/* ============================================================
   抖音鑽石（抖幣）充值 · 單商品專題頁
   風格：簡約（台灣） · 主色：#5859F3 · 自適應
   ============================================================ */
:root {
  --primary: #5859F3;
  --primary-dark: #4546d6;
  --primary-soft: #eef0ff;
  --text: #2b2b35;
  --text-light: #6b6b78;
  --bg: #ffffff;
  --bg-soft: #f6f6fb;
  --border: #ececf4;
  --radius: 14px;
  --radius-sm: 10px;
  --shadow: 0 8px 30px rgba(88, 89, 243, 0.10);
  --shadow-hover: 0 14px 38px rgba(88, 89, 243, 0.18);
  --container: 1200px;
  --sale: #ff7a45;
  --daily: #22b573;
  --new: #5859F3;
}

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

html { scroll-behavior: smooth; scroll-padding-top: 84px; }

body {
  font-family: "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background:
    radial-gradient(900px 600px at 12% 6%,  rgba(88,89,243,.16) 0%, rgba(88,89,243,0) 60%),
    radial-gradient(800px 600px at 90% 10%, rgba(150,120,255,.14) 0%, rgba(150,120,255,0) 62%),
    radial-gradient(900px 700px at 80% 90%, rgba(120,160,255,.10) 0%, rgba(120,160,255,0) 60%),
    linear-gradient(to bottom, #f2f3ff 0%, #ffffff 50%, #ffffff 100%);
  background-repeat: no-repeat;
  background-attachment: fixed;
  min-height: 100vh;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

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

/* ===== 按鈕 ===== */
.btn {
  display: inline-block;
  padding: 13px 32px;
  border-radius: 999px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all .25s ease;
  border: none;
  text-align: center;
}
.btn-sm { padding: 10px 24px; font-size: 14px; }
.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: var(--shadow);
}
.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}
.btn-ghost {
  background: transparent;
  color: var(--primary);
  border: 1.5px solid var(--primary);
}
.btn-ghost:hover {
  background: var(--primary-soft);
  transform: translateY(-2px);
}

.btn-buy {
  width: 100%;
  padding: 12px;
  background: var(--primary-soft);
  color: var(--primary);
  border: 1.5px solid var(--primary-border);
  font-size: 15px;
}
.denom-card:hover .btn-buy { background: var(--primary); color: #fff; box-shadow: 0 8px 20px rgba(88,89,243,0.32); }
/* ===== 頂部導覽 ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 800;
  letter-spacing: .5px;
}
/* .logo__mark { width: 34px; height: 34px; } */
.logo__text { color: var(--text); }
.logo__text span { color: var(--primary); }

.nav ul { display: flex; align-items: center; gap: 6px; }
.nav a {
  display: block;
  padding: 8px 14px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 500;
  color: var(--text);
  transition: all .2s ease;
}
.nav a:hover { color: var(--primary); background: var(--primary-soft); }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 42px;
  height: 42px;
  padding: 0 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: #fff;
  cursor: pointer;
}
.nav-toggle span {
  display: block;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: all .3s ease;
}
.nav-toggle.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.is-open span:nth-child(2) { opacity: 0; }
.nav-toggle.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== Banner 主視覺 ===== */
.banner {
  position: relative;
  overflow: hidden;
  padding: 24px 0 32px;
  background:
    radial-gradient(720px 420px at 18% 20%, rgba(88,89,243,.28) 0%, rgba(88,89,243,0) 62%),
    radial-gradient(640px 420px at 85% 30%, rgba(154,155,253,.22) 0%, rgba(154,155,253,0) 60%),
    linear-gradient(160deg, #ffffff 0%, #f0f1ff 100%);
}
.banner::before,
.banner::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  background: rgba(88, 89, 243, .10);
  animation: float 9s ease-in-out infinite;
}
.banner::before { width: 220px; height: 220px; top: -60px; right: 8%; }
.banner::after { width: 140px; height: 140px; bottom: -40px; left: 6%; animation-delay: 2.5s; }

