:root {
  --gb-bg: #07120d;
  --gb-surface: #06140b;
  --gb-surface-raised: #06140c;
  --gb-text: #f3fff6;
  --gb-text-muted: #a8d5b2;
  --gb-primary: #45f06d;
  --gb-accent: #45f06d;
  --gb-border: #72ff91;
  --gb-border-soft: #0b6f2d;
  --gb-button-bg: #07160c;
  --gb-button-text: #f3fff6;
  --gb-input-bg: #07160c;
  --gb-input-text: #f3fff6;
  --gb-glow: #45f06d;
  --gb-page-max: 1480px;
  --gb-glow-strength: .60;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--gb-bg);
  color: var(--gb-text);
  font-family:
    Inter,
    ui-sans-serif,
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
}

button,
input,
select {
  font: inherit;
}

button,
.file-button,
.secondary-button {
  min-height: 40px;
  border:
    1px solid
    var(--gb-border);
  border-radius: 10px;
  background:
    color-mix(
      in srgb,
      var(--gb-primary) 16%,
      var(--gb-button-bg)
    );
  color: var(--gb-button-text);
  padding: 8px 13px;
  font-weight: 800;
  cursor: pointer;
  text-decoration: none;
}

button:hover,
.file-button:hover,
.secondary-button:hover {
  border-color: var(--gb-accent);
  box-shadow:
    0 0
    calc(
      24px
      *
      var(--gb-glow-strength)
    )
    color-mix(
      in srgb,
      var(--gb-glow) 32%,
      transparent
    );
}

.secondary-button {
  background:
    color-mix(
      in srgb,
      var(--gb-surface-raised) 94%,
      transparent
    );
}

#gb-background-layer {
  position: fixed;
  inset: 0;
  z-index: 0;
  overflow: hidden;
  pointer-events: none;
  background: var(--gb-bg);
}

#gb-background-art {
  position: absolute;
  inset: 0;
  opacity: .70;
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
}

#gb-matrix-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.page-shell {
  position: relative;
  z-index: 10;
  width:
    min(
      var(--gb-page-max),
      calc(100% - 32px)
    );
  margin: 0 auto;
  padding: 22px 0 110px;
}

.page-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 24px;
  padding: 20px 22px;
  border:
    1px solid
    color-mix(
      in srgb,
      var(--gb-border) 60%,
      transparent
    );
  border-radius: 16px;
  background:
    color-mix(
      in srgb,
      var(--gb-surface-raised) 92%,
      transparent
    );
  box-shadow:
    0 18px 50px
    rgba(0,0,0,.28);
  backdrop-filter:
    blur(14px);
}

.brand {
  color: var(--gb-text);
  font-weight: 900;
  text-decoration: none;
  font-size: 18px;
}

.eyebrow {
  color: var(--gb-primary);
  text-transform: uppercase;
  letter-spacing: .12em;
  font-size: 11px;
  font-weight: 900;
}

h1 {
  margin: 5px 0 4px;
  font-size:
    clamp(
      28px,
      3vw,
      42px
    );
}

h2 {
  margin: 4px 0 4px;
  font-size: 21px;
}

.subtitle,
.muted {
  margin: 0;
  color: var(--gb-text-muted);
}

.header-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px;
}

.stage-badge {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 8px 12px;
  border-radius: 999px;
  border:
    1px solid
    var(--gb-primary);
  color: var(--gb-primary);
  font-weight: 900;
  font-size: 11px;
  letter-spacing: .08em;
}

.settings-layout {
  display: grid;
  grid-template-columns:
    220px
    minmax(
      0,
      1fr
    );
  gap: 18px;
  margin-top: 18px;
}

.settings-nav {
  position: sticky;
  top: 16px;
  align-self: start;
  display: grid;
  gap: 6px;
  padding: 12px;
  border:
    1px solid
    color-mix(
      in srgb,
      var(--gb-border) 42%,
      transparent
    );
  border-radius: 14px;
  background:
    color-mix(
      in srgb,
      var(--gb-surface-raised) 92%,
      transparent
    );
  backdrop-filter:
    blur(14px);
}

.settings-nav a {
  color: var(--gb-text);
  text-decoration: none;
  padding: 10px 11px;
  border-radius: 9px;
  font-weight: 750;
}

.settings-nav a:hover {
  background:
    color-mix(
      in srgb,
      var(--gb-primary) 13%,
      transparent
    );
}

