/* Andolfatto Physics Lab — the whole visual identity, in one file.
 *
 * Restrained on purpose. The audience is a curious teenager, a student, or an adult who
 * likes physics — not a buyer of enterprise software and not a child. So: one accent
 * colour, generous line length limits, real typographic hierarchy, tabular numerals for
 * anything measured, and no illustration where a diagram would do.
 *
 * Fenix Spoon's own pages are plain system-font documents with a single blue accent;
 * this stays in that family rather than inventing a second identity for a project built
 * on top of it.
 */

:root {
  color-scheme: light dark;

  --ink: #14181f;
  --ink-soft: #4a5464;
  --ink-faint: #6b7686;
  --surface: #ffffff;
  --surface-sunken: #f4f6f9;
  --surface-raised: #ffffff;
  --line: #dde2ea;
  --line-strong: #c3ccd8;
  --accent: #2563eb;
  --accent-soft: #eaf0fe;
  --accent-ink: #1d4ed8;
  --warn: #b45309;
  --warn-soft: #fdf4e3;
  --ok: #15803d;

  --radius: 8px;
  --radius-lg: 12px;
  --measure: 68ch;

  --font-text:
    ui-sans-serif, system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, 'SF Mono', 'JetBrains Mono', Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #e8ecf2;
    --ink-soft: #a3adbd;
    --ink-faint: #7d8798;
    --surface: #0f1218;
    --surface-sunken: #151a22;
    --surface-raised: #181e27;
    --line: #262d38;
    --line-strong: #39424f;
    --accent: #6b9bff;
    --accent-soft: #1a2438;
    --accent-ink: #9dbcff;
    --warn: #e0a14a;
    --warn-soft: #2a2116;
    --ok: #5bbd7f;
  }
}

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

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--surface);
  color: var(--ink);
  font-family: var(--font-text);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: 1080px;
  margin-inline: auto;
  padding: 0 1.25rem;
}

.prose {
  max-width: var(--measure);
}

a {
  color: var(--accent-ink);
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

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

h1,
h2,
h3 {
  line-height: 1.25;
  letter-spacing: -0.015em;
  margin: 0 0 0.5rem;
  font-weight: 620;
}

h1 {
  font-size: clamp(1.75rem, 1.2rem + 2vw, 2.5rem);
}

h2 {
  font-size: clamp(1.2rem, 1rem + 0.8vw, 1.5rem);
}

h3 {
  font-size: 1.02rem;
  font-weight: 640;
}

p {
  margin: 0 0 1rem;
}

code,
kbd,
.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

code {
  font-size: 0.88em;
  background: var(--surface-sunken);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0.08em 0.34em;
}

/* ---------------------------------------------------------------- site chrome */

.site-header {
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 20;
}

.site-header .wrap {
  display: flex;
  align-items: center;
  gap: 1rem;
  min-height: 58px;
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 0.5rem;
  font-weight: 640;
  letter-spacing: -0.01em;
  color: var(--ink);
  text-decoration: none;
}

.brand .mark {
  color: var(--accent);
  font-size: 1.05em;
}

.brand .sub {
  color: var(--ink-faint);
  font-weight: 400;
  font-size: 0.82rem;
}

.site-nav {
  margin-left: auto;
  display: flex;
  gap: 1.1rem;
  font-size: 0.9rem;
}

.site-nav a {
  color: var(--ink-soft);
  text-decoration: none;
}

.site-nav a:hover,
.site-nav a[aria-current='page'] {
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.site-footer {
  border-top: 1px solid var(--line);
  margin-top: 4rem;
  padding: 2rem 0 3rem;
  color: var(--ink-faint);
  font-size: 0.86rem;
}

.site-footer .wrap {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 1.5rem;
  align-items: baseline;
}

.site-footer a {
  color: var(--ink-soft);
}

/* ---------------------------------------------------------------- disclaimer */

.disclaimer {
  border: 1px solid var(--line-strong);
  border-left: 3px solid var(--warn);
  background: var(--warn-soft);
  border-radius: var(--radius);
  padding: 0.7rem 0.95rem;
  font-size: 0.88rem;
  color: var(--ink-soft);
  margin: 1.25rem 0;
}

.disclaimer strong {
  color: var(--ink);
}

/* ---------------------------------------------------------------- hero + cards */

.hero {
  padding: 3rem 0 1rem;
}

.hero .lede {
  font-size: 1.12rem;
  color: var(--ink-soft);
  max-width: var(--measure);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
  padding: 0;
  list-style: none;
}

.card {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--surface-raised);
  padding: 1.15rem;
  gap: 0.5rem;
}

.card--available {
  border-color: var(--line-strong);
}

.card--planned {
  background: var(--surface-sunken);
  color: var(--ink-faint);
}

.card--planned h3 {
  color: var(--ink-soft);
}

.card h3 {
  margin: 0;
}

.card p {
  margin: 0;
  font-size: 0.92rem;
  color: var(--ink-soft);
  flex: 1;
}

.card--planned p {
  color: var(--ink-faint);
}

.card__foot {
  margin-top: 0.35rem;
  font-size: 0.88rem;
}

.badge {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 0.15rem 0.45rem;
  border-radius: 999px;
  border: 1px solid currentColor;
  align-self: flex-start;
}

