/* ==========================================================================
   龙虎斗游戏官网 — style.css
   Interactive Narrative Lab + Mystery Evidence Room +
   AI Tabletop Desk + Campaign GM Console
   ========================================================================== */

:root{
  --bg: #14161c;
  --bg-alt: #1b1e2a;
  --surface: #20232f;
  --surface-2: #262a39;
  --border: #333850;
  --border-soft: #2a2e42;

  --ink: #eef1f7;
  --ink-dim: #b7bccd;
  --ink-mute: #8b90a6;

  --purple: #8a6bff;
  --purple-dim: #6b53c7;
  --cyan: #4dd8e6;
  --cyan-dim: #2f9aa6;
  --red: #e2555a;
  --gold: #d8b46a;
  --green: #5bc78a;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;

  --radius-s: 6px;
  --radius-m: 12px;
  --radius-l: 18px;

  --container: 1180px;
  --shadow-card: 0 10px 30px rgba(0,0,0,.35);
}

*,*::before,*::after{ box-sizing:border-box; }
html{ scroll-behavior:smooth; overflow-x:hidden; }
body{
  margin:0;
  background:var(--bg);
  color:var(--ink);
  font-family:var(--font-sans);
  line-height:1.75;
  font-size:16px;
  overflow-x:hidden;
  background-image:
    radial-gradient(60rem 30rem at 85% -10%, rgba(138,107,255,.10), transparent 60%),
    radial-gradient(50rem 30rem at -10% 20%, rgba(77,216,230,.08), transparent 60%);
  background-attachment:fixed;
}
img{ max-width:100%; display:block; }
a{ color:var(--cyan); text-decoration:none; }
a:hover{ text-decoration:underline; }
h1,h2,h3,h4{ line-height:1.35; font-weight:700; margin:0 0 .6em; color:var(--ink); }
p{ margin:0 0 1em; color:var(--ink-dim); }
ul,ol{ color:var(--ink-dim); }
.container{ max-width:var(--container); margin:0 auto; padding:0 20px; }
.visually-hidden{ position:absolute!important; width:1px;height:1px; overflow:hidden; clip:rect(0 0 0 0); white-space:nowrap; }

/* ---------- Header / Nav ---------- */
.site-header{
  position:sticky; top:0; z-index:100;
  background:rgba(20,22,28,.92);
  backdrop-filter:blur(10px);
  border-bottom:1px solid var(--border-soft);
}
.header-inner{ display:flex; align-items:center; justify-content:space-between; height:68px; }
.brand{ display:flex; align-items:center; gap:10px; color:var(--ink); font-weight:800; font-size:19px; }
.brand img{ width:34px; height:34px; }
.brand small{ display:block; font-weight:500; font-size:11px; color:var(--ink-mute); }
.main-nav{ display:flex; align-items:center; gap:1px; }
.main-nav a{
  color:var(--ink-dim); font-size:13px; font-weight:600; padding:9px 8px; border-radius:8px;
  white-space:nowrap;
}
.main-nav a:hover{ color:var(--ink); background:var(--surface); text-decoration:none; }
.main-nav a.active{ color:var(--bg); background:var(--cyan); }
.nav-toggle{
  display:none; background:var(--surface); border:1px solid var(--border); color:var(--ink);
  border-radius:8px; width:40px; height:40px; font-size:18px; cursor:pointer;
}

/* ---------- Breadcrumb ---------- */
.breadcrumb{ font-size:13px; color:var(--ink-mute); padding:14px 0; }
.breadcrumb a{ color:var(--ink-mute); }
.breadcrumb span{ margin:0 6px; }

/* ---------- Hero ---------- */
.hero{ padding:44px 0 30px; }
.hero-grid{ display:grid; grid-template-columns:1.1fr .9fr; gap:36px; align-items:center; }
.eyebrow{
  display:inline-flex; align-items:center; gap:8px; font-size:12.5px; font-weight:700; letter-spacing:.02em;
  color:var(--cyan); background:rgba(77,216,230,.1); border:1px solid rgba(77,216,230,.3);
  padding:6px 12px; border-radius:999px; margin-bottom:16px;
}
.hero h1{ font-size:34px; margin-bottom:14px; }
.hero .lead{ font-size:16.5px; color:var(--ink-dim); max-width:56ch; }
.hero-art{ border-radius:var(--radius-l); overflow:hidden; border:1px solid var(--border-soft); background:var(--surface); box-shadow:var(--shadow-card); }
.hero-stats{ display:flex; gap:22px; margin-top:22px; flex-wrap:wrap; }
.hero-stats div{ font-size:13px; color:var(--ink-mute); }
.hero-stats strong{ display:block; font-size:20px; color:var(--ink); }