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-18px); }
}

.banner-inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1.2fr .8fr;
  align-items: center;
  gap: 40px;
}
.banner-eyebrow {
  display: inline-block;
  padding: 6px 16px;
  border-radius: 999px;
  background: var(--primary-soft);
  color: var(--primary);
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 20px;
}
.banner-title {
  font-size: clamp(24px, 3vw, 34px);
  line-height: 1.3;
  font-weight: 800;
  letter-spacing: .5px;
  margin-bottom: 16px;
  color: var(--text);
  white-space: nowrap;
}
.banner-subtitle {
  font-size: clamp(16px, 1.8vw, 20px);
  color: var(--text-light);
  margin-bottom: 30px;
}
.banner-cta { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 28px; }
.banner-cta .btn {
  height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 30px;
  line-height: 1;
}
.banner-trust {
  display: flex;
  gap: 22px;
  flex-wrap: wrap;
  font-size: 14px;
  color: var(--text-light);
}
.banner-trust li { display: flex; align-items: center; gap: 6px; }
.banner-trust img { flex-shrink: 0; }

.banner-visual { display: flex; justify-content: center; }
.banner-diamond {
  width: min(234px, 44vw);
  height: auto;
  animation: float 6s ease-in-out infinite;
  filter: drop-shadow(0 20px 40px rgba(88, 89, 243, .25));
}

/* ===== 區塊通用 ===== */
.section { padding: 76px 0; }
.section--soft { background: var(--bg-soft); }
.section-title {
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 800;
  text-align: center;
  margin-bottom: 10px;
  letter-spacing: .5px;
}
.section-title::after {
  content: "";
  display: block;
  width: 56px;
  height: 4px;
  border-radius: 4px;
  background: var(--primary);
  margin: 14px auto 0;
}
.section-sub {
  text-align: center;
  color: var(--text-light);
  margin-bottom: 44px;
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
}
.section-sub strong { color: var(--primary); }

/* ===== 我們的優勢 ===== */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.feature-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 34px 26px;
  text-align: center;
  transition: all .28s ease;
}
.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(88, 89, 243, .35);
}
.feature-ico { margin: 0 auto 16px; width: 44px; height: 44px; }
.feature-card h3 {
  font-size: 19px;
  font-weight: 700;
  margin-bottom: 8px;
}
.feature-card p { font-size: 14px; color: var(--text-light); }

/* ===== 儲值面額 ===== */
.denom-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}
.denom-card {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  background: #fff;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 16px 22px;
  text-align: center;
  transition: all .25s ease;
  overflow: hidden;
}
.denom-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary);
  box-shadow: var(--shadow-hover);
}
.denom-card--hot {
  border-color: var(--primary);
  background: linear-gradient(180deg, #fff 0%, var(--primary-soft) 100%);
}
.denom-tag {
  position: absolute;
  top: 12px;
  left: 12px;
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 700;
  color: #fff;
  letter-spacing: .3px;
}
.denom-tag--new { background: var(--new); }
.denom-tag--sale { background: var(--sale); }
.denom-tag--daily { background: var(--daily); }
.denom-tag--plain { background: #b9bac8; }
.denom-tag--hot { background: var(--primary); }

.denom-ico { width: 30px; height: 30px; margin-top: 6px; }
.denom-value {
  font-size: 34px;
  font-weight: 800;
  color: var(--text);
  line-height: 1.1;
  letter-spacing: .5px;
}
.denom-value small {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-light);
  margin-left: 4px;
}
.denom-price {
  font-size: 15px;
  font-weight: 700;
  color: var(--primary);
  padding: 4px 14px;
}
.denom-note {
  margin-top: 18px;
  text-align: center;
  font-size: 13px;
  color: var(--text-light);
}
.tag-legend {
  margin-top: 22px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px 28px;
  font-size: 13px;
  color: var(--text-light);
}
.tag-legend li { display: flex; align-items: center; gap: 8px; }
.legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}
.legend-dot--new { background: var(--new); }
.legend-dot--sale { background: var(--sale); }
.legend-dot--daily { background: var(--daily); }

