:root {
  --bg: #0d1117;
  --bg2: #161b22;
  --card: #1c2129;
  --elevated: #242b35;
  --text: #f0f3f6;
  --text2: #9aa7b4;
  --muted: #6b7683;
  --border: #2d3540;
  --primary: #7c5cff;
  --primary-dark: #5b3fd6;
  --accent: #00d4aa;
  --gold: #ffc857;
  --red: #ff5c6c;
  --radius: 14px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: "PingFang SC", "Microsoft YaHei", -apple-system, "Segoe UI", sans-serif;
  min-height: 100vh;
}
button { font-family: inherit; cursor: pointer; }
input, select, textarea {
  font-family: inherit;
  background: var(--bg2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 10px;
  padding: 11px 14px;
  font-size: 14px;
  width: 100%;
}
input:focus, select:focus, textarea:focus { outline: none; border-color: var(--primary); }

/* ---------- auth ---------- */
.auth-wrap { display: flex; min-height: 100vh; }
.auth-hero {
  flex: 1.1; background: linear-gradient(135deg, #1a1040 0%, #0d1117 60%, #06281f 100%);
  padding: 64px 56px; display: flex; flex-direction: column; justify-content: center; gap: 20px;
}
.brand { font-size: 22px; font-weight: 800; letter-spacing: 0.5px; }
.brand.small { font-size: 18px; cursor: pointer; }
.auth-hero h1 { font-size: 44px; line-height: 1.25; }
.hero-sub { color: var(--text2); font-size: 17px; }
.hero-tags { display: flex; gap: 10px; flex-wrap: wrap; }
.hero-tags span {
  background: rgba(124, 92, 255, 0.15); border: 1px solid rgba(124, 92, 255, 0.35);
  padding: 8px 14px; border-radius: 999px; font-size: 13px;
}
.hero-note { color: var(--gold); font-size: 14px; }
.auth-form {
  flex: 1; background: var(--bg2); padding: 64px 56px;
  display: flex; flex-direction: column; justify-content: center; max-width: 520px;
}
.auth-tabs { display: flex; gap: 8px; margin-bottom: 28px; }
.auth-tabs button {
  flex: 1; padding: 12px; border-radius: 10px; border: 1px solid var(--border);
  background: transparent; color: var(--text2); font-size: 15px; font-weight: 600;
}
.auth-tabs button.active { background: var(--primary); border-color: var(--primary); color: #fff; }
#authForm label { display: block; margin-bottom: 16px; font-size: 13px; color: var(--text2); }
#authForm input { margin-top: 6px; }
.form-error { color: var(--red); margin-top: 12px; font-size: 13px; min-height: 18px; }

/* ---------- buttons ---------- */
.btn-primary {
  background: var(--primary); color: #fff; border: none; padding: 12px 22px;
  border-radius: 10px; font-size: 15px; font-weight: 700;
  box-shadow: 0 4px 0 var(--primary-dark); transition: transform 0.1s;
}
.btn-primary:active { transform: translateY(2px); box-shadow: 0 2px 0 var(--primary-dark); }
.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-primary.full { width: 100%; }
.btn-ghost {
  background: transparent; color: var(--text2); border: 1px solid var(--border);
  padding: 8px 14px; border-radius: 8px; font-size: 13px;
}
.btn-ghost:hover { color: var(--text); border-color: var(--text2); }
.btn-accent { background: var(--accent); color: #06281f; border: none; padding: 10px 18px; border-radius: 10px; font-weight: 700; }

