/* ==========================================================================
   NexClinic Modern Healthcare SaaS Showcase — Design System & Stylesheet
   Project: CO2060 — University of Peradeniya | Team: NexAura
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@400;500;600;700;800&family=Plus+Jakarta+Sans:ital,wght@0,400;0,500;0,600;0,700;1,400&family=JetBrains+Mono:wght@400;500;600&display=swap');

/* --- CSS Variables & Design Tokens --- */
:root {
  /* Brand Palettes */
  --color-primary: #0d9488;         /* Clinical Teal */
  --color-primary-dark: #0f766e;
  --color-primary-light: #14b8a6;
  --color-primary-subtle: #ccfbf1;
  --color-primary-tint: #f0fdfa;

  --color-accent: #0284c7;          /* Precision Cyan / Ocean Blue */
  --color-accent-dark: #0369a1;
  --color-accent-subtle: #e0f2fe;

  /* Neutrals & Surfaces */
  --bg-page: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #ffffff;
  --bg-surface-alt: #f1f5f9;
  --bg-surface-subtle: #f8fafc;
  --bg-dark-panel: #0f172a;

  /* Typography Colors */
  --text-main: #0f172a;            /* Deep Slate / Navy */
  --text-secondary: #334155;       /* Charcoal slate */
  --text-muted: #64748b;           /* Steel slate */
  --text-light: #94a3b8;
  --text-inverse: #ffffff;
  --text-inverse-muted: #cbd5e1;

  /* Borders & Dividers */
  --border-light: rgba(226, 232, 240, 0.9);
  --border-subtle: rgba(241, 245, 249, 0.9);
  --border-focus: #0d9488;
  --border-interactive: rgba(13, 148, 136, 0.25);

  /* Status Colors */
  --status-success: #10b981;
  --status-success-bg: #ecfdf5;
  --status-warning: #f59e0b;
  --status-warning-bg: #fffbeb;
  --status-info: #0284c7;
  --status-info-bg: #f0f9ff;
  --status-error: #ef4444;
  --status-error-bg: #fef2f2;

  /* Typography Stacks */
  --font-display: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-body: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  /* Elevation Shadows */
  --shadow-xs: 0 1px 2px 0 rgba(15, 23, 42, 0.04);
  --shadow-sm: 0 2px 4px -1px rgba(15, 23, 42, 0.06), 0 1px 2px -1px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 10px 15px -3px rgba(15, 23, 42, 0.05), 0 4px 6px -4px rgba(15, 23, 42, 0.03);
  --shadow-lg: 0 20px 25px -5px rgba(15, 23, 42, 0.06), 0 8px 10px -6px rgba(15, 23, 42, 0.03);
  --shadow-xl: 0 25px 50px -12px rgba(15, 23, 42, 0.12);
  --shadow-glow: 0 10px 30px -10px rgba(13, 148, 136, 0.25);

  /* Spacing and Radius */
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-2xl: 2rem;
  --radius-full: 9999px;

  /* Layout Containers */
  --max-width: 1240px;
  --header-height: 4.75rem;
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-smooth: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

/* --- Base & Reset --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 1.5rem);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  color: var(--text-main);
  background-color: var(--bg-page);
  line-height: 1.65;
  min-height: 100dvh;
  overflow-x: hidden;
  position: relative;
}

img, svg {
  display: block;
  max-width: 100%;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-dark);
}

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

/* Accessible focus visible */
:focus-visible {
  outline: 2px solid var(--border-focus);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* --- Layout Utility Classes --- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.section {
  padding-top: 6rem;
  padding-bottom: 6rem;
  position: relative;
}

.section-alt {
  background-color: var(--bg-surface);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.section-dark {
  background-color: var(--bg-dark-panel);
  color: var(--text-inverse);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

/* Section Header Styles */
.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 3.5rem auto;
}

