:root{
  --paper:#FBFBF9; --ink:#14161A; --muted:#6B7079; --line:#E7E7E2;
  --primary:#2D5BFF; --primary-press:#1E45D6; --accent2:#7C5CFF;
  --ok:#157F4E; --err:#C23B2B;
  --radius:16px; --maxw:720px;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0; color:var(--ink);
  background:
    radial-gradient(900px 520px at 50% -180px, #E7ECFF 0%, rgba(231,236,255,0) 70%),
    var(--paper);
  font-family:ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  font-size:15px; line-height:1.6; -webkit-font-smoothing:antialiased;
}
.wrap{max-width:var(--maxw); margin:0 auto; padding:28px 20px 72px}
a{color:var(--primary); text-decoration:none}
a:hover{text-decoration:underline}

/* top bar */
.topbar{display:flex; align-items:center; justify-content:space-between; gap:12px; margin-bottom:26px}
.brand{font-weight:700; letter-spacing:-.01em; font-size:16px;
  background:linear-gradient(90deg,#2D5BFF,#7C5CFF); -webkit-background-clip:text; background-clip:text; color:transparent}
.topbar .tag{font-size:11.5px; color:#3B5BFF; background:#EEF1FF; border:1px solid #DDE3FF; padding:4px 11px; border-radius:999px; white-space:nowrap}

h1{font-size:22px; line-height:1.25; letter-spacing:-.02em; margin:0 0 4px; font-weight:650}
.sub{color:var(--muted); font-size:14px; margin:0 0 22px}

/* drop zone (first screen hero = the tool) */
.drop{
  border:1.5px dashed #C3CCFF; border-radius:var(--radius);
  background:linear-gradient(180deg,#F3F6FF 0%,#FBFBFF 100%);
  padding:42px 24px; text-align:center; cursor:pointer;
  box-shadow:0 14px 34px -22px rgba(59,91,255,.55);
  transition:border-color .15s ease, background .15s ease, box-shadow .15s ease; outline:none;
}
.drop:hover{border-color:#9DB0FF; background:linear-gradient(180deg,#ECF1FF 0%,#F8FAFF 100%); box-shadow:0 18px 40px -22px rgba(59,91,255,.65)}
.drop:focus-visible{border-color:var(--primary); box-shadow:0 0 0 4px rgba(45,91,255,.16)}
.drop.drag{border-color:var(--primary); background:#E7EDFF}
.drop .ic{width:56px; height:56px; padding:13px; box-sizing:border-box; color:#fff;
  background:linear-gradient(135deg,#3B5BFF,#7C5CFF); border-radius:16px;
  box-shadow:0 10px 22px -10px rgba(59,91,255,.75);
  margin:0 auto 14px; display:block}
.drop .big{font-weight:600; font-size:16px}
.drop .small{color:var(--muted); font-size:13px; margin-top:6px}
.drop .fmt{color:#5A6280; font-size:12px; margin-top:14px; letter-spacing:.01em}

/* file card */
.filecard{display:none; margin-top:16px; border:1px solid #DDE3FF; border-radius:12px; background:#fff; padding:14px 16px; box-shadow:0 10px 26px -22px rgba(59,91,255,.5)}
.filecard.show{display:block}
.filecard .row{display:flex; align-items:center; gap:12px}
.filecard .nm{font-weight:600; font-size:14px; overflow:hidden; text-overflow:ellipsis; white-space:nowrap}
.filecard .sz{color:var(--muted); font-size:12px; margin-left:auto; white-space:nowrap}
.filecard .meta{color:var(--muted); font-size:12px; margin-top:2px}
canvas.wave{display:block; width:100%; height:56px; margin-top:12px; background:#F4F6FF; border-radius:8px}
.actions{display:flex; gap:10px; margin-top:14px; flex-wrap:wrap}

/* buttons */
.btn{
  appearance:none; border:1px solid transparent; border-radius:10px;
  font:inherit; font-weight:600; font-size:14px; padding:11px 18px; cursor:pointer;
  transition:background .15s ease, border-color .15s ease, transform .05s ease, filter .15s ease;
}
.btn:active{transform:translateY(1px)}
.btn-primary{background:linear-gradient(135deg,#3B5BFF,#6D5CFF); color:#fff; box-shadow:0 8px 20px -10px rgba(59,91,255,.8)}
.btn-primary:hover{filter:brightness(1.06)}
.btn-ghost{background:#fff; border-color:#DDE3FF; color:var(--ink)}
.btn-ghost:hover{border-color:#B9C4FF}
.btn[disabled]{opacity:.5; cursor:not-allowed}
.btn:focus-visible{outline:none; box-shadow:0 0 0 4px rgba(45,91,255,.18)}

/* status */
.status{display:none; margin-top:16px; align-items:center; gap:10px; color:var(--muted); font-size:13px}
.status.show{display:flex}
.spinner{width:16px; height:16px; border:2px solid #DDE3FF; border-top-color:var(--primary); border-radius:50%; animation:spin .7s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}