/* ---------- layout ---------- */
.topbar {
  display: flex; align-items: center; gap: 20px; padding: 14px 28px;
  background: rgba(22, 27, 34, 0.92); border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 50; backdrop-filter: blur(8px); flex-wrap: wrap;
}
.nav { display: flex; gap: 6px; flex-wrap: wrap; }
.nav-btn {
  background: transparent; border: none; color: var(--text2); padding: 9px 14px;
  border-radius: 9px; font-size: 14px; font-weight: 600;
}
.nav-btn.active { background: var(--elevated); color: var(--text); }
.userbox { margin-left: auto; display: flex; align-items: center; gap: 12px; font-size: 14px; }
.credit-pill {
  background: rgba(255, 200, 87, 0.15); color: var(--gold); border: 1px solid rgba(255, 200, 87, 0.4);
  padding: 6px 12px; border-radius: 999px; font-weight: 700; font-size: 13px;
}
main { max-width: 1200px; margin: 0 auto; padding: 32px 24px 80px; }
.foot { text-align: center; color: var(--muted); font-size: 12px; padding: 24px; }
h2.page-title { font-size: 26px; margin-bottom: 6px; }
p.page-sub { color: var(--text2); margin-bottom: 26px; font-size: 14px; }

/* ---------- cards ---------- */
.card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px;
}
.grid { display: grid; gap: 14px; }
.grid.cols-4 { grid-template-columns: repeat(4, 1fr); }
.grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid.cols-2 { grid-template-columns: repeat(2, 1fr); }

.pick-card {
  background: var(--card); border: 2px solid var(--border); border-radius: var(--radius);
  padding: 16px; cursor: pointer; transition: border-color 0.15s, transform 0.15s;
}
.pick-card:hover { transform: translateY(-2px); }
.pick-card.selected { border-color: var(--primary); background: rgba(124, 92, 255, 0.12); }
.pick-card .icon { font-size: 30px; }
.pick-card .name { font-weight: 700; margin: 8px 0 4px; font-size: 15px; }
.pick-card .desc { color: var(--text2); font-size: 12px; line-height: 1.5; }

.section-label { font-size: 13px; color: var(--muted); font-weight: 700; letter-spacing: 1px; margin: 26px 0 12px; text-transform: uppercase; }

/* ---------- studio form ---------- */
.studio-grid { display: grid; grid-template-columns: 1.6fr 1fr; gap: 22px; align-items: start; }
.form-row { display: flex; gap: 14px; margin-bottom: 16px; flex-wrap: wrap; }
.form-row > * { flex: 1; min-width: 140px; }
.slider-row { display: flex; align-items: center; gap: 14px; }
.slider-row input[type=range] { flex: 1; accent-color: var(--primary); }
.slider-val { font-size: 20px; font-weight: 800; color: var(--accent); min-width: 56px; }
.cost-box {
  background: var(--elevated); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px; position: sticky; top: 90px;
}
.cost-big { font-size: 40px; font-weight: 800; color: var(--gold); }
.cost-line { display: flex; justify-content: space-between; color: var(--text2); font-size: 14px; margin: 10px 0; }
.cost-line b { color: var(--text); }
.warn { color: var(--red); font-size: 13px; margin: 10px 0; }

/* ---------- video cards ---------- */
.video-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.video-card video { width: 100%; aspect-ratio: 16/9; background: #000; display: block; }
.video-card .meta { padding: 14px; }
.video-card .title { font-weight: 700; font-size: 14px; margin-bottom: 6px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.video-card .sub { color: var(--muted); font-size: 12px; }
.badge { display: inline-block; padding: 3px 9px; border-radius: 999px; font-size: 11px; font-weight: 700; }
.badge.done { background: rgba(0, 212, 170, 0.15); color: var(--accent); }
.badge.generating { background: rgba(255, 200, 87, 0.15); color: var(--gold); }
.badge.failed { background: rgba(255, 92, 108, 0.15); color: var(--red); }

/* ---------- tables ---------- */
table { width: 100%; border-collapse: collapse; font-size: 13px; }
th { text-align: left; color: var(--muted); font-weight: 700; padding: 10px 12px; border-bottom: 1px solid var(--border); }
td { padding: 10px 12px; border-bottom: 1px solid var(--border); color: var(--text2); }
td b { color: var(--text); }