.badge--available {
  color: var(--ok);
}

.badge--planned {
  color: var(--ink-faint);
}

.badge--mock {
  color: var(--accent-ink);
}

.badge--fenics {
  color: var(--warn);
}

/* ---------------------------------------------------------------- mode table */

.modes {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
  margin: 1.25rem 0;
}

.mode {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem;
  background: var(--surface-raised);
}

.mode h3 {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.4rem;
}

.mode ul {
  margin: 0;
  padding-left: 1.1rem;
  font-size: 0.9rem;
  color: var(--ink-soft);
}

/* ---------------------------------------------------------------- experiment stage */

.experiment {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: minmax(0, 1fr);
  margin: 1.5rem 0;
}

@media (min-width: 940px) {
  .experiment {
    grid-template-columns: minmax(0, 1fr) 310px;
    align-items: start;
  }
}

.stage {
  position: relative;
  aspect-ratio: 3 / 2;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface-sunken);
}

/* The editor is transparent and layers straight over the field viewer — the arrangement
   Fenix Spoon's own airfoil demo uses. */
.stage fs-viewer,
.stage fs-geometry-2d {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

fs-geometry-2d {
  --fs-outline-fill: rgba(18, 22, 30, 0.5);
  --fs-outline-stroke: #ffffff;
  --fs-handle-fill: #ffffff;
  --fs-handle-stroke: #2563eb;
  --fs-handle-focus: #e0a14a;
  --fs-hull-stroke: rgba(255, 255, 255, 0.32);
}

.panel {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-raised);
  padding: 1rem;
}

.panel + .panel {
  margin-top: 1rem;
}

.panel > h3 {
  margin: 0 0 0.75rem;
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-faint);
  font-weight: 620;
}

/* ---------------------------------------------------------------- controls */

.field {
  display: grid;
  gap: 0.3rem;
  margin-bottom: 0.9rem;
}

.field:last-child {
  margin-bottom: 0;
}

.field__label {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--ink-soft);
}

.field__value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.82rem;
  color: var(--ink);
}

.field__hint {
  font-size: 0.76rem;
  color: var(--ink-faint);
  line-height: 1.45;
}

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

select,
input[type='number'] {
  width: 100%;
  font: inherit;
  font-size: 0.9rem;
  padding: 0.35rem 0.5rem;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: 6px;
}

.check {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.85rem;
  color: var(--ink-soft);
}

.check input {
  accent-color: var(--accent);
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
}

button {
  font: inherit;
  font-size: 0.92rem;
  font-weight: 550;
  padding: 0.45rem 1rem;
  border-radius: 6px;
  border: 1px solid var(--line-strong);
  background: var(--surface);
  color: var(--ink);
  cursor: pointer;
}

button:hover:not(:disabled) {
  border-color: var(--ink-faint);
}

button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

button.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

button.primary:hover:not(:disabled) {
  background: var(--accent-ink);
  border-color: var(--accent-ink);
}

button:focus-visible,
a:focus-visible,
select:focus-visible,
input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ---------------------------------------------------------------- status */

.status-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 0.9rem;
  margin-top: 0.75rem;
  font-size: 0.86rem;
  color: var(--ink-soft);
  min-height: 1.9em;
}

.status-bar progress {
  width: 150px;
  height: 6px;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--ink-faint);
  flex: none;
}

.status-dot[data-state='running'] {
  background: var(--accent);
  animation: pulse 1.2s ease-in-out infinite;
}

.status-dot[data-state='done'] {
  background: var(--ok);
}

.status-dot[data-state='error'] {
  background: var(--warn);
}

@keyframes pulse {
  50% {
    opacity: 0.3;
  }
}

@media (prefers-reduced-motion: reduce) {
  .status-dot[data-state='running'] {
    animation: none;
  }
}

.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(96px, 1fr));
  gap: 0.6rem 1rem;
  margin: 0;
}

.stats div {
  display: grid;
  gap: 0.1rem;
}

.stats dt {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-faint);
}

.stats dd {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.98rem;
  color: var(--ink);
}

.artifacts {
  font-size: 0.85rem;
}

.artifacts:empty {
  display: none;
}

/* ---------------------------------------------------------------- didactics */

.lesson {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  margin: 2.5rem 0 0;
}

.lesson section {
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  background: var(--surface-raised);
}

.lesson section.is-caution {
  border-left-color: var(--warn);
}

.lesson h2 {
  font-size: 1rem;
  margin-bottom: 0.45rem;
}

.lesson p,
.lesson li {
  font-size: 0.92rem;
  color: var(--ink-soft);
}

.lesson p:last-child,
.lesson ul:last-child {
  margin-bottom: 0;
}

.lesson ol,
.lesson ul {
  margin: 0 0 1rem;
  padding-left: 1.2rem;
}

.lesson li + li {
  margin-top: 0.4rem;
}

.question {
  font-size: 1.08rem;
  color: var(--ink);
  font-weight: 500;
}

/* ---------------------------------------------------------------- notices */

.notice {
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  padding: 0.7rem 0.95rem;
  font-size: 0.88rem;
  margin: 1rem 0;
  background: var(--surface-sunken);
  color: var(--ink-soft);
}

.notice--warn {
  border-left: 3px solid var(--warn);
  background: var(--warn-soft);
}

.notice[hidden] {
  display: none;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}