/* =========================================================
   CSS Development Lab 14
   CSS Scroll Snap
   ========================================================= */

:root {
  --page-max: 1200px;
  --text: #171717;
  --muted: #686868;
  --line: #e5e5df;
  --surface: #ffffff;
  --soft: #f5f5f1;
  --radius: 20px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--surface);
  font-family: Inter, "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  line-height: 1.65;
}

img {
  display: block;
  width: 100%;
  max-width: 100%;
}

figure {
  margin: 0;
}

.page-wrap {
  width: min(calc(100% - 40px), var(--page-max));
  margin-inline: auto;
}

.eyebrow {
  margin: 0 0 14px;
  color: #858585;
  font-size: .78rem;
  font-weight: 800;
  letter-spacing: .15em;
}

.intro {
  padding: clamp(72px, 10vw, 130px) 0 clamp(58px, 8vw, 90px);
  background:
    radial-gradient(circle at 86% 14%, rgba(0,0,0,.05), transparent 27%),
    linear-gradient(180deg, #fafaf8 0%, #f3f3ef 100%);
}

.intro-inner {
  max-width: 980px;
}

.intro h1,
.section-head h2,
.compare-copy h2 {
  margin: 0;
  line-height: 1.04;
  letter-spacing: -.045em;
}

.intro h1 {
  font-size: clamp(2.8rem, 7vw, 6rem);
}

.intro-desc {
  max-width: 820px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: clamp(1rem, 1.7vw, 1.18rem);
}

.lab,
.gallery-section {
  padding: clamp(80px, 10vw, 130px) 0;
}

.section-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, .78fr);
  align-items: end;
  gap: clamp(28px, 6vw, 80px);
}

.section-head h2,
.compare-copy h2 {
  font-size: clamp(2rem, 4.5vw, 4.5rem);
}

.section-head > p,
.compare-copy > p {
  margin: 0;
  color: var(--muted);
}

/* ---------- Core: horizontal snap track ---------- */

.snap-track {
  margin-top: clamp(38px, 6vw, 60px);
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(280px, 32%);
  gap: 18px;

  overflow-x: auto;
  overscroll-behavior-inline: contain;
  scroll-snap-type: x mandatory;
  scroll-padding-inline: 2px;

  padding: 2px 2px 18px;
  scrollbar-width: thin;
}

.snap-card {
  min-width: 0;
  overflow: hidden;
  scroll-snap-align: start;
  scroll-snap-stop: normal;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.card-media {
  aspect-ratio: 4 / 3;
  overflow: hidden;
  background: #ddd;
}

.card-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.card-body {
  padding: 22px;
}

.card-body > span {
  color: #999;
  font-size: .76rem;
  font-weight: 800;
}

.card-body h3 {
  margin: 10px 0 6px;
  font-size: 1.28rem;
}

.card-body p {
  margin: 0;
  color: var(--muted);
  font-size: .92rem;
}

.scroll-hint {
  margin: 14px 0 0;
  color: #888;
  font-size: .82rem;
}

/* ---------- Gallery ---------- */

.gallery-section {
  background: #fafaf8;
}

.gallery-track {
  margin-top: clamp(38px, 6vw, 60px);
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(560px, 78%);
  gap: 18px;

  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scroll-padding-inline: 2px;
  overscroll-behavior-inline: contain;

  padding: 2px 2px 18px;
  scrollbar-width: thin;
}

.gallery-item {
  scroll-snap-align: start;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border-radius: 22px;
  background: #ddd;
}

.gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- Compare ---------- */

.compare {
  padding: clamp(90px, 11vw, 140px) 0 clamp(90px, 12vw, 150px);
}

.compare-grid {
  padding: clamp(30px, 6vw, 64px);
  display: grid;
  grid-template-columns: minmax(0, .85fr) minmax(320px, 1.15fr);
  align-items: center;
  gap: clamp(36px, 7vw, 90px);
  border-radius: 28px;
  background: var(--soft);
}

.compare-copy > p {
  margin-top: 22px;
}

.decision-list {
  display: grid;
  gap: 12px;
}

.decision-list > div {
  padding: 18px 20px;
  display: grid;
  gap: 4px;
  border-radius: 14px;
  background: #fff;
}

.decision-list strong {
  font-size: .94rem;
}

.decision-list span {
  color: var(--muted);
  font-size: .88rem;
}

/* ---------- Responsive ---------- */

@media (max-width: 900px) {
  .section-head,
  .compare-grid {
    grid-template-columns: 1fr;
  }

  .snap-track {
    grid-auto-columns: minmax(270px, 58%);
  }

  .gallery-track {
    grid-auto-columns: minmax(460px, 86%);
  }
}

@media (max-width: 640px) {
  .page-wrap {
    width: calc(100% - 28px);
  }

  /*
   * 手机端故意让下一张卡片露出一部分，
   * 提示用户这里可以继续横向滑动。
   */
  .snap-track {
    grid-auto-columns: 84%;
    margin-inline: -14px;
    padding-inline: 14px;
    scroll-padding-inline: 14px;
  }

  .gallery-track {
    grid-auto-columns: 92%;
    margin-inline: -14px;
    padding-inline: 14px;
    scroll-padding-inline: 14px;
  }

  .compare-grid {
    padding: 24px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}