/* ==========================================================================
   MissAI · style.css
   暗黑科技 + 多彩点缀（紫 / 金 / 薄荷蓝 / 玫粉）
   ========================================================================== */

/* -------- 1. CSS 变量：主题色与基础尺寸 -------- */
:root {
  /* 主色（紫色系） */
  --color-primary: #8B5CF6;
  --color-primary-hover: #7C3AED;
  --color-primary-light: #A78BFA;
  --color-primary-lighter: #C4B5FD;

  /* 高亮色 */
  --color-gold: #F5C842;
  --color-pink: #F472B6;
  --color-orange: #F97316;
  --color-green: #22C55E;

  /* 渐变 */
  --gradient-mint: linear-gradient(135deg, #5EEAD4 0%, #93C5FD 100%);
  --gradient-purple: linear-gradient(135deg, #8B5CF6 0%, #C4B5FD 100%);
  --gradient-gold: linear-gradient(135deg, #F5C842 0%, #F97316 100%);

  /* 背景层级 */
  --bg-1: #1A1530;
  --bg-2: #15112A;
  --bg-0: #0F0B22;
  --bg-card: #241F3D;
  --bg-input: #2A2545;
  --bg-banner: #3B2D5C;

  /* 文字层级 */
  --text-1: #F5F3FF;
  --text-2: #A8A0C2;
  --text-3: #6F6789;

  /* 描边/分割线 */
  --border-soft: rgba(167, 139, 250, .10);
  --border-medium: rgba(167, 139, 250, .18);

  /* 阴影 */
  --shadow-purple: 0 8px 24px rgba(139, 92, 246, .45);
  --shadow-card: 0 12px 32px rgba(0, 0, 0, .35);

  /* Hero 渐变 */
  --hero-bg: radial-gradient(ellipse at 70% 30%, rgba(139, 92, 246, .18) 0%, var(--bg-1) 70%);

  /* 圆角 */
  --r-sm: 8px;
  --r-md: 12px;
  --r-lg: 16px;
  --r-pill: 9999px;

  /* 容器 */
  --container-max: 1240px;

  /* 字体 */
  --font-sans: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

/* -------- 2. 全局重置 -------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-1);
  color: var(--text-1);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color .2s ease;
}

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

ul {
  list-style: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: transparent;
  color: inherit;
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

/* 文字渐变 / 高亮辅助类 */
.text-gradient {
  background: var(--gradient-purple);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.text-gold {
  color: var(--color-gold);
}

/* -------- 3. 通用按钮 -------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--r-pill);
  transition: transform .25s ease, box-shadow .25s ease, background .25s ease, color .25s ease;
  white-space: nowrap;
  cursor: pointer;
  user-select: none;
}
.btn i { font-size: 14px; }
.btn-primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 6px 18px rgba(139, 92, 246, .35);
}
.btn-primary:hover {
  background: var(--color-primary-hover);
  box-shadow: var(--shadow-purple);
  transform: translateY(-2px);
}
.btn-mint {
  background: var(--gradient-mint);
  color: var(--bg-0);
  box-shadow: 0 6px 18px rgba(94, 234, 212, .35);
}
.btn-mint:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 28px rgba(94, 234, 212, .45);
}
.btn-ghost {
  background: rgba(167, 139, 250, .08);
  color: var(--text-1);
  border: 1px solid var(--border-medium);
}
.btn-ghost:hover {
  background: rgba(167, 139, 250, .16);
  transform: translateY(-2px);
}
.btn-lg {
  padding: 16px 30px;
  font-size: 16px;
}

