-height: 1.3;
}

.project-summary {
  font-size: 13.5px;
  color: var(--text-sub);
  line-height: 1.5;
  margin-bottom: 18px;
}

/* Plain-English 4-Part Matrix */
.matrix-box {
  background: #0B0E17;
  border: 1.5px solid #28344E;
  border-radius: 12px;
  padding: 14px 16px;
  margin-bottom: 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 12px;
  position: relative;
  background-image: radial-gradient(#1A2234 1.5px, transparent 1.5px);
  background-size: 20px 20px;
  box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.4);
}

html[data-theme="light"] .matrix-box {
  background: #F8FAFC;
  border-color: #CBD5E1;
  background-image: radial-gradient(#E2E8F0 1.5px, transparent 1.5px);
  box-shadow: inset 0 1px 4px rgba(0, 0, 0, 0.05);
}

.matrix-row {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  line-height: 1.4;
}

.matrix-lbl {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-dim);
  min-width: 65px;
}

.matrix-val {
  color: var(--text-main);
}

.project-tech-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 18px;
}

.project-footer {
  margin-top: auto;
  padding-top: 16px;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.case-study-link {
  font-weight: 700;
  font-size: 13px;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* ==========================================================================
   SYSTEMS WHITEBOARD INTEGRATION CALLOUT
   ========================================================================== */
.whiteboard-banner-section {
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.08), rgba(129, 140, 248, 0.08));
  border: 1px solid var(--border-medium);
  border-radius: 20px;
  padding: 48px;
  margin: 40px 0;
  position: relative;
  overflow: hidden;
}

.wb-banner-content {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 40px;
  align-items: center;
}

.wb-badge-row {
  display: flex;
  gap: 8px;
  margin-bottom: 16px;
}

.wb-banner-title {
  font-size: 32px;
  font-weight: 800;
  margin-bottom: 14px;
  letter-spacing: -0.02em;
}

.wb-banner-desc {
  font-size: 15px;
  color: var(--text-sub);
  line-height: 1.6;
  margin-bottom: 24px;
}

.wb-features-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 28px;
}

.wb-feature-item {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Mockup Canvas Screen Preview */
.wb-preview-screen {
  background: #0B0E17;
  border: 1.5px solid #28344E;
  border-radius: 12px;
  padding: 16px;
  box-shadow: var(--shadow-lg);
  position: relative;
  min-height: 260px;
  background-image: radial-gradient(#1A2234 1.5px, transparent 1.5px);
  background-size: 20px 20px;
}

.wb-mock-node {
  background: #141B2A;
  border: 1px solid #38BDF8;
  border-radius: 6px;
  padding: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: #fff;
  position: absolute;
  box-shadow: 0 6px 16px rgba(0,0,0,0.5);
}

.wb-mock-sticky {
  background: #FEF08A;
  color: #713F12;
  font-family: var(--font-hand);
  font-size: 15px;
  padding: 8px;
  border-radius: 3px;
  position: absolute;
  transform: rotate(-3deg);
  box-shadow: 0 6px 14px rgba(0,0,0,0.3);
}

/* ==========================================================================
   EXPERIENCE & CAREER TIMELINE
   ========================================================================== */
.timeline {
  position: relative;
  max-width: 900px;
  margin: 0 auto;
}

.timeline::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 20px;
  width: 2px;
  background: var(--border-medium);
}

.timeline-item {
  position: relative;
  padding-left: 56px;
  margin-bottom: 40px;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-dot {
  position: absolute;
  left: 13px;
  top: 4px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--bg-surface);
  border: 3px solid var(--brand-cyan);
  box-shadow: 0 0 10px var(--glow-cyan);
}

.timeline-content {
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: 12px;
  padding: 24px;
  box-shadow: var(--shadow-sm);
}

.timeline-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 8px;
  flex-wrap: wrap;
  gap: 8px;
}

.timeline-role {
  font-size: 18px;
  font-weight: 800;
  color: var(--text-pure);
}

.timeline-org {
  font-weight: 700;
  color: var(--brand-cyan);
  font-size: 14px;
}

.timeline-date {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-sub);
}

.timeline-bullets {
  list-style: none;
  margin-top: 14px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.timeline-bullets li {
  font-size: 13.5px;
  color: var(--text-main);
  position: relative;
  padding-left: 18px;
  line-height: 1.5;
}