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex; align-items:center; gap:8px; padding:11px 18px; border-radius:10px;
  font-weight:700; font-size:14px; border:1px solid transparent; cursor:pointer;
}
.btn-primary{ background:var(--cyan); color:#0c1116; }
.btn-primary:hover{ background:#68e3ee; text-decoration:none; }
.btn-ghost{ background:transparent; color:var(--ink); border-color:var(--border); }
.btn-ghost:hover{ border-color:var(--cyan); color:var(--cyan); text-decoration:none; }
.btn-row{ display:flex; gap:12px; margin-top:22px; flex-wrap:wrap; }

/* ---------- Section shell ---------- */
.section{ padding:52px 0; border-top:1px solid var(--border-soft); }
.section:first-child{ border-top:none; }
.section-head{ max-width:70ch; margin-bottom:30px; }
.section-tag{ font-size:12.5px; font-weight:700; color:var(--purple); text-transform:uppercase; letter-spacing:.08em; margin-bottom:8px; }
.section-head h2{ font-size:25px; }
.section-head p{ color:var(--ink-mute); }

/* ---------- System cards (4 systems) ---------- */
.systems-grid{ display:grid; grid-template-columns:repeat(4,1fr); gap:16px; }
.system-card{
  background:var(--surface); border:1px solid var(--border-soft); border-radius:var(--radius-m);
  padding:20px; display:flex; flex-direction:column; gap:10px;
}
.system-card .icon{ width:38px; height:38px; }
.system-card h3{ font-size:16px; margin-bottom:2px; }
.system-card p{ font-size:13.5px; color:var(--ink-mute); margin-bottom:6px; }
.system-card a{ font-size:13px; font-weight:700; }
.system-card.romance{ border-top:3px solid var(--red); }
.system-card.detective{ border-top:3px solid var(--gold); }
.system-card.tabletop{ border-top:3px solid var(--cyan); }
.system-card.rpg{ border-top:3px solid var(--purple); }

/* ---------- Long-form article ---------- */
.article{ max-width:78ch; margin:0 auto 46px; scroll-margin-top:90px; }
.article + .article{ padding-top:6px; border-top:1px solid var(--border-soft); margin-top:10px; padding-top:40px; }
.article-kicker{ font-size:12.5px; font-weight:700; color:var(--cyan); text-transform:uppercase; letter-spacing:.06em; margin-bottom:10px; }
.article h2{ font-size:23px; margin-bottom:16px; }
.article .meta{ font-size:12.5px; color:var(--ink-mute); margin-bottom:20px; display:flex; gap:14px; flex-wrap:wrap; }
.article .meta span{ background:var(--surface); border:1px solid var(--border-soft); padding:3px 9px; border-radius:999px; }
.article p{ font-size:15.5px; }
.article h4{ font-size:16px; color:var(--gold); margin-top:22px; }
.article figure{ margin:22px 0; background:var(--surface); border:1px solid var(--border-soft); border-radius:var(--radius-m); padding:16px; }
.article figcaption{ font-size:12.5px; color:var(--ink-mute); margin-top:8px; text-align:center; }
.article blockquote{
  margin:20px 0; padding:14px 18px; border-left:3px solid var(--purple);
  background:var(--surface); border-radius:0 var(--radius-s) var(--radius-s) 0;
  color:var(--ink); font-size:15px;
}

/* ---------- Related reading ---------- */
.related-reading{
  margin-top:26px; padding:18px 20px; background:var(--surface); border:1px solid var(--border-soft);
  border-radius:var(--radius-m);
}
.related-reading h3{ font-size:13px; color:var(--ink-mute); text-transform:uppercase; letter-spacing:.06em; margin-bottom:10px; }
.related-reading a{ display:block; font-size:14.5px; font-weight:600; color:var(--ink); padding:6px 0; }
.related-reading a:hover{ color:var(--cyan); text-decoration:none; }
.related-reading a::before{ content:"→ "; color:var(--cyan); }