/* -------- 4. 头部导航 -------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(15, 11, 34, .85);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--border-soft);
  transition: background .25s ease, box-shadow .25s ease;
}
.site-header.scrolled {
  background: rgba(15, 11, 34, .95);
  box-shadow: 0 6px 24px rgba(0, 0, 0, .35);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  height: 70px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  letter-spacing: .3px;
}
.logo-img {
  width: 34px;
  height: 34px;
  border-radius: 8px;
  object-fit: cover;
  box-shadow: 0 2px 10px rgba(139, 92, 246, .35);
}
.logo-text {
  font-size: 20px;
  background: linear-gradient(135deg, #C4B5FD, #F5C842);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.nav-main {
  flex: 1;
  display: flex;
  justify-content: center;
}
.nav-list {
  display: flex;
  gap: 6px;
}
.nav-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border-radius: var(--r-pill);
  font-size: 14px;
  font-weight: 500;
  color: var(--text-2);
  transition: color .2s ease, background .2s ease;
}
.nav-link i { font-size: 13px; }
.nav-link:hover {
  color: var(--text-1);
  background: rgba(167, 139, 250, .08);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

/* 语言切换 */
.lang-switch {
  position: relative;
}
.lang-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 14px;
  border-radius: var(--r-pill);
  font-size: 14px;
  font-weight: 500;
  color: var(--text-1);
  background: rgba(167, 139, 250, .08);
  border: 1px solid var(--border-soft);
  transition: background .2s ease, border-color .2s ease;
}
.lang-btn:hover {
  background: rgba(167, 139, 250, .16);
  border-color: var(--border-medium);
}
.lang-btn .chevron {
  font-size: 11px;
  transition: transform .25s ease;
}
.lang-switch.open .chevron {
  transform: rotate(180deg);
}
.lang-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 180px;
  background: var(--bg-card);
  border: 1px solid var(--border-medium);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-card);
  padding: 6px;
  opacity: 0;
  transform: translateY(-6px);
  pointer-events: none;
  transition: opacity .2s ease, transform .2s ease;
  z-index: 200;
}
.lang-switch.open .lang-menu {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.lang-menu a {
  display: block;
  padding: 10px 14px;
  border-radius: var(--r-sm);
  font-size: 14px;
  color: var(--text-2);
}
.lang-menu a:hover {
  background: rgba(167, 139, 250, .12);
  color: var(--text-1);
}

.menu-toggle {
  display: none;
  font-size: 20px;
  color: var(--text-1);
  padding: 6px 10px;
  border-radius: 8px;
}

/* -------- 5. Hero（单栏居中重构版） -------- */
.hero {
  position: relative;
  padding: 64px 0 72px;
  background: var(--hero-bg);
  overflow: hidden;
  isolation: isolate;
}
/* 背景网格底纹（径向遮罩淡出） */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(167, 139, 250, .055) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(167, 139, 250, .055) 1px, transparent 1px);
  background-size: 48px 48px;
  -webkit-mask-image: radial-gradient(ellipse at center, #000 25%, transparent 75%);
          mask-image: radial-gradient(ellipse at center, #000 25%, transparent 75%);
  pointer-events: none;
  z-index: 0;
}
/* 装饰光斑 */
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}
.hero-bg .orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: .55;
  animation: orbDrift 14s ease-in-out infinite;
}
.orb-1 {
  width: 380px; height: 380px;
  top: -120px; left: 6%;
  background: radial-gradient(circle, #8B5CF6, transparent 70%);
}
.orb-2 {
  width: 320px; height: 320px;
  bottom: -120px; right: 8%;
  background: radial-gradient(circle, #5EEAD4, transparent 70%);
  animation-delay: -4s;
}
.orb-3 {
  width: 240px; height: 240px;
  top: 35%; left: 58%;
  background: radial-gradient(circle, #F472B6, transparent 70%);
  animation-delay: -8s;
}
@keyframes orbDrift {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50%      { transform: translate(20px, -16px) scale(1.06); }
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 880px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}
.hero-text {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: rgba(59, 45, 92, .65);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(167, 139, 250, .28);
  border-radius: var(--r-pill);
  font-size: 12.5px;
  font-weight: 500;
  color: var(--color-primary-lighter);
  margin-bottom: 22px;
  box-shadow: 0 4px 14px rgba(139, 92, 246, .15);
}
.hero-badge i {
  color: var(--color-gold);
  font-size: 12px;
}
.hero-title {
  font-size: clamp(32px, 5.2vw, 60px);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -.6px;
  margin-bottom: 20px;
  max-width: 880px;
}
.hero-subtitle {
  font-size: 15.5px;
  color: var(--text-2);
  margin: 0 auto 28px;
  max-width: 620px;
  line-height: 1.7;
}
.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  margin-bottom: 22px;
}
.hero-cta .btn {
  padding: 13px 24px;
  font-size: 14.5px;
}
.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  justify-content: center;
  color: var(--text-2);
  font-size: 12.5px;
}
.hero-meta li {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  position: relative;
}
.hero-meta li:not(:last-child)::after {
  content: '';
  position: absolute;
  right: -10px;
  top: 50%;
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--text-3);
  transform: translateY(-50%);
}
.hero-meta i { color: var(--color-green); font-size: 11px; }

