/* ============================================
   RenDS — Classless Base Styles
   ============================================
   Beautiful defaults for semantic HTML.
   No classes needed — just write good HTML
   and it looks great automatically.

   Inspired by Pico CSS philosophy + Apple HIG.
   ============================================ */

/* ─── Headings ─── */
h1 {
  font-family: var(--font-heading, var(--font-sans, sans-serif));
  font-size: var(--display-md-size);
  font-weight: var(--display-md-weight);
  line-height: var(--display-md-leading);
  letter-spacing: var(--display-md-tracking, var(--tracking-tight));
  color: var(--color-text);
  margin-block: var(--space-8) var(--space-4);
}

h2 {
  font-family: var(--font-heading, var(--font-sans, sans-serif));
  font-size: var(--title-lg-size);
  font-weight: var(--title-lg-weight);
  line-height: var(--title-lg-leading);
  color: var(--color-text);
  margin-block: var(--space-6) var(--space-3);
}

h3 {
  font-family: var(--font-heading, var(--font-sans, sans-serif));
  font-size: var(--title-md-size);
  font-weight: var(--title-md-weight);
  line-height: var(--title-md-leading);
  color: var(--color-text);
  margin-block: var(--space-5) var(--space-2);
}

h4 {
  font-family: var(--font-heading, var(--font-sans, sans-serif));
  font-size: var(--title-sm-size);
  font-weight: var(--title-sm-weight);
  line-height: var(--title-sm-leading);
  color: var(--color-text);
  margin-block: var(--space-4) var(--space-2);
}

h5 {
  font-family: var(--font-heading, var(--font-sans, sans-serif));
  font-size: var(--headline-size);
  font-weight: var(--headline-weight);
  line-height: var(--headline-leading);
  color: var(--color-text);
  margin-block: var(--space-4) var(--space-2);
}

h6 {
  font-family: var(--font-heading, var(--font-sans, sans-serif));
  font-size: var(--body-size);
  font-weight: var(--weight-semibold);
  line-height: var(--leading-normal);
  color: var(--color-text-secondary);
  margin-block: var(--space-3) var(--space-2);
}

/* First heading: no top margin */
:is(h1, h2, h3, h4, h5, h6):first-child {
  margin-block-start: 0;
}

/* ─── Paragraphs ─── */
p {
  color: var(--color-text);
  margin-block: var(--space-3);
}

p:first-child {
  margin-block-start: 0;
}

p:last-child {
  margin-block-end: 0;
}

/* ─── Lead Paragraph ───
   Introductory / subtitle paragraph.
   Triggered by ARIA doc-subtitle role or .lead class. */
p[role="doc-subtitle"],
:is(h1, h2, h3) + p.lead {
  font-size: var(--lead-size);
  font-weight: var(--lead-weight);
  line-height: var(--lead-leading);
  letter-spacing: var(--lead-tracking);
  color: var(--color-text-secondary);
}

/* ─── Links ─── */
a:not([class]) {
  color: var(--color-text-link);
  text-decoration: underline;
  text-underline-offset: 0.15em;
  text-decoration-thickness: 1px;
  transition: color var(--duration-normal) var(--ease-out);
}

a:not([class]):hover {
  color: var(--color-text-link-hover);
  text-decoration-thickness: 2px;
}

a:not([class]):active {
  opacity: 0.8;
}

/* ─── Strong / Bold ─── */
strong, b {
  font-weight: var(--weight-semibold);
}

/* ─── Emphasis ─── */
em, i {
  font-style: italic;
}

/* ─── Small ─── */
small {
  font-size: var(--caption-size);
  color: var(--color-text-muted);
}

/* ─── Time ───
   Semantic date/time. Tabular numerals so dates and
   times align vertically in lists, tables, logs. */
time {
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum";
}

/* ─── Mark ─── */
mark {
  background-color: var(--yellow-100);
  color: var(--color-text);
  padding-inline: var(--space-1);
  border-radius: var(--radius-xs);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) mark {
    background-color: var(--yellow-800);
  }
}

