/* ============================================================
   电子魔方 · NEON CYBER
   主色 #e74c4b / 辅助 #d6d63d / 强调 #a3f452 / 背景 #150e0e
   卡片 #231a1a / 正文 #f2eeee / 次要 #ae9898 / 描边 #403030
   霓虹网格 · 扫描线 · 发光描边 · 硬朗切角 · 圆角 4px
   ============================================================ */
:root{
  --c-primary:#e74c4b;
  --c-aux:#d6d63d;
  --c-cta:#a3f452;
  --c-bg:#150e0e;
  --c-surface:#231a1a;
  --c-text:#f2eeee;
  --c-muted:#ae9898;
  --c-border:#403030;

  --radius:4px;
  --font-head:'Poppins','Noto Sans SC',system-ui,sans-serif;
  --font-body:'JetBrains Mono','Fira Code',ui-monospace,'SFMono-Regular','Courier New',monospace;
  --cubie:60px;
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0;
  min-height:100vh;
  background:var(--c-bg);
  color:var(--c-text);
  font-family:var(--font-body);
  font-size:14px;
  line-height:1.65;
  overflow-x:hidden;
  -webkit-tap-highlight-color:transparent;
}
h1,h2,h3{margin:0}
button{font:inherit;color:inherit}
::selection{background:var(--c-primary);color:var(--c-bg)}

/* ---------- 背景装饰 ---------- */
.grid-bg{
  position:fixed;inset:0;z-index:0;pointer-events:none;
  background-image:
    linear-gradient(rgba(231,76,75,.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(231,76,75,.07) 1px, transparent 1px);
  background-size:48px 48px;
  -webkit-mask-image:radial-gradient(circle at 50% 12%, #000 0%, rgba(0,0,0,.25) 55%, transparent 78%);
  mask-image:radial-gradient(circle at 50% 12%, #000 0%, rgba(0,0,0,.25) 55%, transparent 78%);
}
.scanlines{
  position:fixed;inset:0;z-index:60;pointer-events:none;opacity:.5;
  background:repeating-linear-gradient(to bottom, rgba(0,0,0,.32) 0 1px, rgba(0,0,0,0) 1px 3px);
  animation:scan 6s linear infinite;
}
@keyframes scan{from{transform:translateY(0)}to{transform:translateY(3px)}}

/* ---------- 顶栏 ---------- */
.topbar{
  position:sticky;top:0;z-index:40;
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  padding:12px 22px;
  background:rgba(21,14,14,.9);
  backdrop-filter:blur(10px);
  border-bottom:1px solid var(--c-border);
}
.brand{display:flex;align-items:center;gap:10px}
.brand-mark{
  width:24px;height:24px;flex:none;transform:rotate(-6deg);
  background:
    linear-gradient(var(--c-primary),var(--c-primary)) 0 0/7px 7px no-repeat,
    linear-gradient(var(--c-aux),var(--c-aux)) 8.5px 0/7px 7px no-repeat,
    linear-gradient(var(--c-cta),var(--c-cta)) 17px 0/7px 7px no-repeat,
    linear-gradient(var(--c-cta),var(--c-cta)) 0 8.5px/7px 7px no-repeat,
    linear-gradient(#332626,#332626) 8.5px 8.5px/7px 7px no-repeat,
    linear-gradient(var(--c-primary),var(--c-primary)) 17px 8.5px/7px 7px no-repeat,
    linear-gradient(var(--c-aux),var(--c-aux)) 0 17px/7px 7px no-repeat,
    linear-gradient(var(--c-primary),var(--c-primary)) 8.5px 17px/7px 7px no-repeat,
    linear-gradient(var(--c-cta),var(--c-cta)) 17px 17px/7px 7px no-repeat;
  box-shadow:0 0 16px rgba(231,76,75,.45);
  border-radius:2px;
}
.brand-name{font-family:var(--font-head);font-weight:800;font-size:16px;letter-spacing:.08em;display:flex;align-items:baseline;gap:10px}
.brand-name em{font-style:normal;font-family:var(--font-body);font-size:11px;font-weight:500;letter-spacing:.22em;color:var(--c-aux)}

.tabs{display:flex;gap:8px}
.tab{
  position:relative;display:flex;align-items:center;gap:8px;
  padding:9px 16px;cursor:pointer;
  background:transparent;color:var(--c-muted);
  border:1px solid var(--c-border);border-radius:var(--radius);
  font-family:var(--font-head);font-weight:600;font-size:13px;letter-spacing:.06em;
  clip-path:polygon(8px 0,100% 0,100% calc(100% - 8px),calc(100% - 8px) 100%,0 100%,0 8px);
  transition:color .16s,background .16s,border-color .16s,box-shadow .16s;
}
.tab i{font-style:normal;font-family:var(--font-body);font-size:11px;color:var(--c-aux)}
.tab:hover{color:var(--c-text);border-color:var(--c-primary)}
.tab.is-active{color:var(--c-bg);background:var(--c-primary);border-color:var(--c-primary);box-shadow:0 0 20px rgba(231,76,75,.45)}
.tab.is-active i{color:var(--c-bg)}

