/* ========================================
   Virtual Simulation Training — Spectra One Theme
   Core: #103143 | #1E88E5 | #F5F7FA
   ======================================== */

@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700;800&family=Noto+Sans+SC:wght@300;400;500;700&display=swap');

:root {
  --c-primary: #103143;
  --c-accent: #1E88E5;
  --c-accent-light: #42A5F5;
  --c-bg: #F5F7FA;
  --c-white: #FFFFFF;
  --c-text: #2C3E50;
  --c-text-light: #607D8B;
  --c-border: #E0E6ED;
  --c-dark-overlay: rgba(16, 49, 67, 0.92);
  --font-display: 'Outfit', sans-serif;
  --font-body: 'Noto Sans SC', 'Outfit', sans-serif;
  --nav-h: 72px;
  --max-w: 1200px;
  --radius: 10px;
  --shadow-sm: 0 2px 8px rgba(16,49,67,0.06);
  --shadow-md: 0 8px 30px rgba(16,49,67,0.10);
  --shadow-lg: 0 16px 48px rgba(16,49,67,0.14);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font-body);
  color: var(--c-text);
  background: var(--c-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; transition: color var(--transition); }
ul { list-style: none; }

/* ---------- Utility ---------- */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 24px; }
.section { padding: 100px 0; }
.section-alt { background: var(--c-white); }
.text-center { text-align: center; }

.section-label {
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--c-accent);
  margin-bottom: 12px;
  display: block;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 700;
  color: var(--c-primary);
  line-height: 1.25;
  margin-bottom: 16px;
}

.section-desc {
  font-size: 16px;
  color: var(--c-text-light);
  max-width: 640px;
  margin: 0 auto 48px;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  padding: 13px 32px;
  border-radius: 50px;
  border: none;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: var(--c-accent);
  color: var(--c-white);
  box-shadow: 0 4px 16px rgba(30,136,229,0.3);
}
.btn-primary:hover {
  background: #1976D2;
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(30,136,229,0.4);
}

.btn-outline {
  background: transparent;
  color: var(--c-white);
  border: 2px solid rgba(255,255,255,0.5);
}
.btn-outline:hover {
  border-color: var(--c-white);
  background: rgba(255,255,255,0.1);
}

.btn-ghost {
  background: transparent;
  color: var(--c-accent);
  border: 2px solid var(--c-accent);
}
.btn-ghost:hover {
  background: var(--c-accent);
  color: var(--c-white);
}

/* ---------- Navigation ---------- */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 1000;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--c-border);
  transition: all var(--transition);
}
.navbar.scrolled {
  box-shadow: var(--shadow-sm);
}
.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  color: var(--c-primary);
}
.nav-logo .logo-icon {
  width: 36px; height: 36px;
  background: linear-gradient(135deg, var(--c-accent), var(--c-primary));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.nav-logo .logo-icon svg { width: 20px; height: 20px; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 6px;
}
.nav-links a {
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 500;
  padding: 8px 16px;
  border-radius: 6px;
  color: var(--c-text);
  transition: all var(--transition);
  position: relative;
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--c-accent);
  background: rgba(30,136,229,0.06);
}

.nav-cta {
  font-family: var(--font-display);
  font-size: 13px !important;
  font-weight: 600 !important;
  padding: 9px 22px !important;
  background: var(--c-accent) !important;
  color: var(--c-white) !important;
  border-radius: 50px !important;
}
.nav-cta:hover {
  background: #1976D2 !important;
}

/* Hamburger */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--c-primary);
  border-radius: 2px;
  transition: all var(--transition);
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: var(--c-primary);
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 70% 40%, rgba(30,136,229,0.15), transparent),
    radial-gradient(ellipse 60% 80% at 20% 80%, rgba(30,136,229,0.08), transparent);
}
.hero-grid-bg {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
  background-size: 60px 60px;
}
.hero-content {
  position: relative;
  z-index: 2;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  padding-top: var(--nav-h);
}
.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  min-height: calc(100vh - var(--nav-h));
  padding: 60px 0;
}
.hero-text h1 {
  font-family: var(--font-display);
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 800;
  color: var(--c-white);
  line-height: 1.15;
  margin-bottom: 24px;
}
.hero-text h1 .accent {
  background: linear-gradient(135deg, var(--c-accent-light), #80D8FF);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-text p {
  font-size: 17px;
  color: rgba(255,255,255,0.7);
  margin-bottom: 36px;
  max-width: 480px;
  line-height: 1.8;
}
.hero-buttons { display: flex; gap: 14px; flex-wrap: wrap; }

