/* ================================================================
   拾光AI创作平台 - Landing Page Design System
   ================================================================ */

/* ---- Reset & Base ---- */
*, *::before, *::after { box-sizing: border-box; }

:root {
  --brand: #60a5fa;
  --brand-dark: #3b82f6;
  --brand-light: rgba(96, 165, 250, 0.14);
  --accent: #38bdf8;
  --text-main: #e5edf7;
  --text-sub: #94a3b8;
  --text-inv: #05070c;
  --text-tertiary: #64748b;
  --bg: #05070c;
  --bg-soft: #0b1220;
  --bg-section: #0b1220;
  --bg-card: #111827;
  --bg-card-hover: #172033;
  --bg-hero: #05070c;
  --border: #253044;
  --border-strong: #334155;
  --radius: 16px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.36);
  --shadow-md: 0 8px 40px rgba(0, 0, 0, 0.5);
  --transition: 0.2s ease;
}

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, sans-serif;
  color: var(--text-main);
  background: var(--bg);
  line-height: 1.6;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }

/* ---- Typography ---- */
h1, h2, h3, h4 { margin: 0; line-height: 1.2; font-weight: 700; }
p { margin: 0; }

.section-label {
  display: inline-block;
  padding: 5px 14px;
  border-radius: 999px;
  background: var(--brand-light);
  color: var(--brand);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.section-title {
  font-size: clamp(28px, 4vw, 40px);
  color: var(--text-main);
  margin: 16px 0 12px;
}

.section-subtitle {
  font-size: 17px;
  color: var(--text-sub);
  max-width: 580px;
  margin: 0 auto;
  line-height: 1.75;
}

/* ---- Layout ---- */
.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

section { padding: 96px 0; }

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 28px;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
  white-space: nowrap;
}

.btn--primary {
  background: var(--brand);
  color: #fff;
  box-shadow: 0 4px 14px rgba(96, 165, 250, 0.25);
}
.btn--primary:hover {
  background: var(--brand-dark);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(96, 165, 250, 0.35);
}

.btn--outline {
  background: rgba(255,255,255,0.15);
  color: #fff;
  border: 1.5px solid rgba(255,255,255,0.5);
  backdrop-filter: blur(4px);
}
.btn--outline:hover {
  background: rgba(255,255,255,0.25);
  transform: translateY(-1px);
}

.btn--ghost {
  background: transparent;
  color: var(--brand);
  border: 1.5px solid var(--brand);
}
.btn--ghost:hover {
  background: var(--brand-light);
}

.btn--lg { padding: 16px 36px; font-size: 16px; border-radius: 12px; }

/* 用于深色渐变背景（Hero / CTA band）上的主 CTA，白底品牌色字 */
.btn--white {
  background: #ffffff;
  color: var(--brand-dark);
  font-weight: 700;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}
.btn--white:hover {
  background: rgba(255, 255, 255, 0.92);
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.4);
}

/* ================================================================
   NAVBAR
   ================================================================ */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(5, 7, 12, 0.85);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(37, 48, 68, 0.6);
  transition: background 0.35s ease, border-color 0.35s ease, backdrop-filter 0.35s ease;
}

.navbar__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

.navbar__logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 700;
  color: var(--text-main);
}

.navbar__logo-icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
}

.navbar__links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.navbar__links a {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-sub);
  transition: color var(--transition);
}
.navbar__links a:hover { color: var(--brand); }
.navbar__links a.active {
  color: var(--brand);
  font-weight: 600;
  position: relative;
}
.navbar__links a.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--brand);
  border-radius: 1px;
}