.timeline-bullets li::before {
  content: '▹';
  position: absolute;
  left: 0;
  color: var(--brand-cyan);
}

/* ==========================================================================
   RESEARCH & IEEE PUBLICATION SPOTLIGHT
   ========================================================================== */
.research-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: 14px;
  padding: 36px;
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.research-card:hover {
  border-color: var(--brand-accent);
}

[data-theme="light"] .research-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  box-shadow: var(--shadow-md);
}

.research-card::after {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 200px;
  height: 200px;
  background: radial-gradient(circle, var(--accent-glow), transparent 70%);
  pointer-events: none;
}

.pub-title {
  font-size: 24px;
  font-weight: 800;
  color: var(--text-pure);
  margin-bottom: 12px;
  line-height: 1.3;
}

.pub-meta {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent-text);
  font-weight: 600;
  margin-bottom: 20px;
}

.pub-abstract {
  font-size: 15px;
  color: var(--text-main);
  line-height: 1.7;
  margin-bottom: 24px;
}

.pub-contributions-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 24px;
}

.pub-contrib-box {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  padding: 18px;
  transition: border-color 0.2s ease;
}

.pub-contrib-box:hover {
  border-color: var(--border-bright);
}

.pub-contrib-title {
  font-weight: 700;
  font-size: 13.5px;
  color: var(--accent-text);
  margin-bottom: 8px;
  font-family: var(--font-mono);
}

.pub-contrib-desc {
  font-size: 13px;
  color: var(--text-sub);
  line-height: 1.5;
}

.btn-research-paper {
  background: var(--brand-accent) !important;
  color: var(--accent-contrast) !important;
  font-weight: 700 !important;
  border-radius: 9999px !important;
  box-shadow: 0 4px 14px var(--accent-glow) !important;
  border: 1px solid rgba(255, 255, 255, 0.15) !important;
  padding: 12px 24px !important;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13.5px;
  text-decoration: none;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn-research-paper:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px var(--accent-glow) !important;
}

/* ==========================================================================
   SKILLS & TECHNICAL MATRIX
   ========================================================================== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.skill-category-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: 12px;
  padding: 24px;
}

.skill-category-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-pure);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.skill-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.skill-chip {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  padding: 4px 10px;
  border-radius: 6px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--text-main);
  transition: all 0.15s ease;
}

.skill-chip:hover {
  border-color: var(--brand-cyan);
  color: var(--brand-cyan);
  background: var(--bg-card-hover);
}

/* ==========================================================================
   CONTACT & FOOTER
   ========================================================================== */
.contact-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: 20px;
  padding: 48px;
  text-align: center;
  max-width: 820px;
  margin: 0 auto;
}

.contact-channels {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px;
  margin: 32px 0;
}

.contact-channel-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-medium);
  color: var(--text-pure);
  padding: 12px 22px;
  border-radius: 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  transition: all 0.2s ease;
}

.contact-channel-btn:hover {
  border-color: var(--brand-cyan);
  color: var(--brand-cyan);
  background: var(--bg-card-hover);
  transform: translateY(-2px);
}

.site-footer {
  padding: 40px 0;
  border-top: 1px solid var(--border-subtle);
  background: var(--bg-surface);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-dim);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

/* ==========================================================================
   RESPONSIVE MEDIA QUERIES (COMPREHENSIVE MULTI-DEVICE OVERHAUL)
   ========================================================================== */

/* 1. Laptop / Landscape Tablet (max-width: 1120px) */
@media (max-width: 1120px) {
  .nav-links {
    display: none !important; /* Switch to clean mobile drawer on <1120px */
  }
  .btn-mobile-menu {
    display: flex !important;
  }
  .nav-inner {
    gap: 12px;
  }
}

/* 2. Tablet & Smaller Viewports (max-width: 1024px) */
@media (max-width: 1024px) {
  .hero-section {
    padding: 60px 0 48px 0;
  }
  .hero-content {
    grid-template-columns: 1fr;
    gap: 36px;
  }
  .hero-visual-card {
    max-width: 720px;
    margin: 0 auto;
    width: 100%;
  }
  .wb-banner-content {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .pub-contributions-grid {
    grid-template-columns: 1fr;
  }
  .about-grid {
    grid-template-columns: 1fr;
    gap: 18px;
  }
  .metrics-strip {
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
  }
}

