/* Berkeley Box Builders — UC Berkeley. Professional company-site look.
   Palette: Berkeley Blue #003262, California Gold #FDB515, Founders Rock #3B7EA1 */

:root {
  --berkeley-blue: #003262;
  --berkeley-deep: #00234a;
  --california-gold: #FDB515;
  --founders-rock: #3B7EA1;
  --bg: #f7f9fb;
  --card-bg: #ffffff;
  --text: #1c2733;
  --text-muted: #5b6b7b;
  --border: #dde4ea;
  --danger: #b3261e;
  --radius: 14px;
  --shadow: 0 1px 3px rgba(0, 20, 40, 0.08), 0 6px 24px rgba(0, 20, 40, 0.07);
  --font-serif: Georgia, "Times New Roman", serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

/* ── Under-construction banner ────────────────────────────────────── */
.construction-banner {
  background: var(--california-gold);
  color: var(--berkeley-deep);
  text-align: center;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 8px 16px;
}

.student-banner {
  background: var(--berkeley-blue);
  color: #eaf2f9;
  text-align: center;
  font-size: 0.85rem;
  padding: 7px 16px;
}

/* ── Student-project disclaimer ───────────────────────────────────── */
.disclaimer-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(0, 20, 40, 0.72);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.disclaimer-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  max-width: 560px;
  padding: 28px 30px;
}
.disclaimer-card h2 {
  margin: 14px 0 10px;
  font-family: var(--font-serif);
  color: var(--berkeley-blue);
  font-size: 1.35rem;
}
.disclaimer-card p,
.disclaimer-card li { color: var(--text); font-size: 0.95rem; }
.disclaimer-card ul { margin: 0 0 14px; padding-left: 20px; }
.disclaimer-card li { margin-bottom: 6px; }
.disclaimer-card .btn { width: 100%; }
.disclaimer-contact { color: var(--text-muted); font-size: 0.88rem; margin: 0 0 18px; }
.disclaimer-contact a { color: var(--founders-rock); }

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  -webkit-tap-highlight-color: transparent;
}

.hidden { display: none !important; }

.warning { color: var(--danger); font-size: 0.88rem; margin: 8px 0 0; }
.warning:empty { display: none; }

/* ── Header ─────────────────────────────────────────────────────── */

.site-header {
  background: var(--berkeley-blue);
  color: #fff;
  border-bottom: 3px solid var(--california-gold);
  position: sticky;
  top: 0;
  z-index: 50;
}

.header-inner {
  max-width: 1140px;
  margin: 0 auto;
  padding: 12px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand { display: flex; align-items: center; gap: 12px; min-width: 0; text-decoration: none; color: #fff; }

.brand-mark {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  background: var(--california-gold);
  color: var(--berkeley-blue);
  font-weight: 800;
  font-size: 1.05rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-serif);
  flex-shrink: 0;
}

.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-name { font-size: 1.12rem; font-weight: 400; letter-spacing: 0.2px; }
.brand-name strong { color: var(--california-gold); font-weight: 700; }
.brand-sub { font-size: 0.68rem; color: #b9c8d6; letter-spacing: 0.04em; }

.header-nav { display: flex; gap: 22px; }
.header-nav a {
  color: #dfe8f0;
  text-decoration: none;
  font-size: 0.9rem;
  padding: 4px 0;
  border-bottom: 2px solid transparent;
}
.header-nav a:hover { border-bottom-color: var(--california-gold); color: #fff; }

.header-right { display: flex; align-items: center; gap: 12px; }

.mode-badge {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(253, 181, 21, 0.16);
  color: var(--california-gold);
  border: 1px solid rgba(253, 181, 21, 0.45);
  white-space: nowrap;
}
.mode-badge.live {
  background: rgba(64, 190, 120, 0.16);
  color: #6fe0a3;
  border-color: rgba(64, 190, 120, 0.5);
}

/* ── Buttons ────────────────────────────────────────────────────── */

.btn {
  font: inherit;
  border-radius: 10px;
  padding: 10px 20px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background 0.15s, box-shadow 0.15s, opacity 0.15s, transform 0.1s;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}
.btn:disabled { opacity: 0.45; cursor: not-allowed; }
.btn:not(:disabled):active { transform: translateY(1px); }

