/* ═══════════════════════════════════════════════
   VIDO 首页 v18 — 三色渐变 + 方形拼接
   cyan #21d4fd · purple #8b5cf6 · pink #ec4899
   ═══════════════════════════════════════════════ */
:root {
  /* —— 三色品牌渐变 —— */
  --c-cyan:        #21d4fd;
  --c-cyan-d:      #0099d4;
  --c-purple:      #8b5cf6;
  --c-purple-d:    #6e2dd8;
  --c-pink:        #ec4899;
  --c-pink-d:      #db2777;

  /* —— 主渐变 —— */
  --c-grad:        linear-gradient(135deg, #21d4fd 0%, #8b5cf6 50%, #ec4899 100%);
  --c-grad-2:      linear-gradient(135deg, #8b5cf6 0%, #21d4fd 100%);
  --c-grad-pink:   linear-gradient(135deg, #ec4899 0%, #8b5cf6 100%);

  /* —— Soft glow —— */
  --c-cyan-soft:   rgba(33,212,253,.14);
  --c-purple-soft: rgba(139,92,246,.16);
  --c-pink-soft:   rgba(236,72,153,.14);
  --c-glow-purple: rgba(139,92,246,.45);
  --c-glow-cyan:   rgba(33,212,253,.40);

  /* —— Slate 中性色 —— */
  --c-bg:          #08091a;
  --c-bg-2:        #11122a;
  --c-bg-3:        #1a1c3d;
  --c-bg-4:        #232651;

  /* —— 文字 —— */
  --c-text:        #f1f5fc;
  --c-text-2:      #a5acc9;
  --c-text-3:      #6e7497;

  /* —— 边框 —— */
  --c-border:      rgba(255,255,255,.06);
  --c-border-2:    rgba(165,172,201,.18);

  /* —— 几何 —— */
  --r:             10px;
  --r-lg:          16px;
  --r-pill:        999px;
  --ease:          .25s cubic-bezier(.34,.69,.1,1);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html, body {
  background: var(--c-bg);
  color: var(--c-text);
  font-family: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 15px;
  -webkit-font-smoothing: antialiased;
  line-height: 1.5;
  scroll-behavior: smooth;
}
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }
input, textarea { font-family: inherit; }

/* ═════════ TOPBAR ═════════ */
.topbar {
  position: fixed; top: 0; left: 0; right: 0;
  height: 64px;
  background: rgba(10,15,26,.78);
  backdrop-filter: blur(20px) saturate(140%);
  -webkit-backdrop-filter: blur(20px) saturate(140%);
  border-bottom: 1px solid var(--c-border);
  z-index: 100;
}
.tb-inner {
  max-width: 1320px; margin: 0 auto;
  height: 100%; padding: 0 32px;
  display: flex; align-items: center; justify-content: space-between;
  gap: 32px;
}
.tb-logo {
  display: flex; align-items: center; gap: 10px;
  font-weight: 800; font-size: 17px; letter-spacing: .2px;
}
.tb-logo-mark {
  width: 32px; height: 32px;
  border-radius: 9px;
  background: var(--c-grad-2);
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-weight: 900; font-size: 16px;
  box-shadow: 0 4px 14px var(--c-glow-purple);
}
.tb-nav {
  display: flex; gap: 4px; flex: 1; justify-content: center;
}
.tb-nav a {
  padding: 8px 18px;
  font-size: 14px; font-weight: 500;
  color: var(--c-text-2);
  border-radius: var(--r);
  transition: color var(--ease);
}
.tb-nav a:hover { color: var(--c-text); }
.tb-nav a.active {
  color: var(--c-cyan);
  background: var(--c-cyan-soft);
}

