/* ============================================================
   藏艺阁 CYG · 宣传页
   风格：Editorial Monochrome（延续小程序设计规范）
   纯白 · 墨黑 · 细线分隔 · 直角矩形 · 留白即层级
   ============================================================ */

:root {
  /* Colors */
  --bg: #ffffff;
  --ink: #111111;
  --muted: #767676;
  --text: #555555;
  --line: #e8e8e6;
  --wash: #F2F2F0;
  --serif: YigeSerif, "Noto Serif SC", "Songti SC", "STSong", "SimSun", serif;
  --serifDisplay: CygOldSong, YigeSerifSemi, "Noto Serif SC", "Songti SC", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Helvetica Neue",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(17,17,17,0.04);
  --shadow-md: 0 4px 20px rgba(17,17,17,0.06);
  --shadow-lg: 0 12px 40px rgba(17,17,17,0.08);

  /* Spacing */
  --space-xs: 8px; --space-sm: 16px; --space-md: 32px;
  --space-lg: 64px; --space-xl: 96px; --space-2xl: 128px;

  /* Easing */
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-smooth: cubic-bezier(0.4, 0, 0.2, 1);

  /* Typography scale */
  --fs-hero: clamp(42px, 6vw, 68px);
  --fs-h2: clamp(28px, 4vw, 44px);
  --fs-h3: clamp(20px, 2.5vw, 26px);
  --fs-body: 16px;
  --fs-caption: 13px;
  --fs-kicker: 12px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: var(--fs-body);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
button { font-family: inherit; }

.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 32px;
}

/* ---------- 通用元素 ---------- */

.kicker {
  font-size: var(--fs-kicker);
  letter-spacing: 0.35em;
  color: var(--muted);
  margin-bottom: var(--space-md);
}

.section-title {
  font-family: var(--serifDisplay);
  font-size: var(--fs-h2);
  font-weight: 600;
  letter-spacing: 0.04em;
  line-height: 1.35;
}

.section { padding: var(--space-2xl) 0; }
.section--wash { background: var(--wash); }

.section-head { margin-bottom: var(--space-lg); }

.section-head--row {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-md);
  flex-wrap: wrap;
}

/* ---------- Buttons ---------- */

.btn {
  display: inline-block;
  padding: 14px 34px;
  font-size: 15px;
  letter-spacing: 0.12em;
  border: 1px solid var(--ink);
  transition: opacity 0.25s var(--ease-out), background 0.25s var(--ease-out),
              color 0.25s var(--ease-out), transform 0.25s var(--ease-out),
              box-shadow 0.25s var(--ease-out);
  cursor: pointer;
}

.btn--solid { background: var(--ink); color: #fff; }
.btn--solid:hover {
  opacity: 0.88;
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.btn--ghost { background: transparent; color: var(--ink); }
.btn--ghost:hover {
  background: var(--ink);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.btn--lg { padding: 17px 44px; font-size: 16px; }

/* ---------- 顶部导航 ---------- */

.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s var(--ease-out), box-shadow 0.3s var(--ease-out);
}

.site-header.is-scrolled {
  border-bottom-color: var(--line);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.wordmark { display: inline-flex; align-items: baseline; gap: 10px; }

.wordmark__cn {
  font-family: var(--serifDisplay);
  font-size: 24px;
  font-weight: 600;
  letter-spacing: 0.18em;
}

.wordmark__en {
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--muted);
}

.wordmark--lg .wordmark__cn { font-size: 30px; }

.site-nav { display: flex; gap: 44px; }

.site-nav a {
  font-size: 14px;
  letter-spacing: 0.2em;
  color: var(--muted);
  padding: 4px 0;
  border-bottom: 1px solid transparent;
  transition: color 0.25s var(--ease-out), border-color 0.25s var(--ease-out),
              transform 0.25s var(--ease-out);
}

.site-nav a:hover {
  color: var(--ink);
  border-bottom-color: var(--ink);
  transform: translateY(-1px);
}

.header-cta {
  padding: 10px 22px;
  font-size: 13px;
}
.header-cta:hover { transform: translateY(-2px); box-shadow: var(--shadow-sm); }

.nav-toggle {
  display: none;
  width: 40px; height: 40px;
  background: none;
  border: none;
  cursor: pointer;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 7px;
}

.nav-toggle span {
  display: block;
  width: 22px; height: 1.5px;
  background: var(--ink);
  transition: transform 0.3s var(--ease-out);
}

