@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@300;400;500;600&display=swap');

:root {
  color-scheme: light dark;

  /* Semantic colors using light-dark() */
  --color-bg: light-dark(#ebe6d5, #1a1a1a);
  --color-bg-alt: light-dark(#f5f2e8, #242424);
  --color-bg-section: light-dark(#dfd9c3, #121212);
  --color-text: light-dark(#3d3929, #e8e4d9);
  --color-text-soft: light-dark(#5c5647, #c4c0b5);
  --color-text-muted: light-dark(#615d4d, #949187);
  --color-border: light-dark(#3d3929, #8a877d);
  --color-border-soft: light-dark(#8a8475, #4a4740);

  --color-accent: light-dark(#8b4513, #d4915a);
  --color-accent-content: light-dark(#ebe6d5, #1a1a1a);

  /* Typography */
  --font-mono: 'JetBrains Mono', 'SF Mono', 'Monaco', 'Consolas', monospace;

  /* Layout */
  --border-width: 1px;
  --section-gap: 2rem;
}

/* Theme override — the server sets data-theme from the visitor's cookie.
   Forcing color-scheme makes every light-dark() above follow the choice;
   without the attribute the OS preference wins. */
:root[data-theme="light"] {
  color-scheme: light;
}

:root[data-theme="dark"] {
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

body {
  font-family: var(--font-mono);
  font-weight: 400;
  font-size: 14px;
  line-height: 1.6;
  background-color: var(--color-bg);
  color: var(--color-text);
  margin: 0;
  padding: 0;
}

a {
  color: var(--color-text);
  text-decoration: none;
  border-bottom: 1px solid var(--color-border-soft);
  transition: border-color 0.2s;

  &:hover {
    border-color: var(--color-border);
  }
}

/* Visible keyboard focus (WCAG 2.4.7 / 2.4.11). Mouse focus stays ring-free. */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

:focus:not(:focus-visible) {
  outline: none;
}

/* Skip link — first tab stop, hidden until focused (WCAG 2.4.1). */
.skip-link {
  position: absolute;
  top: 0.5rem;
  left: 0.5rem;
  z-index: 100;
  padding: 0.5rem 1rem;
  background: var(--color-bg);
  color: var(--color-text);
  border: var(--border-width) solid var(--color-border);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 11px;
  transform: translateY(-200%);
  transition: transform 0.2s;

  &:focus {
    transform: translateY(0);
  }
}

/* Layout */
.body-content {
  display: grid;
  grid-template-areas: "aside main";
  grid-template-columns: 320px 1fr;
  margin: 0;
  min-height: 100vh;

  @media only screen and (max-width: 768px) {
    grid-template-columns: 1fr;
    grid-template-areas:
      "aside"
      "main";
  }
}

/* Aside / Sidebar */
aside {
  grid-area: aside;
  background-color: var(--color-bg-section);
  border-right: var(--border-width) solid var(--color-border);
  padding: 2rem;
  display: flex;
  flex-direction: column;

  @media only screen and (max-width: 768px) {
    border-right: none;
    border-bottom: var(--border-width) solid var(--color-border);
  }

  .header-label {
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--color-text-muted);
    margin-bottom: 1.5rem;
  }

  .avatar {
    display: flex;
    justify-content: center;
    margin-bottom: 1rem;

    img {
      border-radius: 0;
      width: 80px;
      height: 80px;
      object-fit: cover;
      border: var(--border-width) solid var(--color-border);
    }
  }

  .name {
    text-align: center;
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: var(--border-width) solid var(--color-border);

    h1 {
      font-size: 1.25rem;
      font-weight: 500;
      text-transform: uppercase;
      letter-spacing: 0.1em;
      margin: 0 0 0.25rem 0;
    }

    p {
      font-size: 11px;
      text-transform: uppercase;
      letter-spacing: 0.15em;
      color: var(--color-text-muted);
      margin: 0;
    }
  }

