/*
  Junior Physics series — design tokens
  Source: ui-ux-pro-max (education / interactive) adapted for 初中生
  Direction: 实验室日光 Lab Daylight — cool paper, cyan wave, amber energy
  Fonts: Fredoka (display) + Noto Sans SC (body) + IBM Plex Mono (formula)
  Isolation: ALL rules scoped under .physics-series — do NOT edit theme.css
*/

.physics-series {
  --phys-bg: #E8F1F6;
  --phys-bg-accent: #D6E8F0;
  --phys-surface: #FFFFFF;
  --phys-ink: #0F2744;
  --phys-muted: #5A6F85;
  --phys-line: #C5D5E0;
  --phys-cyan: #0B8FA8;
  --phys-cyan-soft: rgba(11, 143, 168, 0.12);
  --phys-amber: #E8913A;
  --phys-amber-soft: rgba(232, 145, 58, 0.14);
  --phys-green: #2A9D6E;
  --phys-red: #D64545;
  --phys-radius: 14px;
  --phys-radius-sm: 10px;
  --phys-shadow: 0 8px 28px rgba(15, 39, 68, 0.08);
  --phys-font-display: "Fredoka", "Baloo 2", cursive;
  --phys-font-body: "Noto Sans SC", sans-serif;
  --phys-font-mono: "IBM Plex Mono", "Roboto Mono", monospace;
  --phys-max: 760px;
  --phys-nav-h: 64px;

  margin: 0;
  font-family: var(--phys-font-body);
  font-size: 17px;
  line-height: 1.7;
  color: var(--phys-ink);
  background:
    radial-gradient(ellipse 80% 50% at 10% -10%, rgba(11, 143, 168, 0.14), transparent 55%),
    radial-gradient(ellipse 60% 40% at 100% 0%, rgba(232, 145, 58, 0.1), transparent 50%),
    var(--phys-bg);
  -webkit-font-smoothing: antialiased;
}

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

.physics-series a {
  color: var(--phys-cyan);
  text-decoration: none;
  transition: color 0.2s ease;
}

.physics-series a:hover {
  color: var(--phys-ink);
}

.physics-series a:focus-visible,
.physics-series button:focus-visible,
.physics-series input:focus-visible {
  outline: 3px solid var(--phys-cyan);
  outline-offset: 3px;
}

/* —— Nav —— */
.physics-series > nav {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: var(--phys-nav-h);
  padding: 0 20px;
  background: rgba(232, 241, 246, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--phys-line);
}

.physics-series > nav .logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--phys-font-display);
  font-weight: 600;
  font-size: 1.15rem;
  color: var(--phys-ink);
}

.physics-series > nav .logo svg {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
}

.physics-series > nav .nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.physics-series > nav .nav-links a {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--phys-muted);
}

.physics-series > nav .nav-links a:hover {
  color: var(--phys-cyan);
}

.physics-series > nav .nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid var(--phys-line);
  border-radius: 10px;
  background: var(--phys-surface);
  color: var(--phys-ink);
  cursor: pointer;
}

.physics-series > nav .nav-toggle svg {
  width: 22px;
  height: 22px;
}

@media (max-width: 768px) {
  .physics-series > nav .nav-toggle {
    display: inline-flex;
  }

  .physics-series > nav .nav-links {
    display: none;
    position: absolute;
    top: var(--phys-nav-h);
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    padding: 12px 16px 20px;
    background: var(--phys-surface);
    border-bottom: 1px solid var(--phys-line);
    box-shadow: var(--phys-shadow);
  }

  .physics-series > nav .nav-links.open {
    display: flex;
  }

  .physics-series > nav .nav-links a {
    padding: 12px 8px;
    min-height: 44px;
    display: flex;
    align-items: center;
  }
}