.nav-toggle.is-open span:nth-child(1) { transform: translateY(4.25px) rotate(45deg); }
.nav-toggle.is-open span:nth-child(2) { transform: translateY(-4.25px) rotate(-45deg); }

/* ---------- 首屏 ---------- */

.hero {
  padding: 190px 0 0;
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 72px;
  align-items: center;
}

.hero-copy { position: relative; }

.hero-copy::before {
  content: '';
  position: absolute;
  left: -20px;
  top: 8px;
  width: 2px;
  height: 48px;
  background: var(--ink);
}

.hero-title {
  font-family: var(--serifDisplay);
  font-size: var(--fs-hero);
  font-weight: 600;
  letter-spacing: 0.06em;
  line-height: 1.3;
  margin-bottom: 28px;
}

.hero-sub {
  color: var(--text);
  font-size: 16.5px;
  max-width: 28em;
  line-height: 1.8;
  margin-bottom: 44px;
}

.hero-actions { display: flex; gap: var(--space-sm); flex-wrap: wrap; }

.hero-art { position: relative; }

.hero-art img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  border: 1px solid var(--line);
  border-radius: 2px;
  box-shadow: var(--shadow-md);
  background: var(--wash);
  transition: opacity 0.5s var(--ease-out), box-shadow 0.4s var(--ease-out);
}

.hero-art img:hover { box-shadow: var(--shadow-lg); }

.hero-art figcaption {
  margin-top: 12px;
  font-size: 12.5px;
  letter-spacing: 0.15em;
  color: var(--muted);
}

.hero-strip {
  margin-top: var(--space-xl);
  padding: 26px 0;
  border-top: 1px solid var(--line);
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
  align-items: center;
}

.hero-strip span {
  font-family: var(--serif);
  font-size: 15px;
  letter-spacing: 0.28em;
  color: var(--ink);
  position: relative;
}

.hero-strip span:not(:last-child)::after {
  content: '·';
  margin-left: var(--space-md);
  color: var(--line);
}

/* ---------- 理念 ---------- */

.idea-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
}

.idea-item {
  padding: 8px 40px 8px 32px;
  border-left: 1px solid var(--line);
  transition: border-color 0.3s var(--ease-out);
}

.idea-item:first-child {
  border-left: none;
  padding-left: 0;
}

.idea-item:hover { border-left-color: var(--ink); }
.idea-item:first-child:hover { border-left: none; }

.idea-num {
  display: block;
  font-family: var(--serifDisplay);
  font-size: 18px;
  color: var(--muted);
  letter-spacing: 0.2em;
  margin-bottom: 22px;
}

.idea-item h3 {
  font-family: var(--serifDisplay);
  font-size: var(--fs-h3);
  font-weight: 600;
  letter-spacing: 0.08em;
  margin-bottom: 14px;
  position: relative;
  padding-bottom: 0;
}

.idea-item h3::after {
  content: '';
  display: block;
  width: 0;
  height: 1px;
  background: var(--ink);
  margin-top: 12px;
  transition: width 0.4s var(--ease-out);
}

.idea-item:hover h3::after { width: 32px; }

.idea-item p {
  font-size: 15px;
  color: var(--text);
  line-height: 1.8;
}

/* ---------- 功能 ---------- */

.feature-list { border-top: 1px solid var(--line); }

.feature-row {
  display: grid;
  grid-template-columns: 90px 240px 1fr;
  gap: var(--space-md);
  align-items: baseline;
  padding: 34px 0;
  border-bottom: 1px solid var(--line);
  position: relative;
  transition: background 0.3s var(--ease-out);
}

.feature-row::before {
  content: '';
  position: absolute;
  left: -12px;
  top: 0;
  bottom: 0;
  width: 0;
  background: var(--ink);
  transition: width 0.3s var(--ease-out);
}

.feature-row:hover {
  background: rgba(0,0,0,0.015);
}

.feature-row:hover::before { width: 3px; }

.feature-index {
  font-family: var(--serifDisplay);
  font-size: 16px;
  color: var(--muted);
  letter-spacing: 0.15em;
}

.feature-row h3 {
  font-family: var(--serifDisplay);
  font-size: var(--fs-h3);
  font-weight: 600;
  letter-spacing: 0.06em;
  transition: color 0.25s var(--ease-out);
}

