:root{
  --bg:#f3f6fb; --card:#fff; --sub:#f1f5fa; --line:#e3e9f1; --line2:#cdd8e5;
  --ink:#102033; --ink2:#4a5a70; --ink3:#7c8ba0;
  --cyan:#0891b2; --a:#0ea5e9; --ad:#0369a1; --b:#d97706; --bd:#b45309;
  --green:#059669; --red:#e11d48; --indigo:#6366f1;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:"PingFang SC","Microsoft YaHei","Hiragino Sans GB",-apple-system,"Segoe UI",sans-serif;
  font-size:16px;line-height:1.7;color:var(--ink);background:var(--bg);
  background-image:
    radial-gradient(circle at 100% 0%, rgba(8,145,178,.10) 7%, transparent 22%),
    radial-gradient(circle at 0% 0%, rgba(99,102,41,.10) 6%, transparent 20%);
  background-attachment:fixed;
  overflow-x:hidden;
}
.mono, .num, .formula, .metric b, .gauge .big{font-family:ui-monospace,"Cascadia Mono",Consolas,monospace}
.wrap{max-width:1720px;margin:0 auto;padding:0 28px}
section{scroll-margin-top:70px;margin-bottom:20px}
.sec-head{margin:34px 0 18px}
.sec-head .kicker{color:var(--cyan);font-weight:700;font-size:14px;letter-spacing:.08em}
.sec-head h2{font-size:28px;margin:6px 0}
.sec-head p{color:var(--ink2);max-width:860px}
.card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:24px}
.card h3{font-size:18px;margin-bottom:10px;display:flex;align-items:center;gap:8px}
.card h4{font-size:16px;margin:14px 0 6px}
.card p{color:var(--ink2)}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.lead{max-width:860px;color:var(--ink2)}
.btn{min-height:44px;border-radius:10px;padding:10px 20px;font-size:15px;cursor:pointer;border:1px solid var(--line2);
  background:#fff;color:var(--ink);transition:transform .15s,box-shadow .15s,background .15s;display:inline-flex;align-items:center;gap:8px;font-family:inherit}
.btn:hover{transform:translateY(-2px);box-shadow:0 6px 16px rgba(16,32,51,.10)}
.btn-primary{background:linear-gradient(135deg,#0ea5e9,#0891b2);color:#fff;border-color:transparent}
.btn-primary:hover{background:linear-gradient(135deg,#0ea5e9,#0e7490)}
.btn:disabled{opacity:.5;cursor:not-allowed;transform:none;box-shadow:none}
.tag{display:inline-block;padding:3px 12px;border-radius:999px;font-size:13px;font-weight:600}
.tag.a{background:#e0f2fe;color:var(--ad)}
.tag.b{background:#fef3c7;color:var(--bd)}
.tag.g{background:#d1fae5;color:var(--green)}
.tag.r{background:#ffe4e6;color:var(--red)}
.pos{color:var(--green)} .neg{color:var(--red)} .zero{color:var(--ink3)}
.formula{background:var(--sub);border:1px solid var(--line);border-radius:12px;padding:14px 18px;font-size:18px;text-align:center;margin:10px 0}
.formula i{font-style:italic;color:var(--ad)}
.note{border-radius:12px;padding:12px 16px;margin-top:12px;font-size:15px}
.note.g{background:#ecfdf5;border:1px solid #a7f3d0;color:#065f46}
.note.r{background:#fff1f2;border:1px solid #fecdd3;color:#9f1239}
.note.o{background:#fffbeb;border:1px solid #fde68a;color:#92400e}
.note.c{background:#ecfeff;border:1px solid #a5f3fc;color:#155e75}
.sub-title{display:flex;align-items:center;gap:10px;margin:22px 0 12px;font-size:19px;font-weight:700}
.sub-title .no{width:30px;height:30px;border-radius:8px;background:linear-gradient(135deg,#0ea5e9,#0891b2);color:#fff;display:inline-flex;align-items:center;justify-content:center;font-size:14px;font-family:ui-monospace,monospace}
input[type=range]{width:100%;accent-color:var(--cyan);height:44px;cursor:pointer}
table{width:100%;border-collapse:collapse;font-size:15px;overflow:hidden;border-radius:12px}
th{background:var(--cyan);color:#fff;padding:10px 12px;text-align:left;font-weight:600}
td{padding:10px 12px;border-bottom:1px solid var(--line)}
tbody tr:nth-child(even){background:var(--sub)}
.svgbox{background:var(--sub);border:1px solid var(--line);border-radius:12px;padding:10px;text-align:center}
.svgbox svg{width:100%;height:auto;display:block}
.figcap{font-size:12.5px;color:var(--ink3);text-align:center;margin:8px 2px 0;line-height:1.5}
.figcap b{color:var(--ink2)}
.card.svgbox,.card .svgbox{max-width:660px;margin-left:auto;margin-right:auto}
.card .svgbox svg{max-height:320px}