.navbar__cta {
  display: flex;
  align-items: center;
  gap: 12px;
}

.navbar__cta .btn { padding: 9px 20px; font-size: 14px; }

/* ====== 右下角客服QQ悬浮按钮 ====== */
.qq-float {
  position: fixed;
  bottom: 32px;
  right: 28px;
  z-index: 999;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.qq-float__preview {
  display: none;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
  padding: 10px;
  margin-bottom: 10px;
  text-align: center;
}
.qq-float__preview img {
  width: 160px;
  height: 160px;
  object-fit: cover;
  border-radius: 8px;
  display: block;
}
.qq-float__preview-label {
  font-size: 12px;
  color: #6b7280;
  margin-top: 7px;
}
.qq-float:hover .qq-float__preview {
  display: block;
}
.qq-float__btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 0 16px;
  height: 38px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--brand) 0%, var(--accent) 100%);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  box-shadow: 0 4px 16px rgba(96, 165, 250, 0.25);
  transition: transform 0.2s, box-shadow 0.2s;
  white-space: nowrap;
  border: 1px solid rgba(255,255,255,0.15);
}
.qq-float__btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(96, 165, 250, 0.4);
  color: #fff;
}
.qq-float__icon {
  font-size: 11px;
  font-weight: 800;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 4px;
  padding: 1px 5px;
  line-height: 1.5;
}

/* Mobile nav toggle */
.navbar__toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
  color: var(--text-main);
  line-height: 0;
}

/* ---- 透明沉浸态（Hero 顶部） ---- */
.navbar--hero-top {
  background: transparent;
  border-bottom-color: transparent;
  backdrop-filter: none;
}
.navbar--hero-top .navbar__logo { color: #fff; }
.navbar--hero-top .navbar__links a { color: rgba(255,255,255,0.8); }
.navbar--hero-top .navbar__links a:hover,
.navbar--hero-top .navbar__links a.active { color: #fff; }
.navbar--hero-top #nav-login-btn {
  color: rgba(255,255,255,0.9);
  border-color: rgba(255,255,255,0.38);
  background: transparent;
}
.navbar--hero-top #nav-login-btn:hover {
  background: rgba(255,255,255,0.12);
  border-color: rgba(255,255,255,0.55);
}
.navbar--hero-top #nav-start-btn {
  background: rgba(255,255,255,0.15);
  border: 1.5px solid rgba(255,255,255,0.45);
  color: #fff;
  box-shadow: none;
}
.navbar--hero-top #nav-start-btn:hover { background: rgba(255,255,255,0.25); }
.navbar--hero-top .navbar__toggle { color: #fff; }

/* ================================================================
   HERO
   ================================================================ */
.hero {
  background:
    radial-gradient(circle at 18% 14%, rgba(45, 212, 191, 0.16), transparent 28%),
    radial-gradient(circle at 88% 8%, rgba(96, 165, 250, 0.18), transparent 30%),
    linear-gradient(135deg, #081326 0%, #0b1020 52%, #15112a 100%);
  padding: 100px 24px 48px;
  margin-top: -65px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.025) 1px, transparent 1px);
  background-size: 56px 56px;
  opacity: 0.35;
  pointer-events: none;
}

.hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 190px;
  background: linear-gradient(180deg, transparent, rgba(8, 19, 38, 0.92));
  pointer-events: none;
}

.hero__inner {
  position: relative;
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1.03fr) minmax(390px, 0.97fr);
  align-items: center;
  gap: 32px 56px;
}

.hero__copy {
  min-width: 0;
}

/* 标题 */
.hero__title {
  max-width: 620px;
  font-size: clamp(40px, 4.35vw, 58px);
  color: #fff;
  line-height: 1.12;
  margin: 0 0 18px;
  letter-spacing: 0;
  font-weight: 800;
}

.hero__subtitle {
  max-width: 590px;
  margin: 0 0 26px;
  color: rgba(226, 232, 240, 0.76);
  font-size: 17px;
  line-height: 1.72;
}

.hero__actions {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.hero__primary,
.hero__secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 800;
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.hero__primary {
  color: #fff;
  background: linear-gradient(135deg, #2563eb, #38bdf8);
  box-shadow: 0 18px 34px rgba(37, 99, 235, 0.34);
}

.hero__primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 22px 42px rgba(37, 99, 235, 0.42);
}

