:root {
  --bg: #fbfbfa;
  --panel: #ffffff;
  --panel-2: #f4f4f2;
  --line: #e4e3df;
  --line-strong: #d3d2cc;
  --ink: #1c1c1a;
  --ink-dim: #6b6b64;
  --ink-faint: #9d9c95;
  --accent: #6366F1;
  --accent-ink: #fff;
  --accent-soft: #eef2ff;
  --teal: #0ea88e;
  --teal-soft: #e3f7f2;
  --red: #d64545;
  --radius: 12px;
  --disp: 'Space Grotesk', sans-serif;
  --body: 'IBM Plex Sans', sans-serif;
  --mono: 'IBM Plex Mono', monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { background: var(--bg); color: var(--ink); font-family: var(--body); }
::selection { background: var(--accent-soft); color: var(--accent); }

.notch-wrap { max-width: 960px; margin: 0 auto; }

.top-actions { display: flex; justify-content: flex-end; margin-bottom: -6px; }

/* ── cards ── */
.card {
  background: var(--panel); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 22px 24px;
  margin-bottom: 18px; box-shadow: 0 1px 2px rgba(20,20,15,.03);
  display: none;
}
.card.visible { display: block; }
.card h2 { font-family: var(--disp); font-size: 15px; font-weight: 600; margin-bottom: 16px; }

/* ── meta grid ── */
.meta-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 12px 20px; }
@media (max-width: 560px) { .meta-grid { grid-template-columns: repeat(2,1fr); } }
.meta-item .label {
  font-family: var(--mono); font-size: 10px; letter-spacing: 1px;
  text-transform: uppercase; color: var(--ink-faint); margin-bottom: 3px;
}
.meta-item .value {
  font-family: var(--mono); font-size: 13px; font-weight: 600; color: var(--ink);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}

/* ── waveform ── */
.wave-box { border: 1px solid var(--line); border-radius: 9px; background: var(--panel-2); margin-top: 14px; overflow: hidden; }
.wave-canvas { display: block; width: 100%; }

/* ── freq response ── */
.freq-box {
  border: 1px solid var(--line); border-radius: 9px;
  background: var(--panel-2); overflow: hidden;
}
.freq-canvas { display: block; width: 100%; height: 130px; }

/* ── section ── */
.section-block { margin-bottom: 20px; }
.section-eyebrow {
  font-family: var(--mono); font-size: 10.5px; letter-spacing: 1px;
  text-transform: uppercase; color: var(--ink-faint); margin-bottom: 10px; display: block;
}

/* ── preset grid ── */
.preset-grid {
  display: grid; grid-template-columns: repeat(5,1fr); gap: 8px;
}
@media (max-width: 640px) { .preset-grid { grid-template-columns: repeat(3,1fr); } }
@media (max-width: 380px) { .preset-grid { grid-template-columns: repeat(2,1fr); } }

.preset-card {
  padding: 12px 8px; border: 1px solid var(--line-strong);
  border-radius: 10px; cursor: pointer; text-align: center;
  background: var(--panel); transition: all .13s ease;
  display: flex; flex-direction: column; align-items: center; gap: 4px;
}
.preset-card:hover { border-color: var(--accent); background: var(--accent-soft); }
.preset-card.active { border-color: var(--accent); background: var(--accent-soft); }
.preset-icon { font-size: 20px; line-height: 1; }
.preset-name {
  font-family: var(--mono); font-size: 11px; font-weight: 700;
  color: var(--ink); line-height: 1.2;
}
.preset-card.active .preset-name { color: var(--accent); }
.preset-sub { font-family: var(--mono); font-size: 9.5px; color: var(--ink-faint); }

/* ── controls ── */
.controls-grid {
  display: grid; grid-template-columns: repeat(3,1fr); gap: 20px; margin-bottom: 20px;
}
@media (max-width: 640px) { .controls-grid { grid-template-columns: 1fr; } }

.ctrl-label {
  display: flex; justify-content: space-between; align-items: baseline;
  font-family: var(--mono); font-size: 10.5px; letter-spacing: .5px;
  text-transform: uppercase; color: var(--ink-faint); margin-bottom: 8px;
}
.ctrl-val { color: var(--accent); font-size: 12px; font-weight: 700; letter-spacing: 0; text-transform: none; }
.ctrl-hints {
  display: flex; justify-content: space-between;
  font-family: var(--mono); font-size: 9.5px; color: var(--ink-faint);
  margin-top: 4px; padding: 0 2px;
}

input[type=range] {
  -webkit-appearance: none; width: 100%; height: 4px;
  border-radius: 2px; background: var(--line-strong); outline: none;
}
input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none; width: 14px; height: 14px; border-radius: 50%;
  background: var(--accent); cursor: pointer;
  border: 2px solid #fff; box-shadow: 0 0 0 1px var(--accent);
}
input[type=range]::-moz-range-thumb {
  width: 14px; height: 14px; border-radius: 50%;
  background: var(--accent); cursor: pointer; border: 2px solid #fff;
}

/* ── export ── */
.export-row { display: flex; gap: 12px; align-items: flex-end; margin-bottom: 12px; }
.fmt-ctrl { flex: 1; margin-bottom: 0; }
.out-select {
  font-family: var(--mono); font-size: 13px; padding: 9px 12px;
  border: 1px solid var(--line-strong); border-radius: 8px;
  background: var(--panel); color: var(--ink); width: 100%; cursor: pointer; outline: none;
}
.out-select:focus { border-color: var(--accent); }

/* ── buttons ── */
.btn {
  font-family: var(--mono); font-size: 12.5px; font-weight: 700;
  letter-spacing: .4px; padding: 13px 22px; border-radius: 8px;
  border: none; background: var(--accent); color: var(--accent-ink);
  cursor: pointer; display: flex; align-items: center;
  justify-content: center; gap: 8px; white-space: nowrap;
}
.btn:hover { filter: brightness(1.08); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn.ghost {
  background: transparent; color: var(--ink-dim);
  border: 1px solid var(--line-strong); width: auto;
}
.btn.ghost:hover { border-color: var(--red); color: var(--red); }
.btn.download { background: var(--teal); }

/* ── progress ── */
.bar { height: 4px; background: var(--line); border-radius: 2px; margin-top: 12px; overflow: hidden; display: none; }
.bar.show { display: block; }
.bar > i { display: block; height: 100%; width: 0%; background: linear-gradient(90deg, var(--teal), var(--accent)); transition: width .2s ease; }
.status-line { display: none; margin-top: 8px; font-family: var(--mono); font-size: 11.5px; color: var(--ink-faint); }
.status-line.show { display: block; }

/* ── info box ── */
.info-box { font-size: 12.5px; line-height: 1.55; padding: 14px 16px; border-radius: 9px; background: var(--accent-soft); color: #1e1b4b; }

/* ── result header ── */
.result-header { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; margin-bottom: 12px; }
.status-pill { display: flex; align-items: center; gap: 7px; font-family: var(--mono); font-size: 11px; font-weight: 600; color: var(--teal); text-transform: uppercase; }
.status-pill .pip { width: 7px; height: 7px; border-radius: 50%; background: var(--teal); }