:root {
  --bg: #F4EFE4;
  --header: #0B3D2E;
  --accent: #1F7A4D;
  --accent-deep: #145C38;
  --card: #FBF7EE;
  --ink: #1A241C;
  --muted: #4A5A50;
  --line: #D4C8B0;
  --tile: #E7F2EA;
}

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

html { scroll-behavior: auto; }

body {
  font-family: Georgia, "Palatino Linotype", "Microsoft YaHei", serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.75;
  font-size: 17px;
}

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

a { color: var(--accent); text-decoration: none; }

.wrap {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

/* 顶栏：左对齐、sticky、深绿底白字 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--header);
  color: #fff;
  border-bottom: 3px solid #C4A35A;
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: 28px;
  min-height: 72px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-size: 18px;
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.brand svg { width: 32px; height: 32px; }

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
}

.nav a {
  color: #E8F3EC;
  font-size: 14px;
  padding: 4px 0;
  border-bottom: 2px solid transparent;
}

.nav a:hover,
.nav a:focus {
  color: #fff;
  border-bottom-color: #C4A35A;
}

/* Hero：左标题右 2×2 瓷砖 */
.hero {
  padding: 48px 0 28px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 36px;
  align-items: center;
}

.hero h1 {
  font-size: 34px;
  line-height: 1.35;
  color: var(--header);
  margin-bottom: 16px;
  font-weight: 700;
}

.hero p { color: var(--muted); margin-bottom: 10px; }

.hero-actions { margin-top: 18px; }

.btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  padding: 10px 20px;
  border-radius: 2px;
  font-size: 15px;
}

.btn:hover { background: var(--accent-deep); }

.tiles {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.tile {
  background: var(--tile);
  border: 1px solid #C9DCCF;
  padding: 16px 14px;
  min-height: 118px;
}

.tile svg { width: 28px; height: 28px; margin-bottom: 8px; color: var(--accent); }

.tile strong { display: block; font-size: 15px; margin-bottom: 4px; }

.tile span { font-size: 13px; color: var(--muted); }

section { padding: 42px 0; }

section h2 {
  font-size: 26px;
  color: var(--header);
  margin-bottom: 22px;
  padding-left: 14px;
  border-left: 4px solid var(--accent);
}

.lead { color: var(--muted); margin-bottom: 20px; max-width: 46em; }

/* 3 列功能卡 */
.cards-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  box-shadow: 3px 3px 0 #E2D6C2;
  padding: 22px 20px;
}

.card svg { width: 30px; height: 30px; margin-bottom: 10px; color: var(--accent); }

.card h3 { font-size: 18px; margin-bottom: 8px; color: var(--header); }

.card p { font-size: 15px; color: var(--muted); }

/* 横向 4 步 */
.steps-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  position: relative;
}

.steps-row::before {
  content: "";
  position: absolute;
  top: 22px;
  left: 8%;
  right: 8%;
  height: 2px;
  background: #C4A35A;
}

.step {
  text-align: center;
  padding: 0 10px 8px;
  position: relative;
}

.step i {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--header);
  color: #fff;
  font-style: normal;
  font-size: 16px;
  position: relative;
  z-index: 1;
  margin-bottom: 12px;
}

.step h3 { font-size: 16px; margin-bottom: 6px; }

.step p { font-size: 14px; color: var(--muted); text-align: left; }

/* 双栏分工 */
.split-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.pane {
  background: var(--card);
  padding: 24px;
  border-top: 6px solid var(--accent);
}

.pane.phone { border-top-color: #8A6B3D; }

.pane h3 { margin-bottom: 10px; font-size: 18px; }

.pane ul { padding-left: 1.2em; color: var(--muted); font-size: 15px; }

.pane li { margin: 8px 0; }

/* 对比表 */
.table-wrap { overflow-x: auto; margin-top: 22px; }

table {
  width: 100%;
  border-collapse: collapse;
  background: var(--card);
  font-size: 15px;
}

th, td {
  border: 1px solid var(--line);
  padding: 12px 14px;
  text-align: left;
  vertical-align: top;
}

th { background: var(--header); color: #fff; font-weight: 600; }

tr:nth-child(even) td { background: #F3EBE0; }

/* 会话铺开示意 */
.layout-demo {
  display: grid;
  grid-template-columns: 220px 1fr 200px;
  min-height: 280px;
  border: 1px solid var(--line);
  background: var(--card);
}

.col-list, .col-thread, .col-side { padding: 14px; }

.col-list { background: #EFE6D6; border-right: 1px solid var(--line); }

.col-side { background: #E7F2EA; border-left: 1px solid var(--line); }

.fake-row {
  padding: 8px 0;
  border-bottom: 1px dashed #C9BCA6;
  font-size: 13px;
}

.bubble {
  max-width: 80%;
  padding: 8px 10px;
  margin: 8px 0;
  font-size: 13px;
  background: #E8F3EC;
}

.bubble.me { margin-left: auto; background: #D8E8C8; }

.note { font-size: 14px; color: var(--muted); margin-top: 12px; }

/* 边界短卡 */
.bound-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

.bound {
  background: #fff;
  border: 1px dashed var(--accent);
  padding: 16px;
  font-size: 14px;
}

.bound strong { display: block; margin-bottom: 6px; color: var(--header); }

/* FAQ dl */
.faq-dl dt {
  background: var(--header);
  color: #fff;
  padding: 10px 14px;
  margin-top: 12px;
  font-weight: 600;
}

.faq-dl dd {
  background: var(--card);
  padding: 12px 14px 16px;
  border: 1px solid var(--line);
  border-top: 0;
  color: var(--muted);
}

.site-footer {
  background: var(--header);
  color: #D5E6DB;
  padding: 32px 0 40px;
  font-size: 14px;
  margin-top: 20px;
}

.site-footer p { margin: 8px 0; }

.site-footer .legal { color: #B7C9BE; }

@media (max-width: 900px) {
  .hero-grid,
  .cards-3,
  .steps-row,
  .split-2,
  .bound-grid,
  .layout-demo { grid-template-columns: 1fr; }
  .steps-row::before { display: none; }
  .site-header .wrap { flex-direction: column; align-items: flex-start; padding: 12px 0; }
}