/* ---------- Summary cards (回流首页) ---------- */
.summary-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:16px; }
.summary-card{
  background:var(--surface); border:1px solid var(--border-soft); border-radius:var(--radius-m);
  padding:18px; display:flex; flex-direction:column;
}
.summary-card h4{ font-size:15.5px; color:var(--ink); margin-bottom:8px; }
.summary-card p{ font-size:13.5px; color:var(--ink-mute); flex:1; }
.summary-card a.readmore{ font-size:13px; font-weight:700; margin-top:10px; }
.summary-more{ margin-top:16px; text-align:right; font-size:13.5px; }

/* ---------- Diagram / evidence-board / relationship components ---------- */
.diagram-box{ background:var(--surface); border:1px solid var(--border-soft); border-radius:var(--radius-m); padding:20px; }
.flow-strip{ display:flex; align-items:center; gap:8px; flex-wrap:wrap; font-size:13px; font-weight:700; color:var(--ink); }
.flow-strip .node{ background:var(--bg-alt); border:1px solid var(--border); padding:8px 12px; border-radius:8px; }
.flow-strip .arrow{ color:var(--cyan); }

.evidence-board{ display:grid; grid-template-columns:repeat(3,1fr); gap:14px; }
.evidence-card{
  background:var(--bg-alt); border:1px dashed var(--gold); border-radius:var(--radius-s);
  padding:14px; position:relative;
}
.evidence-card h5{ font-size:13px; color:var(--gold); margin:0 0 6px; text-transform:uppercase; letter-spacing:.04em; }
.evidence-card p{ font-size:13px; margin:0; color:var(--ink-dim); }
.evidence-tabs{ display:flex; gap:8px; margin-bottom:16px; flex-wrap:wrap; }
.evidence-tab{
  background:var(--bg-alt); border:1px solid var(--border); color:var(--ink-dim); font-size:13px; font-weight:700;
  padding:8px 14px; border-radius:999px; cursor:pointer;
}
.evidence-tab.active{ background:var(--cyan); color:#0c1116; border-color:var(--cyan); }
.evidence-panel{ display:none; }
.evidence-panel.active{ display:block; }

.relation-panel{ display:grid; grid-template-columns:repeat(4,1fr); gap:12px; }
.relation-stat{ background:var(--bg-alt); border:1px solid var(--border); border-radius:var(--radius-s); padding:12px; text-align:center; }
.relation-stat .label{ font-size:12px; color:var(--ink-mute); }
.relation-stat .value{ font-size:18px; font-weight:800; color:var(--cyan); margin-top:4px; }
.relation-bar{ height:6px; background:var(--border); border-radius:3px; margin-top:8px; overflow:hidden; }
.relation-bar i{ display:block; height:100%; background:var(--purple); }

.campaign-timeline{ display:flex; gap:14px; overflow-x:auto; padding-bottom:10px; scrollbar-width:thin; }
.campaign-timeline .step{
  min-width:190px; background:var(--bg-alt); border:1px solid var(--border); border-radius:var(--radius-s);
  padding:14px; flex-shrink:0;
}
.campaign-timeline .step .tag{ font-size:11px; color:var(--purple); font-weight:700; text-transform:uppercase; }
.campaign-timeline .step h5{ font-size:14px; margin:6px 0; color:var(--ink); }
.campaign-timeline .step p{ font-size:12.5px; margin:0; color:var(--ink-mute); }

/* ---------- FAQ ---------- */
.faq-list{ display:flex; flex-direction:column; gap:10px; }
.faq-item{ background:var(--surface); border:1px solid var(--border-soft); border-radius:var(--radius-m); overflow:hidden; }
.faq-q{
  width:100%; text-align:left; background:none; border:none; color:var(--ink); font-family:inherit;
  font-size:15px; font-weight:700; padding:16px 18px; cursor:pointer; display:flex; justify-content:space-between; gap:12px;
}
.faq-q::after{ content:"+"; color:var(--cyan); font-size:20px; font-weight:400; }
.faq-item.open .faq-q::after{ content:"–"; }
.faq-a{ display:none; padding:0 18px 18px; font-size:14px; color:var(--ink-dim); }
.faq-item.open .faq-a{ display:block; }
.faq-groups{ display:flex; gap:8px; flex-wrap:wrap; margin-bottom:18px; }
.faq-groups button{
  background:var(--bg-alt); border:1px solid var(--border); color:var(--ink-dim); font-size:12.5px; font-weight:700;
  padding:7px 12px; border-radius:999px; cursor:pointer;
}
.faq-groups button.active{ background:var(--purple); border-color:var(--purple); color:#fff; }

