/* ==========================================================================
   COULUZ 科技站 - 全站样式（移动端自适应 / 百度SEO友好：内容不依赖JS渲染）
   ========================================================================== */

:root {
  --bg: #0e1016;
  --bg-2: #131824;
  --card: #171d2b;
  --card-hover: #1e2637;
  --line: #242e42;
  --text: #e9edf5;
  --muted: #93a0b5;
  --brand: #ff7a18;
  --brand-2: #ffb020;
  --blue: #2ea8ff;
  --green: #25c26e;
  --red: #ff5c5c;
  --radius: 14px;
  --max: 1180px;
  --shadow: 0 10px 30px rgba(0, 0, 0, .35);
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.8 "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
  word-break: break-word;
}

img { max-width: 100%; height: auto; border: 0; }
a { color: var(--text); text-decoration: none; transition: color .2s; }
a:hover { color: var(--brand); }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 16px; }
.clear { clear: both; }
.sr-only {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap;
}

/* ---------- 顶部导航 ---------- */
.header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(14, 16, 22, .94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(8px);
}
.header .wrap {
  display: flex; align-items: center; gap: 18px;
  height: 62px;
}
.logo { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.logo-mark {
  width: 34px; height: 34px; border-radius: 9px; flex-shrink: 0;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  color: #1a1006; font-weight: 800; font-size: 17px;
  display: flex; align-items: center; justify-content: center;
}
.logo-txt { font-size: 17px; font-weight: 700; letter-spacing: .5px; }
.logo-txt small { display: block; font-size: 11px; color: var(--muted); font-weight: 400; letter-spacing: 0; }

.nav { display: flex; align-items: center; gap: 4px; margin-left: auto; }
.nav a {
  padding: 8px 14px; border-radius: 9px; font-size: 15px; color: #cdd6e6;
}
.nav a:hover { background: var(--card); color: var(--brand); }
.nav a.on { color: var(--brand); background: rgba(255, 122, 24, .12); font-weight: 700; }

.nav-toggle {
  display: none; margin-left: auto; width: 40px; height: 36px;
  background: var(--card); border: 1px solid var(--line); border-radius: 9px;
  color: var(--text); font-size: 18px; cursor: pointer;
}

/* ---------- 通用按钮 ---------- */
.btn {
  display: inline-block; padding: 11px 26px; border-radius: 10px;
  font-size: 15px; font-weight: 700; cursor: pointer; border: 0;
  transition: transform .15s, opacity .2s;
}
.btn:hover { transform: translateY(-2px); }
.btn-main { background: linear-gradient(135deg, var(--brand), var(--brand-2)); color: #1a1006; }
.btn-main:hover { color: #1a1006; opacity: .92; }
.btn-ghost { background: transparent; border: 1px solid var(--line); color: var(--text); }
.btn-ghost:hover { border-color: var(--brand); color: var(--brand); }
.btn-sm { padding: 7px 16px; font-size: 13px; border-radius: 8px; }

/* ---------- 首屏 ---------- */
.hero {
  padding: 54px 0 44px;
  background:
    radial-gradient(900px 340px at 12% -10%, rgba(255, 122, 24, .18), transparent 60%),
    radial-gradient(700px 300px at 92% 0%, rgba(46, 168, 255, .14), transparent 60%);
  border-bottom: 1px solid var(--line);
}
.hero h1 { font-size: 30px; line-height: 1.45; margin: 0 0 14px; }
.hero h1 em { color: var(--brand); font-style: normal; }
.hero p { color: var(--muted); font-size: 15.5px; margin: 0 0 22px; max-width: 780px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 22px; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.hero-tags span {
  font-size: 13px; color: #b9c4d6; background: rgba(255, 255, 255, .05);
  border: 1px solid var(--line); padding: 4px 12px; border-radius: 20px;
}

/* ---------- 区块标题 ---------- */
.section { padding: 42px 0; }
.section-head { display: flex; align-items: flex-end; gap: 14px; margin-bottom: 20px; flex-wrap: wrap; }
.section-head h2 {
  font-size: 22px; margin: 0; padding-left: 12px; border-left: 4px solid var(--brand);
  line-height: 1.3;
}
.section-head p { color: var(--muted); font-size: 13.5px; margin: 0; }
.section-head .more { margin-left: auto; font-size: 14px; color: var(--muted); }

/* ---------- 卡片列表 ---------- */
.grid { display: grid; gap: 16px; grid-template-columns: repeat(4, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }

.card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 18px; display: flex; flex-direction: column; gap: 10px;
  transition: border-color .2s, transform .2s, background .2s;
}
.card:hover { border-color: rgba(255, 122, 24, .55); background: var(--card-hover); transform: translateY(-3px); }
.card-top { display: flex; align-items: center; gap: 12px; }
.card-icon {
  width: 42px; height: 42px; border-radius: 11px; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; background: rgba(255, 122, 24, .14); color: var(--brand);
}
.card h3 { font-size: 16px; margin: 0; line-height: 1.5; }
.card h3 a { color: var(--text); }
.card h3 a:hover { color: var(--brand); }
.card .desc { color: var(--muted); font-size: 13.5px; margin: 0; flex: 1; }
.card-meta { display: flex; align-items: center; gap: 10px; font-size: 12.5px; color: var(--muted); flex-wrap: wrap; }
.card-foot { display: flex; align-items: center; justify-content: space-between; gap: 10px; padding-top: 4px; }
.tag {
  font-size: 12px; padding: 2px 9px; border-radius: 6px;
  background: rgba(46, 168, 255, .14); color: var(--blue);
}
.tag-hot { background: rgba(255, 92, 92, .14); color: var(--red); }
.tag-free { background: rgba(37, 194, 110, .14); color: var(--green); }

/* ---------- 优势 ---------- */
.feats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.feat { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px; }
.feat strong { display: block; font-size: 16px; margin-bottom: 6px; }
.feat strong i { color: var(--brand); font-style: normal; margin-right: 6px; }
.feat p { margin: 0; color: var(--muted); font-size: 13.5px; }

/* ---------- 表格 ---------- */
.table-box { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); }
table { width: 100%; border-collapse: collapse; font-size: 14px; min-width: 560px; }
th, td { padding: 11px 14px; text-align: left; border-bottom: 1px solid var(--line); }
th { background: #141a27; color: #c7d2e4; font-weight: 700; white-space: nowrap; }
tbody tr:last-child td { border-bottom: 0; }
tbody tr:hover td { background: #161d2b; }

/* ---------- 文章页 ---------- */
.crumb { font-size: 13px; color: var(--muted); padding: 16px 0 0; }
.crumb a { color: var(--muted); }
.crumb a:hover { color: var(--brand); }
.crumb span { margin: 0 6px; }

.layout { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 26px; padding: 20px 0 46px; }

.article {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px 28px; min-width: 0;
}
.article h1 { font-size: 25px; line-height: 1.5; margin: 0 0 12px; }
.article-info {
  display: flex; flex-wrap: wrap; gap: 14px; font-size: 13px; color: var(--muted);
  padding-bottom: 16px; border-bottom: 1px solid var(--line); margin-bottom: 20px;
}
.article h2 {
  font-size: 19px; margin: 30px 0 12px; padding-left: 11px;
  border-left: 4px solid var(--brand); line-height: 1.4;
}
.article h3 { font-size: 16px; margin: 20px 0 8px; color: #dbe3f0; }
.article p { margin: 0 0 13px; }
.article ul, .article ol { margin: 0 0 14px; padding-left: 22px; }
.article li { margin-bottom: 7px; }
.article strong { color: #fff; }
.article figure { margin: 0 0 16px; }
.article figcaption { font-size: 12.5px; color: var(--muted); text-align: center; margin-top: 6px; }

.notice {
  background: rgba(255, 122, 24, .08); border: 1px solid rgba(255, 122, 24, .3);
  border-radius: 10px; padding: 13px 16px; font-size: 14px; margin: 0 0 18px;
}
.notice b { color: var(--brand); }

.dl-box {
  background: linear-gradient(135deg, rgba(255, 122, 24, .12), rgba(46, 168, 255, .08));
  border: 1px solid rgba(255, 122, 24, .35); border-radius: 12px;
  padding: 18px 20px; margin: 0 0 20px;
}
.dl-box h3 { margin: 0 0 10px; font-size: 16px; }
.dl-box .kv { font-size: 14px; color: #c8d2e2; margin-bottom: 8px; }
.dl-box .kv b { color: var(--text); }
.dl-box .btn { margin-top: 6px; }

.steps { counter-reset: s; list-style: none; padding: 0; }
.steps li {
  position: relative; padding: 0 0 0 42px; margin-bottom: 16px; counter-increment: s;
}
.steps li::before {
  content: counter(s); position: absolute; left: 0; top: 2px;
  width: 26px; height: 26px; border-radius: 50%; font-size: 13px; font-weight: 700;
  background: linear-gradient(135deg, var(--brand), var(--brand-2)); color: #1a1006;
  display: flex; align-items: center; justify-content: center;
}

.related { margin-top: 30px; padding-top: 20px; border-top: 1px solid var(--line); }
.related h2 { font-size: 17px; margin: 0 0 12px; border: 0; padding: 0; }
.related ul { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(2, 1fr); gap: 8px 20px; }
.related li { margin: 0; font-size: 14px; }
.related li a::before { content: "› "; color: var(--brand); }