.feature-row:hover h3 { color: #000; }

.feature-row p {
  font-size: 15px;
  color: var(--text);
  max-width: 36em;
  line-height: 1.75;
}

/* ---------- 展厅预览 ---------- */

.filter-chips { display: flex; gap: 10px; flex-wrap: wrap; }

.chip {
  background: none;
  border: 1px solid var(--line);
  padding: 8px 20px;
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--muted);
  cursor: pointer;
  transition: color 0.25s var(--ease-out), border-color 0.25s var(--ease-out),
              background 0.25s var(--ease-out), transform 0.25s var(--ease-out);
}

.chip:hover {
  color: var(--ink);
  border-color: var(--ink);
  transform: translateY(-1px);
}

.chip--active {
  color: #fff;
  border-color: var(--ink);
  background: var(--ink);
}

.masonry {
  columns: 3;
  column-gap: 24px;
}

.art-card {
  break-inside: avoid;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--line);
  padding-bottom: 18px;
  transition: transform 0.4s var(--ease-out), box-shadow 0.4s var(--ease-out);
}

.art-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.art-card__img-wrap {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--wash);
}

.art-card__img-wrap img {
  width: 100%;
  transition: transform 0.6s var(--ease-out), opacity 0.4s var(--ease-out);
}

.art-card:hover .art-card__img-wrap img { transform: scale(1.03); }

.art-card figcaption {
  padding-top: 14px;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
}

.art-card__title {
  font-family: var(--serifDisplay);
  font-size: 16.5px;
  font-weight: 600;
  letter-spacing: 0.05em;
}

.art-card__meta {
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.art-card.is-hidden { display: none; }

.gallery-loading {
  padding: var(--space-lg) 0;
  text-align: center;
  color: var(--muted);
  font-size: 14px;
  letter-spacing: 0.1em;
}

.gallery-loading::after {
  content: '';
  display: block;
  width: 120px;
  height: 2px;
  margin: 16px auto 0;
  background: var(--line);
  position: relative;
  overflow: hidden;
}

.gallery-loading::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 40px;
  height: 2px;
  background: var(--ink);
  animation: shimmer 1.4s infinite var(--ease-smooth);
}

@keyframes shimmer {
  0% { transform: translateX(-40px); }
  100% { transform: translateX(120px); }
}

.gallery-note {
  margin-top: 48px;
  font-size: 13.5px;
  color: var(--muted);
  letter-spacing: 0.08em;
  line-height: 2;
}

.gallery-note a {
  border-bottom: 1px solid var(--line);
  transition: color 0.25s var(--ease-out), border-color 0.25s var(--ease-out);
}
.gallery-note a:hover { color: var(--ink); border-bottom-color: var(--ink); }

/* ---------- 入驻 ---------- */

.join-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 56px;
  margin-bottom: 72px;
  position: relative;
}

.join-step { position: relative; }

.join-step:not(:last-child)::after {
  content: '→';
  position: absolute;
  right: -36px;
  top: 0;
  font-size: 20px;
  color: var(--line);
  transition: color 0.3s var(--ease-out);
}

.join-step:hover:not(:last-child)::after { color: var(--ink); }

.join-num {
  display: block;
  font-family: var(--serifDisplay);
  font-size: clamp(40px, 5vw, 56px);
  font-weight: 600;
  line-height: 1;
  margin-bottom: 20px;
  color: var(--ink);
  opacity: 0.12;
}

.join-step h3 {
  font-family: var(--serifDisplay);
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 0.08em;
  margin-bottom: 10px;
  position: relative;
  margin-top: -28px;
}

.join-step p {
  font-size: 14.5px;
  color: var(--text);
  line-height: 1.8;
}

.join-cta {
  border-top: 1px solid var(--line);
  padding-top: 48px;
  text-align: center;
}

.join-tip {
  margin-top: 18px;
  font-size: 13px;
  color: var(--muted);
  letter-spacing: 0.06em;
}

/* ---------- 页脚 ---------- */

.site-footer {
  border-top: 1px solid var(--line);
  padding: 72px 0 56px;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.4fr auto 1fr;
  gap: var(--space-lg);
  align-items: start;
}

.footer-slogan {
  margin-top: var(--space-sm);
  font-size: 13.5px;
  color: var(--muted);
  letter-spacing: 0.22em;
}

.footer-qr { text-align: center; }

.qr-placeholder {
  width: 148px;
  height: 148px;
  border: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 14px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.3s var(--ease-out);
}