.tb-right { display: flex; align-items: center; gap: 10px; }
.tb-link {
  padding: 8px 16px;
  font-size: 13px; font-weight: 500;
  color: var(--c-text-2);
  transition: color var(--ease);
}
.tb-link:hover { color: var(--c-text); }
.tb-cta {
  display: inline-block;
  padding: 10px 22px;
  background: var(--c-grad-2);
  color: #fff;
  border-radius: var(--r-pill);
  font-size: 13px; font-weight: 700;
  transition: all var(--ease);
  box-shadow: 0 4px 16px var(--c-glow-purple);
}
.tb-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 24px var(--c-glow-purple);
  filter: brightness(1.08);
}

/* ═════════ HERO ═════════ */
.hero {
  position: relative;
  min-height: 100vh;
  padding: 140px 32px 80px;
  display: flex; align-items: center; justify-content: center;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: 50%; left: 50%;
  width: 1300px; height: 1300px;
  transform: translate(-50%, -50%);
  background:
    radial-gradient(circle at 30% 40%, var(--c-cyan-soft) 0%, transparent 35%),
    radial-gradient(circle at 70% 60%, var(--c-purple-soft) 0%, transparent 40%),
    radial-gradient(circle at 50% 50%, var(--c-pink-soft) 0%, transparent 55%);
  pointer-events: none;
  animation: pulse-glow 10s ease-in-out infinite;
  filter: blur(20px);
}
@keyframes pulse-glow {
  0%, 100% { opacity: .65; transform: translate(-50%, -50%) scale(1); }
  50%      { opacity: 1;   transform: translate(-50%, -50%) scale(1.05); }
}
.hero::after {
  content: '';
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.018) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.018) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 80% 70% at 50% 50%, #000 30%, transparent 90%);
  -webkit-mask-image: radial-gradient(ellipse 80% 70% at 50% 50%, #000 30%, transparent 90%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  max-width: 880px; width: 100%;
  text-align: center;
}

.hero-eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 16px;
  border: 1px solid var(--c-border-2);
  background: rgba(255,255,255,.02);
  border-radius: var(--r-pill);
  font-size: 12px; font-weight: 600; letter-spacing: 1.5px;
  color: var(--c-text-2);
  margin-bottom: 32px;
  text-transform: uppercase;
}
.hero-eyebrow::before {
  content: '';
  width: 6px; height: 6px;
  background: var(--c-grad);
  border-radius: 50%;
  box-shadow: 0 0 12px var(--c-purple), 0 0 18px var(--c-pink);
}

.hero-title {
  font-size: clamp(40px, 7vw, 72px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -2px;
  margin-bottom: 22px;
  color: var(--c-text);
}
.hero-title em {
  font-style: normal;
  background: var(--c-grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  position: relative;
  display: inline-block;
}

.hero-sub {
  font-size: clamp(15px, 1.4vw, 18px);
  line-height: 1.7;
  color: var(--c-text-2);
  max-width: 540px;
  margin: 0 auto 48px;
  font-weight: 400;
}

/* —— Composer —— */
.composer {
  background: rgba(26, 36, 56, .65);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--c-border-2);
  border-radius: var(--r-lg);
  padding: 8px;
  max-width: 720px;
  margin: 0 auto 24px;
  text-align: left;
  transition: border-color var(--ease), box-shadow var(--ease), background var(--ease);
}
.composer:focus-within {
  border-color: var(--c-purple);
  background: rgba(26, 28, 61, .85);
  box-shadow: 0 0 0 4px var(--c-purple-soft), 0 12px 40px var(--c-glow-purple);
}
.composer-row {
  display: flex; align-items: center; gap: 8px;
}
.composer-add {
  width: 44px; height: 44px;
  border-radius: var(--r);
  background: rgba(255,255,255,.04);
  display: flex; align-items: center; justify-content: center;
  color: var(--c-text-2);
  flex-shrink: 0;
  transition: all var(--ease);
}
.composer-add:hover { color: var(--c-cyan); background: var(--c-cyan-soft); }
.composer-add svg { width: 18px; height: 18px; }

.composer-input {
  flex: 1;
  background: transparent;
  border: none; outline: none;
  color: var(--c-text);
  font-size: 15px;
  padding: 12px 4px;
}
.composer-input::placeholder { color: var(--c-text-3); }

