/**
 * 全站视觉与版式优化（SureThing 风格：留白、轻边框、弱对比条纹）
 * 仅 CSS，不改 index.html 结构与文案
 */

:root {
  --c-bg-elevated: #0d1220;
  --shadow-soft: 0 1px 0 rgba(255, 255, 255, 0.04) inset,
    0 12px 40px rgba(0, 0, 0, 0.18);
  --shadow-card-hover: 0 16px 48px rgba(0, 0, 0, 0.22);
  --border-subtle: rgba(148, 163, 184, 0.12);
  --section-py: clamp(56px, 8vw, 96px);
  --section-py-mob: clamp(44px, 6vw, 60px);
  --section-head-gap: clamp(28px, 4vw, 40px);
  --radius-lg: 18px;
  /* 章节眉标（SureThing 式 eyebrow） */
  --eyebrow-size: 0.72rem;
  --eyebrow-weight: 600;
  --eyebrow-color: var(--c-text-3);
  --eyebrow-spacing: 0.12em;
  --eyebrow-gap: 12px;
  --section-subtitle-size: clamp(0.88rem, 1vw, 0.94rem);
  --section-subtitle-gap: 14px;
  --section-band-bg: rgba(17, 24, 39, 0.32);
}

body {
  line-height: 1.68;
  background-color: var(--c-bg);
  background-image:
    radial-gradient(ellipse 120% 80% at 50% -28%, rgba(139, 92, 246, 0.14), transparent 52%),
    radial-gradient(ellipse 70% 50% at 100% 40%, rgba(217, 70, 239, 0.06), transparent 45%),
    radial-gradient(ellipse 60% 40% at 0% 70%, rgba(16, 185, 129, 0.05), transparent 40%);
  background-attachment: fixed;
}

/* 板块底色：按 section 顺序交替（首页 Hero 有底色，核心认知透明，其余类推） */
section {
  background: transparent;
  box-shadow: none;
}

body > section:nth-of-type(odd) {
  background: var(--section-band-bg);
  box-shadow: inset 0 1px 0 var(--border-subtle), inset 0 -1px 0 var(--border-subtle);
}

body > section:nth-of-type(even) {
  background: transparent;
  box-shadow: none;
}

/* —— 章节眉标 + 标题 + 副标题（两层体系） —— */
:is(
  .section-intro,
  .pricing-tiers-intro,
  #cases-panel .cases-section-head,
  #touch-examples > .wrap > .section-intro
) .tag {
  display: block;
  width: fit-content;
  max-width: 100%;
  margin: 0 auto var(--eyebrow-gap);
  padding: 0;
  border: 0;
  border-radius: 0;
  background: transparent !important;
  color: var(--eyebrow-color) !important;
  font-size: var(--eyebrow-size);
  font-weight: var(--eyebrow-weight);
  letter-spacing: var(--eyebrow-spacing);
  line-height: 1.35;
  text-transform: none;
}

/* 区块眉标上的 tag--success / tag--warn 不再用色 pill，与全站眉标一致 */
:is(.section-intro, .pricing-tiers-intro, #cases-panel .cases-section-head)
  .tag:is(.tag--success, .tag--warn) {
  color: var(--eyebrow-color) !important;
}

body.lang-en :is(
  .section-intro,
  .pricing-tiers-intro,
  #cases-panel .cases-section-head,
  #touch-examples > .wrap > .section-intro
) .tag {
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

/* 眉标内「AI」保留轻量品牌色，不破坏眉标层级 */
:is(.section-intro, .pricing-tiers-intro, #cases-panel .cases-section-head) .tag .logo-aim {
  background: var(--c-accent-g);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  font-weight: inherit;
}

/* H2：结论句，眉标下方主标题 */
:is(
  .section-intro,
  .pricing-tiers-intro,
  #cases-panel .cases-section-head,
  #touch-examples > .wrap > .section-intro
) h2 {
  margin: 0;
  letter-spacing: -0.025em;
  font-weight: 700;
  line-height: 1.18;
  font-size: clamp(1.45rem, 3.2vw, 2.15rem);
  color: var(--c-text);
}