.settings-main {
  display: grid;
  gap: 16px;
  min-width: 0;
}

.settings-card {
  border:
    1px solid
    color-mix(
      in srgb,
      var(--gb-border) 44%,
      transparent
    );
  border-radius: 15px;
  padding: 18px;
  background:
    color-mix(
      in srgb,
      var(--gb-surface-raised) 92%,
      transparent
    );
  box-shadow:
    0 14px 40px
    rgba(0,0,0,.24);
  backdrop-filter:
    blur(14px);
}

.section-heading {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 15px;
}

.overview-status-grid {
  display: grid;
  grid-template-columns:
    repeat(
      3,
      minmax(
        110px,
        1fr
      )
    );
  gap: 8px;
}

.status-tile {
  border:
    1px solid
    color-mix(
      in srgb,
      var(--gb-border-soft) 65%,
      transparent
    );
  border-radius: 10px;
  padding: 10px;
  background:
    color-mix(
      in srgb,
      var(--gb-surface) 78%,
      transparent
    );
}

.status-tile span {
  display: block;
  color: var(--gb-text-muted);
  font-size: 11px;
}

.status-tile strong {
  display: block;
  margin-top: 3px;
}

.theme-grid {
  display: grid;
  grid-template-columns:
    repeat(
      4,
      minmax(
        0,
        1fr
      )
    );
  gap: 10px;
}

.theme-card {
  min-height: 92px;
  padding: 12px;
  text-align: left;
  background:
    var(
      --card-bg,
      var(--gb-surface)
    );
  border-color:
    var(
      --card-border,
      var(--gb-border)
    );
  color:
    var(
      --card-text,
      var(--gb-text)
    );
  position: relative;
  overflow: hidden;
}

.theme-card::after {
  content: "";
  position: absolute;
  inset:
    auto
    -20px
    -35px
    auto;
  width: 90px;
  height: 90px;
  border-radius: 50%;
  background:
    var(
      --card-accent,
      var(--gb-primary)
    );
  opacity: .22;
  filter:
    blur(2px);
}

.theme-card.is-active {
  outline:
    2px solid
    var(--gb-primary);
  outline-offset: 1px;
  box-shadow:
    0 0
    calc(
      28px
      *
      var(--gb-glow-strength)
    )
    color-mix(
      in srgb,
      var(--gb-glow) 36%,
      transparent
    );
}

.theme-name {
  display: block;
  font-weight: 900;
  position: relative;
  z-index: 1;
}

.theme-tagline {
  display: block;
  margin-top: 4px;
  font-size: 11px;
  opacity: .78;
  position: relative;
  z-index: 1;
}

.control-grid {
  display: grid;
  grid-template-columns:
    repeat(
      2,
      minmax(
        0,
        1fr
      )
    );
  gap: 12px;
}

.field-control,
.toggle-control {
  display: grid;
  gap: 8px;
  padding: 13px;
  border:
    1px solid
    color-mix(
      in srgb,
      var(--gb-border-soft) 70%,
      transparent
    );
  border-radius: 11px;
  background:
    color-mix(
      in srgb,
      var(--gb-surface) 76%,
      transparent
    );
}

.field-control > span {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  font-weight: 750;
}

.toggle-control {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.toggle-control small {
  display: block;
  margin-top: 3px;
  color: var(--gb-text-muted);
  font-weight: 500;
}

.toggle-control input {
  width: 22px;
  height: 22px;
}

.wide-control {
  grid-column:
    1
    /
    -1;
}

input[type="range"] {
  width: 100%;
  accent-color:
    var(--gb-primary);
}

input[type="color"] {
  width: 100%;
  min-height: 42px;
  padding: 3px;
  border:
    1px solid
    var(--gb-border);
  border-radius: 8px;
  background:
    var(--gb-input-bg);
}

input[type="text"],
.token-value {
  width: 100%;
  min-height: 40px;
  border:
    1px solid
    var(--gb-border);
  border-radius: 9px;
  background:
    var(--gb-input-bg);
  color:
    var(--gb-input-text);
  padding: 8px 10px;
}

.preset-create-row,
.toolbar-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}

.preset-create-row input {
  flex:
    1
    1
    260px;
}

.saved-preset-list {
  display: grid;
  gap: 8px;
  margin-top: 12px;
}

.saved-preset {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 12px;
  border:
    1px solid
    color-mix(
      in srgb,
      var(--gb-border-soft) 70%,
      transparent
    );
  border-radius: 10px;
  background:
    color-mix(
      in srgb,
      var(--gb-surface) 76%,
      transparent
    );
}

.saved-preset-actions {
  display: flex;
  gap: 6px;
}

.file-button input {
  display: none;
}

.import-preview {
  margin-top: 13px;
  padding: 13px;
  border:
    1px solid
    var(--gb-primary);
  border-radius: 11px;
  background:
    color-mix(
      in srgb,
      var(--gb-surface) 86%,
      transparent
    );
}