/* 3. Mid Tablet (max-width: 860px) */
@media (max-width: 860px) {
  .hero-title {
    font-size: clamp(2rem, 4.5vw, 2.75rem);
  }
  .hero-cta-group {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
    width: 100%;
    margin-bottom: 28px;
  }
  .hero-cta-group .btn-primary,
  .hero-cta-group .btn-secondary {
    width: 100%;
    justify-content: center;
    padding: 10px 14px;
    font-size: 13px;
    text-align: center;
  }
  .metrics-strip {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }
  .section {
    padding: 60px 0;
  }
  .section-title {
    font-size: 28px;
  }
}

/* 4. Filter Bar horizontal swipe & compact controls (max-width: 768px) */
@media (max-width: 768px) {
  .filter-group,
  .project-filter-bar {
    display: flex;
    overflow-x: auto;
    flex-wrap: nowrap;
    gap: 8px;
    padding: 4px 4px 10px 4px;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    width: 100%;
  }
  .filter-group::-webkit-scrollbar,
  .project-filter-bar::-webkit-scrollbar {
    display: none;
  }
  .filter-btn {
    flex-shrink: 0;
    white-space: nowrap;
    font-size: 12px;
    padding: 6px 14px;
  }
  .modal-challenge-solution-grid {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  .db-results-grid,
  .bi-cards-row {
    grid-template-columns: 1fr !important;
    gap: 10px !important;
  }
  .wf-steps-track {
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
  }
  .contact-card {
    padding: 32px 20px;
  }
}

/* 5. Mobile Handhelds (max-width: 640px) */
@media (max-width: 640px) {
  .container {
    padding: 0 16px;
  }
  .nav-actions .btn-resume-nav {
    display: none !important; /* Available in hero and slide drawer */
  }
  .brand-link span:last-child {
    font-size: 13.5px;
  }
  .hero-section {
    padding: 40px 0 32px 0;
  }
  .hero-eyebrow {
    gap: 6px;
    margin-bottom: 14px;
  }
  .hero-eyebrow .badge {
    font-size: 11px;
    padding: 4px 8px;
    white-space: normal;
  }
  .hero-title {
    font-size: 26px;
    line-height: 1.2;
    letter-spacing: -0.01em;
  }
  .hero-lead {
    font-size: 14px;
    line-height: 1.6;
  }
  .hero-cta-group {
    grid-template-columns: 1fr;
    gap: 10px;
  }
  .hero-visual-card {
    padding: 16px 14px;
    border-radius: 12px;
  }
  .visual-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }
  .topo-node {
    padding: 10px 12px;
  }
  .topo-name {
    font-size: 12px;
  }
  .topo-tech {
    font-size: 10px;
  }
  .topo-flow-arrow {
    font-size: 10px;
    margin: 4px 0;
  }
  .metrics-strip {
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
  }
  .metric-item {
    padding: 12px 10px;
  }
  .metric-number {
    font-size: 22px;
  }
  .metric-label {
    font-size: 10px;
  }
  .wf-card-header {
    padding: 16px 14px;
  }
  .wf-steps-track {
    grid-template-columns: 1fr;
  }
  .wf-visualizer {
    padding: 16px 12px;
  }
  .wf-explanation-panel {
    padding: 14px 12px;
  }
  .form-row {
    grid-template-columns: 1fr;
  }
  .contact-channels {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
  }
  .contact-channel-btn {
    font-size: 11.5px;
    padding: 10px 14px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }
  .modal-box {
    padding: 18px 14px;
    width: 95vw;
  }
  .modal-stage-matrix {
    grid-template-columns: 1fr !important;
  }
}

/* 6. Small Phone Viewports (max-width: 420px) */
@media (max-width: 420px) {
  .hero-title {
    font-size: 23px;
  }
  .accent-picker-btn span:not(.accent-preview-pip) {
    display: none; /* Icon-only accent swatch on narrow phone */
  }
  .brand-symbol {
    width: 30px;
    height: 30px;
    font-size: 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ==========================================================================
   SPA ARCHITECTURE & ACCENT CUSTOMIZATION ADDITIONS
   ========================================================================== */

