* { box-sizing: border-box; }

:root {
  --bg: #f4f1eb;
  --surface: #fff;
  --text: #17191f;
  --muted: #70747e;
  --accent: #d9474d;
  --radius: 22px;
  --shadow-sm: 0 2px 8px rgba(30, 28, 24, .08);
  --shadow-lg: 0 26px 70px rgba(30, 28, 24, .18);
}

@view-transition { navigation: auto; }

body {
  margin: 0;
  min-height: 100dvh;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
               "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

a,
button { -webkit-tap-highlight-color: transparent; }

.page-header {
  max-width: 1040px;
  margin: 0 auto;
  padding: 54px 24px 30px;
}

.eyebrow,
.detail-kicker {
  margin: 0 0 5px;
  color: var(--accent);
  font-size: 11px;
  font-weight: 750;
  letter-spacing: .14em;
}

.page-header h1 {
  margin: 0 0 6px;
  font-size: 32px;
  letter-spacing: -.035em;
}

.page-header > p:last-child {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
}

.grid {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 24px 96px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 24px;
}

.card {
  position: relative;
  isolation: isolate;
  display: flex;
  min-width: 0;
  flex-direction: column;
  overflow: hidden;
  border-radius: var(--radius);
  color: inherit;
  text-decoration: none;
}

.card-surface,
.detail-surface {
  position: absolute;
  inset: 0;
  z-index: -1;
  border-radius: inherit;
  background: var(--surface);
  box-shadow: var(--shadow-sm);
}

.card:hover .card-surface { box-shadow: var(--shadow-lg); }

.card:focus-visible,
.back-button:focus-visible,
.buy-btn:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--accent), white 28%);
  outline-offset: 3px;
}

.thumb,
.detail-image {
  display: grid;
  place-items: center;
  overflow: hidden;
  line-height: 1;
  user-select: none;
}

.thumb {
  aspect-ratio: 4 / 3;
  border-radius: var(--radius) var(--radius) 0 0;
  font-size: 64px;
}

.card-body { padding: 16px 18px 20px; }

.card-title {
  margin: 0 0 5px;
  font-size: 16px;
  font-weight: 650;
  letter-spacing: -.015em;
}

.card-price {
  margin: 0;
  color: var(--accent);
  font-size: 15px;
  font-weight: 700;
}

.detail-page {
  padding: 28px;
  background: #efece5;
}

.detail-panel {
  position: relative;
  isolation: isolate;
  width: min(760px, 100%);
  min-height: calc(100dvh - 56px);
  margin: 0 auto;
  overflow: hidden;
  border-radius: 28px;
  box-shadow: var(--shadow-lg);
}

.detail-surface {
  border-radius: 28px;
  box-shadow: none;
}

.back-button {
  position: absolute;
  top: 18px;
  left: 18px;
  z-index: 2;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 15px;
  border-radius: 999px;
  background: rgba(255, 255, 255, .84);
  box-shadow: 0 4px 18px rgba(25, 25, 25, .14);
  color: var(--text);
  font-size: 14px;
  font-weight: 650;
  line-height: 1;
  text-decoration: none;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.detail-image {
  aspect-ratio: 4 / 3;
  border-radius: 28px 28px 0 0;
  font-size: 142px;
}

.detail-info { padding: 30px 30px 34px; }

.detail-title {
  margin: 0 0 8px;
  font-size: clamp(28px, 4vw, 36px);
  line-height: 1.18;
  letter-spacing: -.035em;
}

.detail-price {
  margin: 0 0 22px;
  color: var(--accent);
  font-size: 25px;
  font-weight: 750;
}

.detail-desc {
  margin: 0 0 28px;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.8;
}

.buy-btn {
  width: 100%;
  padding: 16px 22px;
  border: 0;
  border-radius: 999px;
  background: var(--text);
  color: white;
  font: 650 16px/1 inherit;
  cursor: pointer;
}

/* 位移、缩放、页面切换与补充内容的入场都发生在 View Transition 快照层。 */
::view-transition { pointer-events: none; }

::view-transition-group(root),
::view-transition-group(product-surface),
::view-transition-group(product-image),
::view-transition-group(product-title),
::view-transition-group(product-price) {
  animation-duration: .52s;
  animation-timing-function: cubic-bezier(.22, 1, .36, 1);
}

::view-transition-group(product-surface) { z-index: 1; }
::view-transition-group(product-image) { z-index: 2; }
::view-transition-group(product-title),
::view-transition-group(product-price) { z-index: 3; }
::view-transition-group(detail-extra) { z-index: 4; }
::view-transition-group(detail-controls) { z-index: 5; }

::view-transition-old(product-surface),
::view-transition-new(product-surface),
::view-transition-old(product-image),
::view-transition-new(product-image),
::view-transition-old(product-title),
::view-transition-new(product-title),
::view-transition-old(product-price),
::view-transition-new(product-price) {
  width: 100%;
  height: 100%;
  mix-blend-mode: normal;
  object-fit: cover;
}

::view-transition-new(detail-extra),
::view-transition-new(detail-controls) {
  animation: vt-content-in .3s .16s cubic-bezier(.22, 1, .36, 1) both;
}

::view-transition-old(detail-extra),
::view-transition-old(detail-controls) {
  animation: vt-content-out .18s ease-in both;
}

@keyframes vt-content-in {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes vt-content-out {
  from { opacity: 1; transform: translateY(0); }
  to { opacity: 0; transform: translateY(7px); }
}

@media (max-width: 640px) {
  :root { --radius: 18px; }

  .page-header {
    padding: calc(28px + env(safe-area-inset-top)) 16px 22px;
  }

  .page-header h1 { font-size: 27px; }
  .page-header > p:last-child { max-width: 300px; font-size: 14px; }

  .grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
    padding: 0 12px calc(48px + env(safe-area-inset-bottom));
  }

  .thumb {
    aspect-ratio: 1;
    font-size: clamp(44px, 14vw, 60px);
  }

  .card-body { padding: 12px 12px 14px; }

  .card-title {
    min-height: 2.8em;
    font-size: 14px;
    line-height: 1.4;
  }

  .card-price { font-size: 14px; }

  .detail-page {
    padding: 0;
    background: var(--surface);
  }

  .detail-panel {
    width: 100%;
    min-height: 100dvh;
    border-radius: 0;
    box-shadow: none;
  }

  .detail-surface { border-radius: 0; }

  .back-button {
    position: fixed;
    top: calc(12px + env(safe-area-inset-top));
    left: 12px;
  }

  .detail-image {
    aspect-ratio: 1;
    border-radius: 0 0 28px 28px;
    font-size: clamp(112px, 38vw, 158px);
  }

  .detail-info {
    padding: 24px 20px calc(28px + env(safe-area-inset-bottom));
  }

  .detail-title { font-size: 27px; }
  .detail-price { margin-bottom: 17px; font-size: 22px; }
  .detail-desc { font-size: 15px; line-height: 1.75; }

  ::view-transition-group(root),
  ::view-transition-group(product-surface),
  ::view-transition-group(product-image),
  ::view-transition-group(product-title),
  ::view-transition-group(product-price) {
    animation-duration: .46s;
  }
}

@media (max-width: 360px) {
  .grid { grid-template-columns: 1fr; }
  .thumb { aspect-ratio: 4 / 3; }
  .card-title { min-height: auto; }
}

@media (prefers-reduced-motion: reduce) {
  ::view-transition-group(*),
  ::view-transition-old(*),
  ::view-transition-new(*) {
    animation-duration: .01ms !important;
    animation-delay: 0s !important;
  }
}