/* ---------- App feature grid ---------- */
.feature-grid{ display:grid; grid-template-columns:repeat(4,1fr); gap:14px; }
.feature-card{ background:var(--surface); border:1px solid var(--border-soft); border-radius:var(--radius-m); padding:16px; text-align:center; }
.feature-card .num{ width:30px; height:30px; margin:0 auto 10px; border-radius:50%; background:var(--bg-alt); border:1px solid var(--border); display:flex; align-items:center; justify-content:center; font-size:13px; font-weight:800; color:var(--cyan); }
.feature-card h4{ font-size:13.5px; margin:0; }

.notice-box{
  background:var(--bg-alt); border:1px solid var(--gold); border-radius:var(--radius-m); padding:16px 18px;
  font-size:14px; color:var(--ink-dim); margin:20px 0;
}
.notice-box strong{ color:var(--gold); }

/* ---------- Company / disclaimer ---------- */
.company-box{ background:var(--surface); border:1px solid var(--border-soft); border-radius:var(--radius-l); padding:28px; }
.disclaimer{ font-size:12.5px; color:var(--ink-mute); line-height:1.9; }

/* ---------- Footer ---------- */
.site-footer{ border-top:1px solid var(--border-soft); padding:36px 0 24px; background:var(--bg-alt); }
.footer-grid{ display:grid; grid-template-columns:1.4fr 1fr 1fr 1fr; gap:24px; margin-bottom:24px; }
.footer-brand{ font-weight:800; font-size:17px; color:var(--ink); margin-bottom:8px; }
.footer-col h5{ font-size:13px; color:var(--ink-mute); text-transform:uppercase; letter-spacing:.06em; margin-bottom:10px; }
.footer-col a{ display:block; color:var(--ink-dim); font-size:13.5px; padding:4px 0; }
.footer-bottom{ border-top:1px solid var(--border-soft); padding-top:18px; font-size:12.5px; color:var(--ink-mute); display:flex; justify-content:space-between; flex-wrap:wrap; gap:8px; }

/* ---------- Back to top ---------- */
.back-to-top{
  position:fixed; right:20px; bottom:20px; width:44px; height:44px; border-radius:50%;
  background:var(--cyan); color:#0c1116; border:none; font-size:18px; cursor:pointer;
  box-shadow:var(--shadow-card); display:none; align-items:center; justify-content:center; z-index:200;
}
.back-to-top.show{ display:flex; }

/* ---------- Utility ---------- */
.mt-0{ margin-top:0; }
.text-mute{ color:var(--ink-mute); }
.grid-2{ display:grid; grid-template-columns:1fr 1fr; gap:16px; }

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width:1200px){
  .main-nav{
    position:fixed; inset:68px 0 0 0; background:var(--bg); flex-direction:column; align-items:stretch;
    padding:14px; gap:4px; transform:translateX(100%); transition:transform .25s ease; overflow-y:auto;
  }
  .main-nav.open{ transform:translateX(0); }
  .main-nav a{ padding:14px 12px; border-bottom:1px solid var(--border-soft); border-radius:0; font-size:15px; }
  .nav-toggle{ display:block; }
}
@media (max-width:1024px){
  .systems-grid{ grid-template-columns:repeat(2,1fr); }
  .summary-grid{ grid-template-columns:repeat(2,1fr); }
  .evidence-board{ grid-template-columns:repeat(2,1fr); }
  .feature-grid{ grid-template-columns:repeat(2,1fr); }
  .footer-grid{ grid-template-columns:1fr 1fr; }
  .relation-panel{ grid-template-columns:repeat(2,1fr); }
}
@media (max-width:768px){
  .hero-grid{ grid-template-columns:1fr; }
  .hero h1{ font-size:27px; }
  .grid-2{ grid-template-columns:1fr; }
}
@media (max-width:430px){
  .container{ padding:0 16px; }
  .hero h1{ font-size:23px; }
  .section{ padding:38px 0; }
  .evidence-board{ grid-template-columns:1fr; }
  .summary-grid{ grid-template-columns:1fr; }
  .feature-grid{ grid-template-columns:1fr 1fr; }
  .relation-panel{ grid-template-columns:1fr 1fr; }
}