:root{
  --bg:#070912; --bg2:#0c1023;
  --panel:rgba(20,24,46,.62); --panel-border:rgba(140,160,255,.14);
  --txt:#eaf0ff; --muted:#9aa6cf; --faint:#67719c;
  --c1:#7af0ff; --c2:#b388ff; --c3:#ff7ad0; --c4:#7affc0;
  --accent:linear-gradient(120deg,#7af0ff,#b388ff 55%,#ff7ad0);
  --radius:20px; --shadow:0 18px 50px rgba(0,0,0,.45);
}
*{box-sizing:border-box;margin:0;padding:0}
html,body{height:100%}
body{
  font-family:"Noto Sans SC","Space Grotesk",system-ui,sans-serif;
  background:radial-gradient(1200px 800px at 80% -10%,#1a1d3e 0%,transparent 55%),
             radial-gradient(900px 700px at -5% 100%,#172b3a 0%,transparent 50%),
             var(--bg);
  color:var(--txt); min-height:100vh; overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}

/* floating background orbs */
.bg-orbs{position:fixed;inset:0;z-index:0;pointer-events:none;filter:blur(60px);opacity:.5}
.bg-orbs span{position:absolute;border-radius:50%;mix-blend-mode:screen;animation:float 18s ease-in-out infinite}
.bg-orbs span:nth-child(1){width:380px;height:380px;background:#3a6cff;top:-80px;left:10%}
.bg-orbs span:nth-child(2){width:320px;height:320px;background:#b341ff;bottom:-60px;right:12%;animation-delay:-6s}
.bg-orbs span:nth-child(3){width:280px;height:280px;background:#19c6c0;top:40%;left:46%;animation-delay:-11s}
@keyframes float{0%,100%{transform:translate(0,0) scale(1)}33%{transform:translate(40px,-30px) scale(1.1)}66%{transform:translate(-30px,25px) scale(.95)}}

/* topbar */
.topbar{position:relative;z-index:2;display:flex;align-items:center;justify-content:space-between;
  padding:22px clamp(18px,4vw,46px);}
.brand{display:flex;align-items:center;gap:16px}
.brand-mark{display:grid;place-items:center;width:54px;height:54px;border-radius:16px;
  background:rgba(255,255,255,.04);border:1px solid var(--panel-border);
  box-shadow:0 0 30px rgba(122,240,255,.25)}
.brand-text h1{font-size:22px;font-weight:900;letter-spacing:.5px;
  background:var(--accent);-webkit-background-clip:text;background-clip:text;color:transparent}
.brand-text p{font-size:12.5px;color:var(--muted);margin-top:3px}
.brand-badge{font-size:12px;color:var(--c1);border:1px solid rgba(122,240,255,.3);
  padding:7px 14px;border-radius:999px;background:rgba(122,240,255,.06)}
.topbar-right{display:flex;align-items:center;gap:12px}
.key-status{font-size:12px;color:var(--muted);white-space:nowrap}
.cost-chip{font-size:12px;color:var(--c4);white-space:nowrap;padding:7px 13px;border-radius:999px;
  border:1px solid rgba(122,255,192,.3);background:rgba(122,255,192,.07)}
.field-note{font-size:11px;color:var(--faint);margin-top:7px;line-height:1.5}
.key-status.ok{color:var(--c4)} .key-status.no{color:#ff9a9a}
.settings-btn{font-family:inherit;font-size:12.5px;color:#cfd8ff;cursor:pointer;
  padding:8px 14px;border-radius:999px;border:1px solid var(--panel-border);
  background:rgba(255,255,255,.04);transition:.2s}
.settings-btn:hover{border-color:var(--c2);color:#fff}

/* text inputs */
.text-input{width:100%;padding:11px 13px;border-radius:11px;font-family:inherit;font-size:13px;
  color:var(--txt);background:rgba(255,255,255,.04);border:1px solid var(--panel-border);outline:none;transition:.2s}
.text-input::placeholder{color:var(--faint)}
.text-input:focus{border-color:var(--c2);background:rgba(255,255,255,.07)}

