/*
  Audio/MIDI Web UI — Shared Styles
  Version: 1.0.0
  License: MIT
  Philosophy: timeless, plain, restrained; keyboard-first; no dependencies.
*/

/* =============================
   Design Tokens
   ============================= */
:root {
  /* Color system */
  --bg: #0f1115;            /* dark by default; swapped by media query */
  --panel: #151923;
  --elev: #1b2030;
  --text: #e8eaf0;
  --muted: #a9b0c0;
  --subtle: #6c7280;
  --stroke: #2a3142;
  --accent: #3aa3ff;        /* primary accent */
  --accent-2: #59d38c;      /* secondary accent (meters, success) */
  --danger: #ff5d6e;
  --warn: #ffbf4d;

  /* Shadows & radii */
  --radius: 12px;
  --radius-sm: 8px;
  --shadow-1: 0 1px 0 rgba(0,0,0,.3), 0 6px 20px rgba(0,0,0,.35);
  --shadow-focus: 0 0 0 3px color-mix(in oklab, var(--accent) 35%, transparent);

  /* Typography */
  --font-sans: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, "Noto Sans", "Helvetica Neue", Arial, "Apple Color Emoji", "Segoe UI Emoji";
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --fs-1: clamp(12px, 0.78rem, 14px);
  --fs-2: clamp(13px, 0.86rem, 15px);
  --fs-3: clamp(14px, 0.94rem, 16px);
  --fs-4: clamp(16px, 1.1rem, 18px); /* section titles */
  --fs-5: clamp(18px, 1.25rem, 22px); /* page title */

  /* Spacing scale */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-8: 48px;

  /* Component metrics */
  --field-h: 40px;
  --btn-h: 36px;
  --ring: 2px;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f7f8fa;
    --panel: #ffffff;
    --elev: #f2f4f8;
    --text: #111317;
    --muted: #3b4150;
    --subtle: #707789;
    --stroke: #d9dde7;
    --shadow-1: 0 1px 0 rgba(15,17,21,.04), 0 6px 20px rgba(15,17,21,.06);
    --shadow-focus: 0 0 0 3px color-mix(in oklab, var(--accent) 30%, transparent);
  }
}

/* Explicit theme override via data-theme on <html> */
html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0f1115; --panel: #151923; --elev: #1b2030; --text: #e8eaf0;
  --muted: #a9b0c0; --subtle: #6c7280; --stroke: #2a3142;
  --shadow-1: 0 1px 0 rgba(0,0,0,.3), 0 6px 20px rgba(0,0,0,.35);
  --shadow-focus: 0 0 0 3px color-mix(in oklab, var(--accent) 35%, transparent);
}
html[data-theme="light"] {
  color-scheme: light;
  --bg: #f7f8fa; --panel: #ffffff; --elev: #f2f4f8; --text: #111317;
  --muted: #3b4150; --subtle: #707789; --stroke: #d9dde7;
  --shadow-1: 0 1px 0 rgba(15,17,21,.04), 0 6px 20px rgba(15,17,21,.06);
  --shadow-focus: 0 0 0 3px color-mix(in oklab, var(--accent) 30%, transparent);
}

/* =============================
   Base & Layout
   ============================= */
*, *::before, *::after { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font: 400 var(--fs-3)/1.45 var(--font-sans);
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container { max-width: 1100px; margin: 0 auto; padding: var(--space-6) var(--space-5); }
.page-title { font-size: var(--fs-5); letter-spacing: .2px; margin: 0 0 var(--space-4); }
.section-title { font-size: var(--fs-4); margin: var(--space-6) 0 var(--space-3); }
.subtle { color: var(--subtle); }
.mono { font-family: var(--font-mono); font-size: var(--fs-2); }

.card {
  background: var(--panel);
  border: 1px solid var(--stroke);
  border-radius: var(--radius);
  box-shadow: var(--shadow-1);
}
.card.pad { padding: var(--space-5); }
.hr { height: 1px; background: var(--stroke); border: 0; margin: var(--space-6) 0; }