/* 副标题：最多一行语义（fit-lead、价格导语等） */
:is(.section-intro, .pricing-tiers-intro) > p,
#fit-customers .fit-lead {
  margin: var(--section-subtitle-gap) auto 0;
  max-width: min(36em, 100%);
  font-size: var(--section-subtitle-size);
  font-weight: 400;
  line-height: 1.55;
  color: var(--c-text-2);
  letter-spacing: 0.02em;
}

#fit-customers .section-intro {
  margin-bottom: clamp(28px, 4vw, 40px);
}

#fit-customers .section-intro .tag {
  margin-bottom: var(--eyebrow-gap) !important;
}

#fit-customers .fit-lead {
  margin-top: var(--section-subtitle-gap);
  font-size: var(--section-subtitle-size);
  color: var(--c-text-2);
  letter-spacing: 0.04em;
}

/* 嵌套子块：获客对比（无眉标，仅次级标题） */
#channels-compare > .section-intro {
  margin-bottom: clamp(18px, 2.5vw, 24px);
}

#channels-compare > .section-intro h2 {
  font-size: clamp(1.12rem, 2.2vw, 1.38rem);
  font-weight: 600;
  color: var(--c-text);
  letter-spacing: -0.02em;
}

/* FAQ 等仅 H2、无眉标 */
#faq .section-intro h2 {
  font-size: clamp(1.45rem, 3.2vw, 2.15rem);
}

#pricing .pricing-lead-single {
  color: var(--c-text-2);
  line-height: 1.65;
}

/* —— 卡片与数据块 —— */
.card,
.stat-card,
.trifecta-card,
.fit-card,
.case-card,
.platform-chip,
.step-card {
  border-color: var(--border-subtle);
  box-shadow: var(--shadow-soft);
}

.card {
  padding: clamp(28px, 4vw, 44px);
}

.card:hover,
.case-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-card-hover);
  border-color: rgba(139, 92, 246, 0.22);
}

.stat-card {
  background: rgba(26, 34, 54, 0.55);
  border-radius: var(--radius);
  padding: clamp(20px, 3vw, 32px) clamp(16px, 2.5vw, 24px);
}

.stat-val {
  letter-spacing: -0.02em;
}

.grid-2,
.grid-3,
.grid-4,
.trifecta-grid,
.fit-customers-grid,
.platform-grid {
  gap: clamp(18px, 2.5vw, 28px);
}

.trifecta-card {
  padding: clamp(26px, 3.2vw, 36px);
}

.trifecta-card.highlight {
  border-color: rgba(168, 85, 247, 0.45);
  background: linear-gradient(
    165deg,
    rgba(139, 92, 246, 0.1) 0%,
    rgba(17, 24, 39, 0.5) 55%,
    rgba(10, 14, 26, 0.2) 100%
  );
  box-shadow:
    var(--shadow-soft),
    0 0 0 1px rgba(139, 92, 246, 0.12);
}

/* —— 获客对比表 —— */
#channels-compare .card {
  padding: 0;
  overflow: hidden;
  border-radius: var(--radius-lg);
}

#channels-compare .card:hover {
  transform: none;
}

#channels-compare table th {
  background: rgba(15, 23, 42, 0.65);
  text-transform: none;
  letter-spacing: 0.03em;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--c-text-2);
  border-bottom: 1px solid var(--border-subtle);
}

#channels-compare table td {
  border-bottom-color: rgba(148, 163, 184, 0.08);
}

#channels-compare table tbody tr:last-child td {
  border-bottom: none;
}

#channels-compare table tr:hover td {
  background: rgba(139, 92, 246, 0.05);
}

#how-it-works .channels-compare-wrap .divider {
  margin: clamp(32px, 4vw, 48px) 0 clamp(24px, 3vw, 36px);
  background: linear-gradient(90deg, transparent, var(--border-subtle), transparent);
  height: 1px;
}

/* —— Hero —— */
#hero .hero-copy > h1,
#hero .wrap > h1 {
  letter-spacing: -0.03em;
  font-weight: 800;
  line-height: 1.12;
}