/* modal */
.modal-mask{position:fixed;inset:0;z-index:50;background:rgba(5,7,15,.72);backdrop-filter:blur(6px);
  display:flex;align-items:center;justify-content:center;padding:20px;animation:fade .2s ease}
.modal{width:min(480px,100%);background:var(--bg2);border:1px solid var(--panel-border);
  border-radius:18px;padding:26px;box-shadow:var(--shadow)}
.modal h3{font-size:17px;margin-bottom:10px}
.modal-desc{font-size:12.5px;color:var(--muted);line-height:1.7;margin-bottom:16px}
.modal-desc a{color:var(--c1)} .modal-desc code{color:var(--c2);font-size:11.5px}
.modal input{width:100%;padding:12px 14px;border-radius:11px;font-family:inherit;font-size:13.5px;
  color:var(--txt);background:rgba(255,255,255,.05);border:1px solid var(--panel-border);outline:none}
.modal input:focus{border-color:var(--c2)}
.modal-actions{display:flex;justify-content:flex-end;gap:10px;margin-top:16px}
.btn-ghost,.btn-primary{font-family:inherit;font-size:13.5px;padding:10px 18px;border-radius:11px;cursor:pointer;border:none}
.btn-ghost{background:rgba(255,255,255,.06);color:var(--muted)}
.btn-primary{background:var(--accent);color:#0a0c1a;font-weight:700}
.modal-status{font-size:12px;color:var(--c4);margin-top:10px;min-height:16px}

/* layout */
.layout{position:relative;z-index:1;display:grid;grid-template-columns:340px 1fr;
  gap:22px;padding:0 clamp(18px,4vw,46px) 30px;max-width:1480px;margin:0 auto;align-items:start}
.panel{background:var(--panel);backdrop-filter:blur(18px);-webkit-backdrop-filter:blur(18px);
  border:1px solid var(--panel-border);border-radius:var(--radius);box-shadow:var(--shadow)}
.panel-title{font-size:15px;font-weight:700;padding:18px 20px 4px;letter-spacing:.4px}

/* controls */
.controls{padding-bottom:20px;position:sticky;top:18px}
.field{padding:14px 20px}
.field>label{display:flex;align-items:center;gap:8px;font-size:13.5px;font-weight:500;margin-bottom:10px;color:#cfd8ff}
.field .hint{font-size:11px;color:var(--faint);font-weight:400}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{font-size:12.5px;padding:8px 13px;border-radius:11px;cursor:pointer;
  background:rgba(255,255,255,.035);border:1px solid var(--panel-border);color:var(--muted);
  transition:.18s ease;user-select:none;white-space:nowrap}
.chip:hover{border-color:rgba(140,160,255,.4);color:#fff;transform:translateY(-1px)}
.chip.active{background:linear-gradient(120deg,rgba(122,240,255,.22),rgba(179,136,255,.22));
  border-color:rgba(179,136,255,.6);color:#fff;box-shadow:0 0 18px rgba(140,160,255,.25)}

input[type=range]{-webkit-appearance:none;width:100%;height:6px;border-radius:6px;
  background:linear-gradient(90deg,var(--c1),var(--c2));outline:none;cursor:pointer}
input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;width:18px;height:18px;border-radius:50%;
  background:#fff;box-shadow:0 0 0 4px rgba(179,136,255,.35);cursor:pointer}

.toggle-field{display:flex;align-items:center;justify-content:space-between}
.toggle{width:50px;height:28px;border-radius:999px;border:1px solid var(--panel-border);
  background:rgba(255,255,255,.06);position:relative;cursor:pointer;transition:.2s}
.toggle span{position:absolute;top:3px;left:3px;width:20px;height:20px;border-radius:50%;
  background:#cfd8ff;transition:.2s}
.toggle[aria-checked=true]{background:linear-gradient(120deg,var(--c1),var(--c2));border-color:transparent}
.toggle[aria-checked=true] span{left:25px;background:#fff}