/* ---------- 布局 ---------- */
.wrap{position:relative;z-index:2;max-width:1180px;margin:0 auto;padding:24px 20px 40px}
.page{display:none}
.page.is-active{display:block;animation:pageIn .34s ease both}
@keyframes pageIn{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:none}}

.cols{display:grid;grid-template-columns:minmax(0,1.4fr) minmax(300px,1fr);gap:18px;align-items:start}
.cols.single{grid-template-columns:1fr}

.panel{
  position:relative;
  background:var(--c-surface);
  border:1px solid var(--c-border);
  border-radius:var(--radius);
  padding:18px;
  clip-path:polygon(16px 0,100% 0,100% calc(100% - 16px),calc(100% - 16px) 100%,0 100%,0 16px);
}
.panel::before{
  content:'';position:absolute;left:0;top:0;width:100%;height:1px;
  background:linear-gradient(90deg,var(--c-primary),transparent 60%);
}
.panel.stage{clip-path:none;padding:16px 16px 12px}
.panel.stage::before{display:none}
.corner{position:absolute;width:14px;height:14px;border:2px solid var(--c-primary);opacity:.8}
.corner.tl{left:-1px;top:-1px;border-right:0;border-bottom:0}
.corner.br{right:-1px;bottom:-1px;border-left:0;border-top:0}

.panel-head{margin-bottom:14px}
.panel-title{
  font-family:var(--font-head);font-weight:700;font-size:14px;
  letter-spacing:.14em;text-transform:uppercase;
}
.panel-title::before{
  content:'';display:inline-block;width:8px;height:8px;margin-right:10px;
  background:var(--c-primary);box-shadow:0 0 10px var(--c-primary);vertical-align:middle;
}
.panel-sub{margin:6px 0 0;color:var(--c-muted);font-size:12px;line-height:1.5}

/* ---------- 3D 魔方 ---------- */
.scene{
  position:relative;
  height:min(52vh,430px);min-height:290px;
  perspective:1100px;perspective-origin:50% 46%;
  display:flex;align-items:center;justify-content:center;
  overflow:hidden;touch-action:none;cursor:grab;
  border:1px solid var(--c-border);border-radius:var(--radius);
  background:
    radial-gradient(circle at 50% 44%, rgba(231,76,75,.12), transparent 62%),
    linear-gradient(180deg,#1c1313,#110a0a);
}
.scene.is-dragging{cursor:grabbing}
.scene::after{
  content:'';position:absolute;inset:0;pointer-events:none;opacity:0;transition:opacity .3s;
  background:radial-gradient(circle at 50% 50%, rgba(163,244,82,.32), transparent 68%);
}
.scene.is-solved::after{opacity:1;animation:solvedPulse .9s ease-in-out infinite alternate}
@keyframes solvedPulse{from{opacity:.35}to{opacity:1}}

.cube{position:absolute;left:50%;top:50%;width:0;height:0;transform-style:preserve-3d}
.cubie{
  position:absolute;left:0;top:0;
  width:var(--cubie);height:var(--cubie);
  margin:calc(var(--cubie) * -0.5) 0 0 calc(var(--cubie) * -0.5);
  transform-style:preserve-3d;
}
.face{
  position:absolute;inset:0;
  border:2px solid var(--c-bg);
  border-radius:var(--radius);
  box-shadow:inset 0 0 14px rgba(0,0,0,.55);
  cursor:pointer;
  transition:filter .15s;
}
.face::after{
  content:'';position:absolute;inset:12%;border-radius:2px;pointer-events:none;
  background:linear-gradient(140deg, rgba(255,255,255,.3), rgba(255,255,255,0) 58%);
}
.face:hover{filter:brightness(1.16)}
.face.blank{background:#1d1515;box-shadow:none;cursor:grab}
.face.blank::after{display:none}
.f-up{transform:rotateX(90deg) translateZ(calc(var(--cubie) * 0.5))}
.f-dn{transform:rotateX(-90deg) translateZ(calc(var(--cubie) * 0.5))}
.f-fr{transform:translateZ(calc(var(--cubie) * 0.5))}
.f-bk{transform:rotateY(180deg) translateZ(calc(var(--cubie) * 0.5))}
.f-rt{transform:rotateY(90deg) translateZ(calc(var(--cubie) * 0.5))}
.f-lf{transform:rotateY(-90deg) translateZ(calc(var(--cubie) * 0.5))}
.pivot{position:absolute;left:0;top:0;width:0;height:0;transform-style:preserve-3d}