/* —— Hero —— */
.physics-series .phys-hero {
  position: relative;
  min-height: calc(70vh - var(--phys-nav-h));
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
  max-width: var(--phys-max);
  margin: 0 auto;
  padding: 56px 20px 72px;
  overflow: hidden;
}

.physics-series .phys-hero::before {
  content: "";
  position: absolute;
  right: -40px;
  top: 18%;
  width: 220px;
  height: 220px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--phys-cyan-soft), transparent 70%);
  pointer-events: none;
}

.physics-series .phys-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  margin-bottom: 18px;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--phys-cyan);
  background: var(--phys-cyan-soft);
  border-radius: 999px;
  letter-spacing: 0.02em;
}

.physics-series .phys-hero h1 {
  margin: 0 0 16px;
  font-family: var(--phys-font-display);
  font-weight: 650;
  font-size: clamp(2rem, 5.5vw, 3rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--phys-ink);
}

.physics-series .phys-hero h1 .hi {
  color: var(--phys-cyan);
}

.physics-series .phys-hero > p {
  margin: 0 0 28px;
  max-width: 36em;
  font-size: 1.05rem;
  color: var(--phys-muted);
  line-height: 1.75;
}

.physics-series .phys-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 48px;
  padding: 12px 22px;
  font-family: var(--phys-font-display);
  font-size: 1.05rem;
  font-weight: 600;
  color: #fff;
  background: var(--phys-cyan);
  border: none;
  border-radius: 999px;
  cursor: pointer;
  box-shadow: 0 6px 18px rgba(11, 143, 168, 0.35);
  transition: transform 0.2s ease, background 0.2s ease;
}

.physics-series .phys-btn:hover {
  background: #087a90;
  transform: translateY(-1px);
}

.physics-series .phys-btn.secondary {
  color: var(--phys-ink);
  background: var(--phys-surface);
  box-shadow: var(--phys-shadow);
  border: 1px solid var(--phys-line);
}

.physics-series .phys-btn.secondary:hover {
  background: var(--phys-bg-accent);
}

.physics-series .phys-scroll-hint {
  margin-top: 40px;
  font-size: 0.85rem;
  color: var(--phys-muted);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  opacity: 0.85;
}

/* —— Sections —— */
.physics-series section.phys-section,
.physics-series .phys-section {
  max-width: var(--phys-max);
  margin: 0 auto;
  padding: 48px 20px;
}

.physics-series .phys-section-tag {
  display: inline-block;
  margin-bottom: 10px;
  font-family: var(--phys-font-display);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--phys-amber);
  letter-spacing: 0.04em;
}

/* Alias for learning-article section-tag convention */
.physics-series .section-tag {
  display: inline-block;
  margin-bottom: 10px;
  font-family: var(--phys-font-display);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--phys-amber);
  letter-spacing: 0.04em;
}

.physics-series .phys-section h2,
.physics-series section h2 {
  margin: 0 0 20px;
  font-family: var(--phys-font-display);
  font-weight: 600;
  font-size: clamp(1.35rem, 3vw, 1.7rem);
  line-height: 1.35;
  color: var(--phys-ink);
}

.physics-series .phys-section p,
.physics-series section p {
  margin: 0 0 14px;
  color: var(--phys-ink);
}

.physics-series .phys-section p:last-child,
.physics-series section p:last-child {
  margin-bottom: 0;
}

.physics-series strong {
  font-weight: 700;
  color: var(--phys-ink);
}

/* —— Cards —— */
.physics-series .phys-card,
.physics-series .card {
  background: var(--phys-surface);
  border-radius: var(--phys-radius);
  padding: 22px 24px;
  margin: 18px 0;
  box-shadow: var(--phys-shadow);
  border: 1px solid rgba(197, 213, 224, 0.7);
  border-left: 4px solid var(--phys-cyan);
}

.physics-series .phys-card.amber,
.physics-series .card.amber {
  border-left-color: var(--phys-amber);
}