/* nav */
nav.top{position:fixed;top:0;left:0;right:0;height:56px;z-index:100;display:flex;align-items:center;
  background:rgba(255,255,255,.72);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}
nav.top .inner{max-width:1720px;margin:0 auto;padding:0 28px;width:100%;display:flex;align-items:center;justify-content:space-between;gap:12px}
.brand{font-weight:800;font-size:17px;display:flex;align-items:center;gap:8px;white-space:nowrap}
.brand svg{width:22px;height:22px}
.navlinks{display:flex;gap:2px;flex-wrap:wrap}
.navlinks a{font-size:13.5px;color:var(--ink2);text-decoration:none;padding:6px 10px;border-radius:8px;white-space:nowrap;transition:background .15s}
.navlinks a:hover{background:var(--sub)}
.navlinks a.active{background:#cffafe;color:#0e7490;font-weight:700}

/* hero */
.hero{min-height:90vh;display:flex;align-items:center;padding:90px 0 40px}
.hero .grid{display:grid;grid-template-columns:1.15fr .85fr;gap:30px;align-items:center}
.pill{display:inline-block;background:#fff;border:1px solid var(--line2);border-radius:999px;padding:6px 16px;font-size:13.5px;color:var(--ink2);font-weight:600;margin-bottom:18px}
.hero h1{font-size:42px;line-height:1.28;margin-bottom:16px}
.hero h1 .hl{color:var(--cyan)}
.hero p{color:var(--ink2);margin-bottom:22px;max-width:640px}
.chain{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin:22px 0}
.chain .node{background:#fff;border:1px solid var(--line);border-radius:10px;padding:8px 12px;font-size:13.5px;font-weight:600}
.chain .arrow{color:var(--cyan);font-weight:800}
.hero-btns{display:flex;gap:12px;flex-wrap:wrap}
.hero-deco{display:block}

/* back to top */
#toTop{position:fixed;right:26px;bottom:26px;width:48px;height:48px;border-radius:50%;border:1px solid var(--line2);
  background:#fff;color:var(--cyan);cursor:pointer;opacity:0;pointer-events:none;transition:opacity .25s,transform .25s;z-index:90;
  display:flex;align-items:center;justify-content:center;box-shadow:0 8px 20px rgba(16,32,51,.12)}
#toTop.show{opacity:1;pointer-events:auto}
#toTop:hover{transform:translateY(-3px)}

/* control room */
.room{background:linear-gradient(180deg,#f8fbfd,#eef4f9);border:1px solid var(--line2);border-radius:18px;padding:22px}
.scene-btns{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-bottom:16px}
.scene-btns .btn{justify-content:center;min-height:48px}
.scene-btns .btn.sel-a{background:linear-gradient(135deg,#0ea5e9,#0369a1);color:#fff;border-color:transparent}
.scene-btns .btn.sel-b{background:linear-gradient(135deg,#f59e0b,#b45309);color:#fff;border-color:transparent}
.scene-btns .btn.sel-n{background:linear-gradient(135deg,#0891b2,#0e7490);color:#fff;border-color:transparent}
.ctrlbar{display:flex;flex-wrap:wrap;gap:10px;align-items:center;margin-bottom:14px}
.ctrlbar .mag{flex:1;min-width:200px;display:flex;align-items:center;gap:12px}
.stages{display:flex;align-items:center;gap:10px;font-size:14px;color:var(--ink2)}
.stages .dot{width:14px;height:14px;border-radius:50%;background:var(--line2);transition:all .25s}
.stages .dot.cur{background:var(--cyan);transform:scale(1.4);box-shadow:0 0 0 4px rgba(8,145,178,.2)}
.principles{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-bottom:18px}
.principles .p{background:#fff;border:1px solid var(--line);border-radius:12px;padding:14px;font-size:14px}
.principles .p b{display:block;margin-bottom:4px;color:var(--cyan)}
.dash2{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:16px}
.zone-bottom{display:grid;grid-template-columns:1fr;gap:14px;margin-top:16px}
.panel{border-radius:14px;padding:16px;background:#fff;border:1px solid var(--line)}
.panel.A{border-top:4px solid var(--a)}
.panel.B{border-top:4px solid var(--b)}
.panel h4{display:flex;align-items:center;gap:8px;margin-bottom:10px}
.metrics{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.metric{background:var(--sub);border-radius:10px;padding:8px 12px}
.metric span{font-size:12.5px;color:var(--ink3);display:block}
.metric b{font-size:18px}
.verdict{margin-top:12px;border-radius:10px;padding:10px 14px;font-size:14px;font-weight:600;text-align:center}
.acebar{margin-top:10px;border-radius:10px;padding:9px 12px;font-size:13.5px;display:flex;align-items:center;justify-content:space-between;gap:8px;background:#f1f5fa;border:1px solid var(--line);color:var(--ink2)}
.acebar b{font-family:ui-monospace,monospace;font-size:19px}
.acebar.zero{background:#ecfdf5;border-color:#a7f3d0;color:#065f46}
.acebar.neg{background:#fff1f2;border-color:#fecdd3;color:#9f1239}
.acebar.pos{background:#fffbeb;border-color:#fde68a;color:#92400e}
.signbar{display:grid;grid-template-columns:1fr 1fr 1.4fr;gap:16px;margin-top:16px}
.bignum{background:#fff;border:1px solid var(--line);border-radius:12px;padding:16px;text-align:center}
.bignum span{font-size:13px;color:var(--ink3)}
.bignum b{font-size:30px;font-family:ui-monospace,monospace;display:block}
.bignum.combo{display:flex;flex-direction:column;gap:14px}
.bignum.combo .bn-row b{font-size:26px}
.rules{background:#fff;border:1px solid var(--line);border-radius:12px;padding:16px}
.rules .r{border-radius:10px;padding:10px 12px;margin-bottom:8px;font-size:14px;border:1px solid var(--line);transition:all .2s}
.rules .r.hl{background:#ecfeff;border-color:var(--cyan);font-weight:700}
.dynverdict{margin-top:10px;border-radius:10px;padding:12px;font-weight:700;text-align:center;background:var(--sub)}