.stage-foot{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}

/* ---------- 控件 ---------- */
.btn-row{display:flex;gap:10px;margin-bottom:10px;flex-wrap:wrap}
.btn-row .btn{flex:1 1 130px}
.btn-row.center{justify-content:center;margin:14px 0 18px}
.btn-row.center .btn{flex:0 1 auto;min-width:120px}
.btn-row.end{justify-content:flex-end;margin-top:12px}
.btn-row.end .btn{flex:0 0 auto}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:11px 14px;cursor:pointer;
  background:transparent;color:var(--c-text);
  border:1px solid var(--c-border);border-radius:var(--radius);
  font-family:var(--font-head);font-weight:600;font-size:12.5px;letter-spacing:.08em;text-transform:uppercase;
  clip-path:polygon(8px 0,100% 0,100% calc(100% - 8px),calc(100% - 8px) 100%,0 100%,0 8px);
  transition:color .16s,background .16s,border-color .16s,box-shadow .16s,transform .16s;
}
.btn:hover{color:var(--c-primary);border-color:var(--c-primary);box-shadow:0 0 18px rgba(231,76,75,.28);transform:translateY(-1px)}
.btn:active{transform:translateY(0)}
.btn-primary{border-color:var(--c-primary);color:var(--c-primary);text-shadow:0 0 10px rgba(231,76,75,.55)}
.btn-primary:hover{background:var(--c-primary);color:var(--c-bg);text-shadow:none;box-shadow:0 0 22px rgba(231,76,75,.5)}
.btn-accent{border-color:var(--c-aux);color:var(--c-aux)}
.btn-accent:hover{background:var(--c-aux);color:#1c1c05;border-color:var(--c-aux);box-shadow:0 0 22px rgba(214,214,61,.38)}
.btn-cta{border-color:var(--c-cta);color:var(--c-cta);text-shadow:0 0 10px rgba(163,244,82,.55)}
.btn-cta:hover{background:var(--c-cta);color:#101a06;border-color:var(--c-cta);box-shadow:0 0 22px rgba(163,244,82,.45)}
.btn-ghost{color:var(--c-muted)}
.btn.is-off,.btn[disabled]{opacity:.4;pointer-events:none}

.turn-grid{display:grid;grid-template-columns:repeat(6,1fr);gap:6px}
.turn{
  padding:9px 0;cursor:pointer;
  background:#1b1313;color:var(--c-text);
  border:1px solid var(--c-border);border-radius:var(--radius);
  font-family:var(--font-body);font-weight:700;font-size:12px;letter-spacing:.04em;
  transition:color .15s,border-color .15s,background .15s,box-shadow .15s;
}
.turn:hover{color:var(--c-cta);border-color:var(--c-cta);box-shadow:0 0 14px rgba(163,244,82,.25)}

.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin:16px 0 4px}
.stats.wide{grid-template-columns:repeat(4,1fr);margin:6px 0 4px}
.stat{background:#1b1313;border:1px solid var(--c-border);border-radius:var(--radius);padding:10px 8px;text-align:center}
.stat-num{
  display:block;font-family:var(--font-head);font-weight:700;font-size:18px;letter-spacing:.02em;
  color:var(--c-cta);text-shadow:0 0 12px rgba(163,244,82,.35);
}
.stat-lab{display:block;margin-top:2px;font-size:11px;color:var(--c-muted)}

.sub-title{
  margin:18px 0 10px;font-size:11px;letter-spacing:.2em;text-transform:uppercase;color:var(--c-aux);
}
.kbd-hint{margin:14px 0 0;font-size:11.5px;color:var(--c-muted);line-height:1.8}
.kbd-hint b{color:var(--c-text);font-weight:500;padding:1px 5px;border:1px solid var(--c-border);border-radius:2px;background:#1b1313}

.chip{
  display:inline-block;padding:5px 10px;
  border:1px solid var(--c-border);border-radius:var(--radius);
  background:#1b1313;color:var(--c-muted);font-size:11.5px;letter-spacing:.04em;
}
.chip.alt{color:var(--c-aux);border-color:#4a4030}
.chip.hot{color:var(--c-cta);border-color:#3d5427;text-shadow:0 0 10px rgba(163,244,82,.4)}

/* ---------- 计时页 ---------- */
.clock{
  margin:8px 0 4px;text-align:center;
  font-family:var(--font-head);font-weight:800;
  font-size:clamp(38px,10vw,72px);line-height:1.1;letter-spacing:.02em;
  color:var(--c-text);
  text-shadow:0 0 22px rgba(231,76,75,.55), 0 0 60px rgba(231,76,75,.25);
  font-variant-numeric:tabular-nums;
}
.clock.is-running{color:var(--c-cta);text-shadow:0 0 22px rgba(163,244,82,.5), 0 0 60px rgba(163,244,82,.22)}