.section-header.text-left {
  text-align: left;
  margin-left: 0;
}

.badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.375rem 0.875rem;
  border-radius: var(--radius-full);
  background-color: var(--color-primary-tint);
  color: var(--color-primary-dark);
  border: 1px solid rgba(13, 148, 136, 0.2);
  margin-bottom: 1rem;
}

.badge-tag.badge-dark {
  background-color: rgba(13, 148, 136, 0.15);
  color: var(--color-primary-light);
  border-color: rgba(20, 184, 166, 0.3);
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 3.5vw, 2.75rem);
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.2;
  letter-spacing: -0.025em;
  margin-bottom: 1rem;
}

.section-dark .section-title {
  color: var(--text-inverse);
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.section-dark .section-subtitle {
  color: var(--text-inverse-muted);
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.625rem;
  padding: 0.8125rem 1.625rem;
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
  line-height: 1.25;
  text-decoration: none;
  white-space: nowrap;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-accent) 100%);
  color: #ffffff !important;
  box-shadow: 0 4px 12px rgba(13, 148, 136, 0.25);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-accent-dark) 100%);
  box-shadow: 0 6px 20px rgba(13, 148, 136, 0.35);
  transform: translateY(-1px);
}

.btn-secondary {
  background-color: var(--bg-surface);
  color: var(--text-main) !important;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-xs);
}

.btn-secondary:hover {
  background-color: var(--bg-surface-alt);
  border-color: #cbd5e1;
  transform: translateY(-1px);
}

.btn-outline-white {
  background-color: rgba(255, 255, 255, 0.08);
  color: #ffffff !important;
  border: 1px solid rgba(255, 255, 255, 0.25);
  backdrop-filter: blur(8px);
}

.btn-outline-white:hover {
  background-color: rgba(255, 255, 255, 0.16);
  border-color: rgba(255, 255, 255, 0.4);
  transform: translateY(-1px);
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
}

.btn-live-app {
  background: linear-gradient(135deg, #0d9488 0%, #0284c7 100%);
  color: #ffffff !important;
  font-weight: 600;
  box-shadow: 0 4px 14px rgba(13, 148, 136, 0.3);
}

.btn-live-app:hover {
  background: linear-gradient(135deg, #0f766e 0%, #0369a1 100%);
  box-shadow: 0 6px 20px rgba(2, 132, 199, 0.4);
}

.live-dot {
  width: 7px;
  height: 7px;
  background-color: #34d399;
  border-radius: 50%;
  box-shadow: 0 0 0 0 rgba(52, 211, 153, 0.7);
  animation: pulse-ring 2s infinite cubic-bezier(0.66, 0, 0, 1);
  display: inline-block;
  flex-shrink: 0;
}

.mobile-only-link {
  display: none;
}

.btn-icon {
  width: 1.125rem;
  height: 1.125rem;
  flex-shrink: 0;
}

/* --- Navigation Header --- */
.site-header {
  position: sticky;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  z-index: 100;
  background-color: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-light);
  transition: all var(--transition-normal);
}

.site-header.scrolled {
  background-color: rgba(255, 255, 255, 0.95);
  box-shadow: var(--shadow-sm);
  height: 4.25rem;
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.brand-wrapper {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
}

.brand-logo-img {
  width: 2.25rem;
  height: 2.25rem;
  object-fit: contain;
}

.brand-text-group {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-family: var(--font-display);
  font-size: 1.3125rem;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.brand-title span.plus {
  color: var(--color-primary);
  font-weight: 800;
}

.brand-subline {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 500;
  line-height: 1;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.75rem;
  list-style: none;
}

.nav-link {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
  position: relative;
  padding: 0.25rem 0;
}

.nav-link:hover, .nav-link.active {
  color: var(--color-primary);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--color-primary);
  border-radius: var(--radius-full);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.875rem;
}

/* Mobile Toggle */
.mobile-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-sm);
  padding: 0.375rem;
}

.mobile-toggle span {
  display: block;
  height: 2px;
  width: 100%;
  background-color: var(--text-main);
  transition: all var(--transition-normal);
}