.hero__secondary {
  color: rgba(255, 255, 255, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.18);
  background: rgba(255, 255, 255, 0.06);
}

.hero__secondary:hover {
  border-color: rgba(255, 255, 255, 0.34);
  background: rgba(255, 255, 255, 0.1);
}

/* ---- Creation Card (核心卡片) ---- */
.creation-card {
  grid-column: 1 / -1;
  width: 100%;
  max-width: 860px;
  justify-self: center;
  background: rgba(9, 15, 29, 0.74);
  border: 1px solid rgba(148, 163, 184, 0.16);
  border-radius: 14px;
  -webkit-backdrop-filter: blur(24px);
  backdrop-filter: blur(24px);
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.08) inset,
    0 24px 70px rgba(0, 0, 0, 0.38);
  overflow: hidden;
  margin-top: -2px;
}

/* Tabs */
.creation-card__tabs {
  display: flex;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  padding: 0;
  overflow-x: auto;
  scrollbar-width: none;
}
.creation-card__tabs::-webkit-scrollbar { display: none; }
.creation-card__tab {
  flex: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 15px 16px;
  font-size: 13px;
  font-weight: 500;
  color: rgba(226, 232, 240, 0.52);
  text-decoration: none;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  transition: color 0.15s ease, border-color 0.15s ease;
}
.creation-card__tab:hover {
  color: rgba(255, 255, 255, 0.78);
}
.creation-card__tab.is-active {
  color: #7dd3fc;
  border-bottom-color: #7dd3fc;
}
.creation-card__tab-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #34d399;
  box-shadow: 0 0 6px #34d399;
  animation: cc-pulse 2s infinite;
}
@keyframes cc-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.35; }
}
.creation-card__soon {
  font-size: 9px;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.35);
  background: rgba(255, 255, 255, 0.06);
  padding: 1px 5px;
  border-radius: 4px;
  margin-left: 5px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

/* Composer area */
.creation-card__composer {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 20px 16px;
  text-decoration: none;
  color: rgba(226, 232, 240, 0.48);
  transition: color 0.15s ease;
}
.creation-card__composer:hover {
  color: rgba(226, 232, 240, 0.72);
}
.creation-card__placeholder {
  flex: 1;
  font-size: 15px;
  line-height: 1.5;
  min-width: 0;
}
.creation-card__send {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  background: linear-gradient(135deg, #3b82f6, #60a5fa);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: 0 4px 16px rgba(59, 130, 246, 0.3);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.creation-card__composer:hover .creation-card__send {
  transform: translateX(2px);
  box-shadow: 0 6px 20px rgba(59, 130, 246, 0.4);
}

/* ---- Hero Stats ---- */
.hero__stats {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 20px;
  flex-wrap: wrap;
}
.hero__stat {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  min-height: 30px;
  padding: 0 10px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.035);
  border: 1px solid rgba(255, 255, 255, 0.055);
  font-size: 13px;
  color: rgba(226, 232, 240, 0.72);
  white-space: nowrap;
}

.hero__stat strong {
  color: #fff;
  font-weight: 800;
}

/* Free credits CTA */
.hero__free {
  font-size: 14px;
  color: rgba(226, 232, 240, 0.56);
  margin: 0;
}

.hero__showcase {
  position: relative;
  min-width: 0;
  max-width: 510px;
  justify-self: center;
}

/* ---- Hero Gallery ---- */
.hero__gallery {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  transform: rotate(-0.5deg);
}
.hero__gallery-item {
  position: relative;
  min-height: 170px;
  aspect-ratio: 1.38 / 1;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.11);
  background: rgba(255, 255, 255, 0.04);
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.34);
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
  text-decoration: none;
}

.hero__gallery-item:nth-child(2) {
  transform: translateY(22px);
}

.hero__gallery-item:nth-child(3) {
  transform: translateY(-6px);
}

.hero__gallery-item:nth-child(4) {
  transform: translateY(16px);
}

.hero__gallery-item:hover {
  border-color: rgba(125, 211, 252, 0.45);
  box-shadow: 0 30px 80px rgba(37, 99, 235, 0.22);
}
.hero__gallery-item img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
}