  .section {
    margin-bottom: 1.5rem;

    h2 {
      font-size: 10px;
      font-weight: 500;
      text-transform: uppercase;
      letter-spacing: 0.2em;
      color: var(--color-text-muted);
      margin: 0 0 0.75rem 0;
      padding-bottom: 0.5rem;
      border-bottom: var(--border-width) solid var(--color-border-soft);
    }

    .items {
      display: flex;
      flex-direction: column;
      gap: 0.5rem;
      font-size: 13px;

      a,
      span {
        display: block;
      }
    }
  }

  .theme-toggle {
    display: flex;
    border: var(--border-width) solid var(--color-border);

    button {
      flex: 1;
      padding: 0.4rem 0;
      border: none;
      background: transparent;
      color: var(--color-text-muted);
      font-family: var(--font-mono);
      font-size: 10px;
      text-transform: uppercase;
      letter-spacing: 0.1em;
      cursor: pointer;
      transition: all 0.2s;

      & + button {
        border-left: var(--border-width) solid var(--color-border-soft);
      }

      &:hover {
        color: var(--color-text);
      }

      &[aria-pressed="true"] {
        background: var(--color-text);
        color: var(--color-bg);
      }
    }
  }

  .section-code {
    font-size: 10px;
    color: var(--color-text-muted);
    margin-top: auto;
    padding-top: 2rem;
    border-top: var(--border-width) solid var(--color-border-soft);
    text-transform: uppercase;
    letter-spacing: 0.15em;
  }
}

/* Main Content */
main {
  grid-area: main;
  background-color: var(--color-bg);
  padding: 2rem 3rem;
  position: relative;

  @media (max-width: 768px) {
    padding: 1.5rem;
  }

  .page-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: var(--border-width) solid var(--color-border);

    .page-title {
      h1 {
        font-size: 2rem;
        font-weight: 500;
        text-transform: uppercase;
        letter-spacing: 0.05em;
        margin: 0;
        line-height: 1.2;
      }

      .subtitle {
        font-size: 11px;
        text-transform: uppercase;
        letter-spacing: 0.15em;
        color: var(--color-text-muted);
        margin-top: 0.5rem;
      }
    }

    .page-code {
      font-size: 10px;
      text-transform: uppercase;
      letter-spacing: 0.1em;
      color: var(--color-text-muted);
      text-align: right;
    }
  }

  .content-section {
    margin-bottom: var(--section-gap);
    padding-bottom: var(--section-gap);
    border-bottom: var(--border-width) solid var(--color-border-soft);

    &:last-child {
      border-bottom: none;
    }
  }

  .intro-text {
    font-size: 13px;
    line-height: 1.8;
    max-width: 600px;
    color: var(--color-text-soft);
  }

  h2 {
    font-size: 14px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    margin: 0 0 1rem 0;
  }

  h3 {
    font-size: 11px;
    font-weight: 400;
    text-transform: uppercase;
    letter-spacing: 0.2em;
    color: var(--color-text-muted);
    margin: 1.5rem 0 0.75rem 0;
  }

  .item-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem 1.5rem;

    .item {
      font-size: 12px;
      display: flex;
      align-items: center;
      gap: 0.5rem;
      padding: 0.25rem 0;

      &::before {
        content: '—';
        color: var(--color-text-muted);
      }
    }
  }

  .lang-logo {
    width: 1em;
    height: 1em;
    opacity: 0.8;
  }
}

/* Grid decoration */
.dot-grid {
  position: absolute;
  top: 2rem;
  right: 2rem;
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  gap: 8px;

  .dot {
    width: 3px;
    height: 3px;
    background-color: var(--color-border-soft);
    border-radius: 50%;
  }
}

/* Table Demo */
.table-demo-page {
  .table-demo-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.5rem;

    @media only screen and (max-width: 1100px) {
      grid-template-columns: 1fr;
    }
  }

  .demo-card {
    display: flex;
    flex-direction: column;
    gap: 1rem;
  }

  .demo-card-header {
    min-height: 4.75rem;

    h2 {
      margin-bottom: 0.5rem;
    }

    p {
      margin: 0;
      color: var(--color-text-soft);
      font-size: 12px;
    }
  }