[data-theme="dark"] mark {
  background-color: var(--yellow-800);
}

/* ─── Del / Ins ───
   Semantic edit tracking. Del = removed, Ins = added.
   Styled with muted/subtle color fills so that, together,
   they form a lightweight visual "diff" — useful for
   changelogs, AI edit suggestions, revision views.
   No classes required: any <del> or <ins> in the page
   picks up the treatment automatically. */
del {
  text-decoration: line-through;
  text-decoration-thickness: 1px;
  text-decoration-color: var(--color-danger);
  background-color: var(--color-danger-subtle);
  color: var(--color-text);
  padding-inline: 0.15em;
  border-radius: var(--radius-xs);
}

ins {
  /* No underline: the green subtle fill is enough to signal
     "added". Keeping underline would duplicate the signal
     and conflict with <a> underlines. */
  text-decoration: none;
  background-color: var(--color-success-subtle);
  color: var(--color-text);
  padding-inline: 0.15em;
  border-radius: var(--radius-xs);
}

/* Diff pair: when del and ins sit adjacent, they read as
   "this → that". A small gap makes the intent scannable. */
del + ins,
ins + del {
  margin-inline-start: 0.25em;
}

/* ─── Code (inline) ─── */
code:not(pre code) {
  font-family: var(--code-family);
  font-size: var(--code-size);
  background-color: var(--color-fill);
  color: var(--color-text);
  padding: 0.15em 0.4em;
  border-radius: var(--radius-sm);
  font-weight: var(--weight-medium);
}

/* ─── Code Blocks ─── */
pre {
  font-family: var(--code-family);
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
  background-color: var(--color-surface-sunken);
  color: var(--color-text);
  padding: var(--space-4);
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin-block: var(--space-4);
  border: 1px solid var(--color-border);
  tab-size: 2;
}

pre code {
  background: none;
  padding: 0;
  border-radius: 0;
  font-size: inherit;
}

/* ─── Kbd ─── */
kbd {
  font-family: var(--code-family);
  font-size: var(--caption-size);
  font-weight: var(--weight-medium);
  background-color: var(--color-surface-sunken);
  color: var(--color-text);
  border: 1px solid var(--color-border-strong);
  border-bottom-width: 2px;
  padding: 0.1em 0.4em;
  border-radius: var(--radius-sm);
  white-space: nowrap;
}

/* ─── Samp ───
   Sample output from a program. Monospace like <code>,
   but muted color so it reads as output vs. input code. */
samp {
  font-family: var(--code-family);
  font-size: var(--code-size);
  color: var(--color-text-secondary);
  background-color: var(--color-surface-sunken);
  padding: 0.15em 0.4em;
  border-radius: var(--radius-sm);
}

/* Inside <pre>, strip the pill treatment so samp
   blends into block formatting */
pre samp {
  background: none;
  padding: 0;
  border-radius: 0;
  font-size: inherit;
  color: inherit;
}

/* ─── Var ───
   Mathematical/programmatic variable. Italic is the
   classic convention. Inherits font-family from context
   so it blends into prose, and tabular-nums keeps any
   numeric subscripts/exponents aligned. */
var {
  font-style: italic;
  font-variant-numeric: tabular-nums;
  color: var(--color-text);
}

/* ─── Blockquote ─── */
blockquote {
  border-inline-start: 3px solid var(--color-accent);
  padding-inline-start: var(--space-4);
  margin-inline: 0;
  margin-block: var(--space-4);
  color: var(--color-text-secondary);
  font-style: italic;
}

blockquote > p {
  color: inherit;
}

/* ─── Cite ───
   Reference to a creative work, author, or source.
   Standalone: italic + muted. Inside a blockquote, it
   gets an em-dash prefix and separates from the quote. */
cite {
  font-style: italic;
  color: var(--color-text-secondary);
}

blockquote > cite,
blockquote > footer > cite,
blockquote > p + cite {
  display: block;
  font-style: normal;
  font-size: var(--caption-size);
  color: var(--color-text-secondary);
  margin-block-start: var(--space-2);
}

blockquote > cite::before,
blockquote > footer > cite::before,
blockquote > p + cite::before {
  content: "— ";
}