.hero__gallery-model {
  position: absolute;
  left: 10px;
  bottom: 10px;
  max-width: calc(100% - 20px);
  padding: 5px 8px;
  border-radius: 999px;
  background: rgba(2, 6, 23, 0.68);
  color: rgba(255, 255, 255, 0.86);
  font-size: 11px;
  font-weight: 700;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

/* ================================================================
   FEATURES
   ================================================================ */
.features { background: var(--bg-section); }

.features__header { text-align: center; margin-bottom: 64px; }

.features__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 32px 28px;
  border: 1px solid var(--border);
  transition: box-shadow var(--transition), transform var(--transition);
}

.feature-card:hover {
  box-shadow: var(--shadow), inset 3px 0 0 var(--brand);
  transform: translateY(-4px);
}

.feature-card__icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  background: var(--brand-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  margin-bottom: 20px;
}

.feature-card__title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 12px;
}

.feature-card__desc {
  font-size: 15px;
  color: var(--text-sub);
  line-height: 1.7;
}

/* ================================================================
   MODELS
   ================================================================ */
.models { background: var(--bg); }

.models__header { text-align: center; margin-bottom: 56px; }

.models__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.model-card {
  background: var(--bg-card);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 20px;
  text-align: center;
  transition: border-color var(--transition), box-shadow var(--transition), transform var(--transition);
}

.model-card:hover {
  border-color: var(--brand);
  box-shadow: var(--shadow);
  transform: translateY(-3px);
}

.model-card__emoji {
  font-size: 40px;
  margin-bottom: 16px;
}

.model-card__name {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 8px;
}

.model-card__tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  background: var(--brand-light);
  color: var(--brand);
  margin-bottom: 12px;
}

.model-card__desc {
  font-size: 13px;
  color: var(--text-sub);
  line-height: 1.6;
}

.model-card--soon {
  opacity: 0.65;
  filter: grayscale(0.3);
}

.model-card__tag--soon {
  background: #f3f4f6;
  color: #6b7280;
}

.model-card__tag--featured {
  background: linear-gradient(90deg, #f59e0b, #f97316);
  color: #fff;
  box-shadow: 0 2px 8px rgba(245, 158, 11, 0.35);
}

/* ================================================================
   HOW IT WORKS
   ================================================================ */
.how { background: var(--bg-section); }

.how__header { text-align: center; margin-bottom: 64px; }

.how__steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  position: relative;
}

.how__steps::before {
  content: '';
  position: absolute;
  top: 28px;
  left: calc(12.5% + 20px);
  right: calc(12.5% + 20px);
  height: 2px;
  background: linear-gradient(90deg, var(--border), var(--brand), var(--border));
}

.step {
  text-align: center;
  position: relative;
}

.step__num {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, #3b82f6, #60a5fa);
  color: white;
  font-size: 20px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  box-shadow: var(--shadow);
  position: relative;
  z-index: 1;
}

.step__title {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 8px;
}

.step__desc {
  font-size: 14px;
  color: var(--text-sub);
  line-height: 1.65;
}

/* ================================================================
   PRICING
   ================================================================ */
.pricing { background: var(--bg); }

.pricing__header { text-align: center; margin-bottom: 56px; }

.pricing__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  align-items: start;
}

.price-card {
  background: var(--bg-card);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 28px;
  position: relative;
  transition: box-shadow var(--transition);
}

.price-card--featured {
  border-color: var(--brand);
  box-shadow: 0 16px 48px rgba(96, 165, 250, 0.15);
  padding: 44px 32px;
  transform: translateY(-10px);
  background: linear-gradient(160deg, rgba(96, 165, 250, 0.08) 0%, var(--bg-card) 60%);
}

.price-card__badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--brand);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 999px;
  white-space: nowrap;
}

.price-card__name {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-sub);
  margin-bottom: 12px;
}