  .table-shell {
    border: var(--border-width) solid var(--color-border);
    background: var(--color-bg-alt);
  }

  .table-scroll-viewport,
  .table-shell-body-scroll {
    overflow: auto;
    scrollbar-gutter: stable both-edges;
  }

  .table-shell--fixed .table-scroll-viewport {
    max-height: 460px;
  }

  .table-shell--observer {
    position: relative;

    .table-shell-body-scroll {
      overflow-y: visible;
      overflow-x: auto;
    }

    thead {
      position: sticky;
      top: 0;
      z-index: 3;
    }

    &.is-pinned {
      .table-shell-header-overlay {
        display: grid;
      }

      .table-shell-body-scroll thead {
        visibility: hidden;
        position: absolute;
        inset: 0 auto auto 0;
        pointer-events: none;
      }
    }
  }

  .table-shell-observer-target {
    position: relative;
  }

  .table-shell-sentinel {
    height: 1px;
    margin-bottom: -1px;
  }

  .table-shell-header-overlay {
    position: sticky;
    top: 0;
    z-index: 4;
    display: none;
    overflow: hidden;
    background: var(--color-bg-alt);
    border-bottom: var(--border-width) solid var(--color-border);
    grid-template-columns: max-content minmax(0, 1fr);
  }

  .table-shell-header-frozen {
    position: relative;
    z-index: 6;
    overflow: hidden;
    border-right: var(--border-width) solid var(--color-border-soft);
    width: var(--frozen-column-width, auto);
  }

  .table-shell-header-clip {
    overflow: hidden;
  }

  .data-table {
    width: max-content;
    min-width: 100%;
    border-collapse: separate;
    border-spacing: 0;

    th,
    td {
      min-width: 120px;
      padding: 0.9rem 1rem;
      text-align: left;
      white-space: nowrap;
      border-right: var(--border-width) solid var(--color-border-soft);
      border-bottom: var(--border-width) solid var(--color-border-soft);
      font-size: 12px;
    }

    th:last-child,
    td:last-child {
      border-right: none;
    }

    thead th {
      position: sticky;
      top: 0;
      z-index: 2;
      background: var(--color-bg-section);
      text-transform: uppercase;
      letter-spacing: 0.12em;
      font-size: 10px;
    }

    thead th:first-child,
    tbody td:first-child {
      position: sticky;
      left: 0;
    }

    thead th:first-child {
      z-index: 5;
      background: var(--color-bg-section);
    }

    tbody td:first-child {
      z-index: 1;
      background: var(--color-bg-alt);
    }

    tbody tr:nth-child(even) td {
      background: color-mix(in srgb, var(--color-bg-alt) 85%, var(--color-bg-section) 15%);
    }

    tbody tr:nth-child(even) td:first-child {
      background: color-mix(in srgb, var(--color-bg-alt) 85%, var(--color-bg-section) 15%);
    }
  }

  .data-table--header-clone {
    min-width: max-content;
    table-layout: fixed;

    th {
      position: static;
      border-bottom: none;
      background: var(--color-bg-section);
    }
  }

  .data-table--header-scrollable {
    min-width: max-content;
    width: var(--scrollable-header-width, auto);
  }

  .action-cell {
    text-align: right;
  }

  .table-action {
    border: var(--border-width) solid var(--color-border);
    background: transparent;
    color: var(--color-text);
    font-family: var(--font-mono);
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    padding: 0.45rem 0.75rem;
    cursor: pointer;
  }
}

/* Speed Reader */
.speed-reader {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  height: 100%;

  .input-section {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;

    label {
      font-size: 10px;
      text-transform: uppercase;
      letter-spacing: 0.2em;
      color: var(--color-text-muted);
    }

    textarea {
      width: 100%;
      min-height: 150px;
      padding: 1rem;
      border: var(--border-width) solid var(--color-border);
      background: var(--color-bg-alt);
      color: var(--color-text);
      font-family: var(--font-mono);
      font-size: 13px;
      resize: vertical;