.physics-series .phys-card h3,
.physics-series .card h3 {
  margin: 0 0 10px;
  font-family: var(--phys-font-display);
  font-size: 1.1rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 10px;
}

.physics-series .phys-num,
.physics-series .num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  flex-shrink: 0;
  border-radius: 8px;
  font-family: var(--phys-font-display);
  font-size: 0.9rem;
  font-weight: 700;
  color: #fff;
  background: var(--phys-cyan);
}

.physics-series .phys-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 14px;
  margin: 20px 0;
}

.physics-series .phys-mini {
  background: var(--phys-surface);
  border-radius: var(--phys-radius-sm);
  padding: 16px 18px;
  border: 1px solid var(--phys-line);
}

.physics-series .phys-mini h4 {
  margin: 0 0 6px;
  font-family: var(--phys-font-display);
  font-size: 1rem;
  color: var(--phys-cyan);
}

.physics-series .phys-mini p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--phys-muted);
  line-height: 1.6;
}

/* —— Alerts / insight —— */
.physics-series .phys-alert,
.physics-series .alert,
.physics-series .insight {
  margin: 20px 0;
  padding: 16px 18px;
  border-radius: var(--phys-radius-sm);
  background: var(--phys-amber-soft);
  border: 1px solid rgba(232, 145, 58, 0.35);
  font-size: 0.95rem;
  line-height: 1.65;
}

.physics-series .phys-alert.blue,
.physics-series .alert.blue {
  background: var(--phys-cyan-soft);
  border-color: rgba(11, 143, 168, 0.35);
}

/* —— Formula —— */
.physics-series .phys-formula,
.physics-series .formula-box {
  margin: 20px 0;
  padding: 18px 20px;
  background: var(--phys-ink);
  color: #E8F1F6;
  border-radius: var(--phys-radius-sm);
}

.physics-series .phys-formula .formula,
.physics-series .formula-box .formula {
  font-family: var(--phys-font-mono);
  font-size: 1.15rem;
  font-weight: 500;
  margin-bottom: 8px;
}

.physics-series .phys-formula .formula-sub,
.physics-series .formula-box .formula-sub {
  font-size: 0.88rem;
  opacity: 0.85;
  line-height: 1.55;
}

/* —— Demo —— */
.physics-series .phys-demo,
.physics-series .interactive {
  max-width: 900px;
  margin: 24px auto;
  padding: 36px 20px 48px;
  background: linear-gradient(180deg, var(--phys-bg-accent), var(--phys-bg));
  border-top: 1px solid var(--phys-line);
  border-bottom: 1px solid var(--phys-line);
}

.physics-series .phys-demo h2,
.physics-series .interactive h2 {
  margin: 0 0 8px;
  font-family: var(--phys-font-display);
  font-size: 1.5rem;
}

.physics-series .phys-demo > p,
.physics-series .interactive > p {
  color: var(--phys-muted);
  margin: 0 0 20px;
}

.physics-series .phys-demo-panel {
  background: var(--phys-surface);
  border-radius: var(--phys-radius);
  padding: 20px;
  box-shadow: var(--phys-shadow);
  border: 1px solid var(--phys-line);
}

.physics-series .phys-demo-panel canvas {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 21 / 8;
  border-radius: var(--phys-radius-sm);
  background: #F4FAFC;
  cursor: pointer;
  touch-action: none;
}

@media (max-width: 640px) {
  .physics-series .phys-demo-panel canvas {
    aspect-ratio: 16 / 10;
    min-height: 200px;
  }
}

.physics-series .phys-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  margin-top: 16px;
}

.physics-series .phys-hint {
  margin-top: 12px;
  font-size: 0.9rem;
  color: var(--phys-muted);
  min-height: 1.4em;
}

/* —— Textbook tags —— */
.physics-series .phys-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 16px 0 0;
}

