/* ==========================================================================
   Alimul Fazal Nabil — AI Solutions Engineer Portfolio
   Futuristic Dark & Light Architectural Theme
   Inspired by sankar.work design reference
   ========================================================================== */

:root {
  color-scheme: dark;
  --bg: #070913;
  --bg-gradient: radial-gradient(circle at 50% 0%, #101c36 0%, #070913 70%);
  --surface: #0d1322;
  --surface-hover: #121a30;
  --surface-card: #0f172a;
  --surface-elevated: #162038;
  --line: rgba(56, 189, 248, 0.14);
  --line-strong: rgba(56, 189, 248, 0.32);
  --line-faint: rgba(255, 255, 255, 0.07);
  --text: #f1f5f9;
  --text-muted: #94a3b8;
  --text-subtle: #64748b;
  --blue: #38bdf8;
  --blue-glow: rgba(56, 189, 248, 0.35);
  --cyan: #06b6d4;
  --cyan-bright: #22d3ee;
  --violet: #818cf8;
  --violet-glow: rgba(129, 140, 248, 0.35);
  --green: #10b981;
  --green-glow: rgba(16, 185, 129, 0.35);
  --amber: #f59e0b;
  --shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  --wrap: 1180px;
}

html[data-theme="light"] {
  color-scheme: light;
  --bg: #f8fafc;
  --bg-gradient: radial-gradient(circle at 50% 0%, #e2e8f0 0%, #f8fafc 70%);
  --surface: #ffffff;
  --surface-hover: #f1f5f9;
  --surface-card: #ffffff;
  --surface-elevated: #f8fafc;
  --line: rgba(15, 23, 42, 0.12);
  --line-strong: rgba(2, 132, 199, 0.35);
  --line-faint: rgba(15, 23, 42, 0.06);
  --text: #0f172a;
  --text-muted: #475569;
  --text-subtle: #64748b;
  --blue: #0284c7;
  --blue-glow: rgba(2, 132, 199, 0.2);
  --cyan: #0891b2;
  --cyan-bright: #0284c7;
  --violet: #6366f1;
  --violet-glow: rgba(99, 102, 241, 0.2);
  --green: #059669;
  --green-glow: rgba(5, 150, 105, 0.2);
  --shadow: 0 20px 40px rgba(15, 23, 42, 0.08);
}

/* Base & Reset */
*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 96px;
}

section[id], .hero[id] {
  scroll-margin-top: 85px;
}

body {
  margin: 0;
  background: var(--bg);
  background-image: var(--bg-gradient);
  background-attachment: fixed;
  color: var(--text);
  font-family: "DM Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-size: 15px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  transition: background-color 0.25s ease, color 0.25s ease;
}

/* Subtle futuristic background grid */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: -1;
  background-image: 
    linear-gradient(to right, var(--line-faint) 1px, transparent 1px),
    linear-gradient(to bottom, var(--line-faint) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(circle at 50% 30%, black, transparent 85%);
  -webkit-mask-image: radial-gradient(circle at 50% 30%, black, transparent 85%);
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  background: none;
  border: none;
  color: inherit;
  cursor: pointer;
}

button:focus-visible, a:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 3px;
}

/* Skip link */
.skip-link {
  position: absolute;
  left: 16px;
  top: -60px;
  padding: 10px 16px;
  background: var(--blue);
  color: #070913;
  font-weight: 700;
  font-size: 13px;
  border-radius: var(--radius-sm);
  z-index: 1000;
  transition: top 0.2s ease;
}
.skip-link:focus {
  top: 16px;
}

/* Ambient glow blobs */
.ambient {
  position: absolute;
  pointer-events: none;
  filter: blur(100px);
  border-radius: 50%;
  z-index: -1;
  opacity: 0.18;
}
.ambient-one {
  width: 500px;
  height: 500px;
  top: 40px;
  left: -150px;
  background: #2563eb;
}
.ambient-two {
  width: 550px;
  height: 450px;
  top: 300px;
  right: -180px;
  background: #7c3aed;
}

