:root{
  --bg-0:#0a0e27;
  --bg-1:#0f1442;
  --ink:#eef0ff;
  --ink-dim:#9aa3d9;
  --accent:#5b6bff;
  --accent-2:#00e5ff;
  --gold:#ffcf4d;
  --radius:18px;
  --tile-blue:#3b6bff;
  --tile-purple:#8b5bff;
  --tile-cyan:#00c2e5;
  --tile-yellow:#ffb300;
  --tile-coral:#ff6b6b;
  --tile-green:#2fd487;
}
*{box-sizing:border-box; -webkit-tap-highlight-color:transparent;}
html,body{height:100%;}
body{
  margin:0;
  font-family:'Segoe UI', system-ui, -apple-system, Roboto, Helvetica, Arial, sans-serif;
  background:
    radial-gradient(1200px 800px at 20% -10%, #1a2166 0%, transparent 60%),
    radial-gradient(1000px 700px at 110% 10%, #241a5e 0%, transparent 55%),
    linear-gradient(180deg, var(--bg-0), var(--bg-1) 60%, var(--bg-0));
  color:var(--ink);
  overflow-x:hidden;
  min-height:100%;
  display:flex;
  flex-direction:column;
  align-items:center;
  user-select:none;
  touch-action:none;
}
[hidden]{ display:none !important; }
#app{
  width:100%;
  max-width:760px;
  padding:14px 14px 24px;
  display:flex;
  flex-direction:column;
  min-height:100vh;
  min-height:100dvh;
}
.brand{ display:flex; align-items:center; justify-content:space-between; padding:4px 2px 10px; }
.brand .logo{ font-weight:800; letter-spacing:.5px; font-size:15px; color:var(--ink-dim); display:flex; align-items:center; gap:6px; }
.brand .logo b{ color:var(--ink); font-weight:800; }
.brand .logo .dot{ color:var(--accent-2); }
.icon-btn{
  background:rgba(255,255,255,.06); border:1px solid rgba(255,255,255,.08); color:var(--ink);
  width:36px;height:36px;border-radius:12px; display:flex;align-items:center;justify-content:center;
  font-size:16px; cursor:pointer;
}
.icon-btn:active{ transform:scale(.92); }

.screen{ display:none; flex:1; flex-direction:column; }
.screen.active{ display:flex; }

/* ---------- START ---------- */
#screen-start{ align-items:center; text-align:center; padding-top:6px; }
.hero-title{
  font-size:44px; font-weight:900; letter-spacing:1px; margin:10px 0 2px;
  background:linear-gradient(135deg, #fff, var(--accent-2) 70%);
  -webkit-background-clip:text; background-clip:text; color:transparent;
}
.hero-sub{ color:var(--ink-dim); font-size:14px; margin-bottom:18px; letter-spacing:.5px; }
.hero-tiles{ display:flex; gap:8px; margin:6px 0 22px; justify-content:center; }
.hero-tiles .demo-tile{ animation:floaty 3s ease-in-out infinite; }
.hero-tiles .demo-tile:nth-child(2){ animation-delay:.2s; }
.hero-tiles .demo-tile:nth-child(3){ animation-delay:.4s; }
.hero-tiles .demo-tile:nth-child(4){ animation-delay:.6s; }
.hero-tiles .demo-tile:nth-child(5){ animation-delay:.8s; }
@keyframes floaty{ 0%,100%{transform:translateY(0)} 50%{transform:translateY(-8px)} }