/* ---------- 侧栏 ---------- */
.side { display: flex; flex-direction: column; gap: 16px; }
.side-box { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px; }
.side-box h2 { font-size: 16px; margin: 0 0 12px; padding-left: 10px; border-left: 3px solid var(--brand); }
.side-box ul { list-style: none; margin: 0; padding: 0; }
.side-box li { font-size: 14px; padding: 7px 0; border-bottom: 1px dashed var(--line); }
.side-box li:last-child { border-bottom: 0; }
.side-box li a { color: #cbd5e6; }
.side-box li a:hover { color: var(--brand); }
.side-box .rank i {
  display: inline-block; width: 20px; height: 20px; border-radius: 6px; margin-right: 8px;
  font-size: 12px; font-style: normal; text-align: center; line-height: 20px;
  background: var(--line); color: var(--muted);
}
.side-box .rank li:nth-child(1) i { background: var(--brand); color: #1a1006; }
.side-box .rank li:nth-child(2) i { background: var(--brand-2); color: #1a1006; }
.side-box .rank li:nth-child(3) i { background: var(--blue); color: #0a1a26; }
.side-box p { color: var(--muted); font-size: 13.5px; margin: 0 0 10px; }

/* ---------- 搜索 / 筛选 ---------- */
.filter { margin-bottom: 18px; }
.filter input {
  width: 100%; max-width: 380px; padding: 11px 16px; border-radius: 10px;
  background: var(--card); border: 1px solid var(--line); color: var(--text); font-size: 14px;
}
.filter input:focus { outline: 0; border-color: var(--brand); }
.filter .empty { color: var(--muted); font-size: 14px; padding: 14px 0; display: none; }

/* ---------- FAQ ---------- */
.faq { display: flex; flex-direction: column; gap: 10px; }
.faq details {
  background: var(--card); border: 1px solid var(--line); border-radius: 11px;
  padding: 14px 18px;
}
.faq details[open] { border-color: rgba(255, 122, 24, .45); }
.faq summary {
  cursor: pointer; font-weight: 700; font-size: 15.5px; list-style: none;
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--brand); font-size: 19px; font-weight: 400; }
.faq details[open] summary::after { content: "−"; }
.faq .ans { color: #b7c2d4; font-size: 14px; padding-top: 10px; margin: 10px 0 0; border-top: 1px dashed var(--line); }

/* ---------- 页脚 ---------- */
.footer { background: #0a0c11; border-top: 1px solid var(--line); padding: 34px 0 22px; margin-top: 20px; }
.footer-cols { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.2fr; gap: 24px; }
.footer h3 { font-size: 15px; margin: 0 0 12px; color: #dbe3f0; }
.footer ul { list-style: none; margin: 0; padding: 0; }
.footer li { font-size: 13.5px; padding: 4px 0; }
.footer li a, .footer p { color: var(--muted); }
.footer li a:hover { color: var(--brand); }
.footer .about p { font-size: 13.5px; color: var(--muted); margin: 0 0 10px; }
.footer-bottom {
  border-top: 1px solid var(--line); margin-top: 24px; padding-top: 16px;
  text-align: center; font-size: 13px; color: #6f7a8d; line-height: 2;
}
.footer-bottom a { color: #8b96a9; }

/* ---------- 分页 / 其他 ---------- */
.page-404 { text-align: center; padding: 80px 0; }
.page-404 h1 { font-size: 62px; margin: 0 0 8px; color: var(--brand); }
.page-404 p { color: var(--muted); margin: 0 0 22px; }

.back-top {
  position: fixed; right: 20px; bottom: 26px; z-index: 60;
  width: 44px; height: 44px; border-radius: 50%; border: 1px solid var(--line);
  background: var(--card); color: var(--text); font-size: 18px; cursor: pointer;
  display: none; align-items: center; justify-content: center;
}
.back-top.show { display: flex; }

/* ---------- 响应式 ---------- */
@media (max-width: 1000px) {
  .grid { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .feats { grid-template-columns: repeat(2, 1fr); }
  .layout { grid-template-columns: 1fr; }
  .footer-cols { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 640px) {
  .header .wrap { height: 56px; }
  .nav {
    display: none; position: absolute; top: 56px; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 0;
    background: #0e1016; border-bottom: 1px solid var(--line); padding: 8px;
  }
  .nav.open { display: flex; }
  .nav a { padding: 12px 14px; }
  .nav-toggle { display: block; }

  .hero { padding: 34px 0 30px; }
  .hero h1 { font-size: 22px; }
  .section { padding: 28px 0; }
  .section-head h2 { font-size: 19px; }
  .grid, .grid-3, .grid-2, .feats { grid-template-columns: 1fr; }
  .article { padding: 20px 16px; }
  .article h1 { font-size: 20px; }
  .article h2 { font-size: 17px; }
  .related ul { grid-template-columns: 1fr; }
  .footer-cols { grid-template-columns: 1fr; gap: 18px; }
  .logo-txt small { display: none; }
}