.wrap {
  width: min(var(--wrap), calc(100% - 48px));
  margin-inline: auto;
}

/* Header & Navigation */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 14px max(24px, calc((100vw - var(--wrap)) / 2));
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
}
.brand-mark {
  font-family: "Manrope", sans-serif;
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.05em;
  color: var(--text);
}
.brand-mark span {
  color: var(--cyan);
}
.brand-name {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.35vw, 22px);
}
.desktop-nav a {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  transition: color 0.2s ease;
  white-space: nowrap;
}
.desktop-nav a:hover,
.desktop-nav a:focus-visible {
  color: var(--cyan-bright);
}
.desktop-nav a.active {
  color: var(--cyan-bright);
  font-weight: 600;
  position: relative;
}
.desktop-nav a.active::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--cyan-bright);
  border-radius: 2px;
  box-shadow: 0 0 6px var(--cyan-glow);
}

/* More Dropdown */
.nav-dropdown-wrap {
  position: relative;
  display: inline-flex;
  align-items: center;
}
.nav-dropdown-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid transparent;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  white-space: nowrap;
  transition: color 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}
.nav-dropdown-btn:hover,
.nav-dropdown-btn:focus-visible,
.nav-dropdown-btn[aria-expanded="true"] {
  color: var(--cyan-bright);
  background: color-mix(in srgb, var(--surface) 80%, transparent);
  border-color: var(--line);
}
.nav-dropdown-btn.active,
.nav-dropdown-btn.has-active-child {
  color: var(--cyan-bright);
  font-weight: 600;
  position: relative;
}
.nav-dropdown-btn.active::after,
.nav-dropdown-btn.has-active-child::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 6px;
  right: 6px;
  height: 2px;
  background: var(--cyan-bright);
  border-radius: 2px;
  box-shadow: 0 0 6px var(--cyan-glow);
}
.dropdown-chevron {
  transition: transform 0.2s ease;
}
.nav-dropdown-btn[aria-expanded="true"] .dropdown-chevron {
  transform: rotate(180deg);
}

.nav-dropdown-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 250px;
  background: var(--surface-card);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-md);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.45), 0 0 0 1px var(--line);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  padding: 6px;
  display: flex;
  flex-direction: column;
  gap: 2px;
  z-index: 1000;
  animation: navDropIn 0.16s cubic-bezier(0.16, 1, 0.3, 1);
}
.nav-dropdown-menu[hidden] {
  display: none !important;
}
@keyframes navDropIn {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
.dropdown-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  white-space: nowrap;
  transition: background-color 0.15s ease, color 0.15s ease;
}
.dropdown-item:hover,
.dropdown-item:focus-visible {
  background: var(--surface-hover);
  color: var(--cyan-bright);
  outline: none;
}
.dropdown-item.active {
  color: var(--cyan-bright);
  font-weight: 600;
  background: color-mix(in srgb, var(--blue) 12%, transparent);
}
.dropdown-divider {
  height: 1px;
  background: var(--line);
  margin: 4px 6px;
}
.dropdown-item.highlight-item {
  color: var(--cyan);
  font-weight: 600;
}
.dropdown-item.highlight-item:hover {
  color: var(--cyan-bright);
}
.dropdown-item .ext-arrow {
  font-size: 11px;
  color: var(--text-subtle);
}

/* Priority Items in Dropdown (hidden on wide desktop, shown when their desktop link collapses) */
.dropdown-item-p5,
.dropdown-item-p4,
.dropdown-item-p3,
.dropdown-divider-priority {
  display: none;
}

/* Language Switcher */
.lang-switch {
  display: inline-flex;
  align-items: center;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-full);
  padding: 4px 8px;
  font-family: "DM Mono", monospace;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.05em;
  gap: 4px;
}
.lang-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 2px 4px;
  border-radius: 3px;
  transition: all 0.2s ease;
  font-size: 11px;
  line-height: 1;
}
.lang-btn:hover {
  color: var(--cyan-bright);
}
.lang-btn.active {
  color: var(--cyan-bright);
  font-weight: 700;
  text-shadow: 0 0 8px var(--blue-glow);
}
.lang-divider {
  color: var(--line-strong);
  font-size: 10px;
  user-select: none;
  opacity: 0.6;
}

