/*
 * Skimbold design system: tokens and components shared by the popup, options page,
 * Reader and website. Reference with markup examples: docs/brand.md.
 *
 * Themes: light by default, dark follows the OS unless <html data-theme="light">.
 * data-theme="dark" and data-theme="sepia" force a theme (the Reader offers both).
 */

/* ── Tokens ─────────────────────────────────────────────────────────────── */

:root {
  color-scheme: light;

  /* Colour: ledger paper, green-black ink, bottle-green accent, lamp-brass focus */
  --skb-paper: #F2F4EF;
  --skb-surface: #FBFCFA;
  --skb-surface-hover: #EEF1EC;
  --skb-surface-sunk: #E6EAE4;
  --skb-ink: #17221C;
  --skb-ink-soft: #4A5850;
  --skb-line: #D3DAD3;
  --skb-line-strong: #78877E;
  --skb-accent: #1F5E46;
  --skb-accent-hover: #174B37;
  --skb-on-accent: #F4F7F2;
  --skb-accent-ink: #1F5E46;
  --skb-accent-tint: #D5E7DC;
  --skb-focus: #A86A12;
  --skb-danger: #A3302A;
  --skb-danger-tint: #F6E3E0;

  /* Type */
  --skb-font-ui: system-ui, -apple-system, 'Segoe UI', Roboto, 'Noto Sans', 'Liberation Sans', Arial, sans-serif;
  --skb-font-read: Charter, 'Bitstream Charter', 'Sitka Text', Cambria, 'Charis SIL', 'Noto Serif', 'DejaVu Serif', Georgia, serif;
  --skb-text-xs: 12px;
  --skb-text-sm: 13px;
  --skb-text-md: 14px;
  --skb-text-lg: 16px;
  --skb-text-xl: 18px;
  --skb-text-2xl: 21px;
  --skb-text-3xl: 24px;
  --skb-text-4xl: 36px;
  --skb-text-5xl: 48px;
  --skb-leading-ui: 1.4;
  --skb-leading-read: 1.7;

  /* Space (4 px steps) */
  --skb-space-1: 4px;
  --skb-space-2: 8px;
  --skb-space-3: 12px;
  --skb-space-4: 16px;
  --skb-space-5: 20px;
  --skb-space-6: 24px;
  --skb-space-8: 32px;
  --skb-space-10: 40px;
  --skb-space-12: 48px;

  /* Radii grow with the size of the thing they round */
  --skb-radius-xs: 4px;
  --skb-radius-sm: 6px;
  --skb-radius-md: 9px;
  --skb-radius-lg: 14px;
  --skb-radius-pill: 999px;

  /* Shadows are tinted with the ink colour so they read as paper lifting, not grey smudge */
  --skb-shadow-1: 0 1px 1px rgb(23 34 28 / 0.05), 0 1px 3px rgb(23 34 28 / 0.07);
  --skb-shadow-2: 0 2px 4px rgb(23 34 28 / 0.06), 0 12px 32px rgb(23 34 28 / 0.12);

  /* Motion */
  --skb-dur: 140ms;
  --skb-ease: cubic-bezier(0.2, 0.7, 0.2, 1);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]):not([data-theme="sepia"]) {
    color-scheme: dark;
    --skb-paper: #141C18;
    --skb-surface: #1B2520;
    --skb-surface-hover: #233029;
    --skb-surface-sunk: #0F1612;
    --skb-ink: #E3E9E4;
    --skb-ink-soft: #A3B0A8;
    --skb-line: #2D3A33;
    --skb-line-strong: #6B7C72;
    --skb-accent: #86C5A4;
    --skb-accent-hover: #9DD3B6;
    --skb-on-accent: #0F1A14;
    --skb-accent-ink: #8FCDAD;
    --skb-accent-tint: #28443A;
    --skb-focus: #E0A94A;
    --skb-danger: #F0907F;
    --skb-danger-tint: #3A2320;
    --skb-shadow-1: 0 1px 2px rgb(0 0 0 / 0.35);
    --skb-shadow-2: 0 2px 6px rgb(0 0 0 / 0.3), 0 14px 36px rgb(0 0 0 / 0.45);
  }
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --skb-paper: #141C18;
  --skb-surface: #1B2520;
  --skb-surface-hover: #233029;
  --skb-surface-sunk: #0F1612;
  --skb-ink: #E3E9E4;
  --skb-ink-soft: #A3B0A8;
  --skb-line: #2D3A33;
  --skb-line-strong: #6B7C72;
  --skb-accent: #86C5A4;
  --skb-accent-hover: #9DD3B6;
  --skb-on-accent: #0F1A14;
  --skb-accent-ink: #8FCDAD;
  --skb-accent-tint: #28443A;
  --skb-focus: #E0A94A;
  --skb-danger: #F0907F;
  --skb-danger-tint: #3A2320;
  --skb-shadow-1: 0 1px 2px rgb(0 0 0 / 0.35);
  --skb-shadow-2: 0 2px 6px rgb(0 0 0 / 0.3), 0 14px 36px rgb(0 0 0 / 0.45);
}

