/*
 * diladiff project page — forked from jmlemercier.github.io
 * teal/copper palette, IBM Plex Mono headings, light + dark
 */

/* ========== Theme tokens ========== */
:root {
  --color-bg: #f5f3ec;
  --color-text: #1f2d36;
  --color-text-secondary: #8a98a0;
  --color-border: #c3c0b6;
  --color-accent: #2b5f6e;
  --color-accent-light: rgba(43, 95, 110, 0.10);
  --color-link: #1f2d36;
  --color-link-hover: #a86a3d;
  --color-figure-bg: #ffffff;

  --font-size-base: 16px;
  --font-size-sm: 14px;
  --font-size-md: 18px;
  --font-size-lg: 22px;
  --font-size-xl: clamp(28px, 4vw, 44px);
  --font-size-xxl: clamp(32px, 5vw, 56px);

  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: 3rem;
  --space-xl: 4rem;
  --space-xxl: 6rem;

  --max-width: 1200px;
  --content-width: 860px;
  --border-width: 2px;

  --font-mono: 'IBM Plex Mono', 'Courier New', monospace;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
  --line-height-tight: 1.2;
  --line-height-normal: 1.6;
  --line-height-relaxed: 1.8;
}

[data-theme="dark"] {
  --color-bg: #161c22;
  --color-text: #d6dcd6;
  --color-text-secondary: #7a8a8e;
  --color-border: #3a4248;
  --color-accent: #4e8493;
  --color-accent-light: rgba(78, 132, 147, 0.15);
  --color-link: #d6dcd6;
  --color-link-hover: #c89070;
  --color-figure-bg: #f5f3ec;
}

/* ========== Reset & base ========== */
* { margin: 0; padding: 0; box-sizing: border-box; }

html {
  font-size: var(--font-size-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: var(--line-height-normal);
  overflow-x: hidden;
  transition: background-color 0.25s ease, color 0.25s ease;
}

/* ========== Typography ========== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-mono);
  font-weight: 700;
  line-height: var(--line-height-tight);
  margin-bottom: var(--space-sm);
  letter-spacing: -0.02em;
}

h1 { font-size: var(--font-size-xxl); margin-bottom: var(--space-md); }

h2 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--space-md);
  margin-top: var(--space-xl);
  border-left: var(--border-width) solid var(--color-accent);
  padding-left: var(--space-sm);
}

h3 {
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-sm);
  margin-top: var(--space-lg);
}

h4.sub {
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: var(--font-size-md);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  margin-top: var(--space-md);
  margin-bottom: var(--space-xs);
}

p {
  margin-bottom: var(--space-sm);
  max-width: 70ch;
}

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

a:hover {
  color: var(--color-link-hover);
  border-bottom-color: var(--color-link-hover);
}

code, pre {
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
}

pre {
  background: var(--color-accent-light);
  border: 1px solid var(--color-border);
  padding: var(--space-sm);
  overflow-x: auto;
  line-height: var(--line-height-normal);
  white-space: pre-wrap;
  word-break: break-word;
}

pre code { background: none; padding: 0; }

code:not(pre code) {
  background: var(--color-accent-light);
  padding: 0.1em 0.35em;
  border-radius: 2px;
}

/* ========== Layout ========== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.content { max-width: var(--content-width); margin: 0 auto; }

/* ========== Top bar ========== */
.topbar {
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-sm) 0;
  margin-bottom: var(--space-lg);
}

.topbar-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
}

.topbar a { border-bottom: none; color: var(--color-text-secondary); }
.topbar a:hover { color: var(--color-link-hover); }

.theme-toggle {
  background: none;
  border: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  cursor: pointer;
  padding: 0.35em 0.7em;
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  border-radius: 2px;
  transition: all 0.2s ease;
}
.theme-toggle:hover { color: var(--color-link-hover); border-color: var(--color-link-hover); }
.theme-toggle .sun { display: none; }
[data-theme="dark"] .theme-toggle .moon { display: none; }
[data-theme="dark"] .theme-toggle .sun { display: inline; }

/* ========== Hero ========== */
.hero { margin-bottom: var(--space-lg); }

.hero .venue {
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-sm);
}

.hero h1 {
  font-size: clamp(28px, 4.2vw, 48px);
  margin-bottom: var(--space-md);
}

