:root {
  --fg: #ffffff;
  --muted: rgba(255, 255, 255, 0.88);
  --accent: #14b8a6;
  --accent-strong: #0d9488;
  --card: rgba(11, 18, 34, 0.68);
  --line: rgba(255, 255, 255, 0.14);
  /* 背景遮罩：片段多為淺色畫面，加深至 73% 讓白字在淺色畫面上依然清晰易讀(測試會驗算 ≥ 4.5:1) */
  --veil: rgba(8, 15, 30, 0.73);
  --radius: 18px;
  --gutter: clamp(16px, 6vw, 96px);
  color-scheme: dark;
}

* { box-sizing: border-box; }
/* 背景色只能設在 html：設在 body 會蓋住 z-index 為負的固定背景 */
html { background: #0b1220; }
body {
  margin: 0;
  color: var(--fg);
  font-family: "Noto Sans TC", "Microsoft JhengHei", "PingFang TC", system-ui, sans-serif;
  line-height: 1.7;
  letter-spacing: 0.03em;
  overflow-x: hidden;
}
a { color: inherit; }
img { max-width: 100%; }

/* ---------- 背景影片 ---------- */
.bg {
  position: fixed; inset: 0; z-index: -2; overflow: hidden;
  background: #0b1220 center / cover no-repeat;
}
.bg video {
  position: absolute; inset: 0; width: 100%; height: 100%;
  object-fit: cover; object-position: center;
  filter: blur(6px) brightness(0.86) saturate(1.08);
  transform: scale(1.06); /* 模糊後邊緣會透出底色，略放大蓋掉 */
  opacity: 0; transition: opacity 0.9s ease;
}
.bg video.on { opacity: 1; }
.veil { position: fixed; inset: 0; z-index: -1; background: var(--veil); }

/* ---------- 頁首 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; gap: 32px;
  padding: 12px var(--gutter);
  background: rgba(8, 15, 30, 0.6);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; font-weight: 800; font-size: 20px; white-space: nowrap; letter-spacing: 0.02em; }
.brand img { border-radius: 10px; background: #fff; }
.main-nav { display: flex; gap: 26px; }
.main-nav a, .footer-nav a { text-decoration: none; color: var(--muted); letter-spacing: 0.02em; }
.main-nav a:hover, .main-nav a[aria-current="page"] { color: var(--fg); }
.main-nav a[aria-current="page"] { box-shadow: inset 0 -2px 0 var(--accent); }
.header-actions { margin-left: auto; display: flex; align-items: center; gap: 14px; }
.lang { text-decoration: none; color: var(--muted); font-size: 14px; letter-spacing: 0.02em; }

.mobile-nav { display: none; margin-left: auto; position: relative; }
.mobile-nav summary {
  list-style: none; cursor: pointer; padding: 8px 14px;
  border: 1px solid var(--line); border-radius: 999px; font-size: 14px; letter-spacing: 0.02em;
}
.mobile-nav summary::-webkit-details-marker { display: none; }
.mobile-nav nav {
  position: absolute; right: 0; top: calc(100% + 8px); min-width: 200px;
  display: flex; flex-direction: column; padding: 8px;
  background: rgba(8, 15, 30, 0.96); border: 1px solid var(--line); border-radius: 14px;
}
.mobile-nav nav a { padding: 10px 12px; text-decoration: none; border-radius: 10px; }
.mobile-nav nav a[aria-current="page"] { background: rgba(20, 184, 166, 0.2); }

/* ---------- 按鈕 ---------- */
.btn {
  display: inline-block; padding: 14px 28px; border-radius: 999px;
  font-weight: 700; text-decoration: none; border: 1.5px solid transparent;
  font-size: 16px; cursor: pointer; font-family: inherit;
  letter-spacing: 0.035em;
}
.btn.small { padding: 8px 18px; font-size: 14px; letter-spacing: 0.025em; }
.btn.primary { background: var(--accent); color: #fff; }
.btn.primary:hover { background: var(--accent-strong); }
.btn.ghost { border-color: rgba(255, 255, 255, 0.7); color: #fff; }
.btn.ghost:hover { background: rgba(255, 255, 255, 0.1); }
.actions { display: flex; gap: 14px; flex-wrap: wrap; }
.actions.center { justify-content: center; margin-top: 28px; }