.records{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:6px;max-height:280px;overflow:auto}
.records li{
  display:grid;grid-template-columns:34px 1fr auto auto;align-items:center;gap:10px;
  padding:9px 12px;background:#1b1313;border:1px solid var(--c-border);
  border-left:2px solid var(--c-border);border-radius:var(--radius);font-size:12.5px;
}
.records li.rec{border-left-color:var(--c-aux)}
.records li.rec.top{border-left-color:var(--c-cta);box-shadow:inset 0 0 22px rgba(163,244,82,.08)}
.records li.empty{display:block;color:var(--c-muted);text-align:center;border-left-color:var(--c-border)}
.rec-rank{color:var(--c-primary);font-weight:700}
.rec-time{color:var(--c-text);font-weight:700;letter-spacing:.06em}
.rec-moves,.rec-date{color:var(--c-muted);font-size:11.5px}

/* ---------- 教程页 ---------- */
.tut-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:18px}
.note-list{list-style:none;margin:0;padding:0}
.note-list li{
  padding:8px 0 8px 16px;position:relative;font-size:13px;color:var(--c-text);
  border-bottom:1px dashed var(--c-border);
}
.note-list li::before{content:'//';position:absolute;left:0;color:var(--c-primary);font-size:11px}
.note-list li b{color:var(--c-aux);font-weight:500}
.steps{list-style:none;counter-reset:s;margin:0;padding:0}
.steps li{
  counter-increment:s;position:relative;padding:11px 0 11px 36px;
  border-bottom:1px dashed var(--c-border);font-size:13px;
}
.steps li::before{
  content:counter(s,decimal-leading-zero);position:absolute;left:0;top:11px;
  font-family:var(--font-head);font-weight:700;color:var(--c-primary);
  text-shadow:0 0 10px rgba(231,76,75,.45);
}
.steps li b{display:block;color:var(--c-text);font-weight:600}
.fml{display:flex;flex-wrap:wrap;gap:5px;margin-top:8px}
.mv{
  display:inline-block;min-width:26px;text-align:center;
  padding:2px 7px;background:#1b1313;border:1px solid var(--c-border);border-radius:var(--radius);
  color:var(--c-cta);font-weight:700;font-size:12px;
}
.tip{margin:12px 0 0;font-size:11.5px;color:var(--c-muted);padding-left:10px;border-left:2px solid var(--c-primary)}

/* ---------- 页脚 ---------- */
.footer{position:relative;z-index:2;border-top:1px solid var(--c-border);margin-top:26px;background:rgba(35,26,26,.55)}
.foot-inner{max-width:1180px;margin:0 auto;padding:20px;display:flex;flex-wrap:wrap;gap:14px;align-items:center;justify-content:space-between}
.foot-title{font-size:11px;letter-spacing:.2em;color:var(--c-aux);margin-bottom:8px}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.foot-note{margin:0;font-size:11.5px;color:var(--c-muted);max-width:520px;line-height:1.7}

/* ---------- Toast ---------- */
.toast{
  position:fixed;left:50%;bottom:86px;z-index:70;
  transform:translate(-50%,16px);opacity:0;pointer-events:none;
  padding:10px 18px;max-width:80vw;
  background:#1b1313;border:1px solid var(--c-primary);border-radius:var(--radius);
  color:var(--c-text);font-size:12.5px;letter-spacing:.03em;
  box-shadow:0 0 24px rgba(231,76,75,.35);
  transition:opacity .22s,transform .22s;
}
.toast.is-show{opacity:1;transform:translate(-50%,0)}

/* ---------- 响应式 ---------- */
@media (max-width:900px){
  .cols{grid-template-columns:1fr}
  .stats.wide{grid-template-columns:repeat(2,1fr)}
  .scene{height:min(48vh,380px)}
}
@media (max-width:720px){
  body{padding-bottom:74px}
  .topbar{
    position:fixed;left:0;right:0;bottom:0;top:auto;
    padding:8px 10px;justify-content:center;
    background:rgba(21,14,14,.97);
    border-top:1px solid var(--c-border);border-bottom:none;
  }
  .brand{display:none}
  .tabs{width:100%;display:grid;grid-template-columns:repeat(3,1fr);gap:6px}
  .tab{justify-content:center;padding:11px 4px;font-size:12px;font-family:var(--font-head)}
  .wrap{padding:18px 14px 30px}
  .panel{padding:15px}
  .scene{height:min(46vh,340px);min-height:250px}
  .turn-grid{gap:5px}
  .turn{padding:10px 0;font-size:12px}
  .stat-num{font-size:16px}
  .records li{grid-template-columns:30px 1fr auto;font-size:12px}
  .rec-date{display:none}
  .toast{bottom:80px}
}