/* ===== 科睿达官网 - 全局样式 ===== */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500;600;700;900&display=swap');

:root {
  --primary: #4f46e5;
  --primary-light: #818cf8;
  --primary-dark: #3730a3;
  --accent: #f59e0b;
  --accent-pink: #ec4899;
  --accent-cyan: #06b6d4;
  --bg-dark: #0f0f1a;
  --bg-card: #1a1a2e;
  --bg-card-hover: #22223a;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border: rgba(255, 255, 255, 0.08);
  --gradient-hero: linear-gradient(135deg, #0f0f1a 0%, #1a1040 50%, #0f172a 100%);
  --gradient-primary: linear-gradient(135deg, #4f46e5, #7c3aed, #ec4899);
  --gradient-accent: linear-gradient(135deg, #f59e0b, #ec4899);
  --shadow-glow: 0 0 40px rgba(79, 70, 229, 0.3);
  --radius: 16px;
  --radius-sm: 8px;
  --nav-height: 72px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

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

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

ul {
  list-style: none;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== 导航栏 ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  background: rgba(15, 15, 26, 0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
}

.navbar.scrolled {
  background: rgba(15, 15, 26, 0.95);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.4rem;
  font-weight: 700;
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: var(--gradient-primary);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links a {
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text-primary);
  background: rgba(79, 70, 229, 0.15);
}

.nav-dropdown {
  position: relative;
}

.nav-dropdown-trigger {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  cursor: pointer;
}

.nav-dropdown-trigger::after {
  content: '▾';
  font-size: 0.7rem;
  opacity: 0.7;
}

.nav-dropdown-menu {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  min-width: 200px;
  padding: 8px;
  background: rgba(15, 15, 26, 0.98);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.45);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s;
  z-index: 1100;
}

.nav-dropdown:hover .nav-dropdown-menu,
.nav-dropdown.open .nav-dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.nav-dropdown-menu a {
  display: block;
  padding: 10px 14px;
  white-space: nowrap;
  border-radius: 6px;
  font-size: 0.9rem;
}

.nav-cta {
  padding: 10px 24px !important;
  background: var(--gradient-primary) !important;
  color: white !important;
  border-radius: 50px !important;
  font-weight: 600 !important;
}

.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-glow);
}

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.menu-toggle span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: var(--transition);
}

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 50px;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
}

.btn-primary {
  background: var(--gradient-primary);
  color: white;
}

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

.btn-outline {
  background: transparent;
  color: var(--text-primary);
  border: 2px solid var(--border);
}

.btn-outline:hover {
  border-color: var(--primary-light);
  background: rgba(79, 70, 229, 0.1);
}

.btn-accent {
  background: var(--gradient-accent);
  color: white;
}

.btn-accent:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 30px rgba(245, 158, 11, 0.4);
}

/* ===== 章节通用 ===== */
.section {
  padding: 100px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-tag {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(79, 70, 229, 0.15);
  color: var(--primary-light);
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 16px;
  letter-spacing: 0.05em;
}

.section-title {
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 700;
  margin-bottom: 16px;
  background: linear-gradient(135deg, #fff 0%, #c7d2fe 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: var(--gradient-hero);
  position: relative;
  overflow: hidden;
  padding-top: var(--nav-height);
}

.hero-bg {
  position: absolute;
  inset: 0;
  overflow: hidden;
}

.hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.4;
  animation: float 8s ease-in-out infinite;
}

.hero-orb-1 {
  width: 500px;
  height: 500px;
  background: #4f46e5;
  top: -100px;
  right: -100px;
}

.hero-orb-2 {
  width: 400px;
  height: 400px;
  background: #ec4899;
  bottom: -50px;
  left: -100px;
  animation-delay: -4s;
}

.hero-orb-3 {
  width: 300px;
  height: 300px;
  background: #06b6d4;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  animation-delay: -2s;
}

@keyframes float {
  0%, 100% { transform: translateY(0) scale(1); }
  50% { transform: translateY(-30px) scale(1.05); }
}

.hero .container {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-self: stretch;
  align-items: center;
  padding-top: 24px;
  padding-bottom: 24px;
}

.hero-content h1 {
  font-size: clamp(2.5rem, 5vw, 3.8rem);
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 24px;
}

@media (min-width: 969px) {
  .hero-content {
    transform: translateX(44px);
  }
}

.hero-content h1 span {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-content p {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 36px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-card-stack {
  position: relative;
  width: 100%;
  max-width: 420px;
  aspect-ratio: 4/5;
}

.hero-card {
  position: absolute;
  width: 85%;
  border-radius: var(--radius);
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 0;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
}

.hero-card img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.hero-card:nth-child(1) {
  top: 0;
  left: 0;
  aspect-ratio: 373 / 208;
  transform: rotate(-6deg);
  z-index: 1;
}

.hero-card:nth-child(2) {
  top: 15%;
  right: 0;
  aspect-ratio: 368 / 196;
  transform: rotate(4deg);
  z-index: 2;
}

.hero-card:nth-child(3) {
  bottom: 0;
  left: 10%;
  aspect-ratio: 363 / 184;
  transform: rotate(-2deg);
  z-index: 3;
  background: linear-gradient(135deg, #1a1a2e, #2d1b69);
}

.hero-card-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 16px;
}

.hero-card h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.hero-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* ===== 卡片网格 ===== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: var(--transition);
}

.card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(79, 70, 229, 0.3);
  transform: translateY(-4px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.card-icon {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 20px;
}

.card h3 {
  font-size: 1.2rem;
  margin-bottom: 12px;
}

.card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ===== 页脚 ===== */
.footer {
  background: #0a0a14;
  border-top: 1px solid var(--border);
  padding: 60px 0 30px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand p {
  color: var(--text-secondary);
  margin-top: 16px;
  font-size: 0.9rem;
  line-height: 1.7;
}

.footer h4 {
  font-size: 0.95rem;
  margin-bottom: 20px;
  color: var(--text-primary);
}

.footer-links a {
  display: block;
  color: var(--text-secondary);
  font-size: 0.9rem;
  padding: 6px 0;
  transition: var(--transition);
}

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

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* ===== 动画入场 ===== */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 响应式 ===== */
@media (max-width: 968px) {
  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-visual {
    display: none;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    flex-direction: column;
    background: rgba(15, 15, 26, 0.98);
    padding: 20px;
    border-bottom: 1px solid var(--border);
  }

  .nav-links.open {
    display: flex;
  }

  .nav-dropdown {
    width: 100%;
  }

  .nav-dropdown-menu {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    display: none;
    box-shadow: none;
    border: none;
    background: transparent;
    padding: 0 0 0 12px;
    margin-top: 4px;
  }

  .nav-dropdown.open .nav-dropdown-menu {
    display: block;
  }

  .menu-toggle {
    display: flex;
  }

  .footer-grid {
    grid-template-columns: 1fr;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }
}