/* ---------- pack cards ---------- */
.pack-card {
  background: var(--card); border: 2px solid var(--border); border-radius: var(--radius);
  padding: 26px 22px; text-align: center; cursor: pointer; transition: transform 0.15s;
}
.pack-card:hover { transform: translateY(-3px); border-color: var(--primary); }
.pack-card .price { font-size: 36px; font-weight: 800; color: var(--text); }
.pack-card .credits { color: var(--gold); font-weight: 700; margin: 8px 0; }
.pack-card .desc { color: var(--muted); font-size: 12px; }

/* ---------- admin stats ---------- */
.stat-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; }
.stat-card .num { font-size: 32px; font-weight: 800; color: var(--accent); }
.stat-card .lbl { color: var(--muted); font-size: 13px; margin-top: 4px; }

/* ---------- toast ---------- */
#toastWrap { position: fixed; right: 20px; bottom: 20px; z-index: 999; display: flex; flex-direction: column; gap: 10px; }
.toast {
  background: var(--elevated); border: 1px solid var(--border); color: var(--text);
  padding: 13px 18px; border-radius: 10px; font-size: 14px; max-width: 340px;
  animation: toastIn 0.25s ease;
}
.toast.success { border-color: var(--accent); }
.toast.error { border-color: var(--red); }
@keyframes toastIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; } }

.empty { text-align: center; color: var(--muted); padding: 60px 20px; }
.empty .big { font-size: 48px; margin-bottom: 12px; }

@media (max-width: 900px) {
  .auth-wrap { flex-direction: column; }
  .auth-hero { padding: 40px 24px; }
  .auth-hero h1 { font-size: 30px; }
  .auth-form { padding: 32px 24px; max-width: none; }
  .studio-grid { grid-template-columns: 1fr; }
  .grid.cols-4 { grid-template-columns: repeat(2, 1fr); }
  .grid.cols-3, .grid.cols-2 { grid-template-columns: 1fr; }
  .userbox { width: 100%; justify-content: flex-end; }
  .cost-box { position: static; }
  .hero h1 { font-size: 32px; }
  .hero-cards { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr; }
  .about-box { grid-template-columns: 1fr; }
}

/* ---------- landing ---------- */
.landing-section { max-width: 1100px; margin: 0 auto; padding: 72px 24px; }
.landing-section.alt { background: var(--bg2); max-width: none; }
.landing-section.alt > * { max-width: 1100px; margin-left: auto; margin-right: auto; }
.landing-section h2 { font-size: 32px; text-align: center; margin-bottom: 36px; }
.hero {
  padding: 80px 24px 60px; text-align: center;
  background: radial-gradient(1200px 500px at 50% -10%, rgba(124, 92, 255, 0.22), transparent),
              radial-gradient(900px 400px at 80% 10%, rgba(0, 212, 170, 0.12), transparent);
}
.hero-inner { max-width: 820px; margin: 0 auto; }
.hero-badge {
  display: inline-block; background: rgba(124, 92, 255, 0.15); border: 1px solid rgba(124, 92, 255, 0.4);
  padding: 8px 18px; border-radius: 999px; font-size: 13px; margin-bottom: 24px;
}
.hero h1 { font-size: 54px; line-height: 1.2; margin-bottom: 18px; }
.grad { background: linear-gradient(90deg, var(--primary), var(--accent)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-sub { color: var(--text2); font-size: 18px; max-width: 560px; margin: 0 auto 30px; }
.hero-cta { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; margin-bottom: 42px; }
.btn-ghost.big { padding: 12px 22px; font-size: 15px; text-decoration: none; line-height: 1.6; }
.hero-stats { display: flex; gap: 44px; justify-content: center; flex-wrap: wrap; margin-bottom: 48px; }
.hero-stats div { display: flex; flex-direction: column; }
.hero-stats b { font-size: 32px; color: var(--accent); }
.hero-stats span { color: var(--muted); font-size: 13px; }
.hero-cards { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; max-width: 1100px; margin: 0 auto; }
.mini-card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 18px; font-weight: 700; font-size: 14px; text-align: left;
}
.mini-card span { display: block; color: var(--muted); font-weight: 400; font-size: 12px; margin-top: 6px; line-height: 1.6; }