.btn-big { min-height: 52px; font-size: 1.02rem; font-weight: 600; padding: 12px 26px; }

.btn-gold {
  background: var(--california-gold);
  color: var(--berkeley-blue);
  font-weight: 700;
}
.btn-gold:not(:disabled):hover { background: #ffc63d; box-shadow: 0 4px 14px rgba(253, 181, 21, 0.35); }

.btn-primary { background: var(--berkeley-blue); color: #fff; font-weight: 600; }
.btn-primary:not(:disabled):hover { background: #00457f; }

.btn-secondary { background: #fff; color: var(--berkeley-blue); border-color: var(--founders-rock); }
.btn-secondary:not(:disabled):hover { background: #eef5fa; }

.btn-outline { background: transparent; color: #fff; border-color: rgba(255, 255, 255, 0.55); }
.btn-outline:hover { border-color: #fff; background: rgba(255, 255, 255, 0.08); }

.btn-ghost { background: transparent; color: var(--text-muted); border-color: var(--border); }
.btn-ghost:not(:disabled):hover { background: #f0f3f6; }

.btn-link {
  background: none;
  border: none;
  color: var(--founders-rock);
  text-decoration: underline;
  padding: 12px 0;
  display: block;
  margin: 6px auto 0;
  font-size: 0.92rem;
  cursor: pointer;
}

.btn-tool {
  background: #fff;
  border-color: var(--border);
  color: var(--text);
  font-size: 0.86rem;
  padding: 9px 12px;
  min-height: 42px;
}
.btn-tool.is-active { background: var(--berkeley-blue); color: #fff; border-color: var(--berkeley-blue); }

/* ── Hero ───────────────────────────────────────────────────────── */

.hero {
  background:
    radial-gradient(1100px 500px at 75% -10%, rgba(59, 126, 161, 0.55), transparent 60%),
    radial-gradient(800px 420px at 15% 110%, rgba(253, 181, 21, 0.15), transparent 55%),
    linear-gradient(170deg, var(--berkeley-deep) 0%, var(--berkeley-blue) 70%);
  color: #fff;
  text-align: center;
  padding: 72px 20px 84px;
}

.hero-inner { max-width: 860px; margin: 0 auto; }

.hero-eyebrow {
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--california-gold);
  margin: 0 0 18px;
  font-weight: 600;
}

.hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(1.9rem, 5vw, 3.2rem);
  line-height: 1.15;
  margin: 0 0 20px;
  font-weight: 700;
}
.hero h1 em { color: var(--california-gold); font-style: normal; }

.hero-sub {
  font-size: clamp(1rem, 2vw, 1.15rem);
  color: #d4dfe9;
  max-width: 680px;
  margin: 0 auto 30px;
}

.hero-actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

.hero-note { margin: 22px 0 0; font-size: 0.8rem; color: #9fb3c4; }

.br-desktop { display: none; }
@media (min-width: 700px) { .br-desktop { display: block; } }

/* ── Feature band ───────────────────────────────────────────────── */

.feature-band { background: #fff; border-bottom: 1px solid var(--border); }

.feature-grid {
  max-width: 1140px;
  margin: 0 auto;
  padding: 46px 20px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 30px;
}

.feature-icon { font-size: 1.7rem; margin-bottom: 8px; }
.feature h3 { margin: 0 0 6px; font-size: 1.02rem; color: var(--berkeley-blue); }
.feature p { margin: 0; font-size: 0.9rem; color: var(--text-muted); }

/* ── Sections ───────────────────────────────────────────────────── */

.section { padding: 70px 20px; }
.section-inner { max-width: 1020px; margin: 0 auto; }

.section h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 3.4vw, 2.2rem);
  color: var(--berkeley-blue);
  margin: 0 0 10px;
}
.section-lead { color: var(--text-muted); max-width: 640px; margin: 0 0 36px; font-size: 1.02rem; }

.section-dark { background: var(--berkeley-blue); color: #e6edf4; }
.section-dark h2 { color: #fff; }
.section-dark .section-lead { color: #b9c8d6; }

