/* ==========================================================================
   波胆网官网 — 全站样式
   NBA AI比赛分析与战术AI平台 / 上海波胆网体育ai资讯公司
   ========================================================================== */

:root {
  --color-bg: #F7F5F0;
  --color-bg-alt: #FFFFFF;
  --color-bg-panel: #F0EDE5;
  --color-ink: #1B2430;
  --color-ink-soft: #4B5563;
  --color-ink-faint: #7A8494;
  --color-navy: #10233F;
  --color-navy-2: #16345C;
  --color-cyan: #1D8FA6;
  --color-cyan-soft: #E2F1F3;
  --color-orange: #E2672A;
  --color-orange-soft: #FBE6D9;
  --color-graphite: #454C56;
  --color-line: #DCD7CB;
  --color-line-soft: #E8E4DA;
  --color-court: #EFE7D6;
  --color-white: #FFFFFF;
  --shadow-card: 0 2px 10px rgba(16, 35, 63, 0.07);
  --shadow-card-hover: 0 8px 24px rgba(16, 35, 63, 0.12);
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-sm: 6px;
  --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  --maxw: 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, svg { max-width: 100%; height: auto; display: block; }
a { color: var(--color-navy-2); text-decoration: none; }
a:hover { color: var(--color-orange); }
ul, ol { padding-left: 1.3em; }
h1, h2, h3, h4 { font-weight: 700; color: var(--color-navy); line-height: 1.35; margin: 0 0 .6em; }
p { margin: 0 0 1em; }
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }
.section { padding: 56px 0; }
.section-alt { background: var(--color-bg-panel); }
.section-tight { padding: 36px 0; }

/* ---------------- Skip link ---------------- */
.skip-link {
  position: absolute; left: -999px; top: 0; background: var(--color-navy); color: #fff;
  padding: 10px 16px; z-index: 999; border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }

/* ---------------- Header / Nav ---------------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(247, 245, 240, 0.94);
  backdrop-filter: saturate(140%) blur(6px);
  border-bottom: 1px solid var(--color-line);
}
.nav-bar { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 20px; color: var(--color-navy); }
.brand-mark { width: 34px; height: 34px; flex: none; }
.brand-text-en { font-size: 11px; color: var(--color-ink-faint); font-weight: 500; letter-spacing: .04em; display: block; }
.nav-links { display: flex; gap: 2px; align-items: center; }
.nav-links a {
  color: var(--color-ink-soft); font-size: 14px; font-weight: 600; padding: 8px 9px; border-radius: 8px;
  white-space: nowrap;
}
.nav-links a:hover, .nav-links a.is-active { color: var(--color-navy); background: var(--color-orange-soft); }
.nav-cta {
  background: var(--color-navy) !important; color: #fff !important; padding: 8px 14px !important; border-radius: 20px !important;
}
.nav-cta:hover { background: var(--color-orange) !important; color: #fff !important; }
.nav-toggle {
  display: none; flex-direction: column; gap: 4px; background: none; border: 1px solid var(--color-line); border-radius: 8px;
  width: 40px; height: 40px; align-items: center; justify-content: center; cursor: pointer;
}
.nav-toggle span { width: 20px; height: 2px; background: var(--color-navy); display: block; }