.feature { text-align: center; padding: 30px 24px; }
.feature .ficon { font-size: 42px; margin-bottom: 14px; }
.feature h3 { margin-bottom: 10px; font-size: 18px; }
.feature p { color: var(--text2); font-size: 14px; line-height: 1.8; }

.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin-bottom: 48px; }
.step { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
.step .num {
  width: 38px; height: 38px; border-radius: 50%; background: var(--primary); color: #fff;
  display: flex; align-items: center; justify-content: center; font-weight: 800; margin-bottom: 14px;
}
.step h4 { margin-bottom: 8px; }
.step p { color: var(--text2); font-size: 13px; line-height: 1.7; }

.faq { max-width: 760px; margin: 0 auto; }
.faq h3 { margin-bottom: 16px; }
.faq details {
  background: var(--card); border: 1px solid var(--border); border-radius: 10px;
  padding: 14px 18px; margin-bottom: 10px;
}
.faq summary { cursor: pointer; font-weight: 700; font-size: 14px; }
.faq details p { color: var(--text2); font-size: 13px; line-height: 1.8; margin-top: 10px; }

.about-box { display: grid; grid-template-columns: 1.7fr 1fr; gap: 26px; align-items: start; }
.about-box p { color: var(--text2); line-height: 1.9; margin-bottom: 12px; }
.about-box ul { margin: 12px 0 12px 20px; color: var(--text2); line-height: 2; }
.about-box a { color: var(--accent); }
.about-side { display: flex; flex-direction: column; gap: 12px; }

.pack-card.hot { border-color: var(--primary); position: relative; }
.hot-tag {
  position: absolute; top: -12px; left: 50%; transform: translateX(-50%);
  background: var(--primary); color: #fff; padding: 4px 14px; border-radius: 999px; font-size: 11px; font-weight: 700;
}
.landing-section .page-sub { text-align: center; }

/* ---------- image upload ---------- */
.dropzone {
  border: 2px dashed var(--border); border-radius: var(--radius); padding: 36px;
  text-align: center; cursor: pointer; transition: border-color 0.15s, background 0.15s;
}
.dropzone:hover, .dropzone.drag { border-color: var(--primary); background: rgba(124, 92, 255, 0.07); }
.dropzone p { color: var(--text2); margin-top: 8px; }

.card-actions { display: flex; gap: 8px; margin-top: 12px; flex-wrap: wrap; }
.card-actions .btn-ghost { padding: 6px 12px; font-size: 12px; text-decoration: none; }
.card-actions a.btn-ghost { display: inline-flex; align-items: center; }

/* ---------- mobile nav components (hidden on desktop) ---------- */
.hamburger {
  display: none; background: var(--card); border: 1px solid var(--border); color: var(--text);
  width: 38px; height: 38px; border-radius: 10px; font-size: 18px; cursor: pointer;
  align-items: center; justify-content: center;
}
.menu-panel {
  display: none; position: fixed; top: 58px; right: 12px; z-index: 90;
  background: var(--card); border: 1px solid var(--border); border-radius: 14px;
  padding: 8px; width: 190px;
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.5);
}
.menu-panel.open { display: flex; flex-direction: column; gap: 4px; }
.menu-panel .nav-btn {
  text-align: left; justify-content: flex-start; width: 100%; padding: 11px 12px;
  border-radius: 10px; font-size: 14px;
}
.bottom-nav { display: none; }

@media (max-width: 700px) {
  /* topbar: brand + credit + hamburger only */
  .topbar { padding: 8px 12px; gap: 8px; }
  .topbar .nav { display: none; }
  .hamburger { display: inline-flex; }
  #navUser, #logoutBtn { display: none; }
  .credit-pill { padding: 5px 12px; font-size: 13px; }

