:root {
  --navy: #0b1f3a;
  --navy-2: #143056;
  --teal: #1a8a7a;
  --teal-d: #12685c;
  --ice: #eef4f8;
  --card: #ffffff;
  --text: #1b2838;
  --sub: #4a6074;
  --line: #c9d6e2;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--ice);
  color: var(--text);
  line-height: 1.7;
  font-size: 15.5px;
}
a { color: var(--teal-d); text-decoration: none; }
a:hover { text-decoration: underline; }

.masthead {
  background: var(--navy);
  color: #fff;
}
.mast-inner {
  width: min(1280px, calc(100% - 32px));
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
}
.logo {
  color: #fff;
  font-weight: 700;
  font-size: 20px;
  letter-spacing: 0.12em;
}
.logo:hover { text-decoration: none; }
.pills { display: flex; gap: 6px; }
.pills a {
  color: #c5d4e6;
  padding: 6px 14px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: 14px;
}
.pills a.is-on {
  color: #fff;
  background: var(--teal);
  border-color: var(--teal);
}

.app-wrap {
  width: min(1280px, calc(100% - 32px));
  margin: 20px auto 40px;
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 22px;
}
.fn-rail {
  background: var(--card);
  border: 1px solid var(--line);
  padding: 16px 12px;
  position: sticky;
  top: 16px;
  height: max-content;
}
.fn-rail p {
  font-size: 12px;
  color: var(--sub);
  margin-bottom: 8px;
  padding: 0 8px;
}
.fn-rail a {
  display: block;
  padding: 8px 10px;
  color: var(--text);
  border-left: 3px solid transparent;
}
.fn-rail a:hover { background: var(--ice); text-decoration: none; }

.hero-fn {
  background: linear-gradient(120deg, var(--navy) 0%, var(--navy-2) 100%);
  color: #fff;
  padding: 28px 32px;
}
.hero-fn h1 { font-size: 28px; line-height: 1.4; margin: 8px 0 12px; }
.hero-fn p { color: #c9d8ea; margin-bottom: 16px; }
.fn-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.btn-teal {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--teal);
  color: #fff;
  padding: 10px 18px;
  border-radius: 4px;
  font-weight: 600;
}
.btn-teal:hover { background: var(--teal-d); text-decoration: none; }
.btn-line {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 1px solid #8aa4c2;
  color: #fff;
  padding: 10px 18px;
  border-radius: 4px;
}

.fn-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin-top: 16px;
}
.fn-card {
  background: var(--card);
  border: 1px solid var(--line);
  padding: 16px 16px 18px;
  border-top: 4px solid var(--teal);
}
.fn-card h2 { font-size: 18px; margin-bottom: 8px; }
.fn-card p { color: var(--sub); font-size: 14.5px; }

.fn-deep, .cover, .faq-box {
  background: var(--card);
  border: 1px solid var(--line);
  padding: 22px 24px;
  margin-top: 16px;
}
.fn-deep h2, .cover h2, .faq-box h2, .cmp h2 { font-size: 20px; margin-bottom: 10px; }

.cmp { margin-top: 16px; overflow: auto; }
.compare-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--card);
  font-size: 14px;
}
.compare-table th, .compare-table td {
  border: 1px solid var(--line);
  padding: 10px 12px;
  text-align: left;
}
.compare-table th { background: var(--navy); color: #fff; }
.compare-table tr:nth-child(even) td { background: #f4f8fb; }

.faq-box details {
  border-bottom: 1px solid var(--line);
  padding: 10px 0;
}
.faq-box summary { cursor: pointer; font-weight: 600; color: var(--navy); }
.faq-box details p { margin-top: 8px; color: var(--sub); }

.foot-dark {
  background: var(--navy);
  color: #b9c8d8;
  padding: 24px 0;
  font-size: 13px;
}
.foot-in { width: min(1280px, calc(100% - 32px)); margin: 0 auto; }
.foot-in .pills a { color: #b9c8d8; }
.foot-in .pills a.is-on { color: #fff; }
.safe { color: #d7efe9; margin: 10px 0; }

@media (max-width: 900px) {
  .app-wrap { grid-template-columns: 1fr; }
  .fn-rail { position: static; display: flex; flex-wrap: wrap; gap: 4px; }
  .fn-grid { grid-template-columns: 1fr; }
  .hero-fn h1 { font-size: 22px; }
}