/* Shared interactive components: panels, hotspots, quizzes, sliders,
   playground step cards, stat callouts, figure frames. */

@layer components {

  /* ---------- Panels & figures ---------- */

  .panel {
    background: linear-gradient(180deg, var(--panel-raised), var(--panel));
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    padding: var(--sp-4);
    box-shadow: var(--shadow);
  }

  .figure-frame {
    background: var(--bg-deep);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: var(--sp-3);
    position: relative;
  }
  .figure-frame > figcaption,
  .figure-caption {
    font-family: var(--font-mono);
    font-size: var(--fs-tiny);
    color: var(--text-500);
    letter-spacing: 0.04em;
    margin-top: var(--sp-2);
  }

  /* Corner ticks, like a technical drawing */
  .figure-frame::before, .figure-frame::after {
    content: "";
    position: absolute;
    inline-size: 14px;
    block-size: 14px;
    border: 1px solid var(--line-bright);
    pointer-events: none;
  }
  .figure-frame::before { top: -1px; left: -1px; border-width: 1px 0 0 1px; }
  .figure-frame::after { bottom: -1px; right: -1px; border-width: 0 1px 1px 0; }

  /* Traveling-wave figure (probes): short wave travels fast, long wave slow —
     speeds are schematic. Each loop shifts by exactly one wavelength, and the
     paths extend one wavelength past the viewBox so the loop is seamless.
     Reduced motion: the static figure stands on its own. */
  .wave-fast { --wave-period: -36px; }
  .wave-slow { --wave-period: -160px; }
  @media (prefers-reduced-motion: no-preference) {
    .wave-fast { animation: wave-travel 0.45s linear infinite; }
    .wave-slow { animation: wave-travel 6s linear infinite; }
  }
  @keyframes wave-travel {
    to { transform: translateX(var(--wave-period)); }
  }

  .stat {
    font-family: var(--font-mono);
    color: var(--text-100);
  }
  .stat .num {
    font-size: clamp(1.8rem, 1rem + 2.4vw, 2.8rem);
    font-weight: 600;
    color: var(--accent);
    display: block;
    line-height: 1.1;
  }
  .stat .label {
    font-size: var(--fs-tiny);
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--text-500);
  }
  /* unit symbols keep their case — uppercasing turns µA into ΜA (reads as mega-amps) */
  .stat .label .unit { text-transform: none; }

  .footnote {
    font-size: var(--fs-small);
    color: var(--text-500);
    border-inline-start: 2px solid var(--line-bright);
    padding-inline-start: var(--sp-2);
    margin-top: var(--sp-3);
  }

  .two-col {
    display: grid;
    gap: var(--sp-4);
    align-items: start;
  }
  @media (min-width: 56rem) {
    .two-col { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); }
    .two-col.flip { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); }
    .two-col.flip > :first-child { order: 2; }
    .two-col.flip > :last-child { order: 1; }
  }

  .card-grid {
    display: grid;
    gap: var(--sp-3);
    grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr));
  }

  /* ---------- Controls ---------- */

  .control-row {
    display: flex;
    align-items: center;
    gap: var(--sp-2);
    flex-wrap: wrap;
    margin-block: var(--sp-2);
    font-family: var(--font-mono);
    font-size: var(--fs-small);
  }
  .control-row label { color: var(--text-500); white-space: nowrap; }
  .control-row output {
    color: var(--accent);
    min-inline-size: 6.5ch;
    font-variant-numeric: tabular-nums;
  }

  input[type="range"] {
    appearance: none;
    flex: 1 1 10rem;
    min-inline-size: 8rem;
    block-size: 24px;
    background: transparent;
    cursor: pointer;
  }
  input[type="range"]::-webkit-slider-runnable-track {
    block-size: 4px;
    border-radius: 2px;
    background: linear-gradient(to right, var(--accent-dim), var(--accent));
  }
  input[type="range"]::-moz-range-track {
    block-size: 4px;
    border-radius: 2px;
    background: linear-gradient(to right, var(--accent-dim), var(--accent));
  }
  input[type="range"]::-webkit-slider-thumb {
    appearance: none;
    inline-size: 18px;
    block-size: 18px;
    margin-top: -7px;
    border-radius: 50%;
    background: var(--text-100);
    border: 2px solid var(--accent);
    box-shadow: var(--glow-accent);
  }
  input[type="range"]::-moz-range-thumb {
    inline-size: 14px;
    block-size: 14px;
    border-radius: 50%;
    background: var(--text-100);
    border: 2px solid var(--accent);
    box-shadow: var(--glow-accent);
  }
  input[type="range"]:disabled { opacity: 0.35; cursor: not-allowed; }