#hero .hero-lead {
  color: var(--c-text-2);
  line-height: 1.62;
}

#hero .hero-path-box {
  background: linear-gradient(
    165deg,
    rgba(4, 120, 87, 0.07) 0%,
    rgba(17, 24, 39, 0.35) 50%,
    transparent 100%
  );
  border-color: rgba(16, 185, 129, 0.14);
  box-shadow: var(--shadow-soft);
}

#hero .hero-cta-row {
  justify-content: flex-start;
  max-width: min(440px, 100%);
  margin-left: 0;
  margin-right: 0;
}

#hero .hero-cta-row--single {
  max-width: min(320px, 100%);
}

#hero .hero-cta-row--single .btn {
  flex: 0 1 auto;
  width: 100%;
  max-width: 100%;
}

#hero .hero-cta-row .btn-outline {
  border-color: var(--border-subtle);
  background: rgba(17, 24, 39, 0.4);
}

#hero .hero-cta-row .btn-outline:hover {
  background: rgba(139, 92, 246, 0.08);
}

#hero .hero-social-cloud__lines {
  opacity: 0.22;
}

#hero .hero-social-cloud::after {
  background: linear-gradient(180deg, transparent, rgba(10, 14, 26, 0.88) 72%, var(--section-band-bg));
}

#hero .hero-social-tile {
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2), 0 0 0 1px rgba(255, 255, 255, 0.08);
}

/* Hero 底部指标：信任条样式 */
#hero .hero-stats {
  margin-top: clamp(40px, 5vw, 56px);
  padding-top: clamp(24px, 3vw, 32px);
  border-top: 1px solid var(--border-subtle);
  gap: clamp(12px, 2vw, 20px);
}

#hero .stat-card {
  background: transparent;
  border: none;
  box-shadow: none;
  padding: clamp(12px, 2vw, 20px) clamp(10px, 1.8vw, 16px);
}

@media (min-width: 769px) {
  #hero .stat-card + .stat-card {
    border-left: 1px solid var(--border-subtle);
  }
}

#hero .stat-val.accent {
  background: var(--c-accent-g);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* —— 适合客户类型（眉标 + 更松卡片间距） —— */
#fit-customers .fit-customers-grid {
  gap: clamp(18px, 2.4vw, 26px);
  margin-bottom: clamp(22px, 3.2vw, 32px);
}

.fit-card {
  padding: clamp(20px, 2.4vw, 28px);
  gap: 4px;
}

.fit-card-rows {
  gap: clamp(12px, 1.6vw, 16px);
}

.fit-card-title {
  margin-bottom: clamp(16px, 2.2vw, 24px);
}

#fit-customers .fit-card-rows {
  margin-top: clamp(2px, 0.4vw, 4px);
}

.fit-cta-panel {
  border-color: rgba(139, 92, 246, 0.22);
  padding: clamp(20px, 2.8vw, 28px);
}

.fit-cta-item {
  background: rgba(10, 14, 26, 0.25);
  border-color: var(--border-subtle);
}

/* —— 案例 Tab —— */
#cases-panel #cases-nav.case-tabs {
  background: rgba(15, 23, 42, 0.5);
  border-color: var(--border-subtle);
  padding: 6px;
}

#cases-panel #cases-nav .case-tab.active {
  box-shadow: 0 2px 16px rgba(0, 0, 0, 0.12), 0 0 0 1px rgba(139, 92, 246, 0.28);
}

#cases-panel .case-card {
  padding: clamp(28px, 4vw, 40px);
}

/* —— 价格套餐 —— */
#pricing .pkg-card {
  border-color: var(--border-subtle);
  box-shadow: var(--shadow-soft);
}

#pricing .pkg-card.featured {
  border-color: rgba(168, 85, 247, 0.4);
  box-shadow:
    var(--shadow-soft),
    0 0 0 1px rgba(139, 92, 246, 0.15);
}

#pricing .pkg-tiers-grid {
  gap: clamp(18px, 2.5vw, 24px);
}

/* —— 底部号召（全宽渐变带） —— */
.cta-section {
  background: var(--c-accent-g) !important;
  padding: clamp(56px, 7vw, 88px) 0;
}

.cta-inner {
  text-align: center;
  max-width: 760px;
  margin: 0 auto;
  color: #fff;
}