/* ---------------- Hero ---------------- */
.hero {
  background: linear-gradient(160deg, var(--color-navy) 0%, var(--color-navy-2) 62%, #1c4a75 100%);
  color: #F4F1E8;
  padding: 64px 0 52px;
  position: relative;
  overflow: hidden;
}
.hero::after {
  content: ""; position: absolute; inset: 0; opacity: .12; pointer-events: none;
  background-image: radial-gradient(circle at 85% 20%, #fff 0, transparent 45%);
}
.hero .eyebrow {
  display: inline-block; font-size: 13px; font-weight: 700; letter-spacing: .06em;
  background: rgba(255,255,255,0.12); border: 1px solid rgba(255,255,255,0.25);
  padding: 5px 14px; border-radius: 20px; margin-bottom: 18px; color: #FFDFC2;
}
.hero h1 { color: #fff; font-size: 34px; max-width: 880px; margin-bottom: 18px; }
.hero p.lead { max-width: 760px; font-size: 16.5px; color: #DCE4EE; }
.hero-actions { display: flex; gap: 12px; margin-top: 26px; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 12px 22px; border-radius: 24px; font-weight: 700; font-size: 14.5px;
  border: 1px solid transparent; cursor: pointer;
}
.btn-primary { background: var(--color-orange); color: #fff; }
.btn-primary:hover { background: #c9581f; color: #fff; }
.btn-outline { background: transparent; color: #fff; border-color: rgba(255,255,255,0.4); }
.btn-outline:hover { background: rgba(255,255,255,0.12); color: #fff; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 24px; }
.hero-tags span {
  font-size: 12.5px; color: #cfe0ea; background: rgba(255,255,255,0.08); border: 1px solid rgba(255,255,255,0.16);
  padding: 4px 10px; border-radius: 14px;
}

/* Page hero (non-home) */
.page-hero { background: linear-gradient(160deg, var(--color-navy) 0%, var(--color-navy-2) 100%); color: #fff; padding: 46px 0 40px; }
.page-hero h1 { color: #fff; font-size: 28px; margin-bottom: 12px; }
.page-hero p.lead { color: #DCE4EE; max-width: 760px; font-size: 15.5px; }
.crumbs { font-size: 13px; color: #b9c8d6; margin-bottom: 14px; }
.crumbs a { color: #cfe0ea; }

/* ---------------- Section headers ---------------- */
.section-head { max-width: 760px; margin-bottom: 32px; }
.section-head .kicker {
  display: inline-block; font-size: 12.5px; font-weight: 700; color: var(--color-cyan); letter-spacing: .05em;
  background: var(--color-cyan-soft); padding: 4px 12px; border-radius: 14px; margin-bottom: 12px;
}
.section-head h2 { font-size: 25px; }
.section-head p { color: var(--color-ink-soft); font-size: 15px; }

/* ---------------- Cards ---------------- */
.card {
  background: var(--color-bg-alt); border: 1px solid var(--color-line-soft); border-radius: var(--radius-lg);
  padding: 22px; box-shadow: var(--shadow-card);
}
.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); }

/* Trend feed */
.trend-list { display: grid; gap: 14px; grid-template-columns: repeat(2, 1fr); }
.trend-item { background: var(--color-bg-alt); border: 1px solid var(--color-line-soft); border-radius: var(--radius-md); padding: 16px 18px; }
.trend-item .trend-date { font-size: 12px; color: var(--color-cyan); font-weight: 700; letter-spacing: .03em; }
.trend-item h3 { font-size: 15.5px; margin: 6px 0 8px; }
.trend-item p { font-size: 13.6px; color: var(--color-ink-soft); margin: 0; }

/* Diagram figure */
.figure {
  background: var(--color-bg-alt); border: 1px solid var(--color-line-soft); border-radius: var(--radius-lg);
  padding: 18px; margin: 26px 0;
}
.figure img { margin: 0 auto; }
.figure figcaption { text-align: center; font-size: 13px; color: var(--color-ink-faint); margin-top: 12px; }
.court-tint { background: var(--color-court); border-radius: var(--radius-md); }

