/* 问鼎娱乐官网 — 空间计算娱乐技术平台 样式表 */

:root {
  --color-bg: #FAF7F1;
  --color-bg-alt: #F1ECE2;
  --color-surface: #FFFFFF;
  --color-ink: #1B2733;
  --color-ink-soft: #4A5568;
  --color-deep-blue: #16324F;
  --color-deep-blue-2: #1F4A73;
  --color-cyan: #2FB6C7;
  --color-cyan-dark: #1D8C9B;
  --color-violet: #6B5CA5;
  --color-orange: #E0823C;
  --color-graphite: #4A4A4A;
  --color-border: #E4DCCC;
  --color-border-strong: #C9BFA8;
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --shadow-card: 0 2px 10px rgba(22, 50, 79, 0.07);
  --shadow-card-hover: 0 8px 24px rgba(22, 50, 79, 0.12);
  --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", Helvetica, Arial, sans-serif;
  --max-width: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-ink);
  line-height: 1.75;
  font-size: 16px;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-cyan-dark); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3, h4 { font-weight: 700; line-height: 1.4; color: var(--color-deep-blue); margin: 0 0 .6em; }
p { margin: 0 0 1em; }
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }
.visually-hidden {
  position: absolute; width: 1px; height: 1px; margin: -1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0; padding: 0;
}

/* ---------- Header / Nav ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(250, 247, 241, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}
.nav-bar {
  display: flex; align-items: center; justify-content: space-between;
  max-width: var(--max-width); margin: 0 auto; padding: 14px 24px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 20px; color: var(--color-deep-blue); }
.brand img { width: 32px; height: 32px; }
.nav-links { display: flex; gap: 6px; list-style: none; margin: 0; padding: 0; }
.nav-links a {
  color: var(--color-ink); padding: 8px 14px; border-radius: var(--radius-sm);
  font-size: 15px; font-weight: 500; text-decoration: none;
}
.nav-links a:hover, .nav-links a[aria-current="page"] {
  background: var(--color-deep-blue); color: #fff;
}
.nav-toggle {
  display: none; background: none; border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm); width: 42px; height: 38px; cursor: pointer;
  flex-direction: column; align-items: center; justify-content: center; gap: 4px;
}
.nav-toggle span { display: block; width: 20px; height: 2px; background: var(--color-deep-blue); }

/* ---------- Hero ---------- */
.hero {
  padding: 56px 0 40px;
  background: linear-gradient(180deg, #F4EEE0 0%, var(--color-bg) 100%);
  border-bottom: 1px solid var(--color-border);
}
.hero .eyebrow {
  display: inline-block; font-size: 13px; letter-spacing: .06em; font-weight: 700;
  color: var(--color-cyan-dark); text-transform: uppercase; margin-bottom: 12px;
}
.hero h1 { font-size: clamp(26px, 4vw, 38px); max-width: 900px; }
.hero .lede { font-size: 17px; color: var(--color-ink-soft); max-width: 820px; }
.hero-figure { margin-top: 28px; background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: 20px; box-shadow: var(--shadow-card); }
.hero-figure figcaption { font-size: 13px; color: var(--color-ink-soft); margin-top: 10px; text-align: center; }

/* ---------- Section scaffolding ---------- */
section { padding: 46px 0; }
.section-head { max-width: 760px; margin-bottom: 28px; }
.section-head .kicker { color: var(--color-orange); font-weight: 700; font-size: 13px; letter-spacing: .05em; text-transform: uppercase; }
.section-head h2 { font-size: clamp(22px, 3vw, 30px); }
.section-head p { color: var(--color-ink-soft); }
.section-alt { background: var(--color-bg-alt); border-top: 1px solid var(--color-border); border-bottom: 1px solid var(--color-border); }

/* ---------- Cards / grids ---------- */
.grid { display: grid; gap: 20px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.card {
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: 22px; box-shadow: var(--shadow-card);
  transition: box-shadow .2s ease, transform .2s ease;
}
.card:hover { box-shadow: var(--shadow-card-hover); transform: translateY(-2px); }
.card h3 { font-size: 17px; }
.card .meta { font-size: 12px; color: var(--color-cyan-dark); font-weight: 700; letter-spacing: .04em; text-transform: uppercase; margin-bottom: 8px; }
.card p { color: var(--color-ink-soft); font-size: 14.5px; }

/* ---------- Term pills ---------- */
.term-row { display: flex; flex-wrap: wrap; gap: 8px; margin: 14px 0; }
.term-pill {
  font-size: 13px; padding: 5px 12px; border-radius: 999px;
  background: var(--color-deep-blue); color: #fff; font-weight: 600;
}
.term-pill.alt { background: var(--color-violet); }
.term-pill.orange { background: var(--color-orange); }

/* ---------- Article blocks (long-form) ---------- */
.article-block {
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-lg); padding: 32px clamp(20px, 4vw, 44px);
  margin-bottom: 28px; box-shadow: var(--shadow-card);
}
.article-block .article-eyebrow { color: var(--color-cyan-dark); font-weight: 700; font-size: 13px; text-transform: uppercase; letter-spacing: .04em; }
.article-block h2, .article-block h3.article-title { font-size: clamp(19px, 2.6vw, 24px); margin-top: 6px; }
.article-block .article-body p { color: var(--color-ink); font-size: 15.5px; }
.article-block .figure { margin: 22px 0; }
.article-block .figure img { border: 1px solid var(--color-border); border-radius: var(--radius-md); background: #fff; }
.article-block .figure figcaption { font-size: 13px; color: var(--color-ink-soft); margin-top: 8px; }