/* --- ACCENT COLOR SYSTEM --- */
:root {
  --brand-accent: #0284C7;
  --accent-glow: rgba(2, 132, 199, 0.15);
  --accent-border: rgba(2, 132, 199, 0.35);
  --accent-text: #0284C7;
  --accent-contrast: #FFFFFF;
}

:root[data-theme="dark"] {
  --brand-accent: #38BDF8;
  --accent-glow: rgba(56, 189, 248, 0.18);
  --accent-border: rgba(56, 189, 248, 0.4);
  --accent-text: #38BDF8;
  --accent-contrast: #07090E;
}

.gradient-text {
  background: linear-gradient(135deg, var(--brand-accent), var(--brand-indigo)) !important;
  -webkit-background-clip: text !important;
  -webkit-text-fill-color: transparent !important;
}

/* Nav Active and Links bound to accent */
.nav-link:hover, .nav-link.active,
.mobile-nav-link:hover, .mobile-nav-link.active {
  color: var(--accent-text) !important;
}

.nav-link.active::after {
  background: var(--brand-accent) !important;
}

.brand-symbol {
  background: var(--brand-accent) !important;
  color: var(--accent-contrast) !important;
  box-shadow: 0 4px 12px var(--accent-glow) !important;
}

.btn-primary {
  background: var(--brand-accent) !important;
  color: var(--accent-contrast) !important;
  border: 1px solid rgba(255, 255, 255, 0.15) !important;
  box-shadow: 0 2px 10px var(--accent-glow), 0 1px 2px rgba(0, 0, 0, 0.25) !important;
  font-weight: 700 !important;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1) !important;
}

.btn-primary:hover {
  filter: brightness(1.08) !important;
  box-shadow: 0 6px 20px var(--accent-glow) !important;
  transform: translateY(-1.5px) !important;
}

.btn-secondary {
  background: var(--bg-card) !important;
  border: 1px solid var(--border-medium) !important;
  color: var(--text-pure) !important;
  box-shadow: var(--shadow-sm) !important;
  font-weight: 600 !important;
  transition: all 0.2s ease !important;
}

.btn-secondary:hover {
  border-color: var(--brand-accent) !important;
  color: var(--accent-text) !important;
  background: var(--bg-card-hover) !important;
  transform: translateY(-1.5px) !important;
}

@keyframes workflowFocusPulse {
  0% {
    box-shadow: 0 0 0 0 var(--brand-accent);
    border-color: var(--brand-accent);
  }
  30% {
    box-shadow: 0 0 32px var(--accent-glow), 0 0 0 3px var(--brand-accent);
    border-color: var(--brand-accent);
  }
  100% {
    box-shadow: var(--shadow-md);
    border-color: var(--border-medium);
  }
}

.workflow-focus-pulse {
  animation: workflowFocusPulse 2.4s ease-out;
}

.filter-tab.active {
  background: var(--brand-accent) !important;
  color: var(--accent-contrast) !important;
  border-color: var(--brand-accent) !important;
  box-shadow: 0 0 12px var(--accent-glow) !important;
}

.badge-cyan {
  background: var(--accent-glow) !important;
  border-color: var(--accent-border) !important;
  color: var(--accent-text) !important;
}

.wf-step-node.active {
  border-color: var(--brand-accent) !important;
  box-shadow: 0 0 16px var(--accent-glow) !important;
}

.wf-step-node.active .step-num {
  color: var(--accent-text) !important;
}

.wf-contract-code {
  color: var(--accent-text) !important;
}

/* Accessibility focus indicators */
:focus-visible {
  outline: 2px solid var(--brand-accent) !important;
  outline-offset: 3px !important;
}

/* --- ACCENT PICKER WIDGET --- */
.accent-picker-wrapper {
  position: relative;
  display: inline-block;
}

.btn-accent-toggle {
  background: var(--bg-card);
  border: 1px solid var(--border-medium);
  color: var(--text-main);
  padding: 0 14px;
  border-radius: 9999px;
  display: flex;
  align-items: center;
  gap: 7px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 600;
  transition: all 0.2s ease;
  height: 38px;
}