.err{display:none; margin-top:16px; border:1px solid #f0cfc9; background:#fdf3f1; color:var(--err); border-radius:12px; padding:12px 14px; font-size:13px}
.err.show{display:block}

/* results */
.results{display:none; margin-top:24px; border-top:1px solid #E4E8FF; padding-top:22px}
.results.show{display:block}
.res-head{display:flex; align-items:center; gap:12px; flex-wrap:wrap}
.res-head h2{font-size:15px; margin:0; font-weight:650; letter-spacing:.02em; text-transform:uppercase; color:var(--muted)}
.stats{display:grid; grid-template-columns:repeat(4,1fr); gap:10px; margin:16px 0}
.stat{border:1px solid #E4E8FF; border-radius:12px; padding:12px 14px; background:linear-gradient(180deg,#FBFBFF,#fff)}
.stat .k{font-size:11px; text-transform:uppercase; letter-spacing:.04em; color:var(--muted)}
.stat .v{font-size:18px; font-weight:700; margin-top:3px; font-variant-numeric:tabular-nums}
.stat:nth-child(1) .v{color:#2D5BFF}
.stat:nth-child(3) .v{color:#7C5CFF}
.stat .c{font-size:11px; color:var(--muted); margin-top:2px}
.mode{color:var(--muted); font-size:12px; margin:-4px 0 12px}

.roll{position:relative; width:100%; height:84px; border:1px solid #E4E8FF; border-radius:12px; overflow:hidden; margin:4px 0 18px;
  background:#fff;
  background-image:repeating-linear-gradient(to bottom, transparent 0, transparent 20px, #EEF1FF 20px, #EEF1FF 21px)}
.roll .note{position:absolute; background:linear-gradient(135deg,#3B5BFF,#7C5CFF); opacity:.9; border-radius:2px; min-width:2px}
.roll .axis{position:absolute; left:8px; top:6px; font-size:10px; color:var(--muted); font-variant-numeric:tabular-nums}

.notes-wrap{max-height:300px; overflow:auto; border:1px solid #E4E8FF; border-radius:12px}
table.notes{width:100%; border-collapse:collapse; font-size:13px; font-variant-numeric:tabular-nums}
table.notes th, table.notes td{text-align:left; padding:9px 14px; border-bottom:1px solid #EEF1FF}
table.notes th{position:sticky; top:0; background:#F5F7FF; color:#5A6280; font-weight:600; font-size:11px; text-transform:uppercase; letter-spacing:.03em}
table.notes tr:last-child td{border-bottom:none}
table.notes td.n{color:var(--muted); width:34px}
table.notes td.pitch{font-weight:700; color:#2D5BFF}

/* body sections */
section.info{margin-top:40px}
section.info h2{font-size:15px; letter-spacing:.02em; text-transform:uppercase; color:var(--muted); margin:0 0 12px; font-weight:650}
section.info h2::before{content:""; display:inline-block; width:7px; height:7px; border-radius:2px; margin-right:9px; vertical-align:1px;
  background:linear-gradient(135deg,#3B5BFF,#7C5CFF)}
section.info p, section.info li{color:#2b2e34}
.fmt-list{display:flex; flex-wrap:wrap; gap:8px; margin:0 0 12px; padding:0; list-style:none}
.fmt-list li{border:1px solid #DDE3FF; border-radius:999px; padding:5px 12px; font-size:13px; background:#F7F9FF; color:#3B3F55; font-variant-numeric:tabular-nums}
.note-inline{color:var(--muted); font-size:13px; margin-top:8px}
details{border:1px solid #E4E8FF; border-radius:12px; background:#fff; padding:0 16px; margin-bottom:10px}
details summary{cursor:pointer; padding:14px 0; font-weight:600; font-size:14px; list-style:none}
details summary::-webkit-details-marker{display:none}
details summary::before{content:"+"; color:var(--accent2); font-weight:700; margin-right:10px}
details[open] summary::before{content:"–"}
details .body{padding:0 0 14px; color:#2b2e34; font-size:14px}

footer{margin-top:48px; padding-top:18px; border-top:1px solid #E4E8FF; color:var(--muted); font-size:12px; display:flex; justify-content:space-between; gap:12px; flex-wrap:wrap}

.toast{position:fixed; left:50%; bottom:24px; transform:translateX(-50%) translateY(20px); background:#1A1C2B; color:#fff; padding:10px 16px; border-radius:10px; font-size:13px; opacity:0; pointer-events:none; transition:opacity .2s ease, transform .2s ease; z-index:50}
.toast.show{opacity:1; transform:translateX(-50%) translateY(0)}

@media (max-width:560px){
  .wrap{padding:20px 16px 56px}
  .drop{padding:34px 16px}
  .stats{grid-template-columns:repeat(2,1fr)}
  .actions .btn{flex:1 1 auto; text-align:center}
  .res-head .btn{width:100%; order:3}
  .res-head h2{width:100%; order:1}
}
@media (prefers-reduced-motion:reduce){
  *{animation:none !important; transition:none !important}
}