.authors {
  font-family: var(--font-mono);
  font-size: var(--font-size-md);
  margin-bottom: var(--space-sm);
  max-width: none;
}

.authors .author { white-space: nowrap; }
.authors .sep { color: var(--color-text-secondary); }
.authors .corr { color: var(--color-accent); }

.affiliations {
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-md);
}

.action-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
}

.action-btn {
  display: inline-block;
  padding: 0.6em 1.2em;
  border: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  letter-spacing: 0.04em;
  border-radius: 2px;
  transition: all 0.2s ease;
}
.action-btn:hover {
  background: var(--color-accent-light);
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* ========== Figures ========== */
figure {
  margin: var(--space-md) 0;
  background: var(--color-figure-bg);
  border: 1px solid var(--color-border);
  padding: var(--space-sm);
}

figure img { display: block; width: 100%; height: auto; }

figcaption {
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin-top: var(--space-sm);
  padding: 0 var(--space-xs);
  line-height: var(--line-height-normal);
}

figcaption b, figcaption strong {
  color: var(--color-text);
  font-weight: 700;
}

/* ========== Numbered prose steps (used for short HTML+LaTeX arguments) ========== */
.prose-steps {
  list-style: decimal;
  padding-left: var(--space-lg);
  margin: var(--space-md) 0;
}
.prose-steps > li {
  margin-bottom: var(--space-md);
  padding-left: var(--space-xs);
}
.prose-steps > li::marker {
  font-family: var(--font-mono);
  color: var(--color-accent);
  font-weight: 700;
}
.prose-steps strong { color: var(--color-text); }

/* ========== TL;DR card ========== */
.tldr {
  background: var(--color-accent-light);
  border-left: var(--border-width) solid var(--color-accent);
  padding: var(--space-sm) var(--space-md);
  margin: var(--space-md) 0 var(--space-lg);
}

.tldr h3 {
  font-size: var(--font-size-md);
  color: var(--color-accent);
  margin-bottom: var(--space-xs);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.tldr p { margin-bottom: 0; max-width: none; }

/* ========== Abstract ========== */
.abstract {
  font-size: var(--font-size-md);
  line-height: var(--line-height-relaxed);
}

/* ========== Method walkthrough — scrubber ========== */
.stepper {
  margin: var(--space-md) 0 var(--space-lg);
  border: 1px solid var(--color-border);
  background: var(--color-figure-bg);
}

.stepper-stage {
  position: relative;
  aspect-ratio: var(--stage-aspect, 1600 / 864);
  overflow: hidden;
  background: #ffffff;
}

.stepper-slide {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: contain;
  opacity: 0;
  background: #ffffff;
  will-change: opacity;
}

.stepper-scrub {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md) var(--space-md);
  border-top: 1px solid var(--color-border);
  background: var(--color-bg);
}

.stepper-btn {
  background: none;
  border: 1px solid var(--color-border);
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: var(--font-size-md);
  padding: 0.2em 0.7em;
  cursor: pointer;
  border-radius: 2px;
  transition: all 0.2s ease;
  line-height: 1;
}

.stepper-btn:hover:not([disabled]) {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: var(--color-accent-light);
}

.stepper-btn[disabled] { opacity: 0.35; cursor: not-allowed; }

/* ---- Scrub track ---- */
.stepper-track {
  position: relative;
  padding: 0.5em 0 0.25em;
}

/* Native range input, restyled.
   Track height kept thin; thumb is a solid teal circle. */
.stepper-range {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 28px;
  background: transparent;
  margin: 0;
  cursor: grab;
  position: relative;
  z-index: 2;
}
.stepper-range:active { cursor: grabbing; }
.stepper-range:focus { outline: none; }
.stepper-range:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 4px;
  border-radius: 4px;
}

/* WebKit track */
.stepper-range::-webkit-slider-runnable-track {
  height: 4px;
  background: var(--color-border);
  border-radius: 2px;
}
.stepper-range::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--color-accent);
  border: 2px solid var(--color-bg);
  margin-top: -7px;
  box-shadow: 0 0 0 1px var(--color-accent);
  transition: transform 0.15s ease;
}
.stepper-range:hover::-webkit-slider-thumb { transform: scale(1.1); }
.stepper-range:active::-webkit-slider-thumb { transform: scale(1.15); }