.generate-btn{position:relative;margin:14px 20px 4px;width:calc(100% - 40px);padding:15px;border:none;
  border-radius:14px;font-size:15px;font-weight:700;color:#0a0c1a;cursor:pointer;
  background:var(--accent);background-size:200% 100%;box-shadow:0 10px 30px rgba(140,160,255,.35);
  transition:.25s;display:flex;align-items:center;justify-content:center;gap:10px}
.generate-btn:hover{background-position:100% 0;transform:translateY(-2px)}
.generate-btn:disabled{opacity:.7;cursor:wait;transform:none}
.gen-spinner{width:18px;height:18px;border:3px solid rgba(10,12,26,.3);border-top-color:#0a0c1a;
  border-radius:50%;animation:spin .8s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}
.gen-status{padding:6px 20px 0;font-size:12px;color:var(--muted);min-height:16px;text-align:center}

/* stage */
.stage{display:flex;flex-direction:column;gap:22px}
.visual-card{position:relative;height:clamp(340px,42vh,460px);overflow:hidden;padding:0}
#viz{width:100%;height:100%;display:block}
.viz-empty{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;
  justify-content:center;gap:24px;color:var(--muted);text-align:center;font-size:14px;line-height:1.7}
.viz-empty b{color:#fff}
.pulse-ring{width:90px;height:90px;border-radius:50%;border:2px solid var(--c2);
  box-shadow:0 0 40px rgba(179,136,255,.4);animation:pring 2.4s ease-out infinite}
@keyframes pring{0%{transform:scale(.7);opacity:1}100%{transform:scale(1.5);opacity:0}}

/* transport */
.transport{position:absolute;left:0;right:0;bottom:0;display:flex;align-items:center;gap:16px;
  padding:16px 22px;background:linear-gradient(to top,rgba(7,9,18,.85),transparent)}
.play-btn{width:50px;height:50px;border-radius:50%;border:none;cursor:pointer;flex:none;
  background:var(--accent);color:#0a0c1a;display:grid;place-items:center;
  box-shadow:0 6px 22px rgba(140,160,255,.5);transition:.2s}
.play-btn:hover{transform:scale(1.07)}
.play-btn svg{fill:#0a0c1a}
.timeline{flex:1}
.tl-track{position:relative;height:8px;border-radius:8px;background:rgba(255,255,255,.12);cursor:pointer;overflow:visible}
.tl-fill{position:absolute;left:0;top:0;bottom:0;width:0;border-radius:8px;background:linear-gradient(90deg,var(--c1),var(--c2))}
.tl-markers{position:absolute;inset:0}
.tl-mark{position:absolute;top:-3px;height:14px;width:2px;background:rgba(255,255,255,.45);border-radius:2px}
.tl-mark span{position:absolute;top:-20px;left:50%;transform:translateX(-50%);font-size:9.5px;
  color:var(--faint);white-space:nowrap;pointer-events:none}
.tl-time{display:flex;justify-content:space-between;margin-top:7px;font-size:11px;color:var(--muted);font-variant-numeric:tabular-nums}
.download-btn{width:42px;height:42px;border-radius:12px;flex:none;display:grid;place-items:center;
  text-decoration:none;color:var(--c1);font-size:20px;border:1px solid var(--panel-border);
  background:rgba(255,255,255,.04);transition:.2s}
.download-btn:hover{color:#fff;border-color:var(--c1);background:rgba(122,240,255,.1)}

/* song info */
.song-info{padding:20px 22px}
.si-head{display:flex;justify-content:space-between;align-items:flex-start;gap:14px;margin-bottom:16px}
.si-head h2{font-size:20px;font-weight:700}
.si-head #song-sub{font-size:13px;color:var(--muted);margin-top:5px}
.si-seed{font-size:10.5px;color:var(--faint);text-align:right;letter-spacing:1px}
.si-seed b{display:block;color:var(--c1);font-size:15px;letter-spacing:.5px}
.stat-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(120px,1fr));gap:12px}
.stat{background:rgba(255,255,255,.035);border:1px solid var(--panel-border);border-radius:13px;padding:13px 15px}
.stat .k{font-size:11px;color:var(--faint);margin-bottom:5px}
.stat .v{font-size:15px;font-weight:600;color:#fff}
.stat .v small{font-size:11px;color:var(--muted);font-weight:400}