/* -------- 6. Section 通用标题 -------- */
section { padding: 90px 0; }
.section-head {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 60px;
}
.section-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px;
  background: rgba(167, 139, 250, .12);
  color: var(--color-primary-lighter);
  border-radius: var(--r-pill);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .5px;
  text-transform: uppercase;
  margin-bottom: 16px;
}
.section-eyebrow i { color: var(--color-gold); }
.section-title {
  font-size: clamp(28px, 3.4vw, 40px);
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 14px;
}
.section-title.gold-underline {
  position: relative;
  display: inline-block;
  padding-bottom: 8px;
}
.section-title.gold-underline::after {
  content: '';
  position: absolute;
  left: 50%;
  bottom: 0;
  transform: translateX(-50%);
  width: 80px;
  height: 3px;
  background: var(--color-gold);
  border-radius: 2px;
}
.section-desc {
  color: var(--text-2);
  font-size: 16px;
}

/* -------- 7. Features -------- */
.features {
  background: var(--bg-2);
}
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-soft);
  border-radius: var(--r-lg);
  padding: 30px 26px;
  transition: transform .25s ease, border-color .25s ease, box-shadow .25s ease;
}
.feature-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-medium);
  box-shadow: var(--shadow-card);
}
.feature-icon {
  width: 54px;
  height: 54px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  margin-bottom: 18px;
}
.i-purple { background: rgba(139,92,246,.18); color: var(--color-primary-light); }
.i-pink   { background: rgba(244,114,182,.16); color: var(--color-pink); }
.i-orange { background: rgba(249,115,22,.16); color: var(--color-orange); }
.i-mint   { background: rgba(94,234,212,.16); color: #5EEAD4; }
.i-gold   { background: rgba(245,200,66,.16); color: var(--color-gold); }
.i-blue   { background: rgba(147,197,253,.16); color: #93C5FD; }

.feature-card h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 10px;
}
.feature-card p {
  color: var(--text-2);
  font-size: 14.5px;
  line-height: 1.65;
}

/* -------- 8. Categories -------- */
.categories-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}
.category-tag {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 18px 22px;
  background: var(--bg-card);
  border: 1px solid var(--border-soft);
  border-radius: var(--r-md);
  font-size: 16px;
  font-weight: 600;
  color: var(--text-1);
  transition: transform .2s ease, border-color .2s ease, background .2s ease;
}
.category-tag i {
  font-size: 20px;
  color: var(--color-primary-light);
  transition: color .2s ease;
}
.category-tag:hover {
  transform: translateY(-3px);
  border-color: var(--color-primary);
  background: rgba(139, 92, 246, .12);
}
.category-tag:hover i {
  color: var(--color-gold);
}