.price-card__amount {
  font-size: 40px;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1;
}

.price-card__amount span {
  font-size: 16px;
  font-weight: 500;
  color: var(--text-sub);
}

.price-card__credits {
  margin: 8px 0 24px;
  font-size: 14px;
  color: var(--text-sub);
}

.price-card__divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 24px 0;
}

.price-card__features {
  list-style: none;
  margin: 0 0 28px;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.price-card__features li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 14px;
  color: var(--text-sub);
}

.price-card__features li::before {
  content: '✓';
  color: var(--brand);
  font-weight: 700;
  flex-shrink: 0;
  margin-top: 1px;
}

.price-card .btn { width: 100%; }

/* ================================================================
   FAQ
   ================================================================ */
.faq { background: var(--bg-section); }

.faq__header { text-align: center; margin-bottom: 56px; }

.faq__list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--bg-card);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  overflow: hidden;
}

.faq-item__q {
  padding: 20px 24px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  list-style: none;
  user-select: none;
  transition: background var(--transition);
}
.faq-item__q:hover { background: var(--bg-card-hover); }

.faq-item__q::after {
  content: '+';
  font-size: 20px;
  color: var(--brand);
  flex-shrink: 0;
  transition: transform var(--transition);
}

.faq-item.is-open .faq-item__q::after { transform: rotate(45deg); }

.faq-item__a {
  padding: 0 24px 20px;
  font-size: 14px;
  color: var(--text-sub);
  line-height: 1.75;
  /* 展开动画通过 max-height 过渡，JS 控制 */
  overflow: hidden;
  max-height: 0;
  padding-bottom: 0;
  transition: max-height 0.35s ease, padding-bottom 0.35s ease;
}

.faq-item.is-open .faq-item__a {
  max-height: 400px;
  padding-bottom: 20px;
}

/* ================================================================
   CTA BAND
   ================================================================ */
.cta-band {
  background: linear-gradient(135deg, #0b1220 0%, #172033 100%);
  padding: 80px 24px;
  text-align: center;
  position: relative;
}
.cta-band::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 50% 50%, rgba(96, 165, 250, 0.06), transparent 70%);
  pointer-events: none;
}

.cta-band__title {
  font-size: clamp(28px, 4vw, 42px);
  color: #fff;
  margin-bottom: 16px;
}

.cta-band__sub {
  font-size: 17px;
  color: rgba(255,255,255,0.8);
  margin-bottom: 36px;
}

.cta-band__actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* ================================================================
   FOOTER
   ================================================================ */
.footer {
  background: #0f172a;
  color: rgba(255,255,255,0.65);
  padding: 56px 24px 32px;
}

.footer__inner {
  max-width: 1120px;
  margin: 0 auto;
}

.footer__top {
  display: grid;
  grid-template-columns: 1fr auto auto auto;
  gap: 48px;
  margin-bottom: 48px;
  align-items: start;
}

.footer__brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-size: 17px;
  font-weight: 700;
  text-decoration: none;
  margin-bottom: 12px;
}

.footer__brand-icon {
  width: 30px;
  height: 30px;
  border-radius: 7px;
}

.footer__tagline {
  font-size: 13px;
  line-height: 1.6;
  max-width: 220px;
}

.footer__col-title {
  color: #fff;
  font-size: 13px;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.footer__links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer__links a {
  font-size: 14px;
  color: rgba(255,255,255,0.55);
  transition: color var(--transition);
}
.footer__links a:hover { color: #fff; }

.footer__bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  flex-wrap: wrap;
  gap: 12px;
}

.footer__bottom-links {
  display: flex;
  gap: 24px;
}

.footer__bottom-links a {
  color: rgba(255,255,255,0.45);
  transition: color var(--transition);
}
.footer__bottom-links a:hover { color: rgba(255,255,255,0.8); }

/* ================================================================
   LEGAL PAGES
   ================================================================ */
.legal-page {
  max-width: 800px;
  margin: 0 auto;
  padding: 60px 24px 96px;
}