.physics-series .phys-tag {
  display: inline-block;
  padding: 6px 12px;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--phys-ink);
  background: var(--phys-surface);
  border: 1px dashed var(--phys-cyan);
  border-radius: 999px;
}

/* —— Summary —— */
.physics-series .phys-summary,
.physics-series .summary {
  background: var(--phys-surface);
  border-radius: var(--phys-radius);
  padding: 24px 26px;
  box-shadow: var(--phys-shadow);
  border: 1px solid var(--phys-line);
}

.physics-series .phys-summary ul,
.physics-series .summary ul {
  margin: 0;
  padding-left: 1.2em;
}

.physics-series .phys-summary li,
.physics-series .summary li {
  margin: 8px 0;
}

/* —— Article nav —— */
.physics-series .phys-article-nav,
.physics-series .article-nav {
  max-width: var(--phys-max);
  margin: 0 auto;
  padding: 32px 20px 48px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px 20px;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid var(--phys-line);
}

.physics-series .phys-article-nav a,
.physics-series .article-nav a {
  font-family: var(--phys-font-display);
  font-weight: 600;
  font-size: 0.95rem;
}

/* —— Footer —— */
.physics-series > footer {
  max-width: var(--phys-max);
  margin: 0 auto;
  padding: 0 20px 48px;
  font-size: 0.85rem;
  color: var(--phys-muted);
}

/* ============================================================
   Physics hub catalog (physics.html) — mirror stats.html layout
   Scoped under .physics-hub so article pages stay unchanged
   ============================================================ */
.physics-series.physics-hub {
  --phys-block-gap: 48px;
  --phys-radius-lg: 20px;
  background: var(--phys-bg);
}

.physics-series.physics-hub > nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 10px 24px;
  background: rgba(232, 241, 246, 0.9);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.physics-series.physics-hub .skip-link {
  position: absolute;
  left: -9999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}
.physics-series.physics-hub .skip-link:focus {
  position: fixed;
  left: 16px;
  top: 16px;
  z-index: 200;
  width: auto;
  height: auto;
  overflow: visible;
  padding: 12px 18px;
  border-radius: 999px;
  background: var(--phys-cyan);
  color: #fff;
  font-weight: 700;
}

.physics-series.physics-hub .phys-hub-hero {
  position: relative;
  overflow: hidden;
  min-height: 0;
  max-width: none;
  margin: 0;
  padding: calc(var(--phys-nav-h) + 56px) 24px 56px;
  text-align: center;
  align-items: center;
  background:
    radial-gradient(ellipse 80% 60% at 20% 0%, rgba(11, 143, 168, 0.2), transparent 55%),
    radial-gradient(ellipse 70% 50% at 90% 20%, rgba(232, 145, 58, 0.18), transparent 50%),
    linear-gradient(180deg, #D6E8F0 0%, var(--phys-bg) 100%);
}

.physics-series.physics-hub .phys-hub-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  right: auto;
  top: auto;
  width: auto;
  height: auto;
  border-radius: 0;
  background-image:
    linear-gradient(rgba(11, 143, 168, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(11, 143, 168, 0.06) 1px, transparent 1px);
  background-size: 32px 32px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.5), transparent 85%);
  pointer-events: none;
}

.physics-series.physics-hub .phys-hub-hero > * {
  position: relative;
  z-index: 1;
}

.physics-series.physics-hub .phys-hub-hero .phys-badge {
  margin-bottom: 20px;
  padding: 8px 16px;
  font-family: var(--phys-font-display);
  font-weight: 700;
  letter-spacing: 0.04em;
}

.physics-series.physics-hub .phys-hub-hero h1 {
  font-size: clamp(2.4rem, 6vw, 3.4rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin: 0 0 16px;
}

.physics-series.physics-hub .phys-hub-hero h1 .hi {
  background: linear-gradient(135deg, var(--phys-cyan), var(--phys-amber));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  color: transparent;
}