/* ─── Q (inline quote) ─── */
q {
  font-style: italic;
  color: var(--color-text-secondary);
}

/* ─── Lists ─── */
ul, ol {
  padding-inline-start: var(--space-6);
  margin-block: var(--space-3);
}

li {
  margin-block: var(--space-1);
  color: var(--color-text);
}

li::marker {
  color: var(--color-text-muted);
}

/* Nested lists */
:is(ul, ol) :is(ul, ol) {
  margin-block: var(--space-1);
}

/* Description lists */
dl {
  margin-block: var(--space-3);
}

dt {
  font-weight: var(--weight-semibold);
  color: var(--color-text);
  margin-block-start: var(--space-2);
}

dd {
  margin-inline-start: var(--space-4);
  color: var(--color-text-secondary);
}

/* ─── Horizontal Rule ─── */
hr {
  margin-block: var(--space-6);
  border-top-color: var(--color-separator);
}

/* ─── Figure / Figcaption ─── */
figure {
  margin-inline: 0;
  margin-block: var(--space-4);
}

figcaption {
  font-size: var(--caption-size);
  color: var(--color-text-muted);
  margin-block-start: var(--space-2);
  text-align: center;
}

/* ─── Table ─── */
table {
  width: 100%;
  margin-block: var(--space-4);
  font-size: var(--text-sm);
}

caption {
  caption-side: top;
  font-size: var(--label-size);
  font-weight: var(--weight-medium);
  color: var(--color-text-secondary);
  text-align: start;
  padding-block-end: var(--space-2);
}

thead {
  border-block-end: 2px solid var(--color-border-strong);
}

tfoot {
  border-block-start: 2px solid var(--color-border-strong);
  font-weight: var(--weight-medium);
  color: var(--color-text);
}

th {
  font-weight: var(--weight-semibold);
  text-align: start;
  padding: var(--space-2) var(--space-3);
  color: var(--color-text);
}

td {
  padding: var(--space-2) var(--space-3);
  color: var(--color-text-secondary);
  border-block-end: 1px solid var(--color-border);
}

tbody tr:hover {
  background-color: var(--color-fill);
}

/* ─── Forms (native) ─── */
label {
  display: block;
  font-size: var(--label-size);
  font-weight: var(--label-weight);
  color: var(--color-text);
  margin-block-end: var(--space-1);
}

/* ─── Fieldset & Legend ───
   Native HTML grouping for related form controls.
   Reset removes the browser default; Primitive Zero
   re-introduces a subtle group with the legend acting
   as a proper sub-heading. */
fieldset {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-4) var(--space-4) var(--space-3);
  margin-block: var(--space-4);
  min-inline-size: 0; /* prevent fieldset min-width quirk */
}

legend {
  padding-inline: var(--space-2);
  margin-inline-start: calc(var(--space-2) * -1);
  font-size: var(--body-size);
  font-weight: var(--weight-semibold);
  color: var(--color-text);
  line-height: var(--leading-normal);
}

input:not([type="checkbox"]):not([type="radio"]):not([type="range"]):not([type="color"]):not([type="file"]),
select,
textarea {
  display: block;
  width: 100%;
  min-height: var(--touch-min);
  padding: var(--space-2) var(--space-3);
  font-size: var(--body-size);
  color: var(--color-text);
  background-color: var(--color-input-bg);
  border: 1px solid var(--color-input-border);
  border-radius: var(--radius-md);
  transition:
    border-color var(--duration-normal) var(--ease-out),
    background-color var(--duration-normal) var(--ease-out),
    box-shadow var(--duration-normal) var(--ease-out);
}