.legal-page h1 {
  font-size: 32px;
  margin-bottom: 8px;
}

.legal-page .legal-date {
  font-size: 13px;
  color: var(--text-sub);
  margin-bottom: 40px;
}

.legal-page h2 {
  font-size: 20px;
  margin: 36px 0 12px;
}

.legal-page p, .legal-page li {
  font-size: 15px;
  color: var(--text-sub);
  line-height: 1.8;
  margin-bottom: 12px;
}

.legal-page ul {
  padding-left: 24px;
}

/* ================================================================
   PROMPT TOOLS
   ================================================================ */
.prompt-tools {
  background: var(--bg);
}

.prompt-tools__header {
  text-align: center;
  margin-bottom: 56px;
}

.prompt-tools__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.tool-card {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  padding: 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-soft);
  transition: box-shadow var(--transition), border-color var(--transition);
}

.tool-card:hover {
  border-color: var(--brand);
  box-shadow: var(--shadow);
}

.tool-card__icon {
  flex-shrink: 0;
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
}

.tool-card__icon--purple { background: rgba(139, 107, 232, 0.15); }
.tool-card__icon--blue   { background: rgba(96, 165, 250, 0.15); }
.tool-card__icon--green  { background: rgba(52, 211, 153, 0.15); }
.tool-card__icon--orange { background: rgba(251, 146, 60, 0.15); }

.tool-card__body {
  flex: 1;
  min-width: 0;
}

.tool-card__title {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 8px;
}

.tool-card__desc {
  font-size: 14px;
  color: var(--text-sub);
  line-height: 1.7;
}


/* ================================================================
   GALLERY SHOWCASE
   ================================================================ */
.gallery-showcase {
  background: var(--bg-section);
}

.gallery-showcase__header {
  text-align: center;
  margin-bottom: 56px;
}

.gallery-showcase__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.gallery-card {
  display: flex;
  flex-direction: column;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--bg-card);
  transition: box-shadow var(--transition), transform var(--transition);
  cursor: pointer;
  text-decoration: none;
  color: inherit;
}

.gallery-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.gallery-card__img-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  background: var(--bg-soft);
}

.gallery-card__img-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.35s ease;
  display: block;
}

.gallery-card:hover .gallery-card__img-wrap img {
  transform: scale(1.04);
}

.gallery-card__overlay {
  position: absolute;
  inset: 0;
  background: rgba(96, 165, 250, 0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity var(--transition);
}

.gallery-card:hover .gallery-card__overlay {
  opacity: 1;
}

.gallery-card__view-hint {
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  padding: 8px 20px;
  border: 1.5px solid rgba(255, 255, 255, 0.7);
  border-radius: 999px;
  backdrop-filter: blur(4px);
}

.gallery-card__info {
  padding: 14px 16px;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.gallery-card__prompt {
  font-size: 13px;
  color: var(--text-sub);
  line-height: 1.55;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.gallery-card__meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: auto;
}

.gallery-card__likes {
  font-size: 13px;
  color: #e11d48;
  font-weight: 500;
}

.gallery-card__model {
  font-size: 11px;
  color: var(--text-sub);
  background: var(--bg-soft);
  border: 1px solid var(--border);
  padding: 2px 8px;
  border-radius: 999px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 100px;
}

.gallery-showcase__cta {
  text-align: center;
  margin-top: 48px;
}

/* ================================================================
   RESPONSIVE
   ================================================================ */
@media (max-width: 1024px) {
  .hero__inner {
    grid-template-columns: minmax(0, 1fr) minmax(340px, 0.82fr);
    gap: 30px 34px;
  }
  .hero__title {
    font-size: clamp(38px, 4.7vw, 52px);
  }
  .hero__showcase {
    max-width: 430px;
  }
  .hero__gallery-item {
    min-height: 145px;
  }
  .models__grid { grid-template-columns: repeat(2, 1fr); }
  .how__steps { grid-template-columns: repeat(2, 1fr); }
  .how__steps::before { display: none; }
  .footer__top { grid-template-columns: 1fr 1fr; }
  .gallery-showcase__grid { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 768px) {
  section { padding: 48px 0; }