.qr-placeholder:hover { box-shadow: var(--shadow-md); }

.qr-char {
  font-family: var(--serifDisplay);
  font-size: 64px;
  font-weight: 600;
}

.footer-qr p {
  font-size: 12.5px;
  color: var(--muted);
  line-height: 1.9;
  letter-spacing: 0.1em;
}

.footer-meta {
  justify-self: end;
  text-align: right;
  font-size: 13.5px;
  color: var(--muted);
  line-height: 2.2;
  letter-spacing: 0.08em;
}

.footer-meta a {
  border-bottom: 1px solid var(--line);
  transition: color 0.25s var(--ease-out), border-color 0.25s var(--ease-out),
              transform 0.25s var(--ease-out);
  display: inline-block;
}
.footer-meta a:hover {
  color: var(--ink);
  border-bottom-color: var(--ink);
  transform: translateY(-1px);
}

.footer-copy {
  margin-top: 14px;
  font-size: 12px;
  letter-spacing: 0.05em;
}

/* ---------- 滚动显现动画 ---------- */

.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out);
}

.reveal.is-visible {
  opacity: 1;
  transform: none;
}

.reveal--delay { transition-delay: 0.12s; }
.reveal--delay-2 { transition-delay: 0.24s; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
  .gallery-loading::before { animation: none; }
}

/* ---------- 图片加载 fade-in ---------- */

.img-fade {
  opacity: 0;
  transition: opacity 0.5s var(--ease-out);
}
.img-fade.is-loaded { opacity: 1; }

/* ---------- 图片加载失败兜底 ---------- */

.img-failed {
  min-height: 240px;
  background: var(--wash) !important;
  position: relative;
  overflow: hidden;
}
.img-failed::after {
  content: attr(data-alt);
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  font-family: var(--serif);
  font-size: 15px;
  color: var(--muted);
  letter-spacing: 0.08em;
  text-align: center;
  max-width: 80%;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* ---------- 响应式 ---------- */

@media (max-width: 1200px) {
  .container { max-width: 960px; }
  .hero-inner { gap: 48px; }
  .idea-grid { gap: 0; }
  .idea-item { padding: 8px 24px; }
}

@media (max-width: 960px) {
  .container { padding: 0 22px; }
  .section { padding: 72px 0; }

  .hero { padding-top: 140px; }
  .hero-inner { grid-template-columns: 1fr; gap: 48px; }
  .hero-copy::before { display: none; }
  .hero-strip { margin-top: 64px; gap: var(--space-sm); }
  .hero-strip span { font-size: 13.5px; letter-spacing: 0.18em; }

  .idea-grid { grid-template-columns: 1fr; gap: 40px; }
  .idea-item { border-left: none; padding: 0; border-top: 1px solid var(--line); padding-top: 28px; }
  .idea-item:first-child { border-top: none; padding-top: 0; }
  .idea-item:hover { border-left: none; border-top-color: var(--ink); }

  .feature-row { grid-template-columns: 56px 1fr; gap: 12px 20px; }
  .feature-row p { grid-column: 2; }
  .feature-row::before { left: 0; }

  .masonry { columns: 2; column-gap: 20px; }

  .join-steps { grid-template-columns: 1fr; gap: 40px; margin-bottom: 56px; }
  .join-step:not(:last-child)::after { content: '↓'; right: auto; left: 50%;
    transform: translateX(-50%); top: auto; bottom: -24px; }
  .join-step h3 { margin-top: 0; }

  .footer-inner { grid-template-columns: 1fr; gap: 44px; }
  .footer-meta { justify-self: start; text-align: left; }

  .site-nav {
    position: fixed;
    top: 72px; left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
    transform: translateY(-8px);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.25s var(--ease-out), transform 0.25s var(--ease-out);
  }

  .site-nav.is-open {
    transform: none;
    opacity: 1;
    pointer-events: auto;
  }

  .site-nav a {
    padding: 18px 22px;
    border-bottom: 1px solid var(--line);
  }

  .header-cta { display: none; }
  .nav-toggle { display: flex; }
}

@media (max-width: 560px) {
  .masonry { columns: 1; }
  .art-card__meta { white-space: normal; text-align: right; }
  .section-head--row { align-items: flex-start; flex-direction: column; }
  .hero-title { font-size: clamp(34px, 9vw, 48px); }
}