.mobile-toggle.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.mobile-toggle.open span:nth-child(2) {
  opacity: 0;
}

.mobile-toggle.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* --- Hero Section --- */
.hero-section {
  padding-top: 4rem;
  padding-bottom: 5.5rem;
  position: relative;
  overflow: hidden;
  background: radial-gradient(circle at 10% 20%, rgba(13, 148, 136, 0.05) 0%, transparent 40%),
              radial-gradient(circle at 90% 60%, rgba(2, 132, 199, 0.05) 0%, transparent 45%),
              linear-gradient(180deg, #ffffff 0%, var(--bg-page) 100%);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 3.5rem;
  align-items: center;
}

.hero-content {
  max-width: 650px;
}

.hero-badge-container {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.academic-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.3125rem 0.875rem;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-secondary);
  background: #ffffff;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-xs);
}

.pulse-dot {
  width: 8px;
  height: 8px;
  background-color: var(--status-success);
  border-radius: 50%;
  box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7);
  animation: pulse-ring 2s infinite cubic-bezier(0.66, 0, 0, 1);
}

@keyframes pulse-ring {
  0% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
  70% { box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
  100% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.hero-headline {
  font-family: var(--font-display);
  font-size: clamp(2.35rem, 4.2vw, 3.5rem);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.03em;
  color: var(--text-main);
  margin-bottom: 1.25rem;
}

.hero-headline .text-gradient {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-description {
  font-size: 1.1875rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 2rem;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.hero-trust-metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--border-light);
}

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

.metric-number {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-main);
}

.metric-label {
  font-size: 0.8125rem;
  color: var(--text-muted);
  line-height: 1.3;
}

/* Hero Visual Showcase */
.hero-visual-card {
  position: relative;
}

.hero-window-frame {
  background-color: #ffffff;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-xl), var(--shadow-glow);
  overflow: hidden;
  transition: transform var(--transition-smooth);
}

.window-header {
  background-color: #f8fafc;
  padding: 0.75rem 1.25rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  border-bottom: 1px solid var(--border-light);
}

.window-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}
.window-dot.dot-red { background-color: #f87171; }
.window-dot.dot-amber { background-color: #fbbf24; }
.window-dot.dot-green { background-color: #34d399; }

.window-title {
  margin-left: auto;
  margin-right: auto;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.window-body {
  position: relative;
  background-color: #ffffff;
}

.hero-screenshot {
  width: 100%;
  height: auto;
  display: block;
}

/* Floating Badges on Hero Card */
.floating-stat-badge {
  position: absolute;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  padding: 0.875rem 1.25rem;
  border-radius: var(--radius-lg);
  border: 1px solid rgba(226, 232, 240, 0.9);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 0.875rem;
  z-index: 2;
  transition: transform var(--transition-normal);
}

.floating-stat-badge:hover {
  transform: translateY(-3px);
}

.badge-top-right {
  top: -1.25rem;
  right: -1.25rem;
}

.badge-bottom-left {
  bottom: -1.5rem;
  left: -1.25rem;
}

.stat-icon-box {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-md);
  background-color: var(--color-primary-tint);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  flex-shrink: 0;
}

.stat-icon-box.icon-blue {
  background-color: var(--color-accent-subtle);
  color: var(--color-accent);
}

.stat-content-box .stat-title {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.stat-content-box .stat-value {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-main);
}

/* --- Problem vs Solution Section --- */
.comparison-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-top: 2rem;
}

.problem-card {
  background-color: #ffffff;
  border: 1px solid rgba(239, 68, 68, 0.2);
  border-radius: var(--radius-xl);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  position: relative;
}

.problem-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background-color: #ef4444;
  border-top-left-radius: var(--radius-xl);
  border-top-right-radius: var(--radius-xl);
}

.solution-card {
  background-color: #ffffff;
  border: 1px solid rgba(13, 148, 136, 0.25);
  border-radius: var(--radius-xl);
  padding: 2.5rem;
  box-shadow: var(--shadow-md);
  position: relative;
}