/* wave */
.wave-card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:18px 20px;margin-top:16px}
.wave-head{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px;margin-bottom:6px}
.wave-head h4{font-size:16px;margin:0}
.legend{display:flex;flex-wrap:wrap;gap:14px;font-size:13px;color:var(--ink2)}
.legend span{display:inline-flex;align-items:center;gap:6px}
.legend i{width:18px;height:3px;border-radius:2px;display:inline-block}
.legend .la{background:var(--a)}.legend .lb{background:var(--b)}.legend .lt{background:var(--cyan)}.legend .lf{background:var(--red)}
#waveCanvas{width:100%;height:280px;display:block;cursor:crosshair}
.wave-live{display:flex;flex-wrap:wrap;gap:10px;margin:2px 0 10px}
.wave-live .wl{display:inline-flex;align-items:center;gap:6px;font-size:12.5px;color:var(--ink2);background:var(--sub);border:1px solid var(--line);border-radius:8px;padding:5px 10px}
.wave-live .wl i{width:14px;height:3px;border-radius:2px;display:inline-block}
.wave-live .wl b{font-family:ui-monospace,monospace;font-size:13px;color:var(--ink);font-weight:700}
.wave-live .la{background:var(--a)}.wave-live .lb{background:var(--b)}.wave-live .lt{background:var(--cyan)}.wave-live .lf{background:var(--red)}

/* flow */
.vflow{display:flex;flex-direction:column;align-items:center;gap:0}
.vflow .vn{background:#fff;border:2px solid var(--line2);border-radius:10px;padding:8px 14px;font-size:13.5px;text-align:center;transition:all .25s;min-width:220px}
.vflow .vn.cur{border-color:var(--cyan);background:#ecfeff;font-weight:700}
.vflow .vl{width:2px;height:22px;background:var(--line2);transition:background .25s}
.vflow .vl.done{background:var(--cyan)}
.diamond{border:2px solid var(--line2);background:#fff;border-radius:8px;padding:10px 16px;font-size:13.5px}
.diamond.cur{border-color:var(--cyan);background:#ecfeff;font-weight:700}

/* timeline */
.timeline{display:grid;grid-template-columns:repeat(6,1fr);gap:0;position:relative;margin:20px 0}
.tl-node{text-align:center;padding:0 8px;position:relative}
.tl-node .td{width:34px;height:34px;border-radius:50%;background:linear-gradient(135deg,#0ea5e9,#0891b2);color:#fff;display:flex;align-items:center;justify-content:center;margin:0 auto 10px;font-weight:700;font-family:ui-monospace;position:relative;z-index:2}
.tl-node::before{content:"";position:absolute;top:17px;left:50%;width:100%;height:2px;background:var(--line2);z-index:1}
.tl-node:last-child::before{display:none}
.tl-node b{display:block;font-size:14px;margin-bottom:4px}
.tl-node p{font-size:12.5px;color:var(--ink3);line-height:1.5}