.composer-go {
  height: 44px;
  padding: 0 22px;
  border-radius: var(--r-pill);
  background: var(--c-grad-2);
  color: #fff;
  font-size: 14px; font-weight: 700;
  display: flex; align-items: center; gap: 6px;
  transition: all var(--ease);
  flex-shrink: 0;
  box-shadow: 0 4px 16px var(--c-glow-purple);
}
.composer-go:hover {
  filter: brightness(1.1);
  box-shadow: 0 8px 24px var(--c-glow-purple);
  transform: translateY(-1px);
}
.composer-go svg { width: 16px; height: 16px; }

/* —— 示例 chips —— */
.examples {
  display: flex; justify-content: center; gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 56px;
}
.example {
  padding: 7px 16px;
  background: rgba(255,255,255,.03);
  border: 1px solid var(--c-border);
  border-radius: var(--r-pill);
  font-size: 12px;
  color: var(--c-text-2);
  transition: all var(--ease);
  cursor: pointer;
}
.example:hover {
  border-color: var(--c-purple);
  color: var(--c-cyan);
  background: var(--c-purple-soft);
  transform: translateY(-1px);
}

/* —— Hero stats —— */
.hero-stats {
  display: flex; justify-content: center; gap: 56px;
  padding-top: 32px;
  border-top: 1px solid var(--c-border);
  max-width: 600px;
  margin: 0 auto;
}
.stat-num {
  font-size: 26px; font-weight: 700;
  color: var(--c-text);
  letter-spacing: -.5px;
}
.stat-num em {
  font-style: normal;
  background: var(--c-grad-2);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.stat-label {
  font-size: 11px; color: var(--c-text-3);
  margin-top: 2px;
  font-weight: 500;
  letter-spacing: .5px;
  text-transform: uppercase;
}

/* ═════════ CASES ═════════ */
.cases {
  position: relative;
  padding: 100px 32px 120px;
  max-width: 1320px;
  margin: 0 auto;
}
.cases-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: 36px;
  gap: 24px;
  flex-wrap: wrap;
}
.cases-title h2 {
  font-size: 36px; font-weight: 800;
  letter-spacing: -.8px;
  margin: 0 0 8px;
  background: var(--c-grad-2);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  display: inline-block;
}
.cases-title p { color: var(--c-text-2); font-size: 14px; }
.cases-more {
  display: inline-flex; align-items: center; gap: 4px;
  color: var(--c-cyan);
  font-size: 13px; font-weight: 600;
  padding: 8px 0;
  transition: gap var(--ease);
}
.cases-more:hover { gap: 8px; color: var(--c-pink); }

/* —— 方形/矩形拼接 grid —— */
.cases-grid {
  display: grid;
  grid-template-columns: 1.8fr 1fr 1fr;
  grid-template-rows: 200px 200px;
  gap: 14px;
  height: 414px;
}
@media (max-width: 980px) {
  .cases-grid {
    grid-template-columns: 1fr 1fr;
    grid-template-rows: auto;
    height: auto;
  }
  .case--big { grid-column: span 2; grid-row: span 1; height: 280px; }
  .case--sq, .case--rect, .case--wide { grid-column: span 1; grid-row: span 1; height: 180px; }
  .case--wide { grid-column: span 2; }
}
@media (max-width: 540px) {
  .cases-grid { grid-template-columns: 1fr; }
  .case--big, .case--sq, .case--rect, .case--wide { grid-column: span 1; }
}

.case {
  position: relative;
  overflow: hidden;
  background: var(--c-bg-2);
  cursor: pointer;
  transition: all var(--ease);
  border: 2px solid var(--c-border-2);
}
.case:hover { transform: translateY(-4px); }
.case:hover video { transform: scale(1.06); }
.case:hover .case-play {
  background: var(--c-grad-2);
  color: #fff;
  border-color: transparent;
}