.solution-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  border-top-left-radius: var(--radius-xl);
  border-top-right-radius: var(--radius-xl);
}

.card-header-icon {
  width: 3rem;
  height: 3rem;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
  font-size: 1.5rem;
}

.problem-card .card-header-icon {
  background-color: #fef2f2;
  color: #ef4444;
}

.solution-card .card-header-icon {
  background-color: var(--color-primary-tint);
  color: var(--color-primary);
}

.card-h3 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--text-main);
}

.item-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1.5rem;
}

.item-list li {
  display: flex;
  align-items: flex-start;
  gap: 0.875rem;
  font-size: 0.96875rem;
  color: var(--text-secondary);
}

.list-icon {
  width: 1.25rem;
  height: 1.25rem;
  flex-shrink: 0;
  margin-top: 0.2rem;
}

.list-icon.icon-cross { color: #ef4444; }
.list-icon.icon-check { color: var(--color-primary); }

/* --- Interactive Capabilities (Tabs) --- */
.tab-controls {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 3rem;
  background: #f1f5f9;
  padding: 0.375rem;
  border-radius: var(--radius-full);
  max-width: 580px;
  margin-left: auto;
  margin-right: auto;
}

.tab-btn {
  flex: 1;
  padding: 0.6875rem 1.25rem;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-muted);
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
  text-align: center;
}

.tab-btn.active {
  background-color: #ffffff;
  color: var(--color-primary-dark);
  box-shadow: var(--shadow-sm);
}

.tab-pane {
  display: none;
  animation: fadeIn 0.35s ease;
}

.tab-pane.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.feature-bento-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.bento-card {
  background-color: #ffffff;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-light);
  padding: 2rem;
  box-shadow: var(--shadow-xs);
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
}

.bento-card:hover {
  border-color: var(--border-interactive);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.bento-card.span-2 {
  grid-column: span 2;
}

.bento-icon {
  width: 2.75rem;
  height: 2.75rem;
  border-radius: var(--radius-md);
  background: var(--color-primary-tint);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
  font-size: 1.375rem;
}

.bento-title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.625rem;
}

.bento-desc {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.25rem;
}

.bento-tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: auto;
}

.bento-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.25rem 0.625rem;
  background-color: var(--bg-surface-alt);
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  font-weight: 500;
}

/* --- Product Experience Showcase --- */
.experience-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3.5rem;
  align-items: center;
  margin-bottom: 4rem;
}

.experience-layout.reverse {
  direction: rtl;
}

.experience-layout.reverse > * {
  direction: ltr;
}

.experience-info .step-counter {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--color-primary);
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.experience-info h3 {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 1rem;
}

.experience-info p {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.experience-preview-frame {
  background: #ffffff;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  transition: transform var(--transition-smooth);
}

.experience-preview-frame:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

/* --- System Architecture Section --- */
.arch-diagram-wrapper {
  background: #0f172a;
  border-radius: var(--radius-xl);
  border: 1px solid rgba(255, 255, 255, 0.12);
  padding: 2.5rem;
  box-shadow: var(--shadow-xl);
  margin-bottom: 3.5rem;
  color: #ffffff;
}

.arch-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  padding-bottom: 1.25rem;
  margin-bottom: 2rem;
}

.arch-header-title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.arch-legend {
  display: flex;
  gap: 1.25rem;
  font-size: 0.8125rem;
  font-family: var(--font-mono);
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.dot-frontend { background-color: #38bdf8; }
.dot-backend { background-color: #34d399; }
.dot-data { background-color: #a78bfa; }
.dot-edge { background-color: #fb923c; }

/* Visual Architecture Flow Blocks */
.arch-flow-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  position: relative;
}

.arch-node {
  background: rgba(30, 41, 59, 0.7);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all var(--transition-normal);
}

.arch-node:hover {
  background: rgba(30, 41, 59, 0.95);
  border-color: rgba(20, 184, 166, 0.5);
  transform: translateY(-2px);
}