      &:focus {
        border-color: var(--color-text);
      }
    }
  }

  .controls {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    align-items: center;
    padding: 1rem 0;
    border-top: var(--border-width) solid var(--color-border-soft);
    border-bottom: var(--border-width) solid var(--color-border-soft);
  }

  .speed-control {
    display: flex;
    align-items: center;
    gap: 0.75rem;

    label {
      font-size: 10px;
      text-transform: uppercase;
      letter-spacing: 0.15em;
      color: var(--color-text-muted);
    }

    input[type="range"] {
      width: 120px;
      height: 2px;
      background: var(--color-border);
      appearance: none;
      cursor: pointer;

      &::-webkit-slider-thumb {
        appearance: none;
        width: 12px;
        height: 12px;
        background: var(--color-text);
        cursor: pointer;
      }
    }

    .wpm-value {
      min-width: 4rem;
      font-variant-numeric: tabular-nums;
      font-size: 12px;
    }
  }

  .btn {
    padding: 0.5rem 1.25rem;
    border: var(--border-width) solid var(--color-border);
    background: transparent;
    color: var(--color-text);
    cursor: pointer;
    font-family: var(--font-mono);
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    transition: all 0.2s;
    min-width: 6rem;

    &:hover {
      background: var(--color-text);
      color: var(--color-bg);
    }

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

      &:hover {
        background: transparent;
        color: var(--color-text);
      }
    }
  }

  .display-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 140px;
    border: var(--border-width) solid var(--color-border);
    background: var(--color-bg-alt);
    position: relative;
  }

  .word-display {
    font-size: 2.5rem;
    font-family: var(--font-mono);
    font-weight: 500;
    letter-spacing: 0.05em;
    user-select: none;

    .before {
      color: inherit;
    }

    .focus {
      color: var(--color-accent);
    }

    .after {
      color: inherit;
    }

    @media (max-width: 768px) {
      font-size: 1.75rem;
    }
  }

  .focus-line {
    position: absolute;
    top: 0;
    bottom: 0;
    width: 1px;
    background: var(--color-border-soft);
    left: 50%;
    transform: translateX(-50%);
    pointer-events: none;
  }

  .progress-info {
    margin-top: 1rem;
    font-size: 11px;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
  }

  .status {
    font-size: 10px;
    padding: 0.25rem 0.75rem;
    border: var(--border-width) solid var(--color-border);
    background: transparent;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    min-width: 5rem;
    text-align: center;

    &.playing {
      background: var(--color-text);
      color: var(--color-bg);
      border-color: var(--color-text);
    }

    &.paused {
      background: transparent;
      color: var(--color-text-muted);
    }
  }
}

/* WCAG Contrast Checker */
.contrast-checker {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;

  .inputs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;

    @media (max-width: 768px) {
      grid-template-columns: 1fr;
    }
  }

  .color-field {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;

    label {
      font-size: 10px;
      text-transform: uppercase;
      letter-spacing: 0.2em;
      color: var(--color-text-muted);
    }
  }

  .field-row {
    display: flex;
    align-items: center;
    gap: 0.75rem;
  }

  input[type="color"] {
    appearance: none;
    width: 2.5rem;
    height: 2.5rem;
    padding: 0;
    border: var(--border-width) solid var(--color-border);
    background: none;
    cursor: pointer;
    flex-shrink: 0;

    &::-webkit-color-swatch-wrapper {
      padding: 0;
    }

    &::-webkit-color-swatch {
      border: none;
    }

    &::-moz-color-swatch {
      border: none;
    }
  }

  input[type="text"] {
    flex: 1;
    min-width: 0;
    height: 2.5rem;
    padding: 0.6rem 0.75rem;
    border: var(--border-width) solid var(--color-border);
    background: var(--color-bg-alt);
    color: var(--color-text);
    font-family: var(--font-mono);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.05em;