.case--big {
  grid-column: 1;
  grid-row: 1 / span 2;
  border-radius: 22px;
}
.case--big:hover {
  border-color: var(--c-cyan);
  box-shadow: 0 16px 40px var(--c-glow-cyan);
}
.case--sq {
  grid-column: 2;
  grid-row: 1;
  border-radius: 16px;
}
.case--sq:hover {
  border-color: var(--c-purple);
  box-shadow: 0 14px 36px var(--c-glow-purple);
}
.case--rect {
  grid-column: 3;
  grid-row: 1;
  border-radius: 16px;
}
.case--rect:hover {
  border-color: var(--c-pink);
  box-shadow: 0 14px 36px rgba(236,72,153,.36);
}
.case--wide {
  grid-column: 2 / span 2;
  grid-row: 2;
  border-radius: 18px;
}
.case--wide:hover {
  border-color: var(--c-cyan);
  box-shadow: 0 14px 36px var(--c-glow-cyan);
}

.case video {
  position: absolute; inset: 0;
  width: 100%; height: 100%;
  object-fit: cover;
  transition: transform .5s ease;
  background: var(--c-bg-2);
}
.case-fade {
  position: absolute; left: 0; right: 0; bottom: 0; height: 60%;
  background: linear-gradient(180deg, transparent, rgba(0,0,0,.92) 80%);
  pointer-events: none;
}
.case-play {
  position: absolute;
  top: 12px; right: 12px;
  width: 30px; height: 30px;
  border-radius: 50%;
  background: rgba(0,0,0,.55);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,.18);
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 11px;
  z-index: 3;
  transition: all var(--ease);
}
.case-meta {
  position: absolute; left: 16px; right: 16px; bottom: 14px;
  z-index: 2;
}
.case-meta h4 {
  font-size: 13px; font-weight: 700;
  margin-bottom: 3px;
  color: #fff;
}
.case--big .case-meta h4 { font-size: 18px; margin-bottom: 5px; }
.case--big .case-meta { left: 22px; right: 22px; bottom: 20px; }
.case-meta span {
  font-size: 10px;
  color: rgba(255,255,255,.6);
}
.case--big .case-meta span { font-size: 12px; }

.case-skel {
  position: absolute; inset: 0;
  background: linear-gradient(110deg, var(--c-bg-2) 8%, var(--c-bg-3) 18%, var(--c-bg-2) 33%);
  background-size: 200% 100%;
  animation: skel 1.4s linear infinite;
}
@keyframes skel { to { background-position: -200% 0; } }

/* ═════════ FOOTER ═════════ */
.foot {
  border-top: 1px solid var(--c-border);
  padding: 40px 32px 32px;
  text-align: center;
  background: rgba(0,0,0,.2);
}
.foot-inner { max-width: 1320px; margin: 0 auto; }
.foot-logo {
  display: inline-flex; align-items: center; gap: 8px;
  font-weight: 700; font-size: 16px;
  margin-bottom: 12px;
}
.foot-logo .tb-logo-mark { width: 26px; height: 26px; font-size: 13px; }
.foot p {
  color: var(--c-text-3);
  font-size: 12px;
  margin: 4px 0;
}
.foot a { color: var(--c-text-2); transition: color var(--ease); margin: 0 8px; }
.foot a:hover { color: var(--c-cyan); }

/* ═════════ AUTH MODAL ═════════ */
.auth-modal {
  display: none;
  position: fixed; inset: 0;
  background: rgba(8,9,26,.78);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 1000;
  align-items: center; justify-content: center;
  padding: 20px;
  animation: auth-fade .25s ease;
}
.auth-modal.show { display: flex; }
@keyframes auth-fade { from { opacity: 0; } to { opacity: 1; } }

.auth-card {
  position: relative;
  width: 100%;
  max-width: 420px;
  background: linear-gradient(160deg, rgba(26,28,61,.96) 0%, rgba(17,18,42,.98) 100%);
  border: 1px solid var(--c-border-2);
  border-radius: 20px;
  padding: 36px 32px 28px;
  box-shadow:
    0 24px 60px rgba(0,0,0,.55),
    0 0 0 1px var(--c-purple-soft),
    0 0 80px var(--c-purple-soft);
  text-align: center;
  animation: auth-pop .3s cubic-bezier(.34,.69,.1,1.4);
}
@keyframes auth-pop {
  from { opacity: 0; transform: translateY(20px) scale(.95); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