  /* bottom tab bar */
  .bottom-nav {
    display: flex; position: fixed; left: 0; right: 0; bottom: 0; z-index: 80;
    background: rgba(13, 17, 28, 0.92); backdrop-filter: blur(14px);
    border-top: 1px solid var(--border);
    padding: 6px 4px calc(6px + env(safe-area-inset-bottom));
  }
  .bnav-btn {
    flex: 1; background: none; border: 0; color: var(--muted); cursor: pointer;
    display: flex; flex-direction: column; align-items: center; gap: 2px;
    padding: 7px 2px 5px; border-radius: 12px; font-size: 11px;
    transition: color 0.15s, background 0.15s;
  }
  .bnav-btn .bicon { font-size: 21px; line-height: 1; }
  .bnav-btn.active { color: var(--accent); background: rgba(124, 92, 255, 0.14); }
  #mainContent { padding-bottom: calc(88px + env(safe-area-inset-bottom)); }
  .foot { margin-bottom: 76px; }

  /* hero & landing */
  .hero { padding: 48px 16px 36px; }
  .hero h1 { font-size: 30px; }
  .hero-sub { font-size: 15px; }
  .hero-badge { font-size: 11px; padding: 6px 12px; }
  .hero-cta .btn-primary, .hero-cta .btn-ghost.big { width: 100%; justify-content: center; }
  .hero-stats { gap: 18px; margin-bottom: 32px; }
  .hero-stats b { font-size: 24px; }
  .landing-section { padding: 48px 16px; }
  .landing-section h2 { font-size: 24px; margin-bottom: 24px; }
  .mini-card { padding: 14px; }

  /* grids: tidy 2-col for icon cards, 1-col for text blocks */
  .grid.cols-4 { grid-template-columns: repeat(2, 1fr); gap: 10px; }
  .grid.cols-3 { grid-template-columns: 1fr 1fr; gap: 10px; }
  .grid.cols-3 > .pack-card, .grid.cols-3 > .stat-card { grid-column: span 1; }
  .pack-grid-mobile { grid-template-columns: 1fr !important; }
  .pick-card { padding: 14px; }
  .pick-card .icon { font-size: 26px; }
  .pick-card .name { font-size: 13px; }
  .pick-card .desc { font-size: 11px; }

  /* studio / i2v */
  .page-title { font-size: 22px; }
  .page-sub { font-size: 13px; }
  .section-label { font-size: 13px; margin: 22px 4px 10px; }
  .card { padding: 16px; }
  textarea, input, select { font-size: 16px; } /* iOS zoom guard */
  .btn-primary { padding: 13px 18px; min-height: 46px; }
  .slider-val { min-width: 46px; font-size: 14px; }
  .cost-box .cost-big { font-size: 24px; }
  .dropzone { padding: 22px 14px; }

  /* video cards 1-col + bigger thumbs */
  #videoList .grid.cols-3 { grid-template-columns: 1fr; }
  .video-card .title { font-size: 13px; }
  .card-actions .btn-ghost { padding: 9px 14px; font-size: 13px; min-height: 40px; display: inline-flex; align-items: center; }

  /* tables scroll horizontally with smaller type */
  .card table { font-size: 12px; }
  .card th, .card td { padding: 8px 10px; white-space: nowrap; }

  /* auth */
  .auth-hero h1 { font-size: 26px; }

  /* steps: compact horizontal rows (no tall strips) */
  .steps { gap: 10px; }
  .step {
    display: flex; gap: 12px; align-items: flex-start;
    padding: 13px 14px; border-radius: 13px;
  }
  .step .num {
    width: 28px; height: 28px; font-size: 13px; margin: 0; flex-shrink: 0;
  }
  .step h4 { font-size: 14px; margin: 1px 0 3px; }
  .step p { font-size: 12px; line-height: 1.6; margin: 0; }

  /* tighter tips & faq */
  .grid.cols-2 { gap: 10px; }
  .faq details { padding: 12px 14px; }
  .faq summary { font-size: 13px; }
}

@media (max-width: 380px) {
  .hero h1 { font-size: 26px; }
  .grid.cols-4 { grid-template-columns: 1fr 1fr; }
  .bnav-btn { font-size: 10px; }
  .bnav-btn .bicon { font-size: 19px; }
}