/* ---------- Homepage rollup summaries ---------- */
.summary-card {
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: 20px 22px; box-shadow: var(--shadow-card);
}
.summary-card .cat { font-size: 12px; font-weight: 700; color: var(--color-violet); text-transform: uppercase; letter-spacing: .04em; margin-bottom: 6px; }
.summary-card h4 { font-size: 16px; margin-bottom: 8px; }
.summary-card p { font-size: 14px; color: var(--color-ink-soft); margin-bottom: 10px; }
.summary-card .read-link { font-size: 13.5px; font-weight: 700; }

/* ---------- Cluster columns (index rollup) ---------- */
.cluster-col h3 {
  font-size: 15px; text-transform: uppercase; letter-spacing: .04em;
  color: var(--color-deep-blue); border-bottom: 2px solid var(--color-cyan);
  padding-bottom: 8px; margin-bottom: 14px;
}
.cluster-col .cluster-link { font-size: 13.5px; color: var(--color-ink-soft); margin-top: 6px; }

/* ---------- Diagram gallery ---------- */
.diagram-card { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-md); padding: 16px; box-shadow: var(--shadow-card); }
.diagram-card img { border-radius: var(--radius-sm); background: #fff; }
.diagram-card .cap { font-size: 13px; color: var(--color-ink-soft); margin-top: 10px; }

/* ---------- FAQ ---------- */
.faq-item { border-bottom: 1px solid var(--color-border); }
.faq-q {
  width: 100%; text-align: left; background: none; border: none; cursor: pointer;
  padding: 16px 4px; font-size: 16px; font-weight: 600; color: var(--color-deep-blue);
  display: flex; justify-content: space-between; align-items: center; gap: 12px;
  font-family: inherit;
}
.faq-q .icon { font-size: 20px; color: var(--color-cyan-dark); flex-shrink: 0; transition: transform .2s ease; }
.faq-q[aria-expanded="true"] .icon { transform: rotate(45deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .25s ease; font-size: 14.5px; color: var(--color-ink-soft); }
.faq-a-inner { padding: 0 4px 18px; }

/* ---------- Feature list (App page) ---------- */
.feature-item { display: flex; gap: 16px; align-items: flex-start; }
.feature-num {
  flex-shrink: 0; width: 40px; height: 40px; border-radius: 10px;
  background: var(--color-deep-blue); color: #fff; display: flex;
  align-items: center; justify-content: center; font-weight: 700;
}

/* ---------- Table ---------- */
.table-wrap { overflow-x: auto; border: 1px solid var(--color-border); border-radius: var(--radius-md); }
table { border-collapse: collapse; width: 100%; min-width: 560px; font-size: 14px; }
th, td { padding: 10px 14px; text-align: left; border-bottom: 1px solid var(--color-border); }
th { background: var(--color-bg-alt); color: var(--color-deep-blue); font-weight: 700; }

/* ---------- About / company ---------- */
.about-box { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: 30px; box-shadow: var(--shadow-card); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-block; padding: 10px 20px; border-radius: 999px; font-weight: 700;
  font-size: 14.5px; background: var(--color-deep-blue); color: #fff; border: none; cursor: pointer;
}
.btn:hover { background: var(--color-deep-blue-2); text-decoration: none; }
.btn.outline { background: none; border: 1.5px solid var(--color-deep-blue); color: var(--color-deep-blue); }

/* ---------- Back to top ---------- */
.back-to-top {
  position: fixed; right: 20px; bottom: 20px; width: 44px; height: 44px;
  border-radius: 50%; background: var(--color-deep-blue); color: #fff; border: none;
  font-size: 18px; cursor: pointer; box-shadow: var(--shadow-card-hover);
  opacity: 0; pointer-events: none; transition: opacity .2s ease; z-index: 90;
}
.back-to-top.show { opacity: 1; pointer-events: auto; }

/* ---------- Footer ---------- */
.site-footer { background: var(--color-deep-blue); color: #DCE6EF; padding: 44px 0 24px; margin-top: 40px; }
.site-footer a { color: #B9D4E6; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 28px; }
.site-footer h4 { color: #fff; font-size: 14px; margin-bottom: 12px; }
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin-bottom: 8px; font-size: 13.5px; }
.footer-brand { font-weight: 700; font-size: 18px; color: #fff; margin-bottom: 10px; }
.footer-desc { font-size: 13.5px; color: #A9BFD1; max-width: 320px; }
.footer-bottom {
  margin-top: 32px; padding-top: 20px; border-top: 1px solid rgba(255,255,255,.14);
  font-size: 12.5px; color: #93AAC0; display: flex; flex-wrap: wrap; gap: 8px 20px; justify-content: space-between;
}

/* ---------- TOC / anchor nav for long pages ---------- */
.page-toc { display: flex; flex-wrap: wrap; gap: 10px; margin: 18px 0 6px; }
.page-toc a {
  font-size: 13.5px; background: var(--color-surface); border: 1px solid var(--color-border);
  padding: 7px 14px; border-radius: 999px; color: var(--color-deep-blue); font-weight: 600;
}
.page-toc a:hover { border-color: var(--color-cyan); text-decoration: none; }

/* ---------- Breadcrumb ---------- */
.breadcrumb { font-size: 13px; color: var(--color-ink-soft); margin-bottom: 10px; }
.breadcrumb a { color: var(--color-ink-soft); }

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 720px) {
  .nav-links { display: none; }
  .nav-toggle { display: flex; }
  .site-header.nav-open .nav-links {
    display: flex; flex-direction: column; position: absolute; top: 100%; left: 0; right: 0;
    background: var(--color-surface); border-bottom: 1px solid var(--color-border); padding: 10px 24px 16px; gap: 2px;
  }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero { padding: 40px 0 28px; }
  section { padding: 32px 0; }
  .article-block { padding: 24px 16px; }
}