input:not([type="checkbox"]):not([type="radio"]):not([type="range"]):not([type="color"]):not([type="file"]):hover,
select:hover,
textarea:hover {
  background-color: var(--color-input-bg-hover);
}

input:not([type="checkbox"]):not([type="radio"]):not([type="range"]):not([type="color"]):not([type="file"]):focus,
select:focus,
textarea:focus {
  /* Transparent outline is invisible in normal rendering but becomes
     system-colored in Windows Forced Colors mode, where box-shadow
     is stripped. Guarantees a visible focus ring in high contrast. */
  outline: 2px solid transparent;
  outline-offset: 2px;
  border-color: var(--color-input-border-focus);
  box-shadow: 0 0 0 3px var(--color-input-focus-ring);
  background-color: var(--color-input-bg-hover);
}

input:disabled,
select:disabled,
textarea:disabled {
  background-color: var(--color-input-disabled-bg);
  color: var(--color-input-disabled-text);
  cursor: not-allowed;
  opacity: 0.7;
}

::placeholder {
  color: var(--color-input-placeholder);
  opacity: 1;
}

/* ─── Select ─── */

/* Fallback: appearance: none + SVG chevron (all browsers) */
select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%238E8E93' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--space-3) center;
  padding-inline-end: var(--space-10);
}

/* Modern: appearance: base-select (Chrome 135+, Edge 135+)
   Enables full CSS control over the dropdown picker.
   BOTH select and ::picker(select) must opt in.
   Ref: Vanilla Web v3, Ch. 3 — Firtman / Open UI spec */
@supports (appearance: base-select) {
  /* ── Opt-in ── */
  select,
  select::picker(select) {
    appearance: base-select;
  }

  /* ── Trigger button ── */
  select {
    display: flex;
    align-items: center;
    background-image: none;
    padding-inline-end: var(--space-3);
  }

  /* Arrow pushed to far right */
  select::picker-icon {
    color: var(--color-text-muted);
    opacity: 0.6;
    margin-inline-start: auto;
    padding-inline-start: var(--space-3);
    transition: rotate var(--duration-fast) var(--ease-out);
  }

  select:open::picker-icon {
    rotate: 180deg;
  }

  /* Hide native checkmark — we use ::after instead */
  option::checkmark {
    display: none;
  }

  /* ── Dropdown popover ── */
  select::picker(select) {
    background: var(--color-surface-overlay);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: 0 4px 20px rgb(0, 0, 0, 0.08),
                0 1px 3px rgb(0, 0, 0, 0.06);
    padding: var(--space-1);
    margin-block-start: var(--space-1);
    overflow: clip;
  }

  /* ── Options ── */
  option {
    display: flex;
    align-items: center;
    padding: var(--space-2) var(--space-3);
    border-radius: 4px;
    color: var(--color-text);
    background: transparent;
    cursor: pointer;
  }

  option + option {
    margin-block-start: 1px;
  }

  option:hover {
    background: light-dark(var(--gray-50), var(--gray-800));
  }

  option:focus-visible,
  option:active {
    outline: 2px solid var(--color-accent);
    outline-offset: -2px;
    background: light-dark(var(--gray-50), var(--gray-800));
  }

  option:checked:not(:disabled) {
    background: light-dark(var(--blue-50), var(--blue-900));
    color: light-dark(var(--blue-700), var(--blue-200));
    font-weight: var(--weight-medium);
  }

  option:checked:not(:disabled)::after {
    content: "✓";
    margin-inline-start: auto;
    color: light-dark(var(--blue-600), var(--blue-300));
    font-weight: var(--weight-bold);
  }

  option:checked:hover {
    background: light-dark(var(--blue-100), var(--blue-800));
  }

  option:disabled {
    color: light-dark(var(--gray-500), var(--gray-400));
    cursor: not-allowed;
  }