.mode-list{ width:100%; display:flex; flex-direction:column; gap:12px; margin-top:4px; }
.mode-card{
  display:flex; align-items:center; gap:14px;
  background:linear-gradient(145deg, rgba(255,255,255,.07), rgba(255,255,255,.02));
  border:1px solid rgba(255,255,255,.08);
  border-radius:var(--radius);
  padding:14px 16px;
  cursor:pointer;
  text-align:left;
  transition:transform .15s ease, border-color .15s ease, opacity .15s ease;
  font-family:inherit; color:inherit; width:100%;
}
.mode-card:active{ transform:scale(.98); }
.mode-card:hover{ border-color:rgba(255,255,255,.22); }
.mode-card.loading{ opacity:.55; pointer-events:none; }
.mode-card .m-icon{
  font-size:26px; width:52px; height:52px; border-radius:14px;
  display:flex;align-items:center;justify-content:center; flex-shrink:0;
}
.mode-card.classic .m-icon{ background:linear-gradient(145deg,var(--tile-blue),var(--tile-purple)); }
.mode-card.rush .m-icon{ background:linear-gradient(145deg,var(--tile-coral),var(--gold)); }
.mode-card.daily .m-icon{ background:linear-gradient(145deg,var(--tile-green),var(--tile-cyan)); }
.mode-card .m-body{ flex:1; min-width:0; }
.mode-card .m-title{ font-weight:800; font-size:16px; display:flex; align-items:center; gap:6px; }
.mode-card .m-desc{ color:var(--ink-dim); font-size:12.5px; margin-top:2px; }
.mode-card .m-best{ font-size:11.5px; color:var(--accent-2); margin-top:5px; font-weight:700; }
.streak-badge{ font-size:11px; background:rgba(255,207,77,.15); color:var(--gold); border-radius:20px; padding:2px 8px; font-weight:700; margin-left:6px; }

.leaderboard-btn{ width:100%; margin-top:14px; }

.nickname-preview{
  margin-top:16px; background:none; border:none; color:var(--ink-dim); font-size:12.5px;
  cursor:pointer; text-decoration:underline; font-family:inherit;
}

.howto-box{
  background:rgba(255,255,255,.05); border:1px solid rgba(255,255,255,.08);
  border-radius:14px; padding:14px 16px; font-size:13px; color:var(--ink-dim);
  line-height:1.6; text-align:left; margin-top:16px;
}
.howto-box b{ color:var(--ink); }

.how-to-play-seo{ text-align:left; margin-top:26px; color:var(--ink-dim); font-size:12.5px; line-height:1.6; }
.how-to-play-seo h2{ font-size:14px; color:var(--ink); margin:0 0 6px; }

/* ---------- COUNTDOWN ---------- */
#screen-countdown{ align-items:center; justify-content:center; }
.countdown-num{
  font-size:110px; font-weight:900; color:var(--accent-2);
  text-shadow:0 0 40px rgba(0,229,255,.6);
  animation:pulseIn .55s ease;
}
@keyframes pulseIn{ from{transform:scale(.4); opacity:0;} to{transform:scale(1); opacity:1;} }

/* ---------- GAME ---------- */
#screen-game{ padding-top:2px; }
.hud{ display:flex; justify-content:space-between; align-items:flex-start; margin-bottom:10px; }
.hud .hud-block{ display:flex; flex-direction:column; }
.hud .label{ font-size:10.5px; letter-spacing:1px; color:var(--ink-dim); font-weight:700; }
.hud .value{ font-size:22px; font-weight:900; font-variant-numeric:tabular-nums; }
.hud .value.timer{ color:var(--accent-2); }
.hud .value.timer.low{ color:#ff5470; animation:tickShake .4s infinite; }
@keyframes tickShake{ 0%,100%{transform:translateX(0)} 50%{transform:translateX(1.5px)} }
.hud-center{ text-align:center; }
.rule-banner{ text-align:center; font-size:12.5px; font-weight:700; letter-spacing:1px; color:var(--gold); margin-bottom:8px; min-height:16px; }

