/* ============================================
   BuranLab 暴风雪号工作室 — 宣传网站样式
   ============================================ */

/* ===== CSS Variables ===== */
:root {
  /* Colors — based on BuranLab logo (red/cream) */
  --bg-primary: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-card: rgba(18, 18, 26, 0.6);
  --accent: #e63946;
  --accent-glow: rgba(230, 57, 70, 0.3);
  --accent-dim: rgba(230, 57, 70, 0.08);
  --secondary: #c53030;
  --secondary-glow: rgba(197, 48, 48, 0.3);
  --logo-cream: #f5e6d3;
  --logo-cream-glow: rgba(245, 230, 211, 0.15);
  --text-primary: #e0e0e8;
  --text-secondary: #8888a0;
  --border: rgba(230, 57, 70, 0.15);
  --border-hover: rgba(230, 57, 70, 0.4);

  /* Typography */
  --font-heading: 'Orbitron', sans-serif;
  --font-body: 'Noto Sans SC', sans-serif;

  /* Spacing */
  --section-padding: 100px 0;
  --container-width: 1100px;
  --container-padding: 0 24px;

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;

  /* Nav height */
  --nav-height: 70px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

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

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

ul {
  list-style: none;
}

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

/* ===== Utility Classes ===== */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: var(--container-padding);
}

.glass-panel {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: 16px;
  transition: border-color var(--transition-base), box-shadow var(--transition-base), transform var(--transition-base);
}

.glass-panel:hover {
  border-color: var(--border-hover);
  box-shadow: 0 0 30px var(--accent-dim), 0 0 60px rgba(230, 57, 70, 0.05);
}

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

/* Scroll reveal base state */
.reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Section Common ===== */
.section {
  padding: var(--section-padding);
  position: relative;
  z-index: 1;
}

.section-title {
  font-family: var(--font-heading);
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 700;
  text-align: center;
  background: linear-gradient(135deg, var(--accent), var(--text-primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  color: transparent;
  margin-bottom: 16px;
}

.section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  font-size: 1.05rem;
  margin-bottom: 48px;
}

.section-lead {
  max-width: 720px;
  margin: 0 auto 48px;
  text-align: center;
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1.8;
}

.section-motto {
  text-align: center;
  margin-top: 40px;
  padding: 16px 24px;
  font-style: italic;
  color: var(--text-secondary);
  font-size: 0.95rem;
  border-top: 1px solid var(--border);
  display: inline-block;
  margin-left: auto;
  margin-right: auto;
  width: fit-content;
  max-width: 100%;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 32px;
  border-radius: 8px;
  font-family: var(--font-heading);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-base);
  border: none;
  letter-spacing: 0.5px;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--secondary));
  color: #fff;
  box-shadow: 0 4px 20px var(--accent-dim);
}

.btn-primary:hover {
  box-shadow: 0 6px 30px var(--accent-glow);
  transform: translateY(-2px);
}

.btn-outline {
  background: transparent;
  border: 1.5px solid var(--border);
  color: var(--text-primary);
}

.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent);
  box-shadow: 0 0 20px var(--accent-dim);
}

.btn-lg {
  padding: 16px 40px;
  font-size: 1rem;
}

.btn-full {
  width: 100%;
}

/* ===== Canvas Background ===== */
#particleCanvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
  opacity: 0.4;
}

/* ===== Navbar ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  z-index: 1000;
  border-bottom: 1px solid rgba(245, 230, 211, 0.08);
  transition: background-color var(--transition-base), box-shadow var(--transition-base), border-bottom-color var(--transition-base);
}

.navbar.scrolled {
  background-color: rgba(10, 10, 15, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 2px 0 var(--logo-cream), 0 0 20px rgba(245, 230, 211, 0.06);
}

.nav-container {
  max-width: var(--container-width);
  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: 12px;
  line-height: 1.2;
}

.logo-img {
  width: 42px;
  height: 42px;
  object-fit: contain;
  border-radius: 8px;
  border: 1.5px solid var(--logo-cream);
  background: rgba(245, 230, 211, 0.08);
  padding: 4px;
  transition: transform var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
}