/* ---------- 內容 ---------- */
main { padding: 0 var(--gutter); }
.hero { min-height: calc(100vh - 62px); display: flex; flex-direction: column; justify-content: center; max-width: 980px; }
.eyebrow {
  display: inline-block; align-self: flex-start;
  margin: 0 0 14px; padding: 6px 14px; border-radius: 999px;
  font-size: 14px; font-weight: 700; letter-spacing: 0.06em;
  color: var(--accent); background: rgba(20, 184, 166, 0.14); border: 1px solid rgba(20, 184, 166, 0.35);
}
.hero h1 { font-size: clamp(36px, 5.2vw, 72px); line-height: 1.15; margin: 0 0 20px; letter-spacing: 0.02em; text-shadow: 0 2px 16px rgba(0, 0, 0, 0.5); }
.page-hero { padding: clamp(64px, 14vh, 140px) 0 24px; max-width: 900px; }
.page-hero h1 { font-size: clamp(34px, 5vw, 64px); line-height: 1.15; margin: 0 0 16px; letter-spacing: 0.025em; text-shadow: 0 2px 16px rgba(0, 0, 0, 0.5); }
.lead { font-size: clamp(17px, 1.6vw, 21px); color: var(--muted); max-width: 44em; margin: 0 0 32px; line-height: 1.75; letter-spacing: 0.03em; text-shadow: 0 1px 10px rgba(0, 0, 0, 0.45); }
.section { padding: clamp(40px, 8vh, 88px) 0; }
.section > h2 { font-size: clamp(24px, 3vw, 36px); margin: 0 0 12px; letter-spacing: 0.025em; text-shadow: 0 2px 12px rgba(0, 0, 0, 0.45); }
.section-intro { color: var(--muted); font-size: clamp(16px, 1.3vw, 18px); max-width: 46em; margin: 0 0 28px; line-height: 1.75; letter-spacing: 0.03em; text-shadow: 0 1px 10px rgba(0, 0, 0, 0.45); }
.section > h2:not(:has(+ .section-intro)) { margin-bottom: 24px; }
.band { text-align: center; }
.band .lead { margin-left: auto; margin-right: auto; }

.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 18px; }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px;
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
}
.card h2, .card h3 { margin: 0 0 10px; font-size: 20px; letter-spacing: 0.025em; }
.card p { margin: 0; color: var(--muted); line-height: 1.7; letter-spacing: 0.025em; }
.link-card { text-decoration: none; display: flex; flex-direction: column; gap: 6px; transition: transform 0.2s, border-color 0.2s; }
.link-card:hover { transform: translateY(-3px); border-color: var(--accent); }
.link-card .more { margin-top: auto; padding-top: 12px; color: var(--accent); font-weight: 700; letter-spacing: 0.025em; }
/* 9 項組裝圖功能排成 3 × 3，避免 4 欄時最後一張落單；4 項管理功能排 2 × 2 */
@media (min-width: 900px) {
  .viewer-features { grid-template-columns: repeat(3, 1fr); }
  .platform-features { grid-template-columns: repeat(2, 1fr); }
}
.flow { counter-reset: flow; }
.flow .card h3::before { counter-increment: flow; content: counter(flow) ". "; color: var(--accent); }

.plans { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.plan .price { font-size: 24px; font-weight: 800; color: var(--fg); margin: 6px 0 14px; letter-spacing: 0.02em; }
.plan ul { margin: 0; padding-left: 1.2em; color: var(--muted); }
.plan li { margin: 8px 0; line-height: 1.65; letter-spacing: 0.02em; }
.note { color: var(--muted); text-align: center; margin-top: 22px; }

.trial { display: grid; grid-template-columns: minmax(0, 3fr) minmax(0, 2fr); gap: 18px; align-items: start; }
.form { display: flex; flex-direction: column; gap: 14px; }
.form label { display: flex; flex-direction: column; gap: 6px; font-size: 14px; color: var(--muted); letter-spacing: 0.025em; }
.form input, .form textarea {
  font: inherit; color: var(--fg); background: rgba(255, 255, 255, 0.08);
  border: 1px solid var(--line); border-radius: 10px; padding: 10px 12px;
  letter-spacing: 0.02em;
}
.form input:focus, .form textarea:focus { outline: 2px solid var(--accent); outline-offset: 1px; }
.form .btn { align-self: flex-start; }
.form-note { margin: 0; padding: 12px 14px; border-radius: 10px; background: rgba(20, 184, 166, 0.18); color: var(--fg); letter-spacing: 0.025em; }

.contact-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 10px; }
.contact-list li { display: flex; flex-direction: column; }
.contact-list span { font-size: 13px; color: var(--muted); letter-spacing: 0.02em; }
.contact-list strong { letter-spacing: 0.025em; }
.divider { border: 0; border-top: 1px solid var(--line); margin: 20px 0; }
.steps-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 8px; color: var(--muted); font-size: 15px; line-height: 1.6; letter-spacing: 0.025em; }

/* ---------- 頁尾 ---------- */
.site-footer {
  margin-top: 40px; padding: 40px var(--gutter);
  display: grid; grid-template-columns: 1fr auto; gap: 24px;
  background: rgba(8, 15, 30, 0.88); color: var(--muted); border-top: 1px solid var(--line);
}
.site-footer strong { color: var(--fg); display: block; margin-bottom: 6px; letter-spacing: 0.025em; }
.footer-tagline { margin: 0 0 14px; font-size: 14px; color: var(--muted); letter-spacing: 0.025em; }
.footer-nav { display: flex; flex-wrap: wrap; gap: 18px; }
.rights { grid-column: 1 / -1; margin: 0; font-size: 13px; letter-spacing: 0.02em; }

/* ---------- 窄螢幕 ---------- */
@media (max-width: 860px) {
  .main-nav, .header-actions { display: none; }
  .mobile-nav { display: block; }
  .site-header { gap: 12px; }
  .trial { grid-template-columns: 1fr; }
  .site-footer { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  .bg video { display: none; }
  .link-card { transition: none; }
}