/* Utility stacks */
.stack { display: grid; gap: var(--space-4); }
.stack-sm { display: grid; gap: var(--space-2); }
.cluster { display: flex; gap: var(--space-2); align-items: center; flex-wrap: wrap; }
.grid { display: grid; gap: var(--space-4); }
.grid.cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid.cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

@media (max-width: 820px) {
  .grid.cols-2, .grid.cols-3 { grid-template-columns: 1fr; }
}

/* =============================
   Interactive Primitives
   ============================= */
:focus-visible { outline: none; box-shadow: var(--shadow-focus); border-radius: calc(var(--radius-sm) - 2px); }

button, .btn {
  --_bg: linear-gradient(180deg, color-mix(in oklab, var(--accent) 88%, transparent), color-mix(in oklab, var(--accent) 72%, transparent));
  --_text: #07121c;
  appearance: none; border: 0; cursor: pointer; user-select: none;
  height: var(--btn-h); padding: 0 var(--space-4);
  border-radius: var(--radius-sm);
  background: var(--_bg); color: var(--_text);
  font-weight: 600; letter-spacing: .2px;
  box-shadow: inset 0 1px 0 rgba(255,255,255,.18), 0 2px 0 rgba(0,0,0,.1), 0 8px 24px rgba(0,0,0,.25);
  transition: transform .06s ease, box-shadow .2s ease, filter .2s ease;
}
button:hover { filter: brightness(1.04); }
button:active { transform: translateY(1px); }

.btn-ghost {
  background: transparent; color: var(--text);
  border: 1px solid var(--stroke);
  box-shadow: none; font-weight: 500;
}
.btn-muted { background: color-mix(in oklab, var(--panel) 70%, var(--bg)); color: var(--text); }
.btn-danger { --_bg: linear-gradient(180deg, color-mix(in oklab, var(--danger) 88%, transparent), color-mix(in oklab, var(--danger) 72%, transparent)); }
.btn-icon { width: var(--btn-h); padding: 0; display: inline-grid; place-items: center; }

.badge { display: inline-block; padding: 2px 8px; border-radius: 999px; background: color-mix(in oklab, var(--accent) 22%, transparent); color: var(--text); font-size: var(--fs-2); border: 1px solid var(--stroke); }

/* Fieldset & labels */
.field { display: grid; gap: 6px; }
label { font-size: var(--fs-2); color: var(--muted); }
.help { font-size: var(--fs-1); color: var(--subtle); }

input[type="text"], input[type="number"], input[type="search"], select, .select, textarea {
  height: var(--field-h); width: 100%;
  background: color-mix(in oklab, var(--panel) 85%, transparent);
  border: 1px solid var(--stroke);
  border-radius: var(--radius-sm);
  color: var(--text);
  padding: 0 var(--space-3);
  box-shadow: inset 0 1px 0 rgba(255,255,255,.04);
}
textarea { min-height: 120px; padding: var(--space-3); resize: vertical; }
select { background-image: none; }

/* Slider */
input[type="range"] { -webkit-appearance: none; width: 100%; height: 22px; background: transparent; }
input[type="range"]::-webkit-slider-runnable-track { height: 6px; background: color-mix(in oklab, var(--panel) 70%, transparent); border-radius: 999px; border: 1px solid var(--stroke); }
input[type="range"]::-moz-range-track { height: 6px; background: color-mix(in oklab, var(--panel) 70%, transparent); border-radius: 999px; border: 1px solid var(--stroke); }
input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; margin-top: -8px; width: 22px; height: 22px; border-radius: 50%; background: var(--accent); box-shadow: 0 1px 0 rgba(255,255,255,.2), 0 8px 20px rgba(0,0,0,.4); border: 1px solid color-mix(in oklab, var(--accent) 28%, black); }
input[type="range"]::-moz-range-thumb { width: 22px; height: 22px; border-radius: 50%; background: var(--accent); border: 1px solid color-mix(in oklab, var(--accent) 28%, black); box-shadow: 0 1px 0 rgba(255,255,255,.2), 0 8px 20px rgba(0,0,0,.4); }