.nav-logo:hover .logo-img {
  transform: scale(1.05);
  border-color: var(--logo-cream);
  box-shadow: 0 0 12px rgba(245, 230, 211, 0.2);
}

.logo-text-wrap {
  display: flex;
  flex-direction: column;
}

.logo-text {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--logo-cream);
  letter-spacing: 2px;
  -webkit-text-stroke: 0.5px rgba(245, 230, 211, 0.6);
}

.logo-sub {
  font-size: 0.7rem;
  color: var(--logo-cream);
  opacity: 0.7;
  letter-spacing: 1px;
}

.nav-links {
  display: flex;
  gap: 28px;
}

.nav-links a {
  font-size: 0.88rem;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
  position: relative;
  padding: 4px 0;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--logo-cream);
  transition: width var(--transition-base);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--logo-cream);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  z-index: 1001;
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--logo-cream);
  border-radius: 2px;
  transition: all var(--transition-base);
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 120px 24px 60px;
  position: relative;
  z-index: 1;
}

.hero-content {
  max-width: 700px;
}

.hero-title {
  font-size: clamp(48px, 8vw, 88px);
  margin-bottom: 16px;
}

.hero-subtitle {
  font-size: clamp(16px, 2.5vw, 20px);
  color: var(--text-secondary);
  margin-bottom: 12px;
  letter-spacing: 2px;
}

.hero-desc {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 500px;
  margin: 0 auto 36px;
  line-height: 1.8;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.scroll-indicator {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--text-secondary);
  animation: bounce 2s infinite;
  opacity: 0.6;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
  40% { transform: translateX(-50%) translateY(-8px); }
  60% { transform: translateX(-50%) translateY(-4px); }
}

/* ===== About Stats ===== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: 700px;
  margin: 0 auto;
}

.stat-card {
  padding: 32px 16px;
  text-align: center;
}

.stat-number {
  font-family: var(--font-heading);
  font-size: 2.8rem;
  font-weight: 700;
  color: var(--accent);
}

.stat-unit {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  color: var(--accent);
  opacity: 0.7;
  margin-left: 2px;
}

.stat-label {
  display: block;
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

.stat-symbol {
  font-family: var(--font-heading);
  font-size: 2.8rem;
  font-weight: 400;
  color: var(--secondary);
  display: block;
}

.stat-label-solo {
  display: block;
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-top: 0;
}

/* ===== Services Grid ===== */
.services-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.service-card {
  padding: 32px;
  cursor: pointer;
}

.card-icon {
  margin-bottom: 20px;
}

.card-title {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 10px;
  letter-spacing: 1px;
}

.card-desc {
  font-size: 0.93rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ===== Tech Grid ===== */
.tech-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.tech-card {
  padding: 32px;
}

.tech-card-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
}

.tech-icon {
  flex-shrink: 0;
}

.tech-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}

.tag {
  font-size: 0.75rem;
  padding: 4px 12px;
  border: 1px solid var(--border);
  border-radius: 100px;
  color: var(--accent);
  background: var(--accent-dim);
  font-family: var(--font-heading);
  letter-spacing: 0.5px;
}

/* ===== Education Grid ===== */
.edu-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.edu-card {
  padding: 32px;
  position: relative;
  overflow: visible;
}

.edu-icon {
  margin-bottom: 20px;
}

.hot-badge {
  position: absolute;
  top: 12px;
  right: 12px;
  font-size: 0.7rem;
  padding: 3px 10px;
  border-radius: 100px;
  background: linear-gradient(135deg, var(--accent), var(--secondary));
  color: #fff;
  font-family: var(--font-heading);
  letter-spacing: 1px;
}

/* ===== Rural Grid ===== */
.rural-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.rural-card {
  padding: 32px;
}

.rural-icon {
  margin-bottom: 20px;
}

/* ===== Media Grid ===== */
.media-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.media-card {
  padding: 36px 32px;
  text-align: center;
}

.media-thumb {
  margin-bottom: 20px;
  display: flex;
  justify-content: center;
}