  /* Hide placeholder option from dropdown */
  option[hidden] {
    display: none;
  }

  /* ── Optgroups ── */
  optgroup {
    padding: var(--space-1) 0;
    padding-inline-start: 0;
  }

  optgroup:not(:first-of-type) {
    border-block-start: 1px solid var(--color-border);
    margin-block-start: var(--space-2);
    padding-block-start: var(--space-2);
  }

  optgroup > legend,
  optgroup > label {
    padding: var(--space-1) var(--space-3);
    margin-inline-start: var(--space-3);
  }

  /* ── Open state on trigger — no double ring ── */
  select:open {
    border-color: var(--color-input-border-focus);
    box-shadow: 0 0 0 3px var(--color-input-focus-ring);
  }
}

/* ─── Buttons (native) ─── */
button:not([class]),
input[type="submit"],
input[type="reset"],
input[type="button"] {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: var(--touch-min);
  padding: var(--space-2) var(--space-4);
  font-size: var(--label-lg-size);
  font-weight: var(--label-lg-weight);
  color: var(--color-on-accent);
  background-color: var(--color-accent);
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition:
    background-color var(--duration-normal) var(--ease-out),
    transform var(--duration-fast) var(--ease-out);
  user-select: none;
}

button:not([class]):hover,
input[type="submit"]:hover,
input[type="reset"]:hover,
input[type="button"]:hover {
  background-color: var(--color-accent-hover);
}

button:not([class]):active,
input[type="submit"]:active,
input[type="reset"]:active,
input[type="button"]:active {
  background-color: var(--color-accent-active);
  transform: scale(0.98);
}

button:not([class]):disabled,
input[type="submit"]:disabled {
  background-color: var(--color-disabled-bg);
  color: var(--color-disabled-text);
  cursor: not-allowed;
  transform: none;
}

/* ─── Checkbox & Radio ─── */
input[type="checkbox"],
input[type="radio"] {
  width: 1.25rem;
  height: 1.25rem;
  accent-color: var(--color-accent);
  cursor: pointer;
  vertical-align: middle;
}

/* ─── Range ─── */
input[type="range"] {
  accent-color: var(--color-accent);
  cursor: pointer;
}

/* ─── File ─── */
input[type="file"] {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
}

input[type="file"]::file-selector-button {
  font: inherit;
  font-size: var(--label-size);
  font-weight: var(--label-weight);
  padding: var(--space-1) var(--space-3);
  margin-inline-end: var(--space-3);
  background-color: var(--color-fill);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--duration-normal) var(--ease-out);
}

input[type="file"]::file-selector-button:hover {
  background-color: var(--color-fill-hover);
}

/* ─── Output ───
   Form-associated element for showing a calculated
   result. Tabular numerics so values align vertically
   when stacked; medium weight to read as "result". */
output {
  display: inline-block;
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum";
  font-weight: var(--weight-medium);
  color: var(--color-text);
}

/* ─── Progress ─── */
progress {
  width: 100%;
  height: 0.5rem;
  appearance: none;
  border-radius: var(--radius-full);
  overflow: hidden;
  background-color: var(--color-fill);
}

progress::-webkit-progress-bar {
  background-color: var(--color-fill);
  border-radius: var(--radius-full);
}

progress::-webkit-progress-value {
  background-color: var(--color-accent);
  border-radius: var(--radius-full);
  transition: width var(--duration-slow) var(--ease-out);
}

progress::-moz-progress-bar {
  background-color: var(--color-accent);
  border-radius: var(--radius-full);
}

/* ─── Meter ───
   Semantic gauge: renders with different colors based on
   value vs. low/high/optimum attributes.
     - optimum range  → success
     - sub-optimum    → warning
     - far from opt.  → danger
   Browsers require vendor-prefixed pseudo-elements. */
meter {
  width: 100%;
  height: 0.5rem;
  appearance: none;
  border: none;
  border-radius: var(--radius-full);
  overflow: hidden;
  background-color: var(--color-fill);
}