/* Firefox track */
.stepper-range::-moz-range-track {
  height: 4px;
  background: var(--color-border);
  border-radius: 2px;
}
.stepper-range::-moz-range-progress {
  height: 4px;
  background: var(--color-accent);
  border-radius: 2px;
}
.stepper-range::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--color-accent);
  border: 2px solid var(--color-bg);
  box-shadow: 0 0 0 1px var(--color-accent);
  cursor: grab;
  transition: transform 0.15s ease;
}
.stepper-range:hover::-moz-range-thumb { transform: scale(1.1); }

/* ---- Tick labels under the track ----
 *
 * The native range thumb's centre walks from `thumb-radius` to
 * `track-width - thumb-radius`, NOT from 0 to track-width.
 * Each tick is absolutely positioned at the same x as the thumb
 * centre for its step (see --thumb-half = thumb radius).
 */
.stepper-ticks {
  position: relative;
  margin-top: 0.25em;
  height: 2.6em;
  --thumb-half: 9px;
}

.stepper-tick {
  position: absolute;
  top: 0;
  left: calc(var(--thumb-half) + (100% - 2 * var(--thumb-half)) * var(--p, 0));
  transform: translateX(-50%);
  background: none;
  border: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  cursor: pointer;
  color: var(--color-text-secondary);
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  transition: color 0.2s ease;
  text-align: center;
  line-height: 1.3;
  white-space: nowrap;
}

.tick-mark {
  width: 2px;
  height: 6px;
  background: var(--color-border);
  display: block;
  margin-bottom: 0.45em;
  transition: background 0.2s ease, height 0.2s ease;
}

.tick-label { display: block; }

.stepper-tick:hover { color: var(--color-accent); }
.stepper-tick:hover .tick-mark { background: var(--color-accent); }
.stepper-tick.is-active { color: var(--color-accent); font-weight: 700; }
.stepper-tick.is-active .tick-mark { background: var(--color-accent); height: 10px; }

/* ---- Caption stack (cross-fades with scrub) ---- */
.stepper-caption {
  position: relative;
  border-top: 1px solid var(--color-border);
  padding: var(--space-sm) var(--space-md) var(--space-md);
  background: var(--color-bg);
  min-height: 9em;
}

.caption-slot {
  position: absolute;
  inset: var(--space-sm) var(--space-md) var(--space-md);
  opacity: 0;
  pointer-events: none;
  transition: none;
  will-change: opacity;
}

.caption-slot.is-visible { pointer-events: auto; }

.stepper-caption .step-title {
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-xs);
}

.stepper-caption p {
  margin: 0;
  max-width: none;
  color: var(--color-text);
}

/* ========== Highlight list ========== */
.highlights {
  list-style: none;
  padding: 0;
  margin: var(--space-md) 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-sm);
}

.highlights li {
  border-left: var(--border-width) solid var(--color-accent);
  padding: var(--space-xs) var(--space-sm);
  background: var(--color-accent-light);
  font-size: var(--font-size-md);
}

.highlights li strong {
  font-family: var(--font-mono);
  color: var(--color-accent);
}

/* ========== Inline math fallback ========== */
.math { font-style: italic; font-family: 'Times New Roman', serif; }

/* ========== Footer ========== */
.site-footer {
  border-top: 1px solid var(--color-border);
  margin-top: var(--space-xxl);
  padding: var(--space-md) 0;
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.site-footer a { color: var(--color-text-secondary); border-bottom: none; }
.site-footer a:hover { color: var(--color-link-hover); }

/* ========== Responsive ========== */
@media (max-width: 700px) {
  .container { padding: 0 var(--space-sm); }
  h2 { margin-top: var(--space-lg); }
  .action-row { flex-direction: column; }
  .action-btn { text-align: center; }
  .stepper-scrub { padding: var(--space-sm); gap: var(--space-xs); }
  .stepper-tick .tick-label { font-size: 11px; }
  .stepper-caption { min-height: 11em; }
}