.media-thumb svg {
  transition: transform var(--transition-base);
}

.media-card:hover .media-thumb svg {
  transform: scale(1.1);
}

.coming-soon {
  display: inline-block;
  margin-top: 12px;
  font-size: 0.72rem;
  padding: 3px 12px;
  border: 1px solid var(--border);
  border-radius: 100px;
  color: var(--text-secondary);
  font-family: var(--font-heading);
  letter-spacing: 1px;
}

.media-cta {
  text-align: center;
  margin-top: 48px;
}

/* ===== Contact ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: flex-start;
}

.contact-info h3 {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  margin-bottom: 12px;
  color: var(--text-primary);
  letter-spacing: 1px;
}

.contact-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 28px;
  line-height: 1.7;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  color: var(--text-secondary);
  font-size: 0.93rem;
}

.contact-form {
  padding: 32px;
}

.form-group {
  margin-bottom: 18px;
}

.form-group label {
  display: block;
  margin-bottom: 6px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-family: var(--font-heading);
  letter-spacing: 0.5px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.93rem;
  transition: border-color var(--transition-fast);
  outline: none;
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-dim);
}

.form-group textarea {
  resize: vertical;
  min-height: 100px;
}

/* Success toast */
.toast {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: linear-gradient(135deg, var(--accent), var(--secondary));
  color: #fff;
  padding: 16px 24px;
  border-radius: 10px;
  font-family: var(--font-heading);
  font-size: 0.9rem;
  letter-spacing: 1px;
  box-shadow: 0 8px 30px var(--accent-glow);
  transform: translateY(100px);
  opacity: 0;
  transition: all var(--transition-base);
  z-index: 9999;
  pointer-events: none;
}

.toast.show {
  transform: translateY(0);
  opacity: 1;
}

/* ===== Footer ===== */
.footer {
  text-align: center;
  padding: 60px 24px;
  border-top: 1px solid var(--border);
  position: relative;
  z-index: 1;
}

.footer-brand {
  margin-bottom: 12px;
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.footer-brand .logo-img {
  width: 64px;
  height: 64px;
  margin-bottom: 4px;
  border-color: rgba(230, 57, 70, 0.25);
}

.footer-brand .logo-text {
  display: block;
  font-size: 1.4rem;
}

.footer-brand .logo-sub {
  display: block;
  font-size: 0.65rem;
  margin-top: 2px;
}

.footer-slogan {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 12px;
}

.footer-copy {
  color: var(--text-secondary);
  font-size: 0.78rem;
  opacity: 0.6;
}

/* ===== Media Queries ===== */

/* Tablet */
@media (max-width: 900px) {
  .tech-grid,
  .edu-grid,
  .rural-grid,
  .media-grid {
    grid-template-columns: 1fr;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
  }

  .contact-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .services-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .stats-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
  }

  .stat-number { font-size: 2.2rem; }
  .stat-symbol { font-size: 2.2rem; }
}

/* Tablet small / Mobile large */
@media (max-width: 768px) {
  :root {
    --nav-height: 60px;
    --section-padding: 70px 0;
  }

  /* Mobile nav */
  .hamburger {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 260px;
    height: 100vh;
    background: rgba(10, 10, 15, 0.96);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 32px;
    transition: right var(--transition-slow);
    z-index: 1000;
    border-left: 1px solid var(--border);
  }

  .nav-links.active {
    right: 0;
  }

  .nav-links a {
    font-size: 1.05rem;
  }

  .services-grid {
    grid-template-columns: 1fr;
    max-width: 400px;
    margin-left: auto;
    margin-right: auto;
  }

  .stats-grid {
    grid-template-columns: 1fr;
    max-width: 250px;
    margin-left: auto;
    margin-right: auto;
  }

  .hero-title {
    font-size: 40px;
  }

  .section-title {
    font-size: 26px;
  }
}

/* Mobile */
@media (max-width: 480px) {
  .hero-buttons {
    flex-direction: column;
    width: 100%;
    max-width: 280px;
    margin: 0 auto;
  }

  .hero-buttons .btn {
    width: 100%;
  }

  .container {
    padding: 0 16px;
  }

  .section-lead {
    font-size: 0.95rem;
  }
}

/* Accessibility: Reduced motion */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .scroll-indicator {
    animation: none;
  }
}

/* Focus visible for keyboard nav */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}