/* Accessibility note:
   The semantic --color-success/warning/danger tokens are
   tuned for text and icons on surface backgrounds. On the
   meter's gray track they drop below the 3:1 UI contrast
   minimum in light mode. We use light-dark() to swap to
   darker variants on light backgrounds, keeping the Apple
   -400 tones on dark backgrounds where they pop. */

/* WebKit (Chrome, Safari, Edge) */
meter::-webkit-meter-bar {
  background-color: var(--color-fill);
  border: none;
  border-radius: var(--radius-full);
}

meter::-webkit-meter-optimum-value {
  background-color: light-dark(var(--green-600), var(--green-400));
  border-radius: var(--radius-full);
  transition: width var(--duration-slow) var(--ease-out);
}

meter::-webkit-meter-suboptimum-value {
  background-color: light-dark(var(--orange-600), var(--orange-400));
  border-radius: var(--radius-full);
  transition: width var(--duration-slow) var(--ease-out);
}

meter::-webkit-meter-even-less-good-value {
  background-color: light-dark(var(--red-500), var(--red-400));
  border-radius: var(--radius-full);
  transition: width var(--duration-slow) var(--ease-out);
}

/* Firefox */
meter::-moz-meter-bar {
  border-radius: var(--radius-full);
}

meter:-moz-meter-optimum::-moz-meter-bar {
  background-color: light-dark(var(--green-600), var(--green-400));
}

meter:-moz-meter-sub-optimum::-moz-meter-bar {
  background-color: light-dark(var(--orange-600), var(--orange-400));
}

meter:-moz-meter-sub-sub-optimum::-moz-meter-bar {
  background-color: light-dark(var(--red-500), var(--red-400));
}

/* ─── Details / Summary (Accordion) ─── */
details {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-3) var(--space-4);
  margin-block: var(--space-2);
}

details[open] {
  padding-block-end: var(--space-4);
}

summary {
  font-weight: var(--weight-medium);
  color: var(--color-text);
  padding: var(--space-1) 0;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
}

summary::after {
  content: '';
  width: 0.5rem;
  height: 0.5rem;
  border-inline-end: 2px solid var(--color-text-muted);
  border-bottom: 2px solid var(--color-text-muted);
  transform: rotate(-45deg);
  transition: transform var(--duration-normal) var(--ease-out);
  flex-shrink: 0;
}

details[open] > summary::after {
  transform: rotate(45deg);
}

summary::-webkit-details-marker {
  display: none;
}

details[open] > summary {
  margin-block-end: var(--space-3);
  padding-block-end: var(--space-3);
  border-block-end: 1px solid var(--color-border);
}

/* ─── Dialog (native) ─── */
dialog {
  background-color: var(--color-surface-overlay);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  padding: var(--space-6);
  max-width: min(600px, 90vw);
  width: 100%;
  color: var(--color-text);
}

dialog::backdrop {
  background-color: var(--color-overlay);
}

/* ─── Iframe ───
   Embedded content (YouTube, Vimeo, maps, etc.).
   16:9 aspect-ratio is the web's de facto video default,
   so an <iframe> "just works" without a wrapper. If the
   content isn't video, override aspect-ratio locally. */
iframe {
  display: block;
  max-width: 100%;
  width: 100%;
  aspect-ratio: 16 / 9;
  border: none;
  border-radius: var(--radius-md);
  background-color: var(--color-surface-sunken);
}

/* ─── Audio ───
   Native audio player. Full width matches the <video>
   treatment in reset.css for consistent media blocks. */
audio {
  display: block;
  width: 100%;
}

/* ─── Abbr ─── */
abbr[title] {
  text-decoration: underline dotted;
  cursor: help;
}

/* ─── Address ─── */
address {
  font-style: normal;
  color: var(--color-text-secondary);
}

/* ─── Sup / Sub ─── */
sup, sub {
  font-size: 0.75em;
}