.board-wrap{
  position:relative; width:100%;
  background:linear-gradient(180deg, rgba(255,255,255,.05), rgba(255,255,255,.015));
  border:1px solid rgba(255,255,255,.08);
  border-radius:22px; padding:16px; min-height:260px;
  display:flex; align-items:center; justify-content:center;
  box-shadow:inset 0 0 60px rgba(0,0,0,.25);
}
.board{ position:relative; }
.tile{
  position:absolute; top:0; left:0;
  display:flex; align-items:center; justify-content:center;
  border-radius:16px; font-weight:900; color:#fff; cursor:grab; will-change:transform;
  transition:transform .22s cubic-bezier(.2,.8,.3,1.2), box-shadow .15s ease;
  box-shadow:0 6px 0 rgba(0,0,0,.25), 0 10px 18px rgba(0,0,0,.35), inset 0 2px 0 rgba(255,255,255,.35), inset 0 -10px 16px rgba(0,0,0,.15);
  border:1px solid rgba(255,255,255,.18);
}
.tile .num{ position:relative; z-index:2; text-shadow:0 2px 3px rgba(0,0,0,.35); }
.tile.dragging{ cursor:grabbing; z-index:50; box-shadow:0 16px 26px rgba(0,0,0,.5), inset 0 2px 0 rgba(255,255,255,.4); }
.tile.selected{ outline:3px solid #fff; outline-offset:2px; filter:brightness(1.15); }
.tile.correctFlash{ animation:goodPop .35s ease; }
@keyframes goodPop{ 0%{transform-origin:center;} 40%{filter:brightness(1.5);} 100%{filter:brightness(1);} }
.color-swatch{ width:46%; height:46%; border-radius:50%; box-shadow:inset 0 3px 4px rgba(255,255,255,.4), inset 0 -4px 6px rgba(0,0,0,.25); }

.combo-row{ display:flex; justify-content:center; align-items:center; height:30px; margin-top:8px; }
.combo-text{ font-weight:900; font-size:18px; color:var(--gold); text-shadow:0 0 14px rgba(255,207,77,.6); }
.combo-text.pop{ animation:comboPop .4s ease; }
@keyframes comboPop{ 0%{transform:scale(.7); opacity:0;} 50%{transform:scale(1.25);} 100%{transform:scale(1); opacity:1;} }

.float-score{ position:absolute; font-weight:900; color:#33e39a; font-size:16px; pointer-events:none; animation:floatUp .8s ease forwards; }
@keyframes floatUp{ 0%{opacity:1; transform:translateY(0);} 100%{opacity:0; transform:translateY(-34px);} }

.particle{ position:fixed; width:8px;height:8px;border-radius:50%; pointer-events:none; z-index:200; }

/* ---------- RESULT ---------- */
#screen-result{ align-items:center; text-align:center; padding-top:8px; }
.result-title{ font-size:26px; font-weight:900; margin-top:4px; }
.result-score{
  font-size:52px; font-weight:900; margin:6px 0 0;
  background:linear-gradient(135deg,#fff, var(--gold));
  -webkit-background-clip:text; background-clip:text; color:transparent;
}
.best-line{ font-size:13.5px; margin-top:4px; font-weight:700; min-height:18px; }
.best-line.new{ color:var(--gold); }
.best-line.gap{ color:var(--ink-dim); }
.stat-grid{ display:grid; grid-template-columns:repeat(3,1fr); gap:8px; width:100%; margin:16px 0; }
.stat-box{ background:rgba(255,255,255,.05); border:1px solid rgba(255,255,255,.08); border-radius:12px; padding:10px 6px; }
.stat-box .label{ font-size:10px; color:var(--ink-dim); letter-spacing:.5px; font-weight:700; }
.stat-box .val{ font-size:17px; font-weight:900; margin-top:2px; }

.lb-box{ width:100%; background:rgba(255,255,255,.04); border:1px solid rgba(255,255,255,.08); border-radius:14px; padding:10px 6px; margin-top:4px; min-height:60px; }
.lb-title{ font-size:11px; letter-spacing:1px; color:var(--ink-dim); font-weight:800; margin-bottom:6px; }
.lb-row{ display:flex; align-items:center; justify-content:space-between; padding:7px 10px; border-radius:10px; font-size:13.5px; font-weight:700; }
.lb-row.me{ background:rgba(91,107,255,.22); border:1px solid rgba(91,107,255,.4); }
.lb-row .rank{ width:30px; text-align:left; color:var(--ink-dim); }
.lb-row .name{ flex:1; text-align:left; overflow:hidden; text-overflow:ellipsis; white-space:nowrap; }
.lb-row .sc{ font-variant-numeric:tabular-nums; }

