/* 沧蓝工坊 · AI 编程指南 下载站 */

:root {
  --bg: #FBF9F4;
  --card: #FFFFFF;
  --ink: #1A1A1A;
  --body: #2E2C28;
  --muted: #6E675C;
  --faint: #9A938A;
  --accent: #1D4EA8;
  --accent-dark: #163C82;
  --rule: #E4DCCD;
  --code-bg: #F3EFE7;
  --serif: Georgia, "Songti SC", "SimSun", "Noto Serif CJK SC", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
          "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--body);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: 920px;
  margin: 0 auto;
  padding: 0 24px;
}

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

/* ---------- 顶栏 ---------- */

.top {
  border-bottom: 1px solid var(--rule);
  background: rgba(251, 249, 244, 0.92);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: saturate(180%) blur(8px);
}
.top .wrap {
  display: flex;
  align-items: center;
  gap: 10px;
  height: 58px;
  font-size: 14px;
}
.brand {
  font-weight: 700;
  color: var(--ink);
  letter-spacing: 0.02em;
}
.brand:hover { color: var(--accent); text-decoration: none; }
.slash { color: var(--faint); }
.crumb { color: var(--muted); }

/* ---------- 首屏 ---------- */

.hero { padding: 84px 0 56px; }

.kicker {
  margin: 0 0 18px;
  font-size: 13px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 600;
}

.hero h1 {
  margin: 0 0 22px;
  font-family: var(--serif);
  font-size: clamp(38px, 7vw, 62px);
  line-height: 1.15;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: -0.01em;
}

.lead {
  margin: 0 0 20px;
  font-size: 19px;
  line-height: 1.7;
  color: var(--body);
  max-width: 34em;
}

.meta {
  margin: 0;
  font-size: 14px;
  color: var(--faint);
}

/* ---------- 通用区块 ---------- */

section { padding: 60px 0; }
section + section { border-top: 1px solid var(--rule); }

.sec {
  margin: 0 0 26px;
  font-family: var(--serif);
  font-size: 27px;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: 0.01em;
}

section p { margin: 0 0 15px; }
section p:last-child { margin-bottom: 0; }

.sectip {
  font-size: 14.5px;
  color: var(--muted);
}

/* ---------- 下载卡片 ---------- */

.grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 22px;
}

.card {
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: 30px 28px 28px;
  display: flex;
  flex-direction: column;
}

.tag {
  margin: 0 0 10px !important;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--faint);
  font-weight: 600;
}

.card h3 {
  margin: 0 0 12px;
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 700;
  color: var(--ink);
}

.card .desc {
  font-size: 14.5px;
  color: var(--muted);
  margin-bottom: 20px;
  line-height: 1.7;
}

dl {
  margin: 0 0 22px;
  padding: 0;
  font-size: 14px;
  border-top: 1px solid var(--rule);
}
dl > div, dl { }
dt, dd { margin: 0; }
dl::after { content: ""; }

.card dl { display: block; }

.card dl { border-top: 1px solid var(--rule); padding-top: 4px; }
.card dl dt {
  float: left;
  clear: left;
  width: 82px;
  padding: 9px 0;
  color: var(--faint);
  border-bottom: 1px solid #F1ECE2;
}
.card dl dd {
  margin-left: 82px;
  padding: 9px 0;
  color: var(--body);
  border-bottom: 1px solid #F1ECE2;
}

code {
  font-family: ui-monospace, "SFMono-Regular", Consolas, "Courier New", monospace;
  background: var(--code-bg);
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 0.92em;
  color: var(--ink);
}

.btn {
  display: block;
  margin-top: auto;
  text-align: center;
  padding: 14px 20px;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  font-size: 15.5px;
  border-radius: 3px;
  letter-spacing: 0.02em;
  transition: background 0.15s ease;
}
.btn:hover {
  background: var(--accent-dark);
  color: #fff;
  text-decoration: none;
}