  .btn {
    font-family: var(--font-mono);
    font-size: var(--fs-small);
    letter-spacing: 0.04em;
    color: var(--text-100);
    background: var(--ink-700);
    border: 1px solid var(--line-bright);
    border-radius: 999px;
    padding: 0.5rem 1.1rem;
    cursor: pointer;
    min-block-size: 24px;
  }
  .btn:hover:not(:disabled) { background: var(--ink-600); }
  .btn:active:not(:disabled) { background: var(--ink-800); transform: scale(0.97); }
  .btn:disabled { opacity: 0.45; cursor: not-allowed; }
  .btn.primary {
    background: var(--accent);
    border-color: var(--accent);
    color: var(--bg-deep);
    font-weight: 600;
  }
  .btn.primary:hover:not(:disabled) {
    background: color-mix(in oklab, var(--accent) 80%, white);
  }
  .btn.primary:active:not(:disabled) {
    background: color-mix(in oklab, var(--accent) 70%, var(--ink-800));
  }
  .btn.ghost { background: transparent; }

  .seg-toggle {
    display: inline-flex;
    border: 1px solid var(--line-bright);
    border-radius: 999px;
    overflow: hidden;
  }
  .seg-toggle button {
    font-family: var(--font-mono);
    font-size: var(--fs-small);
    background: transparent;
    color: var(--text-500);
    border: 0;
    padding: 0.45rem 1rem;
    cursor: pointer;
  }
  .seg-toggle button:active { opacity: 0.8; }
  .seg-toggle button:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: -2px;
  }
  .seg-toggle button[aria-pressed="true"] {
    background: var(--accent);
    color: var(--bg-deep);
    font-weight: 600;
  }

  /* ---------- SVG hotspots ---------- */

  .hotspot {
    cursor: pointer;
  }
  .hotspot .hit { fill: transparent; }
  /* zero-size shadow as base so the glow fades in instead of popping */
  .hotspot .hotspot-shape {
    filter: drop-shadow(0 0 0 transparent);
    transition: filter 0.25s ease;
  }
  .hotspot:hover .hotspot-shape,
  .hotspot:focus-visible .hotspot-shape,
  .hotspot.active .hotspot-shape {
    filter: drop-shadow(0 0 6px var(--accent));
  }
  .hotspot.active .hotspot-shape { stroke: var(--accent); stroke-width: 2; }
  svg.has-active .hotspot:not(.active) { opacity: 0.38; }
  .hotspot { transition: opacity 0.25s ease; }

  .info-card {
    background: var(--panel-raised);
    border: 1px solid var(--line-bright);
    border-radius: var(--radius);
    padding: var(--sp-3);
    min-block-size: 9rem;
  }
  .info-card h3 { margin-bottom: var(--sp-1); }
  .info-card .stat { margin-top: var(--sp-2); }
  .info-card p { font-size: var(--fs-small); }

  /* One-shot cue when a panel's content is swapped in place (explorer info
     cards, lifecycle phase detail) — without it, similar-length text swaps
     are easy to miss. JS re-triggers by removing and re-adding the class. */
  @media (prefers-reduced-motion: no-preference) {
    .panel-update { animation: panel-update 0.22s ease-out; }
  }
  @keyframes panel-update {
    from { opacity: 0.25; translate: 0 5px; }
  }