    &:focus {
      border-color: var(--color-text);
    }

    &.is-invalid {
      border-color: var(--color-accent);
    }
  }

  .actions {
    display: flex;
    gap: 1rem;
    align-items: center;
  }

  .btn {
    padding: 0.5rem 1.25rem;
    border: var(--border-width) solid var(--color-border);
    background: transparent;
    color: var(--color-text);
    cursor: pointer;
    font-family: var(--font-mono);
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    transition: all 0.2s;
    min-width: 6rem;

    &:hover {
      background: var(--color-text);
      color: var(--color-bg);
    }
  }

  .preview {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    padding: 2rem;
    border: var(--border-width) solid var(--color-border);
    background-color: var(--preview-bg, var(--color-bg-alt));
    color: var(--preview-fg, var(--color-text));

    .sample-heading {
      font-size: 24px;
      font-weight: 600;
    }

    .sample-body {
      font-size: 16px;
      line-height: 1.6;
      max-width: 60ch;
    }

    .sample-caption {
      font-size: 13px;
      line-height: 1.6;
    }

    .sample-icons {
      display: flex;
      align-items: center;
      gap: 1rem;

      svg {
        width: 24px;
        height: 24px;
      }
    }

    .sample-ui {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 1rem;

      .ui-btn-solid,
      .ui-btn-outline {
        padding: 0.5rem 1.25rem;
        font-family: var(--font-mono);
        font-size: 12px;
        cursor: pointer;
      }

      .ui-btn-solid {
        border: var(--border-width) solid var(--preview-fg, var(--color-text));
        background: var(--preview-fg, var(--color-text));
        color: var(--preview-bg, var(--color-bg-alt));
      }

      .ui-btn-outline {
        border: var(--border-width) solid var(--preview-fg, var(--color-text));
        background: transparent;
        color: var(--preview-fg, var(--color-text));
      }

      .ui-link {
        color: var(--preview-fg, var(--color-text));
        border-bottom: none;
        text-decoration: underline;
        text-underline-offset: 2px;
        font-size: 13px;
      }
    }
  }

  .result {
    display: flex;
    flex-wrap: wrap;
    gap: 2rem;
    align-items: stretch;
    padding: 1.5rem 0;
    border-top: var(--border-width) solid var(--color-border-soft);
    border-bottom: var(--border-width) solid var(--color-border-soft);
  }

  .ratio {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 0.5rem;
    min-width: 10rem;

    .ratio-value {
      font-size: 3rem;
      font-weight: 500;
      line-height: 1;
      font-variant-numeric: tabular-nums;
    }

    .ratio-label {
      font-size: 10px;
      text-transform: uppercase;
      letter-spacing: 0.2em;
      color: var(--color-text-muted);
    }
  }

  .checks {
    flex: 1;
    min-width: 280px;
    display: flex;
    flex-direction: column;
  }

  .check {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    padding: 0.6rem 0;
    border-bottom: var(--border-width) solid var(--color-border-soft);

    &:last-child {
      border-bottom: none;
    }
  }

  .check-label {
    display: flex;
    flex-direction: column;
    gap: 0.2rem;

    .check-name {
      font-size: 12px;
    }

    .check-level {
      font-size: 10px;
      text-transform: uppercase;
      letter-spacing: 0.1em;
      color: var(--color-text-muted);
    }
  }

  .check-badge {
    font-size: 10px;
    padding: 0.25rem 0.75rem;
    border: var(--border-width) solid var(--color-border);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    min-width: 4rem;
    text-align: center;
    color: var(--color-text-muted);

    &.pass {
      background: var(--color-text);
      color: var(--color-bg);
      border-color: var(--color-text);
    }

    &.fail {
      color: var(--color-accent);
      border-color: var(--color-accent);
    }
  }
}

/* Utility classes */
.text-center {
  text-align: center;
}

.uppercase {
  text-transform: uppercase;
}

/* Footer decoration */
.footer-line {
  margin-top: auto;
  padding-top: 2rem;
  border-top: var(--border-width) solid var(--color-border-soft);
  display: flex;
  justify-content: space-between;
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--color-text-muted);
}

/* Respect reduced-motion preference (WCAG 2.3.3). */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}