/* style.css —— CSS 变量、布局、排版、响应式、动画 */

:root {
  --primary: #1a3a5c;
  --primary-light: #2a5680;
  --accent: #c8a45c;
  --accent-light: #d9bb7e;
  --bg-light: #f7f9fb;
  --bg-white: #ffffff;
  --text-dark: #1f2937;
  --text-muted: #6b7280;
  --border: #e5e7eb;
  --error: #dc2626;
  --success: #16a34a;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.15);
  --radius: 8px;
  --radius-sm: 4px;
  --max-width: 1200px;
  --font: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 70px;
}

body {
  font-family: var(--font);
  color: var(--text-dark);
  background: var(--bg-white);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

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

ul { list-style: none; }

/* 布局容器 */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.section { padding: 80px 0; }

.section-alt { background: var(--bg-light); }

.section-head {
  text-align: center;
  margin-bottom: 56px;
}

.section-label {
  display: block;
  font-size: 0.85rem;
  letter-spacing: 0.15em;
  color: var(--accent);
  font-weight: 600;
  text-transform: uppercase;
  margin-bottom: 10px;
}

.section-title {
  font-size: 2.4rem;
  font-weight: 700;
  color: var(--primary);
  position: relative;
  display: inline-block;
  padding-bottom: 16px;
}

.section-title::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 56px;
  height: 3px;
  background: var(--accent);
  border-radius: 2px;
}

/* 按钮 */
.btn {
  display: inline-block;
  padding: 12px 32px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  font-family: inherit;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

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

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

.btn-outline:hover {
  background: var(--primary);
  color: #fff;
  transform: translateY(-2px);
}

.btn-secondary {
  background: var(--bg-light);
  color: var(--text-dark);
}

.btn-secondary:hover {
  background: var(--border);
  transform: translateY(-2px);
}

/* Hero */
.hero {
  position: relative;
  height: 100vh;
  min-height: 600px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: #fff;
  background: center/cover no-repeat;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(26, 58, 92, 0.7), rgba(0, 0, 0, 0.45));
}

.hero-content {
  position: relative;
  z-index: 2;
  animation: fadeInUp 1s ease;
}

.hero-tag {
  font-size: 0.9rem;
  letter-spacing: 0.3em;
  color: var(--accent-light);
  margin-bottom: 16px;
}

.hero-title {
  font-size: 4.5rem;
  font-weight: 700;
  margin-bottom: 18px;
  letter-spacing: 0.1em;
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.4);
}

.hero-slogan {
  font-size: 1.3rem;
  margin-bottom: 36px;
  opacity: 0.95;
  letter-spacing: 0.05em;
}

.hero .btn-primary {
  background: var(--accent);
  padding: 14px 40px;
  font-size: 1.05rem;
}

.hero .btn-primary:hover {
  background: #fff;
  color: var(--primary);
}

/* 页脚 */
.footer {
  background: var(--primary);
  color: rgba(255, 255, 255, 0.85);
  padding: 56px 0 0;
}

.footer-grid { padding-bottom: 32px; }

.footer-info {
  display: flex;
  flex-wrap: wrap;
  gap: 40px;
  margin-bottom: 32px;
}

.footer-brand { flex: 1 1 280px; }
.footer-brand h3 { font-size: 1.6rem; color: #fff; margin-bottom: 10px; }
.footer-brand p { color: rgba(255, 255, 255, 0.7); }

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 48px;
  flex: 2 1 400px;
}

.footer-col h4 {
  color: #fff;
  font-size: 1.05rem;
  margin-bottom: 14px;
}

.footer-col li {
  margin-bottom: 8px;
  color: rgba(255, 255, 255, 0.75);
  font-size: 0.92rem;
}

.footer-col a:hover { color: var(--accent-light); }

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  padding: 20px 0;
  text-align: center;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.6);
}

/* 回到顶部 */
.back-to-top {
  position: fixed;
  right: 28px;
  bottom: 28px;
  width: 46px;
  height: 46px;
  border: none;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  font-size: 1.4rem;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all 0.3s ease;
  box-shadow: var(--shadow-md);
  z-index: 100;
}

.back-to-top.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover { background: var(--accent); }

/* 入场动画 */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

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

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* 响应式 */
@media (max-width: 1024px) {
  .section-title { font-size: 2rem; }
  .hero-title { font-size: 3.5rem; }
}

@media (max-width: 768px) {
  .section { padding: 56px 0; }
  .section-head { margin-bottom: 40px; }
  .section-title { font-size: 1.75rem; }
  .container { padding: 0 18px; }
  .hero-title { font-size: 2.6rem; }
  .hero-slogan { font-size: 1.05rem; }
  .footer-info { flex-direction: column; gap: 28px; }
  .footer-links { gap: 32px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .reveal { opacity: 1; transform: none; }
}