  /* ---------- Quiz ---------- */

  .quiz { display: grid; gap: var(--sp-3); }
  .quiz-score {
    font-family: var(--font-mono);
    font-size: var(--fs-small);
    color: var(--text-500);
  }
  .quiz-q {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: var(--sp-3);
  }
  .quiz-q legend, .quiz-q .q-text {
    font-weight: 600;
    color: var(--text-100);
    margin-bottom: var(--sp-2);
    font-family: var(--font-body);
  }
  .quiz-choices { display: grid; gap: var(--sp-1); }
  .quiz-choice {
    text-align: start;
    background: var(--ink-800);
    color: var(--text-300);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 0.6rem 0.9rem;
    cursor: pointer;
  }
  .quiz-choice:hover:not(:disabled) { border-color: var(--line-bright); color: var(--text-100); }
  .quiz-choice:active:not(:disabled) { background: color-mix(in oklab, var(--accent) 12%, var(--ink-800)); }
  .quiz-choice:disabled { cursor: default; }
  .quiz-choice.correct {
    border-color: var(--ok);
    background: color-mix(in oklab, var(--ok) 16%, var(--ink-800));
    color: var(--text-100);
  }
  .quiz-choice.wrong {
    border-color: var(--bad);
    background: color-mix(in oklab, var(--bad) 14%, var(--ink-800));
  }
  .quiz-why {
    font-size: var(--fs-small);
    color: var(--text-300);
    margin-top: var(--sp-2);
    padding-inline-start: var(--sp-2);
    border-inline-start: 2px solid var(--ok);
  }
  .quiz-why.wrong { border-inline-start-color: var(--bad); }

  /* ---------- Playground step cards ---------- */

  .steps { display: grid; gap: var(--sp-2); }
  .step-card {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: var(--sp-3);
    position: relative;
    transition: border-color 0.3s ease, opacity 0.3s ease;
  }
  .step-card .step-no {
    font-family: var(--font-mono);
    font-size: var(--fs-tiny);
    color: var(--text-500);
    letter-spacing: 0.15em;
  }
  .step-card h3 { font-family: var(--font-mono); font-size: 1rem; letter-spacing: 0.02em; }
  .step-card p { font-size: var(--fs-small); margin-top: var(--sp-1); }
  .step-card .step-actions { margin-top: var(--sp-2); display: flex; gap: var(--sp-2); align-items: center; flex-wrap: wrap; }

  /* Locked: dim the chrome, not the copy — text must stay readable. */
  .step-card[data-state="locked"] { opacity: 0.8; }
  .step-card[data-state="locked"] .step-no,
  .step-card[data-state="locked"] h3 { color: var(--text-500); }
  .step-card[data-state="ready"] { border-color: var(--accent); box-shadow: var(--glow-accent); }
  .step-card[data-state="done"] { border-color: var(--ok); }
  .step-card[data-state="done"]::after {
    content: "✓";
    position: absolute;
    top: var(--sp-2);
    right: var(--sp-3);
    color: var(--ok);
    font-weight: 700;
  }

  .history-panel {
    font-family: var(--font-mono);
    font-size: var(--fs-tiny);
    background: var(--bg-deep);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: var(--sp-2) var(--sp-3);
    min-block-size: 3rem;
  }
  .history-panel ol { margin: 0; padding-inline-start: 1.2rem; }
  .history-panel li { margin-block: 0.3rem; color: var(--text-300); }
  .history-panel li .args { color: var(--text-500); }
  .history-panel .hp-title {
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--text-500);
    margin-block: 0.4rem;
  }

  .result-card {
    border: 1px solid var(--peak);
    background: color-mix(in oklab, var(--peak) 9%, var(--panel));
    border-radius: var(--radius);
    padding: var(--sp-3);
    font-family: var(--font-mono);
    font-size: var(--fs-small);
  }
  .result-card dt { color: var(--text-500); font-size: var(--fs-tiny); letter-spacing: 0.1em; text-transform: uppercase; }
  .result-card dd { margin: 0 0 0.5rem; color: var(--peak); font-size: 1.1rem; }

  /* ---------- CTA cards (story end + cross-links) ---------- */

  .cta-card {
    display: block;
    text-decoration: none;
    color: var(--text-300);
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: var(--sp-3);
    transition: border-color 0.25s ease, translate 0.25s ease;
  }
  .cta-card:hover { border-color: var(--accent); color: var(--text-300); }
  @media (prefers-reduced-motion: no-preference) {
    .cta-card:hover { translate: 0 -3px; }
  }
  .cta-card:focus-visible { border-radius: var(--radius); }
  .cta-card .kicker { margin-bottom: var(--sp-1); }
  .cta-card h3 { margin-bottom: var(--sp-1); }
  .cta-card p { font-size: var(--fs-small); }