/* How it works */
.how-grid {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 22px;
  counter-reset: step;
}
.how-grid li {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 22px;
  box-shadow: var(--shadow);
}
.how-num {
  display: inline-flex;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--california-gold);
  color: var(--berkeley-blue);
  font-weight: 800;
  align-items: center;
  justify-content: center;
  margin-bottom: 12px;
}
.how-grid h3 { margin: 0 0 6px; font-size: 1.05rem; color: var(--berkeley-blue); }
.how-grid p { margin: 0; font-size: 0.9rem; color: var(--text-muted); }

/* Technology */
.tech-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 22px;
}
.tech {
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: var(--radius);
  padding: 22px;
  background: rgba(255, 255, 255, 0.04);
}
.tech h3 { margin: 0 0 8px; font-size: 1rem; color: var(--california-gold); }
.tech p { margin: 0; font-size: 0.9rem; color: #c3d1dd; }

/* Accuracy */
.accuracy-cols {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 30px;
}
.accuracy-cols h3 { color: var(--berkeley-blue); font-size: 1.05rem; margin: 0 0 12px; }

.check-list, .cross-list { list-style: none; padding: 0; margin: 0; }
.check-list li, .cross-list li {
  padding: 8px 0 8px 30px;
  position: relative;
  font-size: 0.94rem;
  color: var(--text-muted);
  border-bottom: 1px solid #edf1f5;
}
.check-list li::before {
  content: "✓";
  position: absolute;
  left: 2px;
  color: #2c8a52;
  font-weight: 700;
}
.cross-list li::before {
  content: "—";
  position: absolute;
  left: 2px;
  color: var(--danger);
  font-weight: 700;
}

.cta-band {
  margin-top: 52px;
  background: linear-gradient(135deg, var(--berkeley-blue), #0a4a8a);
  border-radius: var(--radius);
  color: #fff;
  padding: 34px 30px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}
.cta-band p { margin: 0; font-size: 1.15rem; font-family: var(--font-serif); }

/* ── Progress steps (app) ───────────────────────────────────────── */

.progress-steps {
  list-style: none;
  display: flex;
  justify-content: center;
  gap: 4px;
  padding: 18px 10px 4px;
  margin: 0 auto;
  max-width: 560px;
}

.pstep {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  position: relative;
  color: var(--text-muted);
  font-size: 0.72rem;
}

.pstep:not(:first-child)::before {
  content: "";
  position: absolute;
  top: 13px;
  right: 50%;
  width: 100%;
  height: 2px;
  background: var(--border);
  z-index: 0;
}
.pstep.is-done:not(:first-child)::before,
.pstep.is-active:not(:first-child)::before { background: var(--california-gold); }

.pstep-dot {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: #e3e9ef;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.8rem;
  position: relative;
  z-index: 1;
  border: 2px solid transparent;
}

.pstep.is-active .pstep-dot { background: var(--berkeley-blue); color: #fff; border-color: var(--california-gold); }
.pstep.is-active { color: var(--text); font-weight: 600; }
.pstep.is-done .pstep-dot { background: var(--california-gold); color: var(--berkeley-blue); }
.pstep.is-done { cursor: pointer; }

/* ── Wizard screens ─────────────────────────────────────────────── */

main { max-width: 640px; margin: 0 auto; padding: 10px 16px 40px; }

.screen { display: none; }
.screen.is-active { display: block; animation: slide-in 0.25s ease; }

@keyframes slide-in {
  from { opacity: 0; transform: translateX(24px); }
  to { opacity: 1; transform: translateX(0); }
}

.screen h2 { font-size: 1.35rem; color: var(--berkeley-blue); margin: 14px 0 6px; font-family: var(--font-serif); }
.screen-hint { color: var(--text-muted); font-size: 0.92rem; margin: 0 0 16px; }

.tag {
  display: inline-block;
  background: var(--california-gold);
  color: var(--berkeley-blue);
  font-size: 0.66rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-radius: 999px;
  padding: 2px 8px;
  margin-left: 6px;
  vertical-align: 2px;
}

.action-bar {
  position: sticky;
  bottom: 0;
  background: linear-gradient(to top, var(--bg) 75%, transparent);
  padding: 14px 0 calc(16px + env(safe-area-inset-bottom, 0px));
  margin-top: 20px;
  display: flex;
  gap: 10px;
}
.action-bar .btn { flex: 1; }
.action-bar.two .btn-ghost { flex: 0 0 auto; min-width: 110px; }