/* Mobile Language Switcher Wrapper */
.mobile-lang-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 0;
  border-bottom: 1px solid var(--line-faint);
  margin-bottom: 6px;
}
.mobile-lang-label {
  font-size: 12px;
  color: var(--text-muted);
  font-family: "DM Mono", monospace;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}
.header-cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  background: linear-gradient(135deg, var(--blue), var(--cyan-bright));
  color: #070913;
  font-size: 12px;
  font-weight: 700;
  border-radius: var(--radius-sm);
  box-shadow: 0 4px 16px var(--blue-glow);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.header-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 20px var(--blue-glow);
}

.theme-toggle, .menu-toggle {
  width: 36px;
  height: 36px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  background: var(--surface);
  color: var(--text);
  transition: border-color 0.2s ease;
}
.theme-toggle:hover, .menu-toggle:hover {
  border-color: var(--blue);
}
.theme-toggle svg {
  width: 17px;
  height: 17px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
}
html[data-theme="light"] .theme-toggle .sun-icon { display: none; }
html[data-theme="light"] .theme-toggle .moon-icon { display: block; }
html[data-theme="dark"] .theme-toggle .sun-icon { display: block; }
html[data-theme="dark"] .theme-toggle .moon-icon { display: none; }

.menu-toggle {
  display: none;
  padding: 8px;
}
.menu-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
}

.mobile-nav {
  display: none;
}

/* Hero Section */
.hero {
  min-height: 740px;
  padding-top: 75px;
  padding-bottom: 50px;
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(320px, 0.85fr);
  align-items: center;
  gap: 60px;
  position: relative;
}

.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 6px 14px;
  border-radius: var(--radius-full);
  border: 1px solid var(--line-strong);
  background: color-mix(in srgb, var(--surface) 80%, transparent);
  font-family: "DM Mono", monospace;
  font-size: 10px;
  letter-spacing: 0.08em;
  color: var(--cyan-bright);
  margin-bottom: 24px;
}
.status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 10px var(--green-glow);
  animation: pulseDot 2s infinite ease-in-out;
}
@keyframes pulseDot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.85); }
}

.hero h1 {
  font-family: "Manrope", sans-serif;
  font-size: clamp(40px, 5.5vw, 68px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.04em;
  margin: 0;
}
.gradient-text {
  background: linear-gradient(135deg, #60a5fa 0%, #22d3ee 50%, #a78bfa 100%);
  background-clip: text;
  -webkit-background-clip: text;
  color: transparent;
}

.hero-subtitle {
  font-family: "DM Mono", monospace;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--blue);
  margin: 18px 0 10px;
  text-transform: uppercase;
}

.hero-lead {
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-muted);
  max-width: 620px;
  margin: 0 0 28px;
}

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 20px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}
.button-primary {
  background: linear-gradient(135deg, var(--blue), var(--cyan-bright));
  color: #070913;
  font-weight: 700;
  box-shadow: 0 6px 20px var(--blue-glow);
}
.button-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 26px var(--blue-glow);
}
.button-secondary {
  border: 1px solid var(--line-strong);
  background: var(--surface);
  color: var(--text);
}
.button-secondary:hover {
  transform: translateY(-2px);
  border-color: var(--blue);
  background: var(--surface-hover);
}

/* Quick Metrics Bar in Hero */
.metrics-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-top: 38px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
}
.metric-item {
  display: flex;
  flex-direction: column;
}
.metric-value {
  font-family: "Manrope", sans-serif;
  font-size: 24px;
  font-weight: 800;
  color: var(--cyan-bright);
}
.metric-label {
  font-family: "DM Mono", monospace;
  font-size: 9px;
  letter-spacing: 0.05em;
  color: var(--text-subtle);
  margin-top: 2px;
}

/* Hero Interactive Orbital Showcase (Right column) */
.hero-card {
  position: relative;
  background: linear-gradient(145deg, var(--surface), var(--surface-card));
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow);
  overflow: hidden;
}
.hero-card::before {
  content: "";
  position: absolute;
  width: 220px;
  height: 220px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--blue-glow), transparent 70%);
  top: -80px;
  right: -80px;
  pointer-events: none;
}
.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 22px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}
.card-kicker {
  font-family: "DM Mono", monospace;
  font-size: 9px;
  letter-spacing: 0.1em;
  color: var(--blue);
}
.card-status {
  font-family: "DM Mono", monospace;
  font-size: 9px;
  color: var(--green);
  display: flex;
  align-items: center;
  gap: 6px;
}
.card-status::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 8px var(--green-glow);
}