/* -------- 9. Gallery -------- */
.gallery { background: var(--bg-2); }
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.story-card {
  background: var(--bg-card);
  border: 1px solid var(--border-soft);
  border-radius: var(--r-lg);
  overflow: hidden;
  transition: transform .25s ease, box-shadow .25s ease;
}
.story-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-card);
}
.story-cover {
  position: relative;
  aspect-ratio: 16 / 9;
  display: flex;
  align-items: flex-end;
  padding: 14px;
}
.story-cover::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(transparent 50%, rgba(0,0,0,.4));
}
.story-rate {
  position: absolute;
  top: 14px;
  left: 14px;
  background: rgba(0, 0, 0, .55);
  color: var(--color-orange);
  padding: 5px 10px;
  font-size: 12px;
  font-weight: 700;
  border-radius: var(--r-pill);
  display: inline-flex;
  align-items: center;
  gap: 5px;
}
.story-genre {
  position: relative;
  z-index: 2;
  background: rgba(0, 0, 0, .6);
  color: #fff;
  padding: 5px 12px;
  font-size: 12px;
  font-weight: 600;
  border-radius: var(--r-pill);
}
.story-body {
  padding: 18px 18px 20px;
}
.story-body h3 {
  font-size: 18px;
  margin-bottom: 8px;
  font-weight: 700;
}
.story-body p {
  font-size: 14px;
  color: var(--text-2);
  margin-bottom: 14px;
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.story-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.story-tags span {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 9px;
  border-radius: var(--r-pill);
  font-size: 11px;
  background: rgba(167, 139, 250, .12);
  color: var(--color-primary-lighter);
}
.story-tags .tag-pink {
  background: rgba(244, 114, 182, .14);
  color: var(--color-pink);
}
.gallery-more {
  text-align: center;
  margin-top: 50px;
}

/* -------- 10. Stats -------- */
.stats {
  padding: 70px 0;
  background: linear-gradient(180deg, var(--bg-2), var(--bg-1));
}
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}
.stat-item {
  background: var(--bg-card);
  border: 1px solid var(--border-soft);
  border-radius: var(--r-lg);
  text-align: center;
  padding: 30px 18px;
  transition: transform .25s ease, border-color .25s ease;
}
.stat-item:hover {
  transform: translateY(-4px);
  border-color: var(--border-medium);
}
.stat-num {
  font-size: clamp(28px, 3vw, 38px);
  font-weight: 800;
  background: linear-gradient(135deg, #C4B5FD, #F5C842);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-bottom: 8px;
}
.stat-label {
  font-size: 14px;
  color: var(--text-2);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.stat-label i { color: var(--color-primary-light); }

/* -------- 11. Testimonials -------- */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.testimonial-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border-soft);
  border-radius: var(--r-lg);
  padding: 30px 28px;
  transition: transform .25s ease, border-color .25s ease;
}
.testimonial-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-medium);
}
.quote-mark {
  font-size: 22px;
  color: var(--color-primary);
  opacity: .55;
  margin-bottom: 10px;
}
.testimonial-card blockquote {
  font-size: 15.5px;
  line-height: 1.7;
  color: var(--text-1);
  margin-bottom: 22px;
}
.testimonial-card figcaption {
  display: flex;
  align-items: center;
  gap: 12px;
}
.avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #fff;
  font-size: 16px;
}
.a-purple { background: linear-gradient(135deg, #8B5CF6, #C4B5FD); }
.a-mint   { background: linear-gradient(135deg, #5EEAD4, #93C5FD); color: var(--bg-0); }
.a-orange { background: linear-gradient(135deg, #F97316, #F5C842); }
.a-gold   { background: linear-gradient(135deg, #F5C842, #F472B6); color: var(--bg-0); }
.who {
  font-weight: 700;
  color: var(--text-1);
  font-size: 14.5px;
}
.role {
  font-size: 12.5px;
  color: var(--text-3);
}