.btn-accent-toggle:hover {
  border-color: var(--brand-accent);
  color: var(--text-pure);
  background: var(--bg-card-hover);
}

.accent-dot-preview {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--brand-accent);
  box-shadow: 0 0 8px var(--accent-glow);
  display: inline-block;
  flex-shrink: 0;
}

.accent-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: 10px;
  padding: 12px;
  width: 220px;
  box-shadow: var(--shadow-lg);
  display: none;
  z-index: 1100;
}

.accent-dropdown.open {
  display: block;
}

.accent-dropdown-header {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 8px;
}

.accent-presets-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 6px;
  margin-bottom: 10px;
}

.accent-swatch {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, border-color 0.15s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.accent-swatch:hover {
  transform: scale(1.15);
}

.accent-swatch.active {
  border-color: var(--text-pure);
  box-shadow: 0 0 8px currentColor;
}

.accent-custom-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding-top: 8px;
  border-top: 1px solid var(--border-subtle);
}

.accent-custom-label {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-sub);
}

.accent-color-input {
  width: 28px;
  height: 24px;
  padding: 0;
  border: 1px solid var(--border-medium);
  border-radius: 4px;
  background: transparent;
  cursor: pointer;
}

.accent-reset-btn {
  background: transparent;
  border: none;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-dim);
  cursor: pointer;
  text-decoration: underline;
}

.accent-reset-btn:hover {
  color: var(--brand-accent);
}

/* Compact Nav Resume Button */
.btn-resume-nav {
  background: var(--accent-glow);
  border: 1px solid var(--accent-border);
  color: var(--accent-text);
  font-size: 12.5px;
  font-weight: 700;
  padding: 8px 16px;
  border-radius: 9999px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.15s ease;
  white-space: nowrap;
  font-family: var(--font-mono);
}

.btn-resume-nav:hover {
  background: var(--brand-accent);
  color: var(--accent-contrast);
  box-shadow: 0 0 12px var(--accent-glow);
}

/* --- MOBILE NAVIGATION HAMBURGER --- */
.btn-mobile-menu {
  display: none;
  background: var(--bg-card);
  border: 1px solid var(--border-medium);
  color: var(--text-pure);
  width: 38px;
  height: 38px;
  border-radius: 9999px;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  cursor: pointer;
}

.mobile-menu-overlay {
  position: fixed;
  top: 72px;
  left: 0;
  width: 100%;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-medium);
  box-shadow: var(--shadow-lg);
  padding: 16px 24px;
  display: none;
  flex-direction: column;
  gap: 8px;
  z-index: 999;
}

.mobile-menu-overlay.open {
  display: flex;
}

.mobile-nav-link {
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text-main);
  padding: 10px 0;
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.mobile-nav-link:hover, .mobile-nav-link.active {
  color: var(--brand-accent);
}

/* --- PROJECT CARD ACTIONS --- */
.project-card-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px solid var(--border-subtle);
  flex-wrap: wrap;
}

.btn-card-workflow {
  background: var(--accent-glow);
  border: 1px solid var(--accent-border);
  color: var(--accent-text);
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  padding: 7px 14px;
  border-radius: 6px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.15s ease;
}

.btn-card-workflow:hover {
  background: var(--brand-accent);
  color: var(--accent-contrast);
  box-shadow: 0 0 12px var(--accent-glow);
}

.btn-card-case-study {
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 600;
  color: var(--text-sub);
  background: transparent;
  border: 1px solid var(--border-subtle);
  padding: 7px 12px;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.15s ease;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.btn-card-case-study:hover {
  color: var(--text-pure);
  background: var(--bg-card-hover);
  border-color: var(--border-bright);
}

/* --- SPA MODAL & DRAWER SYSTEM --- */
.spa-modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(7, 9, 14, 0.78);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 2000;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
  opacity: 0;
  transition: opacity 0.2s ease;
}

.spa-modal-backdrop.open {
  display: flex;
  opacity: 1;
}

.spa-modal-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: 16px;
  max-width: 860px;
  width: 100%;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  transform: translateY(12px) scale(0.98);
  transition: transform 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.spa-modal-backdrop.open .spa-modal-card {
  transform: translateY(0) scale(1);
}