.focus-rows {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.focus-row {
  display: grid;
  grid-template-columns: 36px 1fr;
  align-items: start;
  gap: 14px;
}
.focus-num {
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  background: rgba(56, 189, 248, 0.08);
  border: 1px solid var(--line-strong);
  display: grid;
  place-items: center;
  font-family: "DM Mono", monospace;
  font-size: 11px;
  color: var(--cyan-bright);
}
.focus-row h4 {
  margin: 0;
  font-size: 14px;
  font-weight: 700;
}
.focus-row p {
  margin: 3px 0 0;
  font-size: 12px;
  color: var(--text-muted);
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 24px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}
.tag {
  font-family: "DM Mono", monospace;
  font-size: 9px;
  padding: 4px 8px;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--line);
  color: var(--text-muted);
}

/* Section Common Styling */
.section {
  padding-block: 100px;
  position: relative;
}
.section-alt {
  background: linear-gradient(180deg, transparent, rgba(16, 28, 54, 0.3) 15%, rgba(16, 28, 54, 0.3) 85%, transparent);
  border-block: 1px solid var(--line);
}

.section-header {
  margin-bottom: 48px;
}
.eyebrow {
  font-family: "DM Mono", monospace;
  font-size: 10px;
  letter-spacing: 0.12em;
  color: var(--cyan-bright);
  text-transform: uppercase;
  margin: 0 0 10px;
}
.section-title {
  font-family: "Manrope", sans-serif;
  font-size: clamp(30px, 3.8vw, 46px);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.035em;
  margin: 0;
}
.section-desc {
  font-size: 15px;
  color: var(--text-muted);
  max-width: 600px;
  margin: 12px 0 0;
}

/* About & Engineering Loop */
.about-grid {
  display: grid;
  grid-template-columns: 0.95fr 1.05fr;
  gap: 60px;
  align-items: center;
}

.about-visual {
  position: relative;
  text-align: center;
}
.profile-frame {
  position: relative;
  display: inline-block;
  border-radius: var(--radius-lg);
  padding: 8px;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.4), rgba(129, 140, 248, 0.2));
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.4);
}
.profile-img {
  display: block;
  width: 280px;
  height: 340px;
  object-fit: cover;
  border-radius: calc(var(--radius-lg) - 6px);
  filter: contrast(1.05);
}
.profile-badge {
  position: absolute;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(13, 19, 34, 0.92);
  border: 1px solid var(--line-strong);
  backdrop-filter: blur(8px);
  padding: 8px 16px;
  border-radius: var(--radius-full);
  font-family: "DM Mono", monospace;
  font-size: 10px;
  color: var(--cyan-bright);
  white-space: nowrap;
}

.about-content .lead-text {
  font-size: 18px;
  line-height: 1.6;
  color: var(--text);
  margin-top: 0;
}
.about-content p {
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.7;
}

/* Engineering Loop Stepper */
.loop-stepper {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 14px;
  margin-top: 36px;
}
.loop-step {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 16px;
  transition: transform 0.2s ease, border-color 0.2s ease;
}
.loop-step:hover {
  transform: translateY(-2px);
  border-color: var(--blue);
}
.step-num {
  font-family: "DM Mono", monospace;
  font-size: 10px;
  color: var(--cyan);
}
.loop-step h4 {
  margin: 8px 0 4px;
  font-size: 13px;
  font-weight: 700;
}
.loop-step p {
  margin: 0;
  font-size: 11px;
  color: var(--text-muted);
  line-height: 1.5;
}

/* Flagship / Featured Projects */
.featured-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(480px, 1fr));
  gap: 28px;
  margin-bottom: 50px;
}

.featured-card {
  background: linear-gradient(160deg, var(--surface), var(--surface-card));
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}
.featured-card:hover {
  transform: translateY(-4px);
  border-color: var(--cyan-bright);
  box-shadow: 0 24px 60px rgba(6, 182, 212, 0.12);
}