/* -------- 12. FAQ -------- */
.faq { background: var(--bg-2); }
.faq-list {
  max-width: 880px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-soft);
  border-radius: var(--r-md);
  overflow: hidden;
  transition: border-color .25s ease;
}
.faq-item[open] {
  border-color: var(--color-primary);
}
.faq-item summary {
  list-style: none;
  cursor: pointer;
  padding: 18px 22px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-weight: 600;
  font-size: 15.5px;
  color: var(--text-1);
}
.faq-item summary::-webkit-details-marker { display: none; }
.q-text {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.q-text i { color: var(--color-gold); font-size: 14px; }
.arrow {
  font-size: 13px;
  color: var(--text-2);
  transition: transform .25s ease;
}
.faq-item[open] .arrow {
  transform: rotate(180deg);
  color: var(--color-primary-light);
}
.faq-answer {
  padding: 0 22px 22px 50px;
  color: var(--text-2);
  font-size: 14.5px;
  line-height: 1.7;
  animation: fadeSlide .3s ease;
}
@keyframes fadeSlide {
  from { opacity: 0; transform: translateY(-4px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* -------- 13. CTA Final -------- */
.cta-final {
  padding: 80px 0;
  background: radial-gradient(ellipse at 50% 50%, rgba(139, 92, 246, .25) 0%, var(--bg-1) 70%);
}
.cta-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 30px;
  background: linear-gradient(135deg, rgba(139,92,246,.12), rgba(94,234,212,.06));
  border: 1px solid var(--border-medium);
  border-radius: 24px;
  padding: 48px 52px;
}
.cta-text h2 {
  font-size: clamp(24px, 2.6vw, 32px);
  font-weight: 800;
  margin-bottom: 8px;
}
.cta-text p {
  color: var(--text-2);
}
.cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

/* -------- 14. Footer -------- */
.site-footer {
  background: var(--bg-0);
  border-top: 1px solid var(--border-soft);
  padding-top: 60px;
}
.footer-inner {
  display: grid;
  grid-template-columns: 1.3fr 2.7fr;
  gap: 50px;
  padding-bottom: 50px;
}
.footer-brand .logo { margin-bottom: 18px; }
.brand-tagline {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.7;
  margin-bottom: 20px;
  max-width: 320px;
}
.social {
  display: flex;
  gap: 10px;
}
.social a {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: var(--bg-card);
  border: 1px solid var(--border-soft);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--text-2);
  transition: all .2s ease;
  font-size: 14px;
}
.social a:hover {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.footer-col h4 {
  font-size: 14px;
  letter-spacing: .5px;
  text-transform: uppercase;
  color: var(--color-primary-lighter);
  margin-bottom: 16px;
}
.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.footer-col a {
  font-size: 14px;
  color: var(--text-2);
}
.footer-col a:hover {
  color: var(--text-1);
}

.footer-bottom {
  border-top: 1px solid var(--border-soft);
  padding: 22px 0;
  font-size: 13px;
  color: var(--text-3);
}
.footer-bottom .container {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: space-between;
  align-items: center;
}
.footer-bottom .legal a:hover {
  color: var(--color-primary-light);
}

/* -------- 15. Back to top -------- */
.back-top {
  position: fixed;
  right: 22px;
  bottom: 28px;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: var(--color-primary);
  color: #fff;
  font-size: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-purple);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity .25s ease, transform .25s ease, background .2s ease;
  z-index: 80;
}
.back-top.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.back-top:hover {
  background: var(--color-primary-hover);
}

/* -------- 16. 响应式 -------- */
@media (max-width: 1024px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .gallery-grid { grid-template-columns: repeat(2, 1fr); }
  .categories-grid { grid-template-columns: repeat(4, 1fr); }
  .footer-inner { grid-template-columns: 1fr; gap: 30px; }
  .hero { padding: 56px 0 64px; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  section { padding: 70px 0; }
  .container { padding: 0 18px; }

  .nav-main {
    position: fixed;
    top: 70px;
    right: 0;
    width: 280px;
    max-width: 80vw;
    height: calc(100vh - 70px);
    background: var(--bg-0);
    border-left: 1px solid var(--border-soft);
    transform: translateX(100%);
    transition: transform .3s ease;
    padding: 24px;
    z-index: 99;
  }
  .nav-main.open { transform: translateX(0); }
  .nav-list { flex-direction: column; gap: 4px; }
  .nav-link { width: 100%; padding: 14px 16px; }

