style.css

/* ─── Design tokens ─────────────────────────────────────────────────────── */

:root {
  color-scheme: light dark;
  --radius: 8px;
  --radius-sm: 4px;
  --font-sans: system-ui, -apple-system, sans-serif;
  --font-mono: ui-monospace, "Cascadia Code", "Fira Code", monospace;
  --shadow: 0 0 3px color-mix(in srgb, CanvasText 10%, Canvas 90%);
  --border-color: color-mix(in srgb, CanvasText 10%, Canvas 90%);
  /* Foreground color rendered over token highlight backgrounds */
  --tok-text: CanvasText;
  /* Hover outline color for highlighted token ranges */
  --tok-hover: AccentColor;

  /* Token color palette — 12 distinct hues in oklch, light-mode values.
     Dark-mode overrides follow in the @media block below. */
  --tok-0: oklch(80% 0.13 30);
  --tok-1: oklch(82% 0.13 80);
  --tok-2: oklch(80% 0.13 140);
  --tok-3: oklch(80% 0.13 195);
  --tok-4: oklch(80% 0.13 250);
  --tok-5: oklch(80% 0.13 300);
  --tok-6: oklch(80% 0.13 340);
  --tok-7: oklch(82% 0.13 55);
  --tok-8: oklch(80% 0.13 165);
  --tok-9: oklch(80% 0.13 220);
  --tok-10: oklch(80% 0.13 270);
  --tok-11: oklch(80% 0.13 320);
}

@media (prefers-color-scheme: dark) {
  :root {
    /* Slightly higher lightness so highlights read on dark Canvas */
    --tok-0: oklch(68% 0.16 30);
    --tok-1: oklch(70% 0.16 80);
    --tok-2: oklch(68% 0.16 140);
    --tok-3: oklch(68% 0.16 195);
    --tok-4: oklch(68% 0.16 250);
    --tok-5: oklch(68% 0.16 300);
    --tok-6: oklch(68% 0.16 340);
    --tok-7: oklch(70% 0.16 55);
    --tok-8: oklch(68% 0.16 165);
    --tok-9: oklch(68% 0.16 220);
    --tok-10: oklch(68% 0.16 270);
    --tok-11: oklch(68% 0.16 320);
  }
}

/* ─── Reset ─────────────────────────────────────────────────────────────── */

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* ─── Base ──────────────────────────────────────────────────────────────── */

body {
  font-family: var(--font-sans);
  background: Canvas;
  color: CanvasText;
  line-height: 1.6;
  min-height: 100dvh;
  padding-block-end: 4rem;
}

/* ─── Header ────────────────────────────────────────────────────────────── */

header {
  background: Canvas;
  padding: 1.25rem 2rem;
  max-width: 1400px;
  margin-inline: auto;
  h1 {
    font-size: 1.35rem;
    font-weight: 700;
    letter-spacing: -0.01em;
  }

  p {
    font-size: 0.875rem;
    opacity: 0.7;
    margin-block-start: 0.2rem;
  }
}

/* ─── Main layout ───────────────────────────────────────────────────────── */

main {
  max-width: 1400px;
  margin-inline: auto;
  padding: 1.5rem 2rem;
  display: grid;
  gap: 1.25rem;
}

/* ─── Input section ─────────────────────────────────────────────────────── */

.input-section {
  display: grid;
  gap: 0.5rem;

  label {
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: GrayText;
  }

  textarea {
    font-family: var(--font-mono);
    font-size: 1.1rem;
    line-height: 1.7;
    background: Field;
    color: FieldText;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 0.75rem 1rem;
    resize: vertical;
    width: 100%;
    transition: border-color 0.15s;

    &:focus {
      outline: none;
      border-color: AccentColor;
      box-shadow: 0 0 0 3px color-mix(in srgb, AccentColor 20%, transparent);
    }
  }
}

/* ─── Add tokenizer row ─────────────────────────────────────────────────── */

.add-tokenizer-section {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  flex-wrap: wrap;

  select {
    font-family: var(--font-sans);
    font-size: 0.9rem;
    background: Field;
    color: FieldText;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 0.45rem 0.75rem;
    flex: 1 1 280px;
    max-width: 480px;
    cursor: pointer;
    transition: border-color 0.15s;

    &:focus {
      outline: none;
      border-color: AccentColor;
    }
  }

  button {
    font-family: var(--font-sans);
    font-size: 0.9rem;
    font-weight: 600;
    background: AccentColor;
    color: AccentColorText;
    border: none;
    border-radius: var(--radius-sm);
    padding: 0.45rem 1.1rem;
    cursor: pointer;
    transition: opacity 0.15s;
    white-space: nowrap;

