/* ===== 基础 ===== */
:root {
  --blue-deep: #1D3B8B;
  --blue: #2E62D6;
  --blue-light: #3B82F6;
  --gold: #F5B845;
  --green: #22A06B;
  --orange: #F2994A;
  --red: #E5484D;
  --bg: #F5F8FC;
  --text: #1F2937;
  --text-sub: #6B7280;
  --radius: 16px;
  --shadow: 0 8px 24px rgba(29, 59, 139, 0.08);
  --font: -apple-system, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { display: block; max-width: 100%; }
a { text-decoration: none; color: inherit; }

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== 导航 ===== */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: #ffffff;
  border-bottom: 1px solid rgba(29, 59, 139, 0.08);
  box-shadow: 0 2px 12px rgba(29, 59, 139, 0.05);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.brand { display: flex; align-items: center; gap: 12px; }
.brand-logo { width: 46px; height: 46px; border-radius: 12px; box-shadow: var(--shadow); }
.brand-text { display: flex; flex-direction: column; line-height: 1.2; }
.brand-name { font-weight: 700; font-size: 17px; color: var(--blue-deep); letter-spacing: 0.5px; }
.brand-sub { font-size: 12px; color: var(--text-sub); }

.nav-links { display: flex; gap: 30px; }
.nav-links a {
  font-size: 15px;
  color: var(--text);
  position: relative;
  padding: 4px 0;
  transition: color 0.25s ease;
}
.nav-links a::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  width: 0; height: 2px;
  background: var(--blue);
  transition: width 0.25s ease;
}
.nav-links a:hover { color: var(--blue); }
.nav-links a:hover::after { width: 100%; }

.nav-toggle { display: none; background: none; border: none; cursor: pointer; flex-direction: column; gap: 5px; padding: 6px; }
.nav-toggle span { width: 24px; height: 2px; background: var(--blue-deep); border-radius: 2px; transition: all 0.25s ease; }

/* ===== Hero ===== */
.hero {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, #1D3B8B 0%, #2E62D6 55%, #3B82F6 100%);
  color: #fff;
  padding: 96px 0 120px;
}
.hero::before,
.hero::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  filter: blur(70px);
  opacity: 0.5;
}
.hero::before {
  width: 420px; height: 420px;
  background: rgba(245, 184, 69, 0.35);
  top: -120px; right: -80px;
}
.hero::after {
  width: 380px; height: 380px;
  background: rgba(255, 255, 255, 0.18);
  bottom: -140px; left: -100px;
}
.hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}

.hero-badge {
  display: inline-block;
  padding: 6px 16px;
  border-radius: 999px;
  background: rgba(245, 184, 69, 0.16);
  border: 1px solid rgba(245, 184, 69, 0.5);
  color: #FCD98A;
  font-size: 13px;
  letter-spacing: 1px;
  margin-bottom: 22px;
}
.hero-title {
  font-size: 46px;
  line-height: 1.2;
  font-weight: 800;
  letter-spacing: 1px;
  margin-bottom: 22px;
}
.hero-title .gold { color: var(--gold); }
.hero-desc {
  font-size: 16px;
  color: rgba(255, 255, 255, 0.86);
  margin-bottom: 26px;
  max-width: 540px;
}
.hero-points { list-style: none; margin-bottom: 30px; }
.hero-points li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 15px;
  color: rgba(255, 255, 255, 0.92);
  padding: 6px 0;
}
.dot {
  width: 22px; height: 22px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  flex-shrink: 0;
}
.dot.gold { background: rgba(245, 184, 69, 0.2); color: var(--gold); }

.hero-cta { display: flex; gap: 16px; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 30px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.25s ease;
  cursor: pointer;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary {
  background: var(--gold);
  color: var(--blue-deep);
  box-shadow: 0 10px 24px rgba(245, 184, 69, 0.35);
}
.btn-primary:hover { background: #F7C35E; }
.btn-outline {
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.4);
}
.btn-outline:hover { background: rgba(255, 255, 255, 0.2); }

.hero-phone { position: relative; display: flex; justify-content: center; }
.phone-frame {
  width: 280px;
  padding: 14px;
  background: #fff;
  border-radius: 34px;
  box-shadow: 0 30px 60px rgba(0, 0, 0, 0.3);
  transform: rotate(4deg);
  transition: transform 0.4s ease;
}
.hero-phone:hover .phone-frame { transform: rotate(0deg) translateY(-6px); }
.phone-frame img {
  border-radius: 22px;
  aspect-ratio: 9/20;
  object-fit: cover;
  width: 100%;
}
.float-chip {
  position: absolute;
  display: flex;
  flex-direction: column;
  background: #fff;
  color: var(--text);
  padding: 10px 18px;
  border-radius: 14px;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.22);
  animation: float 4s ease-in-out infinite;
}
.float-chip-1 { top: 30px; right: 0; }
.float-chip-2 { bottom: 40px; left: 0; animation-delay: 1.5s; }
.fc-num { font-size: 22px; font-weight: 800; line-height: 1.2; }
.fc-num.gold { color: var(--gold); }
.fc-label { font-size: 12px; color: var(--text-sub); }
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

/* ===== 数据概览 ===== */
.stats {
  position: relative;
  margin-top: -56px;
  z-index: 5;
}
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.stat-item {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px 20px;
  text-align: center;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.stat-item:hover { transform: translateY(-4px); box-shadow: 0 16px 32px rgba(29, 59, 139, 0.14); }
.stat-num { display: block; font-size: 34px; font-weight: 800; line-height: 1.2; }
.stat-label { display: block; margin-top: 6px; color: var(--text-sub); font-size: 14px; }
.blue { color: var(--blue); }
.gold { color: var(--gold); }
.green { color: var(--green); }
.orange { color: var(--orange); }