.spa-modal-header {
  padding: 18px 24px;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.spa-modal-title-block h3 {
  font-size: 18px;
  font-weight: 800;
  color: var(--text-pure);
  margin-bottom: 2px;
}

.spa-modal-meta {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-sub);
}

.spa-modal-close {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  color: var(--text-sub);
  width: 32px;
  height: 32px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 15px;
  transition: all 0.15s ease;
  flex-shrink: 0;
}

.spa-modal-close:hover {
  border-color: var(--brand-accent);
  color: var(--text-pure);
  background: var(--bg-card-hover);
}

.spa-modal-body {
  padding: 24px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

/* Modal Stage Matrix 4-part layout */
.modal-stage-matrix {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}

@media (max-width: 768px) {
  .modal-stage-matrix {
    grid-template-columns: 1fr 1fr;
  }
}

.modal-matrix-box {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  padding: 10px 12px;
}

.modal-matrix-lbl {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 4px;
}

.modal-matrix-val {
  font-size: 12px;
  color: var(--text-pure);
  line-height: 1.4;
}

.modal-matrix-box.outcome {
  background: var(--accent-glow);
  border-color: var(--accent-border);
}

.modal-matrix-box.outcome .modal-matrix-val {
  color: var(--accent-text);
  font-weight: 700;
}

/* Modal Controller Row */
.modal-controls-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  padding: 12px 0;
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
}

.modal-playback-btns {
  display: flex;
  align-items: center;
  gap: 8px;
}

.modal-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-medium);
  color: var(--text-main);
  padding: 6px 12px;
  border-radius: 6px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 5px;
  transition: all 0.15s ease;
}

.modal-btn:hover:not(:disabled) {
  border-color: var(--brand-accent);
  color: var(--text-pure);
}

.modal-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.modal-btn.primary {
  background: var(--accent-glow);
  border-color: var(--accent-border);
  color: var(--accent-text);
  font-weight: 700;
}

.modal-btn.primary.playing {
  background: rgba(245, 158, 11, 0.15);
  border-color: rgba(245, 158, 11, 0.4);
  color: var(--brand-amber);
}

.modal-pills {
  display: flex;
  align-items: center;
  gap: 6px;
}

.modal-pill {
  width: 24px;
  height: 24px;
  border-radius: 6px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  color: var(--text-dim);
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.15s ease;
}

.modal-pill:hover {
  border-color: var(--brand-accent);
  color: var(--text-pure);
}

.modal-pill.active {
  background: var(--brand-accent);
  color: var(--accent-contrast);
  border-color: var(--brand-accent);
  box-shadow: 0 0 8px var(--accent-glow);
}

.modal-pill.completed {
  border-color: var(--brand-accent);
  color: var(--accent-text);
}

/* Modal Progress Bar */
.modal-progress-bar {
  width: 100%;
  height: 3px;
  background: var(--bg-card);
  border-radius: 2px;
  overflow: hidden;
  margin-top: 4px;
}

.modal-progress-fill {
  height: 100%;
  background: var(--brand-accent);
  border-radius: 2px;
  transition: width 0.3s ease;
}

/* Modal Code Block */
.modal-code-block {
  background: var(--bg-base);
  border: 1px solid var(--border-medium);
  border-radius: 8px;
  padding: 14px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--accent-text);
  overflow-x: auto;
  line-height: 1.5;
  margin: 0;
}

/* --- CONTACT FORM --- */
.contact-form {
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: 16px;
  padding: 32px;
  margin-top: 28px;
  max-width: 680px;
  margin-left: auto;
  margin-right: auto;
  box-shadow: var(--shadow-md);
  text-align: left;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

@media (max-width: 640px) {
  .form-row {
    grid-template-columns: 1fr;
  }
}

.form-group {
  margin-bottom: 16px;
}

.form-label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-pure);
  margin-bottom: 6px;
}

.required-star {
  color: var(--brand-rose);
}

.form-input, .form-textarea {
  width: 100%;
  background: var(--bg-card);
  border: 1px solid var(--border-medium);
  border-radius: 8px;
  padding: 10px 14px;
  color: var(--text-pure);
  font-family: var(--font-sans);
  font-size: 13.5px;
  transition: all 0.2s ease;
  outline: none;
}

.form-input:focus, .form-textarea:focus {
  border-color: var(--brand-accent);
  box-shadow: 0 0 10px var(--accent-glow);
}