.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}
.hero-graphic {
  width: 100%;
  max-width: 480px;
  aspect-ratio: 1;
  position: relative;
}
.hero-graphic .ring {
  position: absolute;
  border: 1.5px solid rgba(30,136,229,0.2);
  border-radius: 50%;
  animation: spin 30s linear infinite;
}
.hero-graphic .ring:nth-child(1) { inset: 0; }
.hero-graphic .ring:nth-child(2) { inset: 15%; animation-duration: 25s; animation-direction: reverse; border-color: rgba(30,136,229,0.15); }
.hero-graphic .ring:nth-child(3) { inset: 30%; animation-duration: 20s; border-color: rgba(30,136,229,0.1); }
.hero-graphic .center-icon {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 100px; height: 100px;
  background: linear-gradient(135deg, var(--c-accent), var(--c-accent-light));
  border-radius: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 60px rgba(30,136,229,0.4);
}
.hero-graphic .center-icon svg { width: 48px; height: 48px; }
.hero-graphic .node {
  position: absolute;
  width: 48px; height: 48px;
  background: rgba(30,136,229,0.15);
  border: 1.5px solid rgba(30,136,229,0.3);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(8px);
}
.hero-graphic .node svg { width: 22px; height: 22px; }
.hero-graphic .node:nth-child(5) { top: 5%; left: 50%; transform: translateX(-50%); }
.hero-graphic .node:nth-child(6) { top: 50%; right: 2%; transform: translateY(-50%); }
.hero-graphic .node:nth-child(7) { bottom: 5%; left: 50%; transform: translateX(-50%); }
.hero-graphic .node:nth-child(8) { top: 50%; left: 2%; transform: translateY(-50%); }

@keyframes spin { to { transform: rotate(360deg); } }

/* ---------- Page Hero (inner pages) ---------- */
.page-hero {
  position: relative;
  padding: 160px 0 80px;
  background: var(--c-primary);
  overflow: hidden;
}
.page-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 60% at 80% 30%, rgba(30,136,229,0.12), transparent);
}
.page-hero .container { position: relative; z-index: 2; }
.page-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(32px, 4vw, 48px);
  font-weight: 800;
  color: var(--c-white);
  margin-bottom: 16px;
}
.page-hero p {
  font-size: 17px;
  color: rgba(255,255,255,0.65);
  max-width: 560px;
}
.page-hero .breadcrumb {
  display: flex;
  gap: 8px;
  align-items: center;
  margin-bottom: 20px;
  font-size: 13px;
  color: rgba(255,255,255,0.45);
}
.page-hero .breadcrumb a { color: rgba(255,255,255,0.6); }
.page-hero .breadcrumb a:hover { color: var(--c-accent-light); }

/* ---------- Cards ---------- */
.card-grid {
  display: grid;
  gap: 28px;
}
.card-grid.cols-2 { grid-template-columns: repeat(2, 1fr); }
.card-grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
.card-grid.cols-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: var(--c-white);
  border-radius: var(--radius);
  padding: 36px 30px;
  border: 1px solid var(--c-border);
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}
.card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--c-accent), var(--c-accent-light));
  opacity: 0;
  transition: opacity var(--transition);
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: transparent;
}
.card:hover::before { opacity: 1; }

.card-icon {
  width: 52px; height: 52px;
  background: linear-gradient(135deg, rgba(30,136,229,0.1), rgba(30,136,229,0.05));
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}
.card-icon svg { width: 26px; height: 26px; color: var(--c-accent); }

.card h3 {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 600;
  color: var(--c-primary);
  margin-bottom: 10px;
}
.card p {
  font-size: 14px;
  color: var(--c-text-light);
  line-height: 1.7;
}

/* ---------- Stats ---------- */
.stats-bar {
  background: var(--c-white);
  border-radius: var(--radius);
  padding: 48px 40px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--c-border);
}
.stat-item { text-align: center; }
.stat-num {
  font-family: var(--font-display);
  font-size: 42px;
  font-weight: 800;
  color: var(--c-primary);
  line-height: 1.1;
}
.stat-num .unit {
  font-size: 20px;
  font-weight: 600;
  color: var(--c-accent);
}
.stat-label {
  font-size: 14px;
  color: var(--c-text-light);
  margin-top: 6px;
}