    &:hover:not(:disabled) {
      opacity: 0.85;
    }

    &:disabled {
      opacity: 0.4;
      cursor: not-allowed;
    }
  }
}

/* ─── Empty state ───────────────────────────────────────────────────────── */

.empty-state {
  text-align: center;
  color: GrayText;
  font-size: 0.9rem;
  padding: 2.5rem 1rem;
  border: 1.5px dashed var(--border-color);
  border-radius: var(--radius);
  background: Canvas;

  &.hidden {
    display: none;
  }
}

/* ─── Panels grid ───────────────────────────────────────────────────────── */

#panels {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 1rem;
  align-items: start;
}

/* ─── Individual tokenizer panel ────────────────────────────────────────── */

.panel {
  background: Canvas;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  display: grid;
  grid-template-rows: auto auto auto 1fr;
  overflow: hidden;

  /* Panel header bar */
  .panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.5rem;
    padding: 0.65rem 1rem;
    background: ButtonFace;
    border-block-end: 1px solid var(--border-color);

    .panel-title {
      font-size: 0.85rem;
      font-weight: 600;
      color: ButtonText;
      text-decoration: none;
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
    }

    .remove-btn {
      font-size: 0.75rem;
      font-weight: 600;
      color: GrayText;
      background: none;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      padding: 0.2rem 0.5rem;
      cursor: pointer;
      flex-shrink: 0;
      transition:
        color 0.12s,
        border-color 0.12s;

      &:hover {
        color: LinkText;
        border-color: LinkText;
      }
    }
  }

  /* Text mirror with highlights */
  .panel-text {
    font-family: var(--font-mono);
    font-size: 1.05rem;
    line-height: 1.8;
    padding: 0.85rem 1rem;
    border-block-end: 1px solid var(--border-color);
    white-space: pre-wrap;
    word-break: break-all;
    min-height: 3.5rem;
  }

  /* Stats bar */
  .panel-stats {
    display: flex;
    gap: 1.5rem;
    padding: 0.45rem 1rem;
    background: ButtonFace;
    border-block-end: 1px solid var(--border-color);
    font-size: 0.78rem;
    color: GrayText;
    flex-wrap: wrap;

    strong {
      color: CanvasText;
      font-weight: 600;
    }
  }

  /* Token table */
  .panel-table-wrap {
    overflow-y: auto;
    max-height: 360px;
  }

  table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.82rem;

    thead {
      position: sticky;
      top: 0;
      background: ButtonFace;
      z-index: 1;

      th {
        text-align: left;
        padding: 0.4rem 0.75rem;
        font-weight: 600;
        font-size: 0.72rem;
        text-transform: uppercase;
        letter-spacing: 0.05em;
        color: GrayText;
        border-block-end: 1px solid var(--border-color);
      }
    }

    tbody tr {
      cursor: default;
      transition: background 0.08s;

      &:hover {
        background: color-mix(in srgb, ButtonFace 60%, Canvas);
      }

      &.active {
        background: color-mix(
          in srgb,
          var(--row-color, AccentColor) 18%,
          Canvas
        );
      }

      td {
        padding: 0.3rem 0.75rem;
        border-block-end: 1px solid
          color-mix(in srgb, ButtonBorder 60%, transparent);
        vertical-align: middle;

        &.tok-cell {
          font-family: var(--font-mono);
          font-size: 0.88rem;
        }

        &.id-cell {
          font-family: var(--font-mono);
          color: GrayText;
          font-size: 0.8rem;
          text-align: right;
        }

        &.color-swatch {
          width: 18px;
          padding-inline: 0.5rem;

          span {
            display: block;
            width: 10px;
            height: 10px;
            border-radius: 50%;
            background: var(--row-color, var(--border-color));
          }
        }
      }
    }
  }

  /* Loading state */
  &.loading {
    .panel-text,
    .panel-stats,
    .panel-table-wrap {
      opacity: 0.4;
      pointer-events: none;
    }
  }

  .panel-loading {
    display: none;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 1rem;
    font-size: 0.8rem;
    color: GrayText;

    .spinner {
      width: 14px;
      height: 14px;
      border: 2px solid var(--border-color);
      border-top-color: AccentColor;
      border-radius: 50%;
      animation: spin 0.7s linear infinite;
      flex-shrink: 0;
    }
  }

  &.loading .panel-loading {
    display: flex;
  }
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}