:root[data-theme="sepia"] {
  color-scheme: light;
  --skb-paper: #F4ECDC;
  --skb-surface: #FBF6EC;
  --skb-surface-hover: #F1E8D6;
  --skb-surface-sunk: #EADFC9;
  --skb-ink: #3A2E22;
  --skb-ink-soft: #6B5A47;
  --skb-line: #DDD0B8;
  --skb-line-strong: #8E7B63;
  --skb-accent: #2F5E46;
  --skb-accent-hover: #254C38;
  --skb-on-accent: #F8F3E8;
  --skb-accent-ink: #2F5E46;
  --skb-accent-tint: #DCE0C4;
  --skb-focus: #A0600E;
  --skb-danger: #9E2F24;
  --skb-danger-tint: #F3DDD3;
  --skb-shadow-1: 0 1px 1px rgb(58 46 34 / 0.06), 0 1px 3px rgb(58 46 34 / 0.08);
  --skb-shadow-2: 0 2px 4px rgb(58 46 34 / 0.07), 0 12px 32px rgb(58 46 34 / 0.13);
}

@media (prefers-reduced-motion: reduce) {
  :root {
    --skb-dur: 0ms;
  }

  *,
  ::before,
  ::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

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

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

body {
  margin: 0;
  background: var(--skb-paper);
  color: var(--skb-ink);
  font-family: var(--skb-font-ui);
  font-size: var(--skb-text-md);
  line-height: var(--skb-leading-ui);
}

a {
  color: var(--skb-accent-ink);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.2em;
}

a:hover {
  text-decoration-thickness: 2px;
}

::selection {
  background: var(--skb-accent-tint);
  color: var(--skb-ink);
}

:focus-visible {
  outline: 2px solid var(--skb-focus);
  outline-offset: 2px;
}

/* ── Utilities ──────────────────────────────────────────────────────────── */

.skb-muted {
  color: var(--skb-ink-soft);
}

.skb-sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* The name demonstrates the product: the start of the word carries the weight. */
.skb-wordmark {
  font-family: var(--skb-font-read);
  font-weight: 400;
  letter-spacing: -0.01em;
  color: var(--skb-ink);
}

.skb-wordmark > b {
  font-weight: 800;
}

/* ── Button ─────────────────────────────────────────────────────────────── */

.skb-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--skb-space-2);
  min-height: 36px;
  padding: 0 var(--skb-space-4);
  border: 1px solid var(--skb-line-strong);
  border-radius: var(--skb-radius-md);
  background: var(--skb-surface);
  color: var(--skb-ink);
  font: 600 var(--skb-text-md) / 1.2 var(--skb-font-ui);
  text-align: center;
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
  user-select: none;
  transition:
    background-color var(--skb-dur) var(--skb-ease),
    border-color var(--skb-dur) var(--skb-ease),
    color var(--skb-dur) var(--skb-ease);
}

.skb-btn svg {
  flex: none;
  width: 18px;
  height: 18px;
}

/* Hover and press feedback only while the button can be used. */
.skb-btn:where(:not(:disabled, [aria-disabled="true"])):hover {
  background: var(--skb-surface-hover);
}

.skb-btn:where(:not(:disabled, [aria-disabled="true"])):active {
  transform: translateY(1px);
}

.skb-btn--primary {
  border-color: var(--skb-accent);
  background: var(--skb-accent);
  color: var(--skb-on-accent);
}

.skb-btn--primary:where(:not(:disabled, [aria-disabled="true"])):hover {
  border-color: var(--skb-accent-hover);
  background: var(--skb-accent-hover);
}

.skb-btn--ghost {
  border-color: transparent;
  background: transparent;
  color: var(--skb-ink);
}

.skb-btn--ghost:where(:not(:disabled, [aria-disabled="true"])):hover {
  background: var(--skb-surface-sunk);
}

.skb-btn--danger {
  border-color: var(--skb-danger);
  color: var(--skb-danger);
}