/* ---------- Project Cards ---------- */
.project-card {
  background: var(--c-white);
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--c-border);
  transition: all var(--transition);
}
.project-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}
.project-thumb {
  height: 220px;
  background: linear-gradient(135deg, var(--c-primary), #1a4a63);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}
.project-thumb::after {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 30% 70%, rgba(30,136,229,0.2), transparent 50%);
}
.project-thumb svg { width: 64px; height: 64px; color: rgba(255,255,255,0.25); position: relative; z-index: 1; }
.project-tag {
  position: absolute;
  top: 14px;
  left: 14px;
  z-index: 2;
  font-family: var(--font-display);
  font-size: 11px;
  font-weight: 600;
  padding: 4px 12px;
  background: rgba(30,136,229,0.85);
  color: var(--c-white);
  border-radius: 50px;
  backdrop-filter: blur(4px);
}
.project-body { padding: 24px; }
.project-body h3 {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 600;
  color: var(--c-primary);
  margin-bottom: 8px;
}
.project-body p {
  font-size: 14px;
  color: var(--c-text-light);
  margin-bottom: 16px;
  line-height: 1.65;
}
.project-meta {
  display: flex;
  gap: 16px;
  font-size: 12px;
  color: var(--c-text-light);
}
.project-meta span { display: flex; align-items: center; gap: 4px; }

/* ---------- Timeline ---------- */
.timeline { position: relative; padding-left: 32px; }
.timeline::before {
  content: '';
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--c-accent), var(--c-border));
}
.timeline-item {
  position: relative;
  padding-bottom: 40px;
}
.timeline-item::before {
  content: '';
  position: absolute;
  left: -37px; top: 6px;
  width: 12px; height: 12px;
  background: var(--c-accent);
  border-radius: 50%;
  border: 3px solid var(--c-bg);
}
.timeline-item h4 {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 600;
  color: var(--c-primary);
  margin-bottom: 4px;
}
.timeline-item .year {
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 600;
  color: var(--c-accent);
  margin-bottom: 8px;
  display: block;
}
.timeline-item p {
  font-size: 14px;
  color: var(--c-text-light);
}

/* ---------- Form ---------- */
.form-group {
  margin-bottom: 22px;
}
.form-group label {
  display: block;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 500;
  color: var(--c-primary);
  margin-bottom: 8px;
}
.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 12px 16px;
  border: 1.5px solid var(--c-border);
  border-radius: 8px;
  font-family: var(--font-body);
  font-size: 14px;
  color: var(--c-text);
  background: var(--c-white);
  transition: border-color var(--transition);
  outline: none;
}
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  border-color: var(--c-accent);
  box-shadow: 0 0 0 3px rgba(30,136,229,0.1);
}
.form-group textarea { resize: vertical; min-height: 120px; }

/* ---------- Footer ---------- */
.footer {
  background: var(--c-primary);
  color: rgba(255,255,255,0.7);
  padding: 64px 0 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 48px;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}
.footer-brand p {
  font-size: 14px;
  line-height: 1.7;
  margin-top: 16px;
  max-width: 300px;
}
.footer h4 {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  color: var(--c-white);
  margin-bottom: 20px;
}
.footer ul li { margin-bottom: 10px; }
.footer ul a {
  font-size: 14px;
  color: rgba(255,255,255,0.55);
  transition: color var(--transition);
}
.footer ul a:hover { color: var(--c-accent-light); }
.footer-bottom {
  padding: 24px 0;
  font-size: 13px;
  color: rgba(255,255,255,0.35);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* ---------- Scroll Animations ---------- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1), transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .hero-inner { grid-template-columns: 1fr; text-align: center; }
  .hero-text p { margin-left: auto; margin-right: auto; }
  .hero-buttons { justify-content: center; }
  .hero-visual { display: none; }
  .card-grid.cols-4 { grid-template-columns: repeat(2, 1fr); }
  .stats-bar { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: fixed;
    top: var(--nav-h);
    left: 0; right: 0;
    background: var(--c-white);
    flex-direction: column;
    padding: 20px 24px;
    box-shadow: var(--shadow-md);
    border-top: 1px solid var(--c-border);
    gap: 4px;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 16px; width: 100%; }
  .nav-toggle { display: flex; }

  .section { padding: 64px 0; }
  .card-grid.cols-2,
  .card-grid.cols-3,
  .card-grid.cols-4 { grid-template-columns: 1fr; }
  .stats-bar { grid-template-columns: 1fr 1fr; padding: 32px 24px; gap: 24px; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .footer-bottom { flex-direction: column; gap: 8px; text-align: center; }

  .page-hero { padding: 120px 0 60px; }
}

@media (max-width: 480px) {
  .stats-bar { grid-template-columns: 1fr; }
  .hero-text h1 { font-size: 32px; }
  .btn { padding: 11px 24px; font-size: 14px; }
}