.arch-node-badge {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  display: inline-block;
  align-self: flex-start;
  margin-bottom: 0.75rem;
}

.badge-edge { background: rgba(251, 146, 60, 0.2); color: #fb923c; }
.badge-fe { background: rgba(56, 189, 248, 0.2); color: #38bdf8; }
.badge-be { background: rgba(52, 211, 153, 0.2); color: #34d399; }
.badge-db { background: rgba(167, 139, 250, 0.2); color: #a78bfa; }

.arch-node-title {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: #ffffff;
}

.arch-node-desc {
  font-size: 0.8125rem;
  color: #94a3b8;
  line-height: 1.5;
  margin-bottom: 1rem;
}

.arch-node-tech {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: #cbd5e1;
  background: rgba(15, 23, 42, 0.6);
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-sm);
  margin-top: auto;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

/* Architecture Features List */
.arch-details-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.arch-detail-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
}

.arch-detail-card h4 {
  font-family: var(--font-display);
  font-size: 1.1875rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.75rem;
}

.arch-detail-card p {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* --- Technology Stack --- */
.tech-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.5rem;
}

.tech-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  display: flex;
  align-items: center;
  gap: 1.25rem;
  box-shadow: var(--shadow-xs);
  transition: all var(--transition-normal);
}

.tech-card:hover {
  border-color: var(--border-interactive);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.tech-icon-box {
  width: 3rem;
  height: 3rem;
  border-radius: var(--radius-md);
  background-color: var(--bg-surface-alt);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 1.375rem;
  color: var(--color-primary);
}

.tech-name {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.2rem;
}

.tech-role {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

/* --- Security & Reliability --- */
.security-highlight-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
  margin-top: 1.5rem;
}

.security-box {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  padding: 2.25rem;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
}

.security-box:hover {
  border-color: var(--border-interactive);
  box-shadow: var(--shadow-md);
}

.security-box-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.security-icon {
  width: 2.75rem;
  height: 2.75rem;
  border-radius: var(--radius-md);
  background: var(--color-primary-tint);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.375rem;
  flex-shrink: 0;
}

.security-title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
}

.security-desc {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 1rem;
}

.code-snippet {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  background-color: #0f172a;
  color: #38bdf8;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-md);
  overflow-x: auto;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

/* --- Roadmap & Status --- */
.roadmap-timeline {
  position: relative;
  max-width: 900px;
  margin: 0 auto;
}

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

.roadmap-item {
  position: relative;
  padding-left: 5rem;
  margin-bottom: 3rem;
}

.roadmap-marker {
  position: absolute;
  left: 1.25rem;
  top: 0.25rem;
  width: 1.5rem;
  height: 1.5rem;
  border-radius: 50%;
  background: var(--bg-surface);
  border: 3px solid var(--color-primary);
  box-shadow: 0 0 0 4px var(--color-primary-tint);
  z-index: 2;
}

.roadmap-marker.future {
  border-color: #94a3b8;
  box-shadow: 0 0 0 4px #f1f5f9;
}

.roadmap-content {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
}

.roadmap-status-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  padding: 0.25rem 0.625rem;
  border-radius: var(--radius-full);
  margin-bottom: 0.75rem;
}

.badge-completed {
  background-color: var(--status-success-bg);
  color: var(--status-success);
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.badge-future {
  background-color: var(--status-info-bg);
  color: var(--status-info);
  border: 1px solid rgba(2, 132, 199, 0.3);
}

.roadmap-title {
  font-family: var(--font-display);
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.75rem;
}

.roadmap-feature-list {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin-top: 1rem;
}

.roadmap-feature-list li {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* --- Team Section --- */
.team-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  margin-top: 2rem;
}

.team-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  padding: 2rem 1.5rem;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
  align-items: center;
}

.team-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-interactive);
  box-shadow: var(--shadow-md);
}

.team-avatar-box {
  width: 5.5rem;
  height: 5.5rem;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-primary-tint) 0%, var(--color-accent-subtle) 100%);
  border: 3px solid var(--bg-surface);
  box-shadow: var(--shadow-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary-dark);
  margin-bottom: 1.25rem;
}