.schematic-box {
  height: 200px;
  background: #090e1a;
  border-bottom: 1px solid var(--line);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* RAG Interactive Schematic */
.schematic-rag {
  background: radial-gradient(ellipse at 50% 50%, #132747 0%, #090e1a 75%);
}
.rag-flow {
  display: flex;
  align-items: center;
  gap: 8px;
  z-index: 2;
  padding: 0 16px;
}
.rag-node {
  padding: 8px 12px;
  background: rgba(15, 23, 42, 0.85);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  font-family: "DM Mono", monospace;
  font-size: 9px;
  color: var(--cyan-bright);
  box-shadow: 0 0 16px rgba(56, 189, 248, 0.15);
  text-align: center;
}
.rag-arrow {
  color: var(--blue);
  font-size: 14px;
}

/* Traffic Signal Simulation Schematic */
.schematic-traffic {
  background: radial-gradient(ellipse at 50% 50%, #0e2e38 0%, #090e1a 75%);
}
.traffic-grid-vis {
  position: relative;
  width: 260px;
  height: 120px;
  border: 1px dashed rgba(6, 182, 212, 0.35);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: space-around;
}
.traffic-node {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 16px var(--green-glow);
}
.traffic-node-alt {
  background: var(--amber);
  box-shadow: 0 0 16px rgba(245, 158, 11, 0.5);
}
.traffic-line-pulse {
  position: absolute;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), transparent);
  width: 80%;
  top: 50%;
}

.featured-body {
  padding: 26px;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}
.project-topline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}
.project-cat {
  font-family: "DM Mono", monospace;
  font-size: 9px;
  color: var(--cyan-bright);
  letter-spacing: 0.08em;
}
.project-badge {
  font-family: "DM Mono", monospace;
  font-size: 8px;
  padding: 3px 8px;
  border-radius: var(--radius-full);
  border: 1px solid var(--line-strong);
  color: var(--blue);
}

.featured-body h3 {
  font-family: "Manrope", sans-serif;
  font-size: 20px;
  font-weight: 700;
  margin: 0 0 10px;
}
.featured-body p {
  color: var(--text-muted);
  font-size: 13px;
  line-height: 1.65;
  margin: 0 0 20px;
  flex-grow: 1;
}

.card-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  margin-top: auto;
}
.repo-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--cyan-bright);
  font-size: 12px;
  font-weight: 700;
  transition: color 0.2s ease, transform 0.2s ease;
}
.repo-btn:hover {
  color: var(--text);
  transform: translateX(2px);
}

/* Filterable Project Gallery */
.filter-bar {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 30px;
}
.filter-btn {
  padding: 8px 16px;
  border-radius: var(--radius-full);
  border: 1px solid var(--line);
  background: var(--surface);
  font-family: "DM Mono", monospace;
  font-size: 11px;
  color: var(--text-muted);
  transition: all 0.2s ease;
}
.filter-btn:hover {
  border-color: var(--blue);
  color: var(--text);
}
.filter-btn.active {
  background: rgba(56, 189, 248, 0.12);
  border-color: var(--blue);
  color: var(--cyan-bright);
  font-weight: 600;
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
}

.gallery-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 24px;
  display: flex;
  flex-direction: column;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}
.gallery-card:hover {
  transform: translateY(-3px);
  border-color: var(--line-strong);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.25);
}
.gallery-card[hidden] {
  display: none !important;
}

.gallery-card h4 {
  font-family: "Manrope", sans-serif;
  font-size: 17px;
  font-weight: 700;
  margin: 10px 0 8px;
}
.gallery-card p {
  color: var(--text-muted);
  font-size: 12px;
  line-height: 1.6;
  margin: 0 0 18px;
  flex-grow: 1;
}

/* Professional Experience Timeline */
.timeline-stream {
  position: relative;
  margin-left: 20px;
  border-left: 1px solid var(--line-strong);
  padding-left: 32px;
  display: flex;
  flex-direction: column;
  gap: 36px;
}