.skb-btn--danger:where(:not(:disabled, [aria-disabled="true"])):hover {
  background: var(--skb-danger-tint);
}

.skb-btn--small {
  min-height: 28px;
  padding: 0 var(--skb-space-3);
  border-radius: var(--skb-radius-sm);
  font-size: var(--skb-text-sm);
}

.skb-btn--small svg {
  width: 16px;
  height: 16px;
}

/* Square, icon-only. Always give it an aria-label. */
.skb-btn--icon {
  width: 36px;
  padding: 0;
}

.skb-btn--icon.skb-btn--small {
  width: 28px;
}

.skb-btn:disabled,
.skb-btn[aria-disabled="true"] {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ── Segmented control ──────────────────────────────────────────────────
 * Real radio inputs, visually hidden but focusable, so Tab reaches the group and the
 * arrow keys move the selection natively. The chosen option is set in bold, the same
 * signal Skimbold uses for emphasis everywhere else.
 */

.skb-seg {
  position: relative;
  display: flex;
  gap: 2px;
  padding: 3px;
  border: 1px solid var(--skb-line);
  border-radius: var(--skb-radius-md);
  background: var(--skb-surface-sunk);
}

.skb-seg > input {
  position: absolute;
  top: 0;
  left: 0;
  width: 1px;
  height: 1px;
  margin: 0;
  opacity: 0;
  pointer-events: none;
}

.skb-seg > label {
  display: flex;
  flex: 1 1 0;
  align-items: center;
  justify-content: center;
  min-width: 0;
  min-height: 30px;
  padding: 0 var(--skb-space-2);
  border-radius: var(--skb-radius-sm);
  color: var(--skb-ink-soft);
  font-size: var(--skb-text-sm);
  font-weight: 500;
  white-space: nowrap;
  cursor: pointer;
  user-select: none;
  transition:
    background-color var(--skb-dur) var(--skb-ease),
    color var(--skb-dur) var(--skb-ease);
}

.skb-seg > input:not(:checked, :disabled) + label:hover {
  color: var(--skb-ink);
  background: var(--skb-surface-hover);
}

.skb-seg > input:checked + label {
  background: var(--skb-surface);
  box-shadow: inset 0 0 0 1px var(--skb-line-strong), var(--skb-shadow-1);
  color: var(--skb-ink);
  font-weight: 700;
}

.skb-seg > input:focus-visible + label {
  outline: 2px solid var(--skb-focus);
  outline-offset: 1px;
}

.skb-seg > input:disabled + label {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ── Switch ─────────────────────────────────────────────────────────────
 * A styled checkbox with role="switch". The knob is a background gradient rather than a
 * pseudo-element, because Firefox does not render ::before on form controls.
 */

.skb-switch {
  display: flex;
  align-items: center;
  gap: var(--skb-space-3);
  cursor: pointer;
}

.skb-switch > :not(input) {
  flex: 1 1 auto;
  min-width: 0;
}

.skb-switch > input {
  flex: none;
  appearance: none;
  width: 36px;
  height: 20px;
  margin: 0;
  border-radius: var(--skb-radius-pill);
  background:
    radial-gradient(circle closest-side, var(--skb-surface) 90%, transparent 100%) 3px 50% / 14px 14px no-repeat,
    var(--skb-line-strong);
  cursor: pointer;
  transition: background-position var(--skb-dur) var(--skb-ease), background-color var(--skb-dur) var(--skb-ease);
}

.skb-switch > input:checked {
  background-color: var(--skb-accent);
  background-position: 19px 50%;
}

.skb-switch > input:disabled,
.skb-switch > input:disabled ~ * {
  opacity: 0.5;
  cursor: not-allowed;
}

.skb-switch:has(> input:disabled) {
  cursor: not-allowed;
}

/* ── Range ──────────────────────────────────────────────────────────────
 * Firefox paints the filled part itself. Chromium needs the percentage in --skb-fill,
 * which the page sets on input (see docs/brand.md).
 */

.skb-range {
  --skb-fill: 0%;
  display: block;
  width: 100%;
  height: 22px;
  margin: 0;
  appearance: none;
  background: transparent;
  cursor: pointer;
}

.skb-range::-webkit-slider-runnable-track {
  height: 4px;
  border-radius: var(--skb-radius-pill);
  background: linear-gradient(to right, var(--skb-accent) var(--skb-fill), var(--skb-line-strong) var(--skb-fill));
}