.team-name {
  font-family: var(--font-display);
  font-size: 1.1875rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.25rem;
}

.team-id-badge {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--color-primary);
  font-weight: 600;
  background-color: var(--color-primary-tint);
  padding: 0.2rem 0.625rem;
  border-radius: var(--radius-full);
  margin-bottom: 0.75rem;
  display: inline-block;
}

.team-email-link {
  font-size: 0.875rem;
  color: var(--text-muted);
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  transition: color var(--transition-fast);
}

.team-email-link:hover {
  color: var(--color-primary);
}

.academic-meta-card {
  margin-top: 3.5rem;
  background: #ffffff;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  padding: 2rem 2.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: var(--shadow-xs);
  flex-wrap: wrap;
  gap: 1.5rem;
}

.academic-meta-content h4 {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.25rem;
}

.academic-meta-content p {
  font-size: 0.9375rem;
  color: var(--text-muted);
}

/* --- Footer --- */
.site-footer {
  background-color: var(--bg-dark-panel);
  color: var(--text-inverse-muted);
  padding-top: 5rem;
  padding-bottom: 3rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1.2fr;
  gap: 3.5rem;
  margin-bottom: 4rem;
}

.footer-brand p {
  margin-top: 1rem;
  font-size: 0.9375rem;
  line-height: 1.65;
  color: var(--text-inverse-muted);
  max-width: 320px;
}

.footer-col-title {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 1.25rem;
  letter-spacing: -0.01em;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-links a {
  color: var(--text-inverse-muted);
  font-size: 0.9375rem;
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--color-primary-light);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 0.875rem;
  color: #64748b;
  flex-wrap: wrap;
  gap: 1rem;
}

/* --- Back to Top Floating Button --- */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 50%;
  background-color: var(--bg-surface);
  color: var(--text-main);
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 90;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background-color: var(--color-primary);
  color: #ffffff;
  transform: translateY(-2px);
}

/* --- Responsive Media Queries --- */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
  .hero-content {
    max-width: 100%;
    text-align: center;
  }
  .hero-badge-container {
    justify-content: center;
  }
  .hero-cta-group {
    justify-content: center;
  }
  .hero-trust-metrics {
    justify-content: center;
  }
  .arch-flow-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .feature-bento-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .bento-card.span-2 {
    grid-column: span 1;
  }
  .team-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 2.5rem;
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 4.25rem;
  }
  .section {
    padding-top: 4.25rem;
    padding-bottom: 4.25rem;
  }
  .nav-links {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: 100%;
    background-color: #ffffff;
    border-bottom: 1px solid var(--border-light);
    flex-direction: column;
    padding: 1.5rem;
    gap: 1.25rem;
    box-shadow: var(--shadow-lg);
    transform: translateY(-120%);
    transition: transform var(--transition-normal);
  }
  .nav-links.open {
    transform: translateY(0);
  }
  .mobile-only-link {
    display: block;
  }
  .mobile-toggle {
    display: flex;
  }
  .comparison-grid,
  .experience-layout,
  .arch-details-grid,
  .security-highlight-grid {
    grid-template-columns: 1fr;
    gap: 1.75rem;
  }
  .experience-layout.reverse {
    direction: ltr;
  }
  .arch-flow-grid {
    grid-template-columns: 1fr;
  }
  .feature-bento-grid {
    grid-template-columns: 1fr;
  }
  .team-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .floating-stat-badge {
    position: static;
    margin-top: 1rem;
    width: 100%;
  }
  .roadmap-timeline::before {
    left: 1rem;
  }
  .roadmap-item {
    padding-left: 3rem;
  }
  .roadmap-marker {
    left: 0.35rem;
  }
  .roadmap-feature-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 600px) {
  .nav-btn-hide-mobile {
    display: none;
  }
}

/* Reduced Motion Safety */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  .pulse-dot {
    animation: none;
  }
}