/* ---------------- Long-form articles ---------------- */
.article-block {
  border-top: 1px solid var(--color-line); padding: 40px 0;
}
.article-block:first-of-type { border-top: none; }
.article-tag {
  display: inline-block; font-size: 12px; font-weight: 700; color: var(--color-orange);
  background: var(--color-orange-soft); padding: 3px 11px; border-radius: 12px; margin-bottom: 12px;
}
.article-block h2 { font-size: 22px; margin-bottom: 6px; }
.article-meta { font-size: 12.5px; color: var(--color-ink-faint); margin-bottom: 18px; }
.article-body p { font-size: 15.3px; color: #2b3441; }
.article-body strong { color: var(--color-navy); }
.pull-quote {
  border-left: 3px solid var(--color-orange); background: var(--color-bg-panel);
  padding: 14px 18px; margin: 20px 0; font-size: 14.5px; color: var(--color-graphite); border-radius: 0 8px 8px 0;
}
.callout {
  background: var(--color-cyan-soft); border: 1px solid #bfe0e6; border-radius: var(--radius-md);
  padding: 14px 18px; margin: 18px 0; font-size: 14px; color: #113b45;
}

/* ---------------- Observation posts ---------------- */
.obs-card { background: var(--color-bg-alt); border: 1px solid var(--color-line-soft); border-radius: var(--radius-lg); padding: 24px; }
.obs-card .article-tag { background: var(--color-cyan-soft); color: var(--color-cyan); }

/* ---------------- Cluster / summary cards for homepage ---------------- */
.cluster { margin-bottom: 44px; }
.cluster-head { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; flex-wrap: wrap; margin-bottom: 18px; }
.cluster-head h3 { font-size: 19px; margin: 0; }
.cluster-head a.cluster-link { font-size: 13.5px; font-weight: 700; }
.summary-card {
  background: var(--color-bg-alt); border: 1px solid var(--color-line-soft); border-radius: var(--radius-md);
  padding: 18px 20px; margin-bottom: 14px;
}
.summary-card h4 { font-size: 16px; margin-bottom: 8px; }
.summary-card h4 a { color: var(--color-navy); }
.summary-card p { font-size: 14px; color: var(--color-ink-soft); margin-bottom: 8px; }
.summary-card .read-more { font-size: 13px; font-weight: 700; }

/* ---------------- Tabs (tactic diagram switcher) ---------------- */
.tabs { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 16px; }
.tab-btn {
  background: var(--color-bg-alt); border: 1px solid var(--color-line); color: var(--color-ink-soft);
  padding: 8px 16px; border-radius: 18px; font-size: 13.5px; font-weight: 600; cursor: pointer;
}
.tab-btn.is-active { background: var(--color-navy); color: #fff; border-color: var(--color-navy); }
.tab-panel { display: none; }
.tab-panel.is-active { display: block; }

/* ---------------- Term tooltip / glossary chip ---------------- */
.term {
  border-bottom: 1px dashed var(--color-cyan); cursor: help; position: relative; font-weight: 600; color: var(--color-navy-2);
}
.term[data-tip]:hover::after, .term[data-tip]:focus::after {
  content: attr(data-tip); position: absolute; left: 0; bottom: 130%; background: var(--color-navy); color: #fff;
  font-size: 12.5px; font-weight: 400; padding: 8px 12px; border-radius: 8px; width: 240px; line-height: 1.5;
  box-shadow: var(--shadow-card-hover); z-index: 20;
}

/* ---------------- FAQ ---------------- */
.faq-item { border-bottom: 1px solid var(--color-line); }
.faq-q {
  width: 100%; text-align: left; background: none; border: none; padding: 18px 4px; font-size: 15.5px;
  font-weight: 700; color: var(--color-navy); cursor: pointer; display: flex; justify-content: space-between; gap: 12px;
  align-items: center;
}
.faq-q::after { content: "+"; font-size: 20px; color: var(--color-orange); flex: none; }
.faq-item.is-open .faq-q::after { content: "\2212"; }
.faq-a { display: none; padding: 0 4px 18px; color: var(--color-ink-soft); font-size: 14.5px; }
.faq-item.is-open .faq-a { display: block; }

/* ---------------- Table wrap ---------------- */
.table-wrap { overflow-x: auto; border: 1px solid var(--color-line-soft); border-radius: var(--radius-md); margin: 20px 0; }
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-line-soft); }
th { background: var(--color-bg-panel); color: var(--color-navy); font-weight: 700; }