  /* ---------- Timeline (experiment page) ---------- */

  .timeline {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(7.5rem, 1fr));
    gap: var(--sp-1);
    counter-reset: phase;
  }
  .timeline-node {
    counter-increment: phase;
    font-family: var(--font-mono);
    font-size: var(--fs-tiny);
    letter-spacing: 0.04em;
    text-align: center;
    background: var(--panel);
    color: var(--text-300);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: var(--sp-2) var(--sp-1);
    cursor: pointer;
    position: relative;
  }
  .timeline-node::before {
    content: "0" counter(phase);
    display: block;
    color: var(--text-500);
    margin-bottom: 0.3rem;
    letter-spacing: 0.2em;
  }
  .timeline-node:hover { border-color: var(--line-bright); color: var(--text-100); }
  .timeline-node[aria-pressed="true"] {
    border-color: var(--accent);
    color: var(--text-100);
    box-shadow: var(--glow-accent);
  }
  .timeline-node[aria-pressed="true"]::before { color: var(--accent); }

  /* ---------- Technique cards ---------- */

  .tech-card {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    padding: var(--sp-3);
    display: grid;
    gap: var(--sp-2);
  }
  .tech-card .instruments {
    font-family: var(--font-mono);
    font-size: var(--fs-tiny);
    color: var(--muon);
    letter-spacing: 0.06em;
  }
  .tech-card .answers {
    font-size: var(--fs-small);
    color: var(--peak);
    font-style: italic;
  }

  /* ---------- Section sub-nav tabs (facility: overview / TS1 / TS2) ---------- */
  /* Folder-style tabs sitting on a baseline, placed directly above the first
     content section. Plain links — each tab is its own page, so the "tabbed
     view" needs no JS and keeps every page light and file://-safe. */

  .subnav {
    display: flex;
    align-items: flex-end;
    gap: 8px;
    flex-wrap: wrap;
    font-family: var(--font-mono);
    font-size: var(--fs-small);
    letter-spacing: 0.08em;
    border-bottom: 1px solid var(--line-bright);
    margin-top: var(--sp-3);
  }
  .subnav .subnav-label {
    color: var(--text-500);
    font-size: var(--fs-tiny);
    letter-spacing: 0.22em;
    padding: 0 var(--sp-2) 0.95rem 0;
  }
  .subnav a {
    position: relative;
    display: inline-flex;
    align-items: center;
    min-block-size: 44px;                /* tap target */
    padding: 0 1.25rem;
    color: var(--text-500);
    text-decoration: none;
    background: var(--bg);
    border: 1px solid var(--line);
    border-bottom: 0;
    border-radius: 10px 10px 0 0;
  }
  /* top indicator bar: hinted on hover, full-width on the selected tab */
  .subnav a::before {
    content: "";
    position: absolute;
    top: -1px;
    left: 50%;
    translate: -50%;
    inline-size: 0;
    block-size: 2px;
    border-radius: 0 0 2px 2px;
    background: var(--accent);
  }
  @media (prefers-reduced-motion: no-preference) {
    .subnav a { transition: color 0.18s ease, background-color 0.18s ease, border-color 0.18s ease; }
    .subnav a::before { transition: inline-size 0.18s ease; }
  }
  .subnav a:hover:not([aria-current="page"]),
  .subnav a:focus-visible:not([aria-current="page"]) {
    color: var(--text-100);
    background: var(--ink-700);
    border-color: var(--line-bright);
  }
  .subnav a:hover:not([aria-current="page"])::before,
  .subnav a:focus-visible:not([aria-current="page"])::before {
    inline-size: 45%;
  }
  /* selected: raised taller, bold accent text, full indicator, glow, and the
     gradient fades to the page background so the tab opens into the content */
  .subnav a[aria-current="page"] {
    color: var(--accent);
    font-weight: 600;
    min-block-size: 50px;
    background: linear-gradient(180deg, var(--ink-700), var(--bg) 85%);
    border-color: var(--line-bright);
    margin-bottom: -1px;
    box-shadow: 0 -8px 18px -10px color-mix(in oklab, var(--accent) 55%, transparent);
  }
  .subnav a[aria-current="page"]::before {
    left: 9px;
    translate: none;
    inline-size: calc(100% - 18px);
  }
}