  .menu-toggle { display: inline-flex; }
  .header-cta span { display: none; }
  .header-cta { padding: 10px 14px; }
  .lang-btn span:not(.chevron) { display: none; }
  .lang-btn { padding: 9px 12px; }

  .features-grid { grid-template-columns: 1fr; }
  .gallery-grid { grid-template-columns: 1fr; }
  .categories-grid { grid-template-columns: repeat(2, 1fr); }
  .testimonials-grid { grid-template-columns: 1fr; }
  .footer-cols { grid-template-columns: repeat(2, 1fr); }

  .cta-inner { padding: 36px 24px; flex-direction: column; text-align: center; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }

  .hero { padding: 44px 0 52px; }
  .hero-meta { gap: 14px; }
  .hero-meta li:not(:last-child)::after { right: -8px; }
  .hero-cta .btn { padding: 11px 20px; font-size: 14px; }
}

@media (max-width: 480px) {
  .stats-grid { grid-template-columns: 1fr; }
  .footer-cols { grid-template-columns: 1fr; }
  .hero-cta { flex-direction: column; align-items: stretch; }
  .hero-cta .btn { justify-content: center; }
  .cta-actions { flex-direction: column; align-items: stretch; }
  .cta-actions .btn { justify-content: center; }
  .hero { padding: 36px 0 40px; }
  .hero-badge { font-size: 11.5px; padding: 5px 12px; margin-bottom: 16px; }
  .hero-subtitle { font-size: 14.5px; margin-bottom: 22px; }
  .hero-meta { row-gap: 8px; gap: 12px; }
  .hero-meta li:not(:last-child)::after { display: none; }
}

/* -------- 14. 内页（doc）：FAQ / 用户手册 / 法律 / 反馈 -------- */
.doc-hero {
  position: relative;
  padding: 56px 0 36px;
  background: var(--hero-bg);
  overflow: hidden;
  isolation: isolate;
}
.doc-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(167, 139, 250, .055) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(167, 139, 250, .055) 1px, transparent 1px);
  background-size: 48px 48px;
  -webkit-mask-image: radial-gradient(ellipse at center, #000 25%, transparent 80%);
          mask-image: radial-gradient(ellipse at center, #000 25%, transparent 80%);
  pointer-events: none;
  z-index: 0;
}
.doc-hero .container {
  position: relative;
  z-index: 1;
  max-width: 920px;
}
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 8px;
  font-size: 13px;
  color: var(--text-3);
  margin-bottom: 14px;
}
.breadcrumb a {
  color: var(--text-2);
  text-decoration: none;
  transition: color .2s ease;
}
.breadcrumb a:hover { color: var(--color-primary-light); }
.breadcrumb i { font-size: 9px; color: var(--text-3); }
.breadcrumb .current { color: var(--text-1); }
.doc-title {
  font-size: clamp(28px, 4.4vw, 42px);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -.4px;
  margin: 4px 0 14px;
}
.doc-lead {
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-2);
  max-width: 760px;
}
.doc-meta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 16px;
  padding: 5px 12px;
  background: rgba(139, 92, 246, .12);
  border: 1px solid var(--border-medium);
  border-radius: var(--r-pill);
  font-size: 12px;
  color: var(--color-primary-light);
}
.doc-meta i { font-size: 11px; }

.doc-body {
  padding: 56px 0 80px;
  background: var(--bg-1);
}
.doc-grid {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 40px;
  align-items: start;
}
.doc-toc {
  position: sticky;
  top: 96px;
  background: var(--bg-card);
  border: 1px solid var(--border-soft);
  border-radius: var(--r-lg);
  padding: 20px;
}
.doc-toc h4 {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: .12em;
  color: var(--text-3);
  margin-bottom: 12px;
  font-weight: 600;
}
.doc-toc ul { list-style: none; }
.doc-toc li + li { margin-top: 2px; }
.doc-toc a {
  display: block;
  padding: 8px 12px;
  border-radius: var(--r-sm);
  color: var(--text-2);
  font-size: 13.5px;
  text-decoration: none;
  transition: background .2s ease, color .2s ease;
}
.doc-toc a:hover {
  background: rgba(139, 92, 246, .12);
  color: var(--text-1);
}