/* ===== 商品介紹 ===== */
.intro-inner {
  display: grid;
  grid-template-columns: 1.4fr .6fr;
  gap: 48px;
  align-items: center;
}
.intro-text p { margin-bottom: 14px; color: var(--text); }
.intro-text strong { color: var(--primary); }
.sub-title {
  font-size: 18px;
  font-weight: 700;
  margin: 22px 0 10px;
}
.intro-list li {
  position: relative;
  padding-left: 22px;
  margin-bottom: 8px;
  color: var(--text);
}
.intro-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--primary);
}
.intro-card {
  background: linear-gradient(160deg, var(--primary) 0%, #7677f8 100%);
  color: #fff;
  border-radius: var(--radius);
  padding: 38px 30px;
  text-align: center;
  box-shadow: var(--shadow-hover);
}
.intro-card__img { margin: 0 auto 16px; width: 72px; height: 72px; filter: drop-shadow(0 8px 18px rgba(255,255,255,.35)); }
.intro-card__title { font-size: 20px; font-weight: 800; margin-bottom: 6px; }
.intro-card__desc { font-size: 14px; opacity: .92; margin-bottom: 22px; }
.intro-card .btn-primary { background: #fff; color: var(--primary); box-shadow: none; }
.intro-card .btn-primary:hover { background: var(--primary-soft); }

/* ===== UID 教學 ===== */
.guide-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-bottom: 28px;
}
.guide-step {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 22px;
  text-align: center;
  transition: all .25s ease;
}
.guide-step:hover { box-shadow: var(--shadow); transform: translateY(-4px); }
.guide-ico { margin: 0 auto 14px; width: 40px; height: 40px; }
.guide-step h3 { font-size: 17px; font-weight: 700; margin-bottom: 6px; }
.guide-step p { font-size: 14px; color: var(--text-light); }

.alert-box {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  background: #fff7f0;
  border: 1px solid #ffd9bd;
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  color: #b35c22;
  font-size: 14px;
}
.alert-box__ico { flex-shrink: 0; margin-top: 3px; }

/* ===== 充值流程 ===== */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  max-width: 1200px;
  margin: 0 auto;
}
.step-card {
  position: relative;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px 26px;
  transition: all .25s ease;
  overflow: hidden;
}
.step-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), #9a9bfd);
}
.step-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(88, 89, 243, .35);
}
.step-no {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 40px;
  padding: 0 16px;
  border-radius: 999px;
  background: var(--primary);
  color: #fff;
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 1px;
  margin-bottom: 16px;
  box-shadow: 0 4px 12px rgba(88, 89, 243, .3);
  transition: background .25s ease, transform .25s ease;
}
.step-card:hover .step-no {
  background: var(--primary-dark);
  transform: scale(1.05);
}
.step-card__body h3 { font-size: 17px; font-weight: 700; margin-bottom: 8px; }
.step-card__body p { font-size: 14.5px; color: var(--text-light); }
.steps-note {
  margin-top: 24px;
  font-size: 14px;
  color: var(--text-light);
  background: var(--primary-soft);
  border-left: 4px solid var(--primary);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 12px 18px;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
}

/* ===== 常見問題 FAQ ===== */
.faq-container { max-width: 1200px; }
.faq-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  column-gap: 18px;
  row-gap: 14px;
  align-items: start;
}
.faq-item {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color .25s ease;
}
.faq-item[open] { border-color: rgba(88, 89, 243, .4); }
.faq-item summary {
  list-style: none;
  cursor: pointer;
  padding: 18px 22px;
  font-size: 15.5px;
  font-weight: 600;
  color: var(--text);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  transition: color .2s ease;
  user-select: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary h2 {
  margin: 0;
  font-size: inherit;
  font-weight: inherit;
  line-height: inherit;
  color: inherit;
  letter-spacing: inherit;
}
.faq-item summary::after {
  content: "+";
  flex-shrink: 0;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--primary-soft);
  color: var(--primary);
  font-size: 18px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all .25s ease;
}
.faq-item[open] summary { color: var(--primary); }
.faq-item[open] summary::after { transform: rotate(45deg); background: var(--primary); color: #fff; }
.faq-a { padding: 0 22px 18px; }
.faq-a p { font-size: 15px; color: var(--text-light); }