/* ===== 通用段落 ===== */
.section { padding: 88px 0; }
.section-alt { background: #fff; }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 46px; }
.kicker {
  display: inline-block;
  font-size: 12px;
  letter-spacing: 3px;
  color: var(--blue);
  font-weight: 600;
  margin-bottom: 10px;
}
.section-title {
  font-size: 32px;
  font-weight: 800;
  color: var(--blue-deep);
  letter-spacing: 1px;
  margin-bottom: 14px;
}
.section-sub { color: var(--text-sub); font-size: 16px; }

/* ===== 功能卡片 ===== */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.feature-card {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px 26px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  position: relative;
}
.feature-card:hover { transform: translateY(-4px); box-shadow: 0 16px 32px rgba(29, 59, 139, 0.14); }
.feature-icon {
  width: 58px; height: 58px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  color: #fff;
  margin-bottom: 20px;
}
.feature-icon.blue { background: linear-gradient(135deg, #2E62D6, #3B82F6); }
.feature-icon.orange { background: linear-gradient(135deg, #F2994A, #F7C35E); }
.feature-icon.green { background: linear-gradient(135deg, #22A06B, #34C491); }
.feature-icon.red { background: linear-gradient(135deg, #E5484D, #F06A6F); }
.feature-card h3 { font-size: 19px; margin-bottom: 10px; color: var(--blue-deep); }
.feature-card p { font-size: 14px; color: var(--text-sub); min-height: 72px; }
.feature-tag {
  display: inline-block;
  margin-top: 16px;
  padding: 4px 12px;
  border-radius: 999px;
  background: var(--bg);
  color: var(--blue);
  font-size: 12px;
  border: 1px solid rgba(46, 98, 214, 0.2);
}
.feature-tag.hot { background: rgba(229, 72, 77, 0.08); color: var(--red); border-color: rgba(229, 72, 77, 0.25); }

/* ===== 功能展示 ===== */
.showcase-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 26px;
}
.showcase-item { text-align: center; }
.mini-phone {
  width: 200px;
  margin: 0 auto 18px;
  padding: 10px;
  background: linear-gradient(160deg, #f0f4fb, #e3ebf7);
  border-radius: 26px;
  box-shadow: var(--shadow);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.showcase-item:hover .mini-phone { transform: translateY(-6px); box-shadow: 0 18px 36px rgba(29, 59, 139, 0.16); }
.mini-phone img { border-radius: 17px; aspect-ratio: 9/20; object-fit: cover; width: 100%; }
.showcase-item h4 { font-size: 17px; margin-bottom: 6px; color: var(--blue-deep); }
.showcase-item p { font-size: 13px; color: var(--text-sub); }

/* ===== 题库分类 ===== */
.tag-grid { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; }
.tag {
  padding: 12px 26px;
  border-radius: 999px;
  background: #fff;
  color: var(--text);
  font-size: 15px;
  border: 1px solid rgba(29, 59, 139, 0.14);
  transition: all 0.25s ease;
  cursor: default;
}
.tag:hover { transform: translateY(-2px); border-color: var(--blue); color: var(--blue); }
.tag-active { background: var(--blue-deep); color: #fff; border-color: var(--blue-deep); }

/* ===== 关于 ===== */
.about-card {
  display: flex;
  gap: 36px;
  align-items: center;
  background: var(--bg);
  border-radius: 22px;
  padding: 46px 42px;
  box-shadow: var(--shadow);
}
.about-logo { flex-shrink: 0; }
.about-logo img {
  width: 128px; height: 128px;
  border-radius: 24px;
  box-shadow: var(--shadow);
}
.about-text .section-title { font-size: 26px; }
.about-text p { color: var(--text-sub); font-size: 15px; margin-bottom: 12px; }

/* ===== 页脚 ===== */
.site-footer {
  background: #16294f;
  color: rgba(255, 255, 255, 0.8);
  padding: 48px 0 36px;
  text-align: center;
}
.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: #fff;
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 12px;
}
.footer-logo { width: 38px; height: 38px; border-radius: 10px; }
.footer-desc { font-size: 14px; margin-bottom: 20px; opacity: 0.85; }
.footer-links { display: flex; gap: 28px; justify-content: center; flex-wrap: wrap; margin-bottom: 26px; }
.footer-links a { font-size: 14px; opacity: 0.85; transition: opacity 0.25s ease; }
.footer-links a:hover { opacity: 1; color: var(--gold); }
.footer-icp {
  font-size: 13px;
  opacity: 0.65;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  padding-top: 22px;
}

/* ===== 滚动动效 ===== */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .hero { padding: 64px 0 120px; }
  .hero-inner { grid-template-columns: 1fr; text-align: center; }
  .hero-desc { margin-left: auto; margin-right: auto; }
  .hero-points { text-align: left; max-width: 480px; margin-left: auto; margin-right: auto; }
  .hero-cta { justify-content: center; }
  .hero-title { font-size: 36px; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-card p { min-height: auto; }
  .showcase-grid { grid-template-columns: repeat(2, 1fr); }
  .about-card { flex-direction: column; text-align: center; }
  .nav-links {
    display: none;
    position: absolute;
    top: 72px; left: 0; right: 0;
    background: #fff;
    flex-direction: column;
    gap: 0;
    box-shadow: 0 20px 30px rgba(29, 59, 139, 0.12);
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 16px 24px; border-top: 1px solid var(--bg); }
  .nav-links a::after { display: none; }
  .nav-toggle { display: flex; }
}

@media (max-width: 560px) {
  .feature-grid, .showcase-grid, .stats-grid { grid-template-columns: 1fr; }
  .section-title { font-size: 26px; }
  .float-chip-1 { right: -4px; }
}