.timeline-node {
  position: relative;
}
.timeline-dot {
  position: absolute;
  left: -39px;
  top: 5px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--cyan-bright);
  box-shadow: 0 0 12px var(--cyan);
}
.timeline-dot-active {
  background: var(--cyan-bright);
  box-shadow: 0 0 16px var(--cyan-bright);
}

.timeline-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 22px;
  transition: border-color 0.2s ease;
}
.timeline-card:hover {
  border-color: var(--line-strong);
}

.timeline-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 6px;
}
.timeline-head h3 {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
}
.timeline-period {
  font-family: "DM Mono", monospace;
  font-size: 10px;
  color: var(--cyan-bright);
  letter-spacing: 0.05em;
}
.timeline-org {
  font-size: 13px;
  font-weight: 600;
  color: var(--blue);
  margin-bottom: 12px;
}

.timeline-bullets {
  margin: 0;
  padding-left: 18px;
  color: var(--text-muted);
  font-size: 12.5px;
  line-height: 1.7;
}
.timeline-bullets li {
  margin-bottom: 6px;
}

/* Education & Certifications */
.edu-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
}

.edu-column {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.edu-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 24px;
}
.edu-year {
  font-family: "DM Mono", monospace;
  font-size: 10px;
  color: var(--cyan-bright);
}
.edu-card h3 {
  font-family: "Manrope", sans-serif;
  font-size: 16px;
  font-weight: 700;
  margin: 8px 0 4px;
}
.edu-inst {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 8px;
}
.edu-detail {
  font-size: 12px;
  color: var(--text-subtle);
  line-height: 1.6;
}

/* Peer-Reviewed Publications subsection */
.pub-item {
  border-top: 1px solid var(--line);
  padding-top: 14px;
  margin-top: 14px;
}
.pub-item h4 {
  margin: 0 0 4px;
  font-size: 13px;
  font-weight: 600;
}
.pub-meta {
  font-size: 11px;
  color: var(--text-muted);
}
.pub-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: var(--cyan-bright);
  font-size: 11px;
  font-weight: 600;
  margin-top: 6px;
}
.pub-link:hover {
  text-decoration: underline;
}

/* Technical Skills Matrix */
.skills-primary-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

@media (max-width: 900px) {
  .skills-primary-grid {
    grid-template-columns: 1fr;
  }
}

.skill-card-primary {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.skill-card-primary:hover {
  border-color: var(--blue);
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.25);
  transform: translateY(-2px);
}

.skill-card-head {
  display: flex;
  flex-direction: column;
  gap: 4px;
  border-bottom: 1px solid var(--line);
  padding-bottom: 14px;
}

.skill-card-head .card-kicker {
  font-family: "DM Mono", monospace;
  font-size: 10px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.skill-card-head h3 {
  margin: 0;
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 8px;
}

.skill-domain-icon {
  font-size: 19px;
  line-height: 1;
}

.skill-group-container {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.skill-subgroup {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.skill-subgroup-title {
  font-family: "DM Mono", monospace;
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--text-subtle);
  letter-spacing: 0.06em;
}

.skill-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.skill-chip {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 5px 10px;
  background: var(--surface-card);
  border: 1px solid var(--line);
  border-radius: 6px;
  font-size: 12px;
  color: var(--text);
  text-decoration: none;
  transition: all 0.18s ease;
  line-height: 1.4;
}

.skill-chip:hover {
  background: rgba(56, 189, 248, 0.12);
  border-color: var(--blue);
  color: var(--cyan);
  transform: translateY(-1px);
}

.chip-link-indicator {
  font-size: 10px;
  color: var(--cyan);
  opacity: 0.6;
  transition: transform 0.15s ease, opacity 0.15s ease;
}

.skill-chip:hover .chip-link-indicator {
  transform: translate(1px, -1px);
  opacity: 1;
}

/* Supporting Domains Section */
.supporting-domains-wrap {
  margin-top: 48px;
  padding-top: 36px;
  border-top: 1px dashed var(--line-strong);
}

.supporting-domains-head {
  margin-bottom: 24px;
}

.supporting-domains-head .eyebrow-sub {
  font-family: "DM Mono", monospace;
  font-size: 11px;
  font-weight: 600;
  color: var(--text-subtle);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  display: block;
  margin-bottom: 6px;
}