.note {
  margin: 22px 0 0 !important;
  font-size: 14px;
  color: var(--muted);
}

/* ---------- 目录 ---------- */

.part {
  border: 1px solid var(--rule);
  border-radius: 4px;
  background: var(--card);
  margin-bottom: 12px;
  overflow: hidden;
}
.part summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 15px 20px;
  cursor: pointer;
  list-style: none;
  user-select: none;
}
.part summary::-webkit-details-marker { display: none; }
.part summary:hover { background: #FAF7F0; }
.part[open] summary { border-bottom: 1px solid var(--rule); }

.pk {
  font-size: 13px;
  color: var(--accent);
  font-weight: 600;
  letter-spacing: 0.04em;
  flex: 0 0 auto;
}
.pn {
  font-weight: 700;
  color: var(--ink);
  font-size: 16px;
}
.pc {
  margin-left: auto;
  font-size: 13px;
  color: var(--faint);
  white-space: nowrap;
}

.chapters {
  margin: 0;
  padding: 8px 20px 16px 20px;
  list-style: none;
}
.chapters li {
  display: flex;
  gap: 14px;
  padding: 6px 0;
  border-bottom: 1px solid #F5F1E8;
  font-size: 14.5px;
}
.chapters li:last-child { border-bottom: none; }
.chapters .num {
  flex: 0 0 26px;
  color: var(--faint);
  font-family: ui-monospace, "SFMono-Regular", Consolas, monospace;
  font-size: 13px;
  padding-top: 1px;
}
.chapters .ttl { color: var(--body); }

/* ---------- 联系 / 版权 ---------- */

.mails {
  margin: 0 0 18px;
  padding: 0;
  list-style: none;
}
.mails li { padding: 3px 0; }
.mails a {
  font-family: ui-monospace, "SFMono-Regular", Consolas, monospace;
  font-size: 15.5px;
}

.qq {
  padding: 14px 18px;
  background: var(--code-bg);
  border-left: 3px solid var(--accent);
  border-radius: 0 3px 3px 0;
  font-size: 15px;
}

.lh {
  margin-top: 22px !important;
  font-weight: 600;
  color: var(--ink);
  font-size: 15px;
}

.license ul {
  margin: 0 0 18px;
  padding-left: 20px;
  color: var(--body);
  font-size: 15px;
}
.license li { margin-bottom: 6px; }
.license > .wrap > p { font-size: 15px; color: var(--muted); }

/* ---------- 页脚 ---------- */

footer {
  border-top: 1px solid var(--rule);
  padding: 34px 0 46px;
  font-size: 13.5px;
  color: var(--faint);
}
footer .dot { margin: 0 8px; }
footer a { color: var(--muted); }

/* ---------- 窄屏 ---------- */

@media (max-width: 720px) {
  .wrap { padding: 0 18px; }
  .hero { padding: 56px 0 40px; }
  .lead { font-size: 17px; }
  .grid { grid-template-columns: 1fr; }
  .sec { font-size: 22px; }
  section { padding: 44px 0; }
  .part summary { padding: 13px 15px; gap: 8px; flex-wrap: wrap; }
  .pc { margin-left: 0; width: 100%; }
  .chapters { padding: 6px 15px 12px; }
  .card dl dt { width: 74px; }
  .card dl dd { margin-left: 74px; }
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15171B;
    --card: #1C1F24;
    --ink: #ECE8E0;
    --body: #C9C4BA;
    --muted: #93907F;
    --faint: #6E6A60;
    --accent: #6E9BEE;
    --accent-dark: #8AB0F5;
    --rule: #2C3038;
    --code-bg: #24272D;
  }
  .top { background: rgba(21, 23, 27, 0.92); }
  .btn { background: var(--accent); color: #10131A; }
  .btn:hover { background: var(--accent-dark); color: #10131A; }
  .part summary:hover { background: #202329; }
  .chapters li { border-bottom-color: #262A31; }
  .card dl dt, .card dl dd { border-bottom-color: #262A31; }
}