.btn-row{ display:flex; gap:10px; width:100%; margin-top:16px; }
.btn{ flex:1; padding:13px 10px; border-radius:14px; border:none; font-weight:800; font-size:14px; cursor:pointer; letter-spacing:.3px; font-family:inherit; }
.btn.primary{ background:linear-gradient(135deg,var(--accent),var(--accent-2)); color:#fff; box-shadow:0 8px 18px rgba(91,107,255,.35); }
.btn.secondary{ background:rgba(255,255,255,.08); color:var(--ink); border:1px solid rgba(255,255,255,.14); }
.btn:active{ transform:scale(.97); }

.toast{
  position:fixed; bottom:22px; left:50%; transform:translateX(-50%);
  background:#111633; border:1px solid rgba(255,255,255,.15); color:#fff;
  padding:10px 18px; border-radius:30px; font-size:13px; font-weight:700;
  opacity:0; transition:opacity .25s ease, transform .25s ease; z-index:500; pointer-events:none;
}
.toast.show{ opacity:1; transform:translateX(-50%) translateY(-6px); }

.ad-slot{
  width:100%; min-height:60px; border:1px dashed rgba(255,255,255,.15); border-radius:12px;
  display:flex; align-items:center; justify-content:center; color:var(--ink-dim); font-size:11px; letter-spacing:1px; margin:14px 0 2px;
}

/* ---------- nickname modal ---------- */
.modal-overlay{
  position:fixed; inset:0; background:rgba(5,7,20,.72); backdrop-filter:blur(3px);
  display:none; align-items:center; justify-content:center; z-index:600; padding:20px;
}
.modal-overlay.show{ display:flex; }
.modal-card{
  width:100%; max-width:340px; background:#131a44; border:1px solid rgba(255,255,255,.12);
  border-radius:18px; padding:20px; text-align:center;
}
.modal-title{ font-weight:900; font-size:14px; letter-spacing:1px; margin-bottom:12px; }
.nickname-input{
  width:100%; padding:12px 14px; border-radius:12px; border:1px solid rgba(255,255,255,.15);
  background:rgba(255,255,255,.06); color:var(--ink); font-size:15px; text-align:center; font-family:inherit;
}
.nickname-input:focus{ outline:2px solid var(--accent-2); }
.nickname-error{ color:#ff5470; font-size:12px; font-weight:700; min-height:16px; margin-top:8px; }

/* ---------- leaderboard modal ---------- */
.lb-modal-card{ max-width:380px; }
.lb-tabs{ display:flex; gap:6px; margin-bottom:12px; background:rgba(255,255,255,.05); border-radius:12px; padding:4px; }
.lb-tab{
  flex:1; padding:9px 6px; border-radius:9px; border:none; background:none; color:var(--ink-dim);
  font-weight:800; font-size:12.5px; cursor:pointer; font-family:inherit;
}
.lb-tab.active{ background:linear-gradient(135deg,var(--accent),var(--accent-2)); color:#fff; }
.lb-modal-box{ text-align:left; max-height:340px; overflow-y:auto; }
.lb-modal-list{ min-height:120px; }
.lb-modal-list .lb-empty, .lb-modal-list .lb-loading{
  padding:24px 10px; color:var(--ink-dim); font-size:12.5px; text-align:center;
}

@media (prefers-reduced-motion: reduce){
  *{ animation-duration:.001s !important; transition-duration:.001s !important; }
}
body.reduced-motion *{ animation:none !important; }

@media (max-width:420px){
  .hero-title{ font-size:34px; }
  .result-score{ font-size:42px; }
}