.supporting-domains-head h3 {
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
  margin: 0 0 6px;
}

.supporting-domains-head p {
  font-size: 13.5px;
  color: var(--text-muted);
  max-width: 680px;
  margin: 0;
}

.skills-supporting-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

@media (max-width: 1024px) {
  .skills-supporting-grid {
    grid-template-columns: 1fr;
  }
}

.skill-card-supporting {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.skill-card-supporting:hover {
  border-color: var(--line-strong);
  transform: translateY(-2px);
}

.skill-card-supporting .skill-card-head h4 {
  margin: 0;
  font-size: 16px;
  font-weight: 700;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 6px;
}


/* Contact CTA Box */
.contact-box {
  background: linear-gradient(145deg, var(--surface), var(--surface-card));
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-lg);
  padding: 60px 36px;
  text-align: center;
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}
.contact-box::before {
  content: "";
  position: absolute;
  width: 400px;
  height: 400px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--blue-glow), transparent 70%);
  top: -150px;
  left: 50%;
  transform: translateX(-50%);
  pointer-events: none;
}

.contact-box h2 {
  font-family: "Manrope", sans-serif;
  font-size: clamp(32px, 4.5vw, 52px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.04em;
  margin: 14px 0 16px;
}
.contact-box p {
  color: var(--text-muted);
  max-width: 540px;
  margin: 0 auto 32px;
  font-size: 15px;
}
.contact-links {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--line);
  padding-block: 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-size: 12px;
  color: var(--text-subtle);
}
.footer-copy {
  margin: 0;
}
.back-top {
  color: var(--text-muted);
  font-family: "DM Mono", monospace;
  font-size: 10px;
  letter-spacing: 0.05em;
  transition: color 0.2s ease;
}
.back-top:hover {
  color: var(--cyan-bright);
}

/* Priority+ Progressive Collapse Breakpoints */
@media (max-width: 1240px) {
  .nav-link-p5 {
    display: none !important;
  }
  .dropdown-item-p5,
  .dropdown-divider-priority {
    display: flex !important;
  }
}

@media (max-width: 1160px) {
  .site-header .header-cta {
    display: none !important;
  }
}

@media (max-width: 1060px) {
  .nav-link-p4 {
    display: none !important;
  }
  .dropdown-item-p4 {
    display: flex !important;
  }
}

@media (max-width: 960px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 48px;
    padding-top: 60px;
    min-height: auto;
  }
  .about-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .edu-grid {
    grid-template-columns: 1fr;
  }
  .featured-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 920px) {
  .nav-link-p3 {
    display: none !important;
  }
  .dropdown-item-p3 {
    display: flex !important;
  }
}

@media (max-width: 768px) {
  .desktop-nav, .header-cta {
    display: none !important;
  }
  .menu-toggle {
    display: flex !important;
    flex-direction: column;
    justify-content: center;
    gap: 4px;
  }
  .mobile-nav:not([hidden]) {
    display: flex !important;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    max-height: calc(100vh - 72px);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    background: var(--bg);
    border-bottom: 1px solid var(--line-strong);
    padding: 14px 20px 28px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.65);
    z-index: 999;
  }
  .mobile-nav a {
    min-height: 44px;
    display: flex;
    align-items: center;
    padding: 10px 4px;
    border-bottom: 1px solid var(--line-faint);
    color: var(--text);
    font-size: 14px;
    font-weight: 500;
  }
  .mobile-nav a.active {
    color: var(--cyan-bright);
    font-weight: 700;
  }
  .metrics-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }
  .section {
    padding-block: 70px;
  }
  .contact-box {
    padding: 40px 20px;
  }
  .site-footer {
    flex-direction: column;
    text-align: center;
  }
}

@media (max-width: 520px) {
  .header-search-btn span,
  .header-search-btn kbd {
    display: none;
  }
  .header-search-btn {
    padding: 8px;
    width: 36px;
    height: 36px;
    justify-content: center;
    border-radius: var(--radius-sm);
  }
  .site-header {
    gap: 10px;
    padding: 12px 16px;
  }
  .brand-name {
    display: none;
  }
}

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