.physics-series.physics-hub .phys-hub-hero > p {
  margin: 0 auto 28px;
}

.physics-series.physics-hub .phys-pills {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin: 0 auto 28px;
  max-width: 640px;
}

.physics-series.physics-hub .phys-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border-radius: 999px;
  background: var(--phys-surface);
  border: 1px solid var(--phys-line);
  box-shadow: 0 4px 12px rgba(15, 39, 68, 0.05);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--phys-ink);
}

.physics-series.physics-hub .phys-pill svg {
  width: 16px;
  height: 16px;
  color: var(--phys-cyan);
  flex-shrink: 0;
}

.physics-series.physics-hub .phys-cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}

.physics-series.physics-hub .phys-btn.accent {
  background: var(--phys-amber);
  color: #1C1917;
  box-shadow: 0 8px 22px rgba(232, 145, 58, 0.35);
}

.physics-series.physics-hub .phys-btn.accent:hover {
  background: #f0a354;
  color: #1C1917;
}

.physics-series.physics-hub .phys-main {
  max-width: 840px;
  margin: 0 auto;
  padding: 8px 24px 64px;
}

.physics-series.physics-hub .phys-chapter {
  margin: 0 0 var(--phys-block-gap);
  padding: 28px 28px 24px;
  background: var(--phys-surface);
  border-radius: var(--phys-radius-lg);
  border: 1px solid var(--phys-line);
  box-shadow: var(--phys-shadow);
  position: relative;
  overflow: hidden;
  max-width: none;
}

.physics-series.physics-hub .phys-chapter::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 5px;
  background: var(--chapter-accent, var(--phys-cyan));
}

.physics-series.physics-hub .phys-chapter[data-tone="cyan"] { --chapter-accent: #0B8FA8; }
.physics-series.physics-hub .phys-chapter[data-tone="amber"] { --chapter-accent: #E8913A; }
.physics-series.physics-hub .phys-chapter[data-tone="coral"] { --chapter-accent: #D64545; }
.physics-series.physics-hub .phys-chapter[data-tone="slate"] { --chapter-accent: #5A6F85; }
.physics-series.physics-hub .phys-chapter[data-tone="gold"] { --chapter-accent: #C9A227; }
.physics-series.physics-hub .phys-chapter[data-tone="green"] { --chapter-accent: #2A9D6E; }

.physics-series.physics-hub .phys-chapter-head {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 20px;
}

.physics-series.physics-hub .phys-chapter-num {
  flex-shrink: 0;
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  background: #D6E8F0;
  color: var(--chapter-accent, var(--phys-cyan));
  font-family: var(--phys-font-display);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.03em;
}
.physics-series.physics-hub .phys-chapter[data-tone="cyan"] .phys-chapter-num { background: #D6E8F0; }
.physics-series.physics-hub .phys-chapter[data-tone="amber"] .phys-chapter-num { background: #FCE9D4; }
.physics-series.physics-hub .phys-chapter[data-tone="coral"] .phys-chapter-num { background: #F9DADA; }
.physics-series.physics-hub .phys-chapter[data-tone="slate"] .phys-chapter-num { background: #E4E9EE; }
.physics-series.physics-hub .phys-chapter[data-tone="gold"] .phys-chapter-num { background: #F5EDD0; }
.physics-series.physics-hub .phys-chapter[data-tone="green"] .phys-chapter-num { background: #D5F0E4; }

.physics-series.physics-hub .phys-chapter-meta {
  min-width: 0;
  flex: 1;
}

.physics-series.physics-hub .phys-chapter-tag {
  display: block;
  font-family: var(--phys-font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--phys-muted);
  margin-bottom: 4px;
}

.physics-series.physics-hub .phys-chapter h2 {
  font-family: var(--phys-font-display);
  font-size: clamp(1.35rem, 3vw, 1.65rem);
  font-weight: 700;
  color: var(--phys-ink);
  line-height: 1.25;
  margin: 0;
  letter-spacing: -0.02em;
}