/* Switch */
.switch { --w: 46px; --h: 26px; position: relative; width: var(--w); height: var(--h); }
.switch input { position: absolute; inset: 0; opacity: 0; }
.switch .track { position: absolute; inset: 0; border-radius: 999px; background: color-mix(in oklab, var(--panel) 70%, transparent); border: 1px solid var(--stroke); box-shadow: inset 0 1px 0 rgba(255,255,255,.04); transition: background .2s ease; }
.switch .thumb { position: absolute; top: 2px; left: 2px; width: 22px; height: 22px; border-radius: 999px; background: #fff; transition: transform .2s ease; box-shadow: 0 2px 10px rgba(0,0,0,.3); }
.switch input:checked + .track { background: color-mix(in oklab, var(--accent) 22%, transparent); }
.switch input:checked + .track .thumb { transform: translateX(20px); }

/* Tabs */
.tabs { display: flex; gap: 2px; padding: 2px; background: color-mix(in oklab, var(--panel) 85%, transparent); border: 1px solid var(--stroke); border-radius: var(--radius-sm); }
.tabs button { flex: 1; background: transparent; color: var(--muted); border-radius: 8px; box-shadow: none; height: 34px; font-weight: 600; }
.tabs button[aria-selected="true"] { background: var(--panel); color: var(--text); box-shadow: inset 0 1px 0 rgba(255,255,255,.04); border: 1px solid var(--stroke); }

/* Toolbar */
.toolbar { display: flex; gap: var(--space-2); align-items: center; padding: var(--space-2); background: var(--panel); border: 1px solid var(--stroke); border-radius: var(--radius-sm); }
.toolbar .spacer { flex: 1; }

/* Table */
.table { width: 100%; border-collapse: collapse; font-size: var(--fs-2); }
.table th, .table td { padding: 10px 12px; border-bottom: 1px solid var(--stroke); text-align: left; }
.table th { color: var(--muted); font-weight: 600; }
.table tr:hover { background: color-mix(in oklab, var(--panel) 82%, transparent); }

/* Progress / Meters */
progress { width: 100%; height: 10px; appearance: none; }
progress::-webkit-progress-bar { background: color-mix(in oklab, var(--panel) 75%, transparent); border-radius: 999px; border: 1px solid var(--stroke); }
progress::-webkit-progress-value { background: linear-gradient(90deg, var(--accent-2), color-mix(in oklab, var(--accent) 65%, var(--accent-2))); border-radius: 999px; }
progress::-moz-progress-bar { background: linear-gradient(90deg, var(--accent-2), color-mix(in oklab, var(--accent) 65%, var(--accent-2))); border-radius: 999px; }

.meter { height: 10px; display: grid; grid-template-columns: repeat(20, 1fr); gap: 2px; }
.meter span { display: block; height: 100%; background: color-mix(in oklab, var(--panel) 70%, transparent); border-radius: 2px; }
.meter span.on { background: linear-gradient(180deg, var(--accent-2), color-mix(in oklab, var(--accent-2) 65%, black)); }

/* Pads (MPC-style) */
.pad-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(64px, 1fr)); gap: var(--space-3); width: 100%; }
.pad-btn { aspect-ratio: 1 / 1; display: grid; place-items: center; border-radius: 16px; background: linear-gradient(180deg, color-mix(in oklab, var(--panel) 88%, transparent), color-mix(in oklab, var(--panel) 65%, transparent)); border: 1px solid var(--stroke); box-shadow: var(--shadow-1); font-weight: 700; color: var(--muted); }
.pad-btn[data-active="true"], .pad-btn:active { background: linear-gradient(180deg, color-mix(in oklab, var(--accent) 30%, var(--panel)), color-mix(in oklab, var(--accent) 18%, var(--panel))); color: #0e1722; }

/* Code */
code, pre { font-family: var(--font-mono); font-size: var(--fs-2); }
pre { background: var(--elev); border: 1px solid var(--stroke); border-radius: var(--radius); padding: var(--space-4); overflow: auto; }

/* Helpers */
.sr-only { position: absolute !important; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); border: 0; }
.mute { color: var(--muted); }

/* Footer */
footer { margin-top: var(--space-8); color: var(--subtle); font-size: var(--fs-2); }