.doc-article {
  background: var(--bg-card);
  border: 1px solid var(--border-soft);
  border-radius: var(--r-lg);
  padding: 36px 40px;
  font-size: 15px;
  line-height: 1.78;
  color: var(--text-2);
}
.doc-article > section {
  margin-bottom: 36px;
  scroll-margin-top: 96px;
}
.doc-article > section:last-child { margin-bottom: 0; }
.doc-article h2 {
  font-size: 22px;
  color: var(--text-1);
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-soft);
  font-weight: 700;
}
.doc-article h3 {
  font-size: 16.5px;
  color: var(--text-1);
  margin: 22px 0 10px;
  font-weight: 600;
}
.doc-article p { margin: 0 0 12px; }
.doc-article p:last-child { margin-bottom: 0; }
.doc-article ul,
.doc-article ol {
  margin: 0 0 14px 0;
  padding-left: 22px;
}
.doc-article li { margin-bottom: 6px; }
.doc-article li::marker { color: var(--color-primary-light); }
.doc-article a {
  color: var(--color-primary-light);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: rgba(167, 139, 250, .35);
}
.doc-article a:hover { text-decoration-color: var(--color-primary-light); }
.doc-article strong { color: var(--text-1); font-weight: 600; }
.doc-article code {
  background: rgba(139, 92, 246, .12);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 13px;
  color: var(--color-primary-lighter);
}
.doc-callout {
  display: flex;
  gap: 12px;
  padding: 16px 18px;
  background: rgba(139, 92, 246, .10);
  border: 1px solid var(--border-medium);
  border-left: 3px solid var(--color-primary);
  border-radius: var(--r-md);
  margin: 14px 0;
  font-size: 14px;
  color: var(--text-2);
}
.doc-callout i { color: var(--color-primary-light); margin-top: 3px; }

.support-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
  margin: 14px 0 6px;
}
.support-card {
  background: var(--bg-2);
  border: 1px solid var(--border-soft);
  border-radius: var(--r-md);
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: transform .25s ease, border-color .25s ease;
}
.support-card:hover {
  transform: translateY(-3px);
  border-color: var(--color-primary);
}
.support-card .s-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--r-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  background: var(--gradient-purple);
  color: var(--bg-0);
}
.support-card h3 { color: var(--text-1); font-size: 15.5px; margin: 0; }
.support-card p { color: var(--text-2); font-size: 13.5px; line-height: 1.65; margin: 0; }
.support-card .s-link {
  color: var(--color-primary-light);
  font-size: 13.5px;
  text-decoration: none;
  margin-top: auto;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding-top: 4px;
}
.support-card .s-link:hover { color: var(--text-1); }

.feedback-form {
  display: grid;
  gap: 16px;
  margin-top: 6px;
}
.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-group label {
  font-size: 13px;
  color: var(--text-2);
  font-weight: 500;
}
.form-group input,
.form-group select,
.form-group textarea {
  padding: 12px 14px;
  background: var(--bg-input);
  border: 1px solid var(--border-medium);
  border-radius: var(--r-md);
  color: var(--text-1);
  font-size: 14px;
  font-family: inherit;
  transition: border-color .2s ease, box-shadow .2s ease;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(139, 92, 246, .18);
}
.form-group textarea { resize: vertical; min-height: 140px; }
.form-actions { display: flex; gap: 12px; flex-wrap: wrap; }

@media (max-width: 900px) {
  .doc-grid { grid-template-columns: 1fr; gap: 22px; }
  .doc-toc { position: static; }
  .doc-article { padding: 26px 22px; }
  .form-row { grid-template-columns: 1fr; }
}
@media (max-width: 480px) {
  .doc-hero { padding: 40px 0 28px; }
  .doc-body { padding: 36px 0 56px; }
  .doc-article { padding: 22px 18px; font-size: 14.5px; }
  .doc-article h2 { font-size: 19px; }
}