/* tabs */
.tabs-card{padding:0;overflow:hidden}
.tabs{display:flex;gap:4px;padding:8px;background:rgba(255,255,255,.02);border-bottom:1px solid var(--panel-border)}
.tab{flex:1;padding:12px;border:none;background:transparent;color:var(--muted);font-size:13.5px;
  font-weight:500;cursor:pointer;border-radius:11px;transition:.18s;font-family:inherit}
.tab:hover{color:#fff}
.tab.active{background:linear-gradient(120deg,rgba(122,240,255,.16),rgba(179,136,255,.16));color:#fff}
.tab-body{padding:22px}
.tab-pane{display:none;animation:fade .3s ease}
.tab-pane.active{display:block}
@keyframes fade{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}

.overview-box{background:rgba(122,240,255,.06);border:1px solid rgba(122,240,255,.18);
  border-radius:14px;padding:16px 18px;font-size:14px;line-height:1.85;color:#dbe4ff;margin-bottom:18px}
.an-block{margin-bottom:16px}
.an-block h4{font-size:13.5px;color:var(--c1);margin-bottom:6px;display:flex;align-items:center;gap:7px}
.an-block h4::before{content:"";width:6px;height:6px;border-radius:50%;background:var(--c2)}
.an-block p{font-size:13.5px;line-height:1.8;color:#c4cdf0}

.steps{list-style:none;counter-reset:s;margin-top:18px}
.steps li{counter-increment:s;position:relative;padding:11px 0 11px 42px;font-size:13.5px;
  line-height:1.7;color:#c4cdf0;border-top:1px dashed rgba(140,160,255,.14)}
.steps li::before{content:counter(s);position:absolute;left:0;top:9px;width:26px;height:26px;
  border-radius:8px;display:grid;place-items:center;font-size:12px;font-weight:700;color:#0a0c1a;
  background:linear-gradient(120deg,var(--c1),var(--c2))}

/* structure timeline */
.struct-bar{display:flex;height:64px;border-radius:13px;overflow:hidden;border:1px solid var(--panel-border);margin-bottom:18px}
.struct-seg{display:flex;flex-direction:column;justify-content:center;align-items:center;gap:3px;
  color:#fff;font-size:12px;font-weight:600;position:relative;transition:.2s;min-width:34px;padding:0 4px;text-align:center}
.struct-seg small{font-size:9.5px;opacity:.85;font-weight:400}
.struct-list .sl-row{display:flex;gap:14px;padding:12px 0;border-top:1px dashed rgba(140,160,255,.14);font-size:13px;align-items:baseline}
.struct-list .sl-name{font-weight:600;color:#fff;min-width:64px}
.struct-list .sl-time{color:var(--c1);font-variant-numeric:tabular-nums;min-width:90px;font-size:12px}
.struct-list .sl-tip{color:#b9c2e8;line-height:1.6}

/* lyrics */
.lyrics-wrap h3{font-size:17px;margin-bottom:4px}
.lyrics-wrap .ly-lang{font-size:12px;color:var(--faint);margin-bottom:18px}
.ly-sec{margin-bottom:18px}
.ly-sec .ly-tag{display:inline-block;font-size:11px;color:var(--c2);border:1px solid rgba(179,136,255,.3);
  padding:3px 10px;border-radius:999px;margin-bottom:9px}
.ly-sec p{font-size:14.5px;line-height:2;color:#dbe4ff}

.foot{position:relative;z-index:1;text-align:center;color:var(--faint);font-size:12px;padding:20px}

/* responsive */
@media(max-width:900px){
  .layout{grid-template-columns:1fr}
  .controls{position:static}
  .brand-badge{display:none}
}
.chip,.tab,.toggle,.play-btn,.generate-btn{ -webkit-tap-highlight-color:transparent }