.auth-close {
  position: absolute; top: 14px; right: 14px;
  width: 32px; height: 32px;
  border-radius: 8px;
  background: rgba(255,255,255,.04);
  color: var(--c-text-2);
  display: flex; align-items: center; justify-content: center;
  transition: all var(--ease);
}
.auth-close:hover { background: rgba(255,255,255,.10); color: var(--c-text); }

.auth-brand {
  display: flex; justify-content: center;
  margin-bottom: 16px;
}
.auth-brand .tb-logo-mark {
  width: 56px; height: 56px;
  border-radius: 16px;
  font-size: 26px;
  box-shadow: 0 8px 24px var(--c-glow-purple);
}
.auth-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--c-text);
  margin-bottom: 6px;
}
.auth-sub {
  font-size: 13px;
  color: var(--c-text-2);
  margin-bottom: 22px;
}

.auth-tabs {
  display: flex;
  gap: 0;
  background: rgba(255,255,255,.04);
  border-radius: var(--r-pill);
  padding: 4px;
  margin-bottom: 22px;
}
.auth-tab {
  flex: 1;
  padding: 9px 0;
  font-size: 13px; font-weight: 600;
  color: var(--c-text-2);
  border-radius: var(--r-pill);
  transition: all var(--ease);
}
.auth-tab:hover { color: var(--c-text); }
.auth-tab.active {
  background: var(--c-grad-2);
  color: #fff;
  box-shadow: 0 4px 14px var(--c-glow-purple);
}

.auth-err {
  display: none;
  background: rgba(236,72,153,.10);
  border: 1px solid rgba(236,72,153,.32);
  color: #f87aab;
  font-size: 12px;
  padding: 10px 14px;
  border-radius: var(--r);
  margin-bottom: 14px;
  text-align: left;
}
.auth-err.show { display: block; }

.auth-form {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.auth-field {
  position: relative;
}
.auth-field input {
  width: 100%;
  padding: 16px 14px 8px;
  background: rgba(255,255,255,.04);
  border: 1px solid var(--c-border-2);
  border-radius: var(--r);
  color: var(--c-text);
  font-size: 14px;
  outline: none;
  transition: all var(--ease);
}
.auth-field input:focus {
  border-color: var(--c-purple);
  background: rgba(139,92,246,.06);
  box-shadow: 0 0 0 3px var(--c-purple-soft);
}
.auth-field label {
  position: absolute;
  left: 14px; top: 50%;
  transform: translateY(-50%);
  font-size: 13px;
  color: var(--c-text-3);
  pointer-events: none;
  transition: all .18s ease;
  background: transparent;
  padding: 0 4px;
}
.auth-field input:focus + label,
.auth-field input:not(:placeholder-shown) + label {
  top: 8px;
  font-size: 10px;
  color: var(--c-cyan);
  transform: translateY(0);
}

.auth-submit {
  margin-top: 6px;
  padding: 14px 0;
  background: var(--c-grad-2);
  color: #fff;
  border-radius: var(--r-pill);
  font-size: 14px; font-weight: 700;
  transition: all var(--ease);
  box-shadow: 0 6px 22px var(--c-glow-purple);
}
.auth-submit:hover {
  filter: brightness(1.1);
  box-shadow: 0 10px 30px var(--c-glow-purple);
  transform: translateY(-1px);
}
.auth-submit:disabled {
  opacity: .55;
  cursor: not-allowed;
  transform: none;
}

.auth-foot {
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px dashed var(--c-border-2);
  font-size: 12px;
  color: var(--c-text-3);
}
.auth-foot strong {
  color: var(--c-cyan);
  font-weight: 700;
}

/* topbar 按钮变 button (从 a 标签) */
.tb-link, .tb-cta { cursor: pointer; }