/* ============================================
   Layout — 栅格与布局
   ============================================ */

body {
  position: relative;
}

/* 极光背景层 — 多个光斑缓慢漂移 */
.aurora-bg {
  position: fixed;
  inset: 0;
  z-index: -2;
  overflow: hidden;
  pointer-events: none;
}

.aurora-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.55;
  will-change: transform;
}

.aurora-orb--1 {
  width: 60vw;
  height: 60vw;
  top: -20%;
  left: -10%;
  background: radial-gradient(circle, var(--aurora-1) 0%, transparent 60%);
  animation: drift-1 28s var(--ease-in-out) infinite;
}

.aurora-orb--2 {
  width: 50vw;
  height: 50vw;
  top: 20%;
  right: -15%;
  background: radial-gradient(circle, var(--aurora-2) 0%, transparent 60%);
  animation: drift-2 35s var(--ease-in-out) infinite;
}

.aurora-orb--3 {
  width: 55vw;
  height: 55vw;
  bottom: -20%;
  left: 20%;
  background: radial-gradient(circle, var(--aurora-3) 0%, transparent 60%);
  animation: drift-3 42s var(--ease-in-out) infinite;
}

.aurora-orb--4 {
  width: 40vw;
  height: 40vw;
  top: 50%;
  right: 30%;
  background: radial-gradient(circle, var(--aurora-4) 0%, transparent 60%);
  opacity: 0.3;
  animation: drift-4 50s var(--ease-in-out) infinite;
}

/* 颗粒纹理叠加 */
.noise-overlay {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: 0.04;
  background-image: url("data:image/svg+xml;utf8,<svg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'><filter id='noiseFilter'><feTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/></filter><rect width='100%' height='100%' filter='url(%23noiseFilter)'/></svg>");
}

/* 容器 */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

/* 网格 */
.grid-books {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-6);
}

.grid-editorial {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: var(--space-6);
}

/* Section 通用 */
.section {
  position: relative;
  padding: var(--space-24) 0;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: var(--space-12);
  gap: var(--space-8);
  flex-wrap: wrap;
}

.section-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  font-weight: var(--fw-medium);
  letter-spacing: var(--tracking-widest);
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.section-eyebrow::before {
  content: '';
  width: 24px;
  height: 1px;
  background: var(--color-accent);
}

.section-title {
  font-family: var(--font-serif);
  font-size: var(--text-7xl);
  font-weight: var(--fw-regular);
  line-height: 0.95;
  letter-spacing: var(--tracking-tight);
  color: var(--color-text);
}

.section-title em {
  font-style: italic;
  color: var(--color-accent);
}

.section-subtitle {
  font-size: var(--text-xl);
  color: var(--color-text-muted);
  max-width: 520px;
  margin-top: var(--space-4);
  line-height: 1.5;
}

/* 响应式 */
@media (max-width: 1100px) {
  .grid-books { grid-template-columns: repeat(3, 1fr); }
  .grid-editorial { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .grid-books { grid-template-columns: repeat(2, 1fr); gap: var(--space-4); }
  .section { padding: var(--space-16) 0; }
  .section-header { margin-bottom: var(--space-8); }
}

@media (max-width: 480px) {
  .grid-books { grid-template-columns: 1fr; }
}