.skb-range::-webkit-slider-thumb {
  box-sizing: border-box;
  width: 18px;
  height: 18px;
  margin-top: -7px;
  appearance: none;
  border: 2px solid var(--skb-accent);
  border-radius: 50%;
  background: var(--skb-surface);
  box-shadow: var(--skb-shadow-1);
}

.skb-range::-moz-range-track {
  height: 4px;
  border-radius: var(--skb-radius-pill);
  background: var(--skb-line-strong);
}

.skb-range::-moz-range-progress {
  height: 4px;
  border-radius: var(--skb-radius-pill);
  background: var(--skb-accent);
}

.skb-range::-moz-range-thumb {
  box-sizing: border-box;
  width: 18px;
  height: 18px;
  border: 2px solid var(--skb-accent);
  border-radius: 50%;
  background: var(--skb-surface);
  box-shadow: var(--skb-shadow-1);
}

/* The ring goes on the thumb, where the eye already is. */
.skb-range:focus-visible {
  outline: none;
}

.skb-range:focus-visible::-webkit-slider-thumb {
  box-shadow: 0 0 0 2px var(--skb-surface), 0 0 0 4px var(--skb-focus);
}

.skb-range:focus-visible::-moz-range-thumb {
  box-shadow: 0 0 0 2px var(--skb-surface), 0 0 0 4px var(--skb-focus);
}

.skb-range:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ── Text input and select ──────────────────────────────────────────────── */

.skb-input,
.skb-select {
  display: block;
  width: 100%;
  min-height: 36px;
  padding: 7px var(--skb-space-3);
  border: 1px solid var(--skb-line-strong);
  border-radius: var(--skb-radius-md);
  background-color: var(--skb-surface);
  color: var(--skb-ink);
  font: var(--skb-text-md) / 1.4 var(--skb-font-ui);
}

.skb-input::placeholder {
  color: var(--skb-ink-soft);
  opacity: 1;
}

textarea.skb-input {
  resize: vertical;
}

/* Chevron drawn with two gradients so it follows currentColor in every theme. */
.skb-select {
  padding-right: 32px;
  appearance: none;
  background-image:
    linear-gradient(45deg, transparent 50%, currentColor 50%),
    linear-gradient(135deg, currentColor 50%, transparent 50%);
  background-position: calc(100% - 17px) 55%, calc(100% - 12px) 55%;
  background-size: 5px 5px;
  background-repeat: no-repeat;
  cursor: pointer;
}

.skb-input:focus-visible,
.skb-select:focus-visible {
  outline-offset: 0;
  border-color: var(--skb-focus);
}

.skb-input:disabled,
.skb-select:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ── Field: label, optional value readout, control, hint ────────────────── */

.skb-field {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: baseline;
  gap: 6px var(--skb-space-3);
}

:where(.skb-field) > * {
  grid-column: 1 / -1;
  margin: 0;
}

.skb-field__label {
  grid-column: 1;
  color: var(--skb-ink);
  font-size: var(--skb-text-md);
  font-weight: 600;
}

.skb-field__value {
  grid-column: 2;
  color: var(--skb-ink-soft);
  font-size: var(--skb-text-sm);
  font-variant-numeric: tabular-nums;
}

.skb-field__hint {
  color: var(--skb-ink-soft);
  font-size: var(--skb-text-sm);
}

/* ── Card ───────────────────────────────────────────────────────────────── */

.skb-card {
  padding: var(--skb-space-4);
  border: 1px solid var(--skb-line);
  border-radius: var(--skb-radius-lg);
  background: var(--skb-surface);
  box-shadow: var(--skb-shadow-1);
}

/* ── Notice: a short explanation in the flow (restricted page, unreadable PDF) ── */

.skb-notice {
  margin: 0;
  padding: var(--skb-space-3) var(--skb-space-4);
  border-left: 3px solid var(--skb-accent);
  border-radius: var(--skb-radius-xs);
  background: var(--skb-surface-sunk);
  color: var(--skb-ink);
  font-size: var(--skb-text-sm);
}

.skb-notice--danger {
  border-left-color: var(--skb-danger);
  background: var(--skb-danger-tint);
}

/* ── Keyboard shortcut chip ─────────────────────────────────────────────── */

.skb-kbd {
  display: inline-block;
  min-width: 1.9em;
  padding: 1px 6px;
  border: 1px solid var(--skb-line-strong);
  border-bottom-width: 2px;
  border-radius: var(--skb-radius-xs);
  background: var(--skb-surface);
  color: var(--skb-ink);
  font: 600 var(--skb-text-xs) / 1.5 var(--skb-font-ui);
  text-align: center;
  white-space: nowrap;
  vertical-align: 0.1em;
}