/* quiz */
.quiz-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.qcard{background:#fff;border:1px solid var(--line);border-radius:14px;padding:18px}
.qcard .qt{font-weight:700;margin-bottom:12px;font-size:15.5px}
.qcard .opt{display:block;width:100%;text-align:left;border:1px solid var(--line2);background:#fff;border-radius:10px;padding:10px 14px;margin-bottom:8px;cursor:pointer;font-size:14.5px;transition:all .15s;font-family:inherit;min-height:44px}
.qcard .opt:hover{background:var(--sub)}
.qcard .opt.correct{background:#d1fae5;border-color:var(--green);color:#065f46;font-weight:700}
.qcard .opt.wrong{background:#ffe4e6;border-color:var(--red);color:#9f1239}
.qcard .opt:disabled{cursor:default}
.qcard .expl{display:none;margin-top:8px;font-size:13.5px;background:var(--sub);border-radius:8px;padding:8px 12px;color:var(--ink2)}
.qcard .expl.show{display:block}
.quiz-score{position:sticky;top:66px;z-index:50}
.three{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.three .t{background:#fff;border:1px solid var(--line);border-radius:12px;padding:16px}
.three .t b{color:var(--cyan);display:block;margin-bottom:6px}
footer{border-top:1px solid var(--line2);background:#fff;margin-top:40px;padding:30px 0}
.foot-tags{display:flex;gap:10px;flex-wrap:wrap;margin:12px 0}
@keyframes pulse{0%{transform:scale(.8);opacity:.8}100%{transform:scale(1.8);opacity:0}}
.pulsering{animation:pulse 1.6s ease-out infinite;transform-box:fill-box;transform-origin:center}
@media (prefers-reduced-motion: reduce){
  *{animation:none!important;transition:none!important;scroll-behavior:auto!important}
}
@media(max-width:1023px){
  .grid2,.dash2{grid-template-columns:1fr}
  .hero .grid{grid-template-columns:1fr}
  .hero-deco{display:none}
  .principles,.signbar,.three{grid-template-columns:1fr}
  .quiz-grid{grid-template-columns:1fr}
  .timeline{grid-template-columns:1fr;gap:14px}
  .tl-node::before{display:none}
  .navlinks{display:none}
  #waveCanvas{height:300px}
  .legend{gap:8px}
}

/* ===== 宽屏：分区调频核心区一屏网格布局 ===== */
@media(min-width:1100px){
  .room{
    display:grid;
    grid-template-columns:minmax(0,1.12fr) minmax(0,1fr);
    gap:12px 16px;
    padding:16px;
    align-items:start;
    grid-template-areas:
      "scene scene"
      "ctrl ctrl"
      "anim wave"
      "bottom bottom";
  }
  .scene-btns{grid-area:scene;margin-bottom:0}
  .scene-btns .btn{min-height:44px}
  .ctrlbar{grid-area:ctrl;margin-bottom:0}
  .room>.svgbox{grid-area:anim;margin:0;max-width:none;align-self:stretch;display:flex;flex-direction:column;justify-content:center}
  .room>.svgbox svg{max-height:none;width:100%;height:auto}
  .wave-card{grid-area:wave;margin:0;padding:14px 16px;align-self:start}
  .wave-head{margin-bottom:4px}
  .wave-live{margin:2px 0 8px;gap:8px}
  .wave-live .wl{padding:4px 8px}
  #waveCanvas{height:248px}
  .zone-bottom{
    grid-area:bottom;
    display:grid;
    grid-template-columns:1fr 1fr 0.9fr 1.3fr;
    gap:12px;
    margin-top:0;
    align-items:stretch;
  }
  .zone-bottom .panel{padding:12px 14px;display:flex;flex-direction:column}
  .zone-bottom .panel h4{margin-bottom:8px;font-size:14.5px}
  .zone-bottom .metric{padding:6px 10px}
  .zone-bottom .metric b{font-size:16px}
  .zone-bottom .acebar{margin-top:8px;padding:7px 10px;font-size:12.5px}
  .zone-bottom .acebar b{font-size:16px}
  .zone-bottom .verdict{margin-top:auto;padding:8px 10px;font-size:13px}
  .zone-bottom .bignum.combo{padding:12px 10px;display:flex;flex-direction:column;justify-content:center;gap:16px}
  .zone-bottom .bignum .bn-row{display:flex;flex-direction:column;align-items:center;gap:2px}
  .zone-bottom .bignum .bn-row span{font-size:12px;color:var(--ink3)}
  .zone-bottom .bignum .bn-row b{font-size:22px;font-family:ui-monospace}
  .zone-bottom .rules{padding:12px 14px;display:flex;flex-direction:column}
  .zone-bottom .rules .r{padding:7px 10px;margin-bottom:6px;font-size:13px}
  .zone-bottom .dynverdict{margin-top:auto;padding:9px 10px;font-size:13px}
}