.form-input.invalid, .form-textarea.invalid {
  border-color: var(--brand-rose) !important;
  box-shadow: 0 0 8px rgba(244, 63, 94, 0.2) !important;
}

.field-error {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--brand-rose);
  margin-top: 4px;
  min-height: 16px;
}

.form-feedback-banner {
  margin-top: 16px;
  padding: 14px;
  border-radius: 8px;
  font-size: 13px;
  line-height: 1.5;
  background: var(--accent-glow);
  border: 1px solid var(--accent-border);
  color: var(--accent-text);
}

/* ==========================================================================
   INTERACTIVE 3D SYSTEMS ARCHITECTURE BACKGROUND CANVAS
   ========================================================================== */
#systems-bg-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 0;
  opacity: 0.90;
  transition: opacity 0.5s ease;
}

[data-theme="light"] #systems-bg-canvas {
  opacity: 0.88;
}

@media (max-width: 768px) {
  #systems-bg-canvas {
    opacity: 0.85;
  }
}

/* Ensure interactive content layers sit cleanly above the 3D canvas */
main,
.site-footer,
.spa-modal-backdrop {
  position: relative;
  z-index: 1;
}

.site-header {
  position: sticky !important;
  top: 0 !important;
  z-index: 1000 !important;
}

/* ==========================================================================
   LAUNCH ANIMATION & TELEMETRY INITIALIZATION
   ========================================================================== */

.hero-content {
  animation: heroLaunchFade 0.85s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes heroLaunchFade {
  0% {
    opacity: 0;
    transform: translateY(18px);
  }
  100% {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ==========================================================================
   CONTAINER ANIMATIONS & DYNAMIC HOVER SPOTLIGHT
   ========================================================================== */
.project-card,
.workflow-card,
.about-card,
.hero-visual-card,
.research-card {
  position: relative;
  overflow: hidden;
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1),
              border-color 0.25s ease,
              box-shadow 0.25s ease;
}

/* Dynamic radial gradient light tracking */
.project-card::before,
.workflow-card::before,
.about-card::before,
.hero-visual-card::before,
.research-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  pointer-events: none;
  background: radial-gradient(
    420px circle at var(--mouse-x, -999px) var(--mouse-y, -999px),
    var(--accent-glow),
    transparent 65%
  );
  opacity: 0;
  transition: opacity 0.3s ease;
  border-radius: inherit;
  z-index: 0;
}

.project-card:hover::before,
.workflow-card:hover::before,
.about-card:hover::before,
.hero-visual-card:hover::before,
.research-card:hover::before {
  opacity: 1;
}

.project-card > *,
.workflow-card > *,
.about-card > *,
.hero-visual-card > *,
.research-card > * {
  position: relative;
  z-index: 1;
}

.project-card:hover {
  transform: translateY(-6px);
  border-color: var(--brand-accent);
  box-shadow: 0 16px 36px -10px var(--accent-glow), 0 0 24px rgba(56, 189, 248, 0.25);
}

.workflow-card:hover {
  transform: translateY(-4px);
  border-color: var(--brand-accent);
  box-shadow: 0 16px 40px -8px var(--accent-glow), 0 0 28px rgba(56, 189, 248, 0.25);
}

/* ==========================================================================
   ARCHITECTURAL VECTOR BADGES SUITED TO EACH PROJECT
   ========================================================================== */
.project-vector-banner {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  padding: 8px 10px;
  margin-bottom: 12px;
  transition: border-color 0.25s ease, background 0.25s ease, transform 0.25s ease;
}

.project-card:hover .project-vector-banner {
  border-color: var(--brand-accent);
  background: var(--bg-card-hover);
  transform: translateY(-1px);
}

.project-vector-icon-box {
  width: 30px;
  height: 30px;
  border-radius: 6px;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--brand-accent);
  transition: all 0.25s ease;
}

.project-card:hover .project-vector-icon-box {
  border-color: var(--brand-accent);
  box-shadow: 0 0 10px var(--accent-glow);
  transform: scale(1.08);
}

.project-vector-info {
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.project-vector-id {
  font-family: var(--font-mono);
  font-size: 9.5px;
  font-weight: 700;
  color: var(--brand-accent);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  display: flex;
  align-items: center;
  gap: 4px;
}