/* Dropzone & file preview */

.dropzone {
  border: 2px dashed var(--founders-rock);
  border-radius: var(--radius);
  padding: 34px 18px;
  text-align: center;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
  background: #fff;
}
.dropzone:hover, .dropzone:focus-visible { background: #eef5fa; outline: none; }
.dropzone.is-dragover { background: #e3f0f9; border-color: var(--berkeley-blue); }
.dropzone p { margin: 4px 0; }
.dropzone-icon { font-size: 2.2rem; }
.dropzone-sub { color: var(--text-muted); font-size: 0.82rem; }

.file-info {
  margin-top: 14px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px;
  box-shadow: var(--shadow);
}
.file-info video {
  width: 100%;
  max-height: 260px;
  border-radius: 10px;
  background: #000;
}
.thumb-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(72px, 1fr));
  gap: 6px;
}
.thumb-grid img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
  border-radius: 8px;
}
.thumb-grid .thumb-more {
  display: flex;
  align-items: center;
  justify-content: center;
  background: #e9eef3;
  color: var(--text-muted);
  border-radius: 8px;
  aspect-ratio: 1;
  font-size: 0.85rem;
  font-weight: 600;
}
.file-meta { margin-top: 10px; }
.file-meta p { margin: 3px 0; }
#fileName { font-weight: 600; word-break: break-all; }
#fileDetails { color: var(--text-muted); font-size: 0.88rem; }

/* Scale options */

.scale-options { display: flex; flex-direction: column; gap: 10px; }

.scale-option {
  display: flex;
  gap: 12px;
  padding: 16px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  background: var(--card-bg);
  transition: border-color 0.15s, background 0.15s;
}
.scale-option:hover { background: #fafcfe; }
.scale-option:has(input:checked) {
  border-color: var(--founders-rock);
  background: #f2f8fc;
  box-shadow: inset 3px 0 0 var(--california-gold);
}
.scale-option input[type="radio"] { margin-top: 4px; accent-color: var(--berkeley-blue); flex-shrink: 0; }
.scale-option p { margin: 4px 0 8px; color: var(--text-muted); font-size: 0.88rem; }

.ref-length { display: flex; align-items: center; gap: 8px; font-size: 0.9rem; }
.ref-length input {
  width: 90px;
  padding: 9px 8px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font: inherit;
}
.ref-length input:disabled { background: #f0f3f6; color: var(--text-muted); }

/* Processing */

.progress-track {
  height: 8px;
  border-radius: 999px;
  background: #e3e9ef;
  overflow: hidden;
  margin: 6px 0 18px;
}
.progress-fill {
  height: 100%;
  width: 0%;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--founders-rock), var(--california-gold));
  transition: width 0.5s ease;
}

.stage-list { list-style: none; padding: 0; margin: 0; }

.stage {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 11px 4px;
  border-bottom: 1px solid #eef2f5;
  font-size: 0.92rem;
}
.stage:last-child { border-bottom: none; }

.stage-icon {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.72rem;
  background: #e3e9ef;
  color: var(--text-muted);
}

.stage.is-running .stage-icon {
  background: var(--founders-rock);
  color: #fff;
  animation: pulse 1.1s ease-in-out infinite;
}
.stage.is-done .stage-icon { background: var(--california-gold); color: var(--berkeley-blue); }
.stage.is-error .stage-icon { background: var(--danger); color: #fff; }

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.18); }
}

.stage-name { font-weight: 600; flex-shrink: 0; }
.stage-detail { color: var(--text-muted); font-size: 0.8rem; flex: 1; min-width: 0; }

.log-details { margin-top: 16px; }
.log-details summary {
  cursor: pointer;
  color: var(--founders-rock);
  font-size: 0.88rem;
  padding: 6px 0;
}

.log-panel { margin-top: 8px; border-radius: 10px; overflow: hidden; border: 1px solid #10243a; }
.log-panel pre {
  margin: 0;
  background: #06131f;
  color: #b6e3a8;
  font-family: Consolas, "Courier New", monospace;
  font-size: 0.74rem;
  padding: 12px;
  height: 200px;
  overflow-y: auto;
  white-space: pre-wrap;
  word-break: break-word;
}

