@layer pages {

  /* ===== Intro ===== */
  .physics-intro {
    padding-block: var(--space-5) var(--space-7);
  }

  .physics-intro-inner {
    max-width: var(--content-width);
    margin-inline: auto;
  }

  .physics-intro-inner p {
    font-size: var(--text-lg);
    line-height: var(--leading-relaxed);
    color: var(--color-neutral-200);
  }

  /* ===== Papers Section ===== */
  .papers-section {
    padding-block: var(--space-7);
  }

  .papers-ornament-divider {
    text-align: center;
    margin-block: var(--space-5) var(--space-7);
    color: var(--color-secondary-300);
    font-size: var(--text-sm);
    letter-spacing: 0.4em;
    opacity: 0.6;
  }

  .papers-stack {
    display: flex;
    flex-direction: column;
    gap: var(--space-7);
  }

  /* ===== Paper Card ===== */
  .paper-card {
    display: grid;
    grid-template-columns: 1fr;
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    text-decoration: none;
    color: inherit;
    transition: border-color var(--transition-normal), box-shadow var(--transition-normal);
  }

  .paper-card:hover {
    border-color: var(--color-secondary-400);
    box-shadow: var(--shadow-glow-blue);
  }

  @media (min-width: 1024px) {
    .paper-card {
      grid-template-columns: 420fr 580fr;
    }
  }

  /* Preview area */
  .paper-card-preview {
    background: var(--color-background);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-4);
    min-height: 200px;
  }

  @media (min-width: 1024px) {
    .paper-card-preview {
      border-bottom: none;
      border-right: 1px solid var(--color-border);
      min-height: 280px;
    }
  }

  .paper-card-preview svg {
    width: 100%;
    height: auto;
    border-radius: var(--radius-md);
  }

  /* Card body */
  .paper-card-body {
    padding: var(--space-6);
    display: flex;
    flex-direction: column;
  }

  .paper-card-tag {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    font-weight: 500;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--color-secondary-300);
    margin-bottom: var(--space-3);
  }

  .paper-card-title {
    font-family: var(--font-heading);
    font-size: clamp(var(--text-2xl), 3vw, var(--text-3xl));
    font-weight: 400;
    line-height: var(--leading-tight);
    color: var(--color-foreground);
    margin-bottom: var(--space-2);
  }

  .paper-card-subtitle {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    color: var(--color-neutral-300);
    margin-bottom: var(--space-5);
  }

  /* Summary sections */
  .paper-card-summary {
    display: flex;
    flex-direction: column;
    gap: var(--space-5);
    flex: 1;
  }

  .paper-card-summary h4 {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    font-weight: 500;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    margin-bottom: var(--space-2);
  }

  .paper-card-question h4 {
    color: var(--color-gold-300);
  }

  .paper-card-idea h4 {
    color: var(--color-primary-300);
  }

  .paper-card-significance h4 {
    color: var(--color-secondary-300);
  }

  .paper-card-summary p {
    font-size: var(--text-sm);
    line-height: var(--leading-normal);
    color: var(--color-neutral-200);
  }

  .paper-card-summary p + p {
    margin-top: var(--space-3);
  }

  .paper-card-summary em {
    color: var(--color-foreground);
    font-style: italic;
  }

  .paper-card-summary strong {
    color: var(--color-foreground);
    font-weight: 500;
  }

  /* Card footer */
  .paper-card-rule {
    border: none;
    height: 1px;
    background: var(--color-border);
    margin-block: var(--space-5) var(--space-4);
  }

  .paper-card-cta {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    font-weight: 400;
    color: var(--color-secondary-300);
    display: flex;
    align-items: center;
    gap: var(--space-2);
    transition: color var(--transition-fast);
  }

  .paper-card-cta::after {
    content: '\2192';
    transition: transform var(--transition-fast);
  }

  .paper-card:hover .paper-card-cta {
    color: var(--color-secondary-200);
  }

  .paper-card:hover .paper-card-cta::after {
    transform: translateX(4px);
  }

  /* ===== Connecting Thread ===== */
  .physics-thread {
    padding-block: var(--space-6) var(--space-9);
  }

  .physics-thread-inner {
    max-width: var(--content-width);
    margin-inline: auto;
    text-align: center;
    border-top: 1px solid var(--color-border);
    padding-top: var(--space-6);
  }

  .physics-thread-inner p {
    font-size: var(--text-base);
    line-height: var(--leading-relaxed);
    color: var(--color-neutral-300);
    font-style: italic;
  }
}