.project-vector-desc {
  font-size: 11px;
  color: var(--text-dim);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* ==========================================================================
   SYSTEM VECTOR CONDUIT (CLEAN KALYAN ARCHITECTURE)
   ========================================================================== */
.system-vector-spine {
  display: none !important;
}

.vec-status-badge {
  font-size: 10px;
  font-family: var(--font-mono);
  background: rgba(56, 189, 248, 0.14);
  border: 1px solid var(--border-glow);
  padding: 2px 7px;
  border-radius: 4px;
  color: var(--brand-cyan);
  margin-left: 6px;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  letter-spacing: 0.04em;
  transition: all 0.25s ease;
}

.contact-channel-btn:hover .vec-status-badge {
  background: var(--brand-accent, #38BDF8);
  color: var(--text-inverse, #07090E);
  box-shadow: 0 0 12px var(--accent-glow);
}

/* ==========================================================================
   CONTACT SECTION: 2-COLUMN SPLIT GRID (DETAILS LEFT / FORM RIGHT)
   ========================================================================== */
.contact-split-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  max-width: 1200px;
  margin: 0 auto;
  align-items: stretch;
}

@media (max-width: 960px) {
  .contact-split-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

.contact-details-panel,
.contact-form-panel {
  position: relative;
  background: rgba(14, 19, 32, 0.40);
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  border: 1px solid var(--border-glow);
  border-radius: 20px;
  padding: 38px 34px;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.35), 0 0 24px var(--glow-cyan);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

[data-theme="light"] .contact-details-panel,
[data-theme="light"] .contact-form-panel {
  background: rgba(255, 255, 255, 0.55);
  border: 1px solid rgba(2, 132, 199, 0.28);
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.06);
}

.contact-details-panel:hover,
.contact-form-panel:hover {
  border-color: var(--brand-accent);
}

.contact-split-title {
  font-size: 30px;
  font-weight: 800;
  margin: 8px 0 10px 0;
  color: var(--text-pure);
  letter-spacing: -0.02em;
}

.contact-split-lead {
  font-size: 14.5px;
  color: var(--text-sub);
  line-height: 1.6;
  margin-bottom: 16px;
}

.contact-opp-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 22px;
}

.contact-channels-stack {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.contact-channel-card {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 13px 18px;
  background: var(--bg-card);
  border: 1px solid var(--border-medium);
  border-radius: 12px;
  text-decoration: none;
  color: var(--text-primary);
  cursor: pointer;
  width: 100%;
  box-sizing: border-box;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.contact-channel-card:hover {
  border-color: var(--brand-accent);
  background: var(--bg-surface);
  transform: translateY(-1.5px);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.2);
}

.channel-card-icon {
  font-size: 20px;
  line-height: 1;
}

.channel-card-content {
  display: flex;
  flex-direction: column;
  flex: 1;
  text-align: left;
}

.channel-card-label {
  font-size: 11px;
  font-family: var(--font-mono);
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 2px;
}

.channel-card-value {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-pure);
}

.channel-card-arrow,
.channel-card-action {
  font-size: 12px;
  font-family: var(--font-mono);
  color: var(--brand-accent);
  font-weight: 600;
}

.contact-actions-pair {
  display: flex;
  gap: 10px;
  margin-top: 6px;
}

@media (max-width: 480px) {
  .contact-actions-pair {
    flex-direction: column;
  }
}

.contact-meta-badge {
  margin-top: 12px;
  padding: 12px 16px;
  background: rgba(0, 0, 0, 0.22);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  font-size: 12px;
  color: var(--text-sub);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

[data-theme="light"] .contact-meta-badge {
  background: rgba(0, 0, 0, 0.03);
}

.meta-item {
  display: flex;
  align-items: center;
  gap: 8px;
}

.form-header-block {
  margin-bottom: 18px;
}

.form-panel-title {
  font-size: 22px;
  font-weight: 800;
  color: var(--text-pure);
  margin: 6px 0 4px 0;
}

.form-panel-subtitle {
  font-size: 13.5px;
  color: var(--text-sub);
}

.form-split-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

@media (max-width: 600px) {
  .form-split-row {
    grid-template-columns: 1fr;
  }
}