.physics-series.physics-hub .phys-catalog-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.physics-series.physics-hub .phys-catalog-list a {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  min-height: 56px;
  padding: 14px 16px;
  border-radius: var(--phys-radius-sm);
  background: #F3F8FB;
  border: 1px solid transparent;
  color: var(--phys-ink);
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s, border-color 0.2s, transform 0.2s, box-shadow 0.2s, color 0.2s;
}

.physics-series.physics-hub .phys-catalog-list a:hover {
  background: #E5F4F8;
  border-color: rgba(11, 143, 168, 0.25);
  color: var(--phys-cyan);
  transform: translateY(-2px);
  box-shadow: 0 8px 18px rgba(15, 39, 68, 0.08);
}

.physics-series.physics-hub .phys-catalog-list a.is-featured {
  background: linear-gradient(90deg, rgba(232, 145, 58, 0.12), #F3F8FB 42%);
  border-color: rgba(232, 145, 58, 0.25);
}

.physics-series.physics-hub .phys-catalog-list a.is-featured:hover {
  background: linear-gradient(90deg, rgba(232, 145, 58, 0.18), #E5F4F8 50%);
  border-color: rgba(232, 145, 58, 0.4);
}

.physics-series.physics-hub .phys-catalog-list .idx {
  font-family: var(--phys-font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--phys-muted);
  min-width: 1.6em;
}

.physics-series.physics-hub .phys-catalog-list .title {
  font-weight: 600;
  font-size: 0.98rem;
  line-height: 1.45;
  min-width: 0;
}

.physics-series.physics-hub .phys-catalog-list .meta {
  font-family: var(--phys-font-display);
  font-size: 0.72rem;
  font-weight: 700;
  padding: 5px 10px;
  border-radius: 999px;
  white-space: nowrap;
  line-height: 1;
}

.physics-series.physics-hub .phys-catalog-list .meta.star {
  color: #8A4B12;
  background: var(--phys-amber-soft);
}

.physics-series.physics-hub .phys-catalog-list .meta.lvl {
  color: var(--phys-muted);
  background: rgba(90, 111, 133, 0.12);
}

.physics-series.physics-hub .phys-foot {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px 18px;
  margin: 8px 0 40px;
  padding: 0 24px;
  max-width: none;
  background: none;
  border: none;
  box-shadow: none;
  min-height: 0;
  position: static;
}

.physics-series.physics-hub .phys-foot a {
  font-weight: 600;
  color: var(--phys-cyan);
  padding: 0;
  background: none;
  border-radius: 0;
}

.physics-series.physics-hub .phys-foot a:hover {
  text-decoration: underline;
  color: var(--phys-ink);
  transform: none;
  background: none;
}

.physics-series.physics-hub > footer {
  max-width: none;
  text-align: center;
  padding: 28px 24px 40px;
  font-size: 0.9rem;
  border-top: 1px solid var(--phys-line);
}

.physics-series.physics-hub > footer a {
  font-weight: 600;
}

@media (max-width: 768px) {
  .physics-series.physics-hub .phys-hub-hero {
    padding: calc(var(--phys-nav-h) + 36px) 16px 40px;
  }
  .physics-series.physics-hub .phys-main {
    padding: 0 16px 48px;
  }
  .physics-series.physics-hub .phys-chapter {
    padding: 22px 16px 18px;
    margin-bottom: 28px;
  }
  .physics-series.physics-hub {
    --phys-block-gap: 28px;
  }
  .physics-series.physics-hub .phys-catalog-list a {
    grid-template-columns: auto minmax(0, 1fr);
    grid-template-rows: auto auto;
    row-gap: 8px;
  }
  .physics-series.physics-hub .phys-catalog-list .meta {
    grid-column: 2;
    justify-self: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .physics-series *,
  .physics-series *::before,
  .physics-series *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}