/* ---------------- App feature grid ---------------- */
.feature-card { background: var(--color-bg-alt); border: 1px solid var(--color-line-soft); border-radius: var(--radius-lg); padding: 20px; }
.feature-num { font-size: 12px; font-weight: 800; color: var(--color-orange); letter-spacing: .05em; }
.feature-card h3 { font-size: 16.5px; margin: 8px 0; }
.feature-card p { font-size: 13.6px; color: var(--color-ink-soft); margin: 0; }

/* ---------------- About / disclaimer ---------------- */
.about-box { background: var(--color-bg-alt); border: 1px solid var(--color-line-soft); border-radius: var(--radius-lg); padding: 28px; }
.disclaimer {
  background: #FBF3EC; border: 1px solid #EBD3BC; border-radius: var(--radius-md); padding: 14px 18px; font-size: 13.5px;
  color: #6b4423; margin-top: 18px;
}

/* ---------------- Footer ---------------- */
.site-footer { background: var(--color-navy); color: #cdd8e2; padding: 44px 0 24px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 28px; margin-bottom: 28px; }
.footer-brand { font-weight: 800; color: #fff; font-size: 18px; margin-bottom: 10px; }
.site-footer h4 { color: #fff; font-size: 14px; margin-bottom: 12px; }
.site-footer a { color: #b9c8d6; font-size: 13.6px; }
.site-footer a:hover { color: #fff; }
.site-footer ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; }
.footer-note { font-size: 13px; color: #9fb0c0; line-height: 1.8; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.14); padding-top: 18px; font-size: 12.6px; color: #8fa0b1; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; }
.footer-disclaimer {
  background: rgba(255,255,255,0.06); border: 1px solid rgba(255,255,255,0.12); border-radius: var(--radius-md);
  padding: 12px 16px; font-size: 12.8px; color: #d7c9b8; margin-bottom: 20px;
}

/* ---------------- Back to top ---------------- */
.back-top {
  position: fixed; right: 18px; bottom: 22px; width: 44px; height: 44px; border-radius: 50%;
  background: var(--color-navy); color: #fff; border: none; display: none; align-items: center; justify-content: center;
  cursor: pointer; box-shadow: var(--shadow-card-hover); z-index: 90; font-size: 18px;
}
.back-top.is-visible { display: flex; }

/* ---------------- Utilities ---------------- */
.mt-0 { margin-top: 0; }
.text-center { text-align: center; }
.tag-row { display: flex; flex-wrap: wrap; gap: 8px; margin: 14px 0; }
.tag-chip {
  font-size: 12.5px; color: var(--color-navy-2); background: var(--color-cyan-soft); padding: 4px 11px; border-radius: 12px;
  font-weight: 600;
}
.stat-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin: 20px 0; }
.stat-box { background: var(--color-bg-panel); border-radius: var(--radius-md); padding: 14px; text-align: center; }
.stat-box .num { font-size: 20px; font-weight: 800; color: var(--color-navy); }
.stat-box .lbl { font-size: 12px; color: var(--color-ink-faint); }

/* ---------------- Responsive ---------------- */
@media (max-width: 980px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .trend-list { grid-template-columns: 1fr; }
}
@media (max-width: 1040px) {
  .nav-links { display: none; }
  .nav-toggle { display: flex; }
  .site-header.is-open .nav-links {
    display: flex; flex-direction: column; position: absolute; top: 68px; left: 0; right: 0;
    background: var(--color-bg-alt); border-bottom: 1px solid var(--color-line); padding: 10px 20px 16px; gap: 2px;
  }
  .site-header.is-open .nav-links a { white-space: normal; }
}
@media (max-width: 760px) {
  .hero h1 { font-size: 26px; }
  .page-hero h1 { font-size: 22px; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .stat-row { grid-template-columns: repeat(2, 1fr); }
  .section { padding: 40px 0; }
  .cluster-head { flex-direction: column; align-items: flex-start; }
}