.import-diff {
  max-height: 230px;
  overflow: auto;
  margin: 9px 0;
  color:
    var(--gb-text-muted);
  font-size: 12px;
}

.token-details > summary {
  cursor: pointer;
  font-weight: 850;
}

.token-list {
  display: grid;
  gap: 8px;
  margin-top: 13px;
}

.token-row {
  display: grid;
  grid-template-columns:
    42px
    minmax(
      140px,
      1fr
    )
    minmax(
      150px,
      .8fr
    )
    auto;
  gap: 9px;
  align-items: center;
  padding: 10px;
  border:
    1px solid
    color-mix(
      in srgb,
      var(--gb-border-soft) 70%,
      transparent
    );
  border-radius: 10px;
  background:
    color-mix(
      in srgb,
      var(--gb-surface) 76%,
      transparent
    );
}

.token-swatch {
  width: 38px;
  height: 34px;
  border: 0;
  padding: 0;
  background: transparent;
}

.token-label {
  font-weight: 800;
}

.token-name,
.token-specs {
  color:
    var(--gb-text-muted);
  font-size: 11px;
}

.token-specs {
  grid-column:
    2
    /
    4;
  display: grid;
  grid-template-columns:
    repeat(
      4,
      minmax(
        0,
        1fr
      )
    );
  gap: 6px;
}

.copy-button {
  min-height: 34px;
  padding: 6px 9px;
  font-size: 11px;
}

.diagnostics-grid {
  display: grid;
  grid-template-columns:
    repeat(
      3,
      minmax(
        0,
        1fr
      )
    );
  gap: 8px;
  margin-top: 16px;
}

.diagnostics-grid > div {
  padding: 10px;
  border:
    1px solid
    color-mix(
      in srgb,
      var(--gb-border-soft) 70%,
      transparent
    );
  border-radius: 9px;
  background:
    color-mix(
      in srgb,
      var(--gb-surface) 76%,
      transparent
    );
}

.diagnostics-grid span {
  display: block;
  color:
    var(--gb-text-muted);
  font-size: 11px;
}

.diagnostics-grid strong {
  display: block;
  margin-top: 4px;
}

.sticky-action-bar {
  position: fixed;
  z-index: 30;
  left: 50%;
  bottom: 14px;
  transform:
    translateX(-50%);
  width:
    min(
      var(--gb-page-max),
      calc(100% - 32px)
    );
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 12px 14px;
  border:
    1px solid
    var(--gb-border);
  border-radius: 13px;
  background:
    color-mix(
      in srgb,
      var(--gb-surface-raised) 96%,
      transparent
    );
  box-shadow:
    0 18px 60px
    rgba(0,0,0,.38);
  backdrop-filter:
    blur(16px);
}

.sticky-action-bar > div:first-child {
  display: grid;
  gap: 2px;
}

#save-detail {
  color:
    var(--gb-text-muted);
  font-size: 11px;
}

@media (
  max-width: 1050px
) {

  .settings-layout {
    grid-template-columns:
      1fr;
  }

  .settings-nav {
    position: static;
    grid-template-columns:
      repeat(
        3,
        minmax(
          0,
          1fr
        )
      );
  }

  .theme-grid {
    grid-template-columns:
      repeat(
        3,
        minmax(
          0,
          1fr
        )
      );
  }
}

@media (
  max-width: 760px
) {

  .page-header,
  .section-heading,
  .sticky-action-bar {
    flex-direction: column;
    align-items: stretch;
  }

  .header-actions {
    justify-content:
      flex-start;
  }

  .theme-grid,
  .control-grid,
  .diagnostics-grid,
  .overview-status-grid {
    grid-template-columns:
      1fr;
  }

  .settings-nav {
    grid-template-columns:
      repeat(
        2,
        minmax(
          0,
          1fr
        )
      );
  }

  .token-row {
    grid-template-columns:
      38px
      1fr;
  }

  .token-value,
  .token-specs {
    grid-column:
      1
      /
      -1;
  }

  .token-specs {
    grid-template-columns:
      repeat(
        2,
        minmax(
          0,
          1fr
        )
      );
  }

  .sticky-action-bar {
    bottom: 8px;
  }
}



/* Production layering:
   background art < central Matrix < application/settings UI */
:root {
  --gb-effect-z-index: 1;
}

#gb-background-layer {
  z-index: 0 !important;
}

.page-shell {
  z-index: 10 !important;
}

.sticky-action-bar {
  z-index: 30 !important;
}