.cta-inner h2 {
  color: #fff;
  margin-bottom: 18px;
}

.cta-inner p {
  color: rgba(255, 255, 255, 0.92);
  font-size: clamp(1rem, 1.5vw, 1.18rem);
  line-height: 1.65;
  margin-bottom: 32px;
  white-space: nowrap;
}

.cta-inner p strong {
  color: #fff;
  font-weight: 600;
}

.cta-btn-wide {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: clamp(280px, 40%, 420px);
}

@media (max-width: 640px) {
  .cta-section {
    padding: clamp(44px, 10vw, 56px) 0;
  }

  .cta-inner h2 {
    margin-bottom: 24px;
  }

  .cta-inner p {
    display: none;
  }

  .cta-btn-wide {
    width: 100%;
    min-width: 0;
    padding: 16px 24px;
    font-size: 1rem;
    line-height: 1.25;
    min-height: 50px;
  }
}

@media (max-width: 480px) {
  .cta-btn-wide {
    padding: 15px 20px;
    min-height: 48px;
  }
}

/* —— FAQ —— */
#faq .wrap > div:not(.section-intro) {
  background: rgba(26, 34, 54, 0.35);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 4px clamp(20px, 3vw, 28px);
  box-shadow: var(--shadow-soft);
  max-width: 720px;
  margin-inline: auto;
}

.faq-item {
  border-bottom-color: rgba(148, 163, 184, 0.1);
}

.faq-item:last-child {
  border-bottom: none;
}

.faq-q {
  padding: clamp(18px, 2.5vw, 22px) 0;
  font-size: clamp(0.98rem, 1.2vw, 1.05rem);
  font-weight: 600;
  line-height: 1.45;
}

.faq-q::after {
  font-size: 1.25rem;
  font-weight: 400;
  opacity: 0.7;
}

.faq-item.open .faq-a {
  padding-bottom: clamp(18px, 2.5vw, 24px);
}

/* —— 导航 —— */
.navbar {
  background: rgba(10, 14, 26, 0.72);
  border-bottom-color: transparent;
}

.navbar.scrolled {
  background: rgba(10, 14, 26, 0.88);
  border-bottom-color: var(--border-subtle);
}

.nav-links a {
  font-weight: 500;
}

/* —— 按钮 —— */
.btn-primary {
  box-shadow: 0 4px 20px rgba(139, 92, 246, 0.28);
}

.btn-primary:hover {
  box-shadow: 0 8px 28px rgba(139, 92, 246, 0.36);
}

/* —— 平台 chips —— */
.platform-chip {
  padding: 16px 12px 18px;
  background: rgba(26, 34, 54, 0.45);
}

.platform-chip:hover {
  transform: translateY(-1px);
}

/* —— 合作流程 —— */
.step-card {
  background: rgba(26, 34, 54, 0.45);
}

/* —— 优势卡片 —— */
#why-us .wu-feature-card.card {
  border-color: var(--border-subtle);
}

#why-us .wu-feature-card.card:hover {
  transform: translateY(-2px);
}

/* —— 页脚 —— */
.site-footer {
  background: #060912;
  border-top-color: var(--border-subtle);
}

/* —— 动效更轻 —— */
.reveal {
  transform: translateY(18px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}

/* —— 大屏 Hero 左对齐 CTA —— */
@media (min-width: 901px) {
  #hero .hero-cta-row {
    justify-content: flex-start;
    margin-left: 0;
  }
}

@media (max-width: 768px) {
  #hero .hero-stats {
    border-top: none;
    padding-top: 0;
  }

  #hero .stat-card {
    background: rgba(26, 34, 54, 0.45);
    border: 1px solid var(--border-subtle);
    box-shadow: none;
  }

  #hero .stat-card + .stat-card {
    border-left: none;
  }

  #hero .hero-cta-row {
    justify-content: stretch;
    max-width: 100%;
    margin-inline: auto;
  }

  #faq .wrap > div:not(.section-intro) {
    padding-inline: clamp(14px, 4vw, 20px);
  }
}

@media (prefers-reduced-motion: reduce) {
  body {
    background-attachment: scroll;
  }
}