/* ===== 重要須知 ===== */
.notice-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
  max-width: 1200px;
  margin: 0 auto;
}
.notice-card {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  background: #fff;
  border: 1px solid var(--border);
  border-left: 4px solid var(--primary);
  border-radius: var(--radius-sm);
  padding: 20px 22px;
  transition: all .25s ease;
}
.notice-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(88, 89, 243, .35);
  border-left-color: var(--primary);
}
.notice-ico {
  flex-shrink: 0;
  width: 30px;
  height: 30px;
  margin-top: 2px;
}
.notice-card p {
  font-size: 15px;
  color: var(--text);
  line-height: 1.7;
}

/* ===== 頁尾 ===== */
.site-footer {
  background: #23233b;
  color: #c8c9e2;
  padding: 44px 0 28px;
}
.footer-inner { text-align: center; }
.footer-brand .logo { justify-content: center; margin-bottom: 10px; }
.footer-brand .logo__text { color: #fff; }
.footer-brand .logo__text span { color: #9a9bfd; }
.footer-brand p { font-size: 14px; margin-bottom: 20px; }
.footer-links {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px 26px;
  margin-bottom: 24px;
}
.footer-links a {
  font-size: 14px;
  color: #c8c9e2;
  transition: color .2s ease;
}
.footer-links a:hover { color: #fff; }
.footer-copy { font-size: 13px; color: #8a8ba8; }

/* ===== 回到頂部 ===== */
.back-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 90;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  border: none;
  background: var(--primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow-hover);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: all .3s ease;
}
.back-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
.back-top:hover { background: var(--primary-dark); }

/* ============================================================
   響應式
   ============================================================ */
@media (max-width: 992px) {
  .denom-grid { grid-template-columns: repeat(3, 1fr); }
  .guide-list { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .steps-grid { grid-template-columns: repeat(2, 1fr); }
  .banner-inner { grid-template-columns: 1fr; text-align: center; }
  .banner-eyebrow { margin-left: auto; margin-right: auto; }
  .banner-cta, .banner-trust { justify-content: center; }
  .banner-visual { order: -1; margin-bottom: 8px; }
  .banner-diamond { width: min(190px, 38vw); }
  .intro-inner { grid-template-columns: 1fr; gap: 28px; }
  .intro-card { max-width: 420px; margin: 0 auto; width: 100%; }
}

@media (max-width: 768px) {
  .section { padding: 30px 0; }
  .banner { padding: 16px 0 20px; }
  .section-title { font-size: 22px; margin-bottom: 8px; }
  .section-sub { margin-bottom: 26px; }

  .nav-toggle { display: flex; }
  .nav {
    position: fixed;
    top: 68px;
    left: 0;
    right: 0;
    background: #fff;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow);
    padding: 12px 24px 20px;
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height .35s ease, opacity .3s ease, padding .3s ease;
  }
  .nav.is-open {
    max-height: 420px;
    opacity: 1;
    padding: 12px 24px 20px;
  }
  .nav ul { flex-direction: column; align-items: stretch; gap: 2px; }
  .nav a { padding: 11px 14px; border-radius: var(--radius-sm); }

  .denom-grid { grid-template-columns: repeat(2, 1fr); gap: 14px; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .feature-card { padding: 22px 16px; }
  .guide-list { grid-template-columns: 1fr; gap: 14px; }
  .faq-list { grid-template-columns: 1fr; }
  .steps-grid { grid-template-columns: 1fr; }
  .notice-grid { grid-template-columns: 1fr; }
  .banner-title { font-size: 24px; white-space: normal; }
}

@media (max-width: 480px) {
  .container { padding: 0 16px; }
  .denom-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .denom-value { font-size: 28px; }
  .banner-cta .btn { width: 100%; }
  .back-top { right: 16px; bottom: 16px; }
}