/* Result */

.result-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex-wrap: wrap;
}
.result-head h2 { margin: 14px 0 8px; }

.segmented {
  display: flex;
  border: 1px solid var(--border);
  border-radius: 999px;
  overflow: hidden;
  background: #fff;
}
.seg-btn {
  font: inherit;
  font-size: 0.84rem;
  padding: 7px 14px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
}
.seg-btn.is-active { background: var(--berkeley-blue); color: #fff; font-weight: 600; }

.viewer-layout { display: flex; flex-direction: column; gap: 16px; margin-top: 10px; }

.viewer-wrap { width: 100%; }

#viewer {
  position: relative;
  width: 100%;
  height: 56vh;
  min-height: 320px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  background: #0d1b2a;
  touch-action: none;
}

#viewer canvas { display: block; }

#viewer .measure-label {
  position: absolute;
  transform: translate(-50%, -120%);
  background: var(--berkeley-blue);
  color: #fff;
  font-size: 0.78rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 6px;
  pointer-events: none;
  white-space: nowrap;
  box-shadow: 0 2px 6px rgba(0,0,0,0.35);
}
#viewer .box-label { background: var(--california-gold); color: var(--berkeley-blue); }

#viewer.measure-mode canvas { cursor: crosshair; }

.viewer-toolbar { display: flex; gap: 8px; margin-top: 10px; flex-wrap: wrap; }
.viewer-toolbar .btn-tool { flex: 1 1 auto; }

.side-panel {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  box-shadow: var(--shadow);
}
.side-panel h4 { margin: 0 0 10px; color: var(--berkeley-blue); font-size: 0.95rem; }
.side-panel h4 + .dims-table { margin-bottom: 16px; }
.side-sub { font-weight: 400; color: var(--text-muted); font-size: 0.76rem; margin-left: 6px; }

.dims-table { width: 100%; border-collapse: collapse; font-size: 0.95rem; }
.dims-table td { padding: 7px 0; border-bottom: 1px solid #eef2f5; }
.dims-table td:last-child { text-align: right; font-weight: 700; color: var(--berkeley-blue); }

.side-note { font-size: 0.8rem; color: var(--text-muted); margin: 10px 0 18px; }

.measure-list { list-style: none; padding: 0; margin: 0; font-size: 0.9rem; }
.measure-list li {
  padding: 7px 0;
  border-bottom: 1px solid #eef2f5;
  display: flex;
  justify-content: space-between;
  gap: 10px;
}
.measure-list li:last-child { border-bottom: none; }
.measure-list .measure-value { font-weight: 700; color: var(--berkeley-blue); }
.measure-empty { color: var(--text-muted); font-size: 0.85rem; }
.btn-ref { padding: 4px 10px; font-size: 0.78rem; min-height: 0; flex-shrink: 0; }

/* ── Footer ─────────────────────────────────────────────────────── */

.site-footer {
  background: var(--berkeley-deep);
  color: #b9c8d6;
  margin-top: 40px;
  border-top: 3px solid var(--california-gold);
}

.footer-inner {
  max-width: 1140px;
  margin: 0 auto;
  padding: 44px 20px 30px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 30px;
}

.footer-col { display: flex; flex-direction: column; gap: 8px; font-size: 0.86rem; }
.footer-col h5 {
  margin: 0 0 4px;
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--california-gold);
}
.footer-col a { color: #b9c8d6; text-decoration: none; }
.footer-col a:hover { color: #fff; }
.footer-brand p { margin: 10px 0 0; line-height: 1.6; }

.footer-bar {
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  text-align: center;
  padding: 16px 20px;
  font-size: 0.76rem;
  color: #8fa3b5;
}
.footer-bar p { margin: 0; }

/* ── Responsive tweaks ──────────────────────────────────────────── */

@media (max-width: 720px) {
  .header-nav { display: none; }
  .brand-sub { display: none; }
}

@media (min-width: 900px) {
  main { max-width: 720px; }
  .viewer-layout { flex-direction: row; align-items: flex-start; }
  .viewer-wrap { flex: 2 1 520px; }
  .side-panel { flex: 1 1 260px; min-width: 250px; }
  #viewer { height: 500px; }
  main:has(#screen4.is-active) { max-width: 1080px; }
}