  /* Navbar */
  .navbar__links { display: none; }
  .navbar__toggle { display: flex; }
  .navbar__inner { justify-content: flex-start; }
  .navbar__cta { margin-left: auto; margin-right: 4px; }
  .navbar__cta #nav-start-btn { display: none; }
  .navbar__cta #nav-login-btn {
    border: none;
    background: transparent;
    color: var(--text-main);
    padding: 6px 10px;
    font-size: 14px;
    font-weight: 600;
    box-shadow: none;
  }
  .navbar--hero-top .navbar__cta #nav-login-btn {
    color: rgba(255, 255, 255, 0.92);
  }
  .navbar.mobile-open .navbar__links {
    display: flex !important;
    flex-direction: column;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: rgba(5, 7, 12, 0.97);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    padding: 8px 0 20px;
    gap: 0;
    z-index: 99;
    border-bottom: 1px solid var(--border);
  }
  .navbar.mobile-open .navbar__links a {
    display: block;
    padding: 14px 24px;
    font-size: 15px;
    font-weight: 500;
    color: var(--text-sub);
    border-bottom: 1px solid var(--border);
  }
  .navbar.mobile-open .navbar__links li:last-child a { border-bottom: none; }
  .navbar.mobile-open .navbar__links a:hover { color: var(--text-main); background: var(--bg-card); }

  .qq-float { bottom: 20px; right: 16px; }
  .qq-float__btn { width: 40px; height: 40px; padding: 0; border-radius: 50%; justify-content: center; }
  .qq-float__btn span:not(.qq-float__icon) { display: none; }
  .qq-float__icon { margin: 0; }
  .qq-float__preview img { width: 140px; height: 140px; }

  /* Hero 移动端 */
  .hero { padding: 90px 20px 40px; }
  .hero__inner {
    grid-template-columns: 1fr;
    gap: 22px;
  }
  .hero__title {
    max-width: none;
    font-size: clamp(30px, 9vw, 39px);
    line-height: 1.12;
    margin-bottom: 14px;
  }
  .hero__subtitle {
    font-size: 15px;
    line-height: 1.7;
    margin-bottom: 22px;
  }
  .hero__actions {
    gap: 10px;
    margin-bottom: 12px;
  }
  .hero__primary,
  .hero__secondary {
    flex: 1 1 150px;
    min-height: 44px;
    padding: 0 14px;
    font-size: 14px;
  }
  .hero__free {
    font-size: 13px;
  }
  .hero__stats {
    gap: 8px;
    margin-top: 18px;
  }
  .hero__stat {
    min-height: 30px;
    padding: 0 9px;
    font-size: 12px;
  }
  .hero__showcase {
    order: 2;
    max-width: none;
  }
  .hero__gallery {
    gap: 10px;
    transform: none;
  }
  .hero__gallery-item {
    min-height: 128px;
    border-radius: 8px;
  }
  .hero__gallery-item:nth-child(2),
  .hero__gallery-item:nth-child(3),
  .hero__gallery-item:nth-child(4) {
    transform: none;
  }
  .hero__gallery-model {
    left: 8px;
    bottom: 8px;
    font-size: 10px;
  }
  /* Creation card 移动端 */
  .creation-card {
    order: 3;
    max-width: none;
    border-radius: 12px;
    margin-top: -2px;
  }
  .creation-card__tabs { padding: 0; }
  .creation-card__tab {
    padding: 12px 14px;
    font-size: 12px;
    flex: 0 0 auto;
  }
  .creation-card__composer { padding: 14px 16px 16px; }
  .creation-card__placeholder { font-size: 13px; }
  .creation-card__send { width: 34px; height: 34px; border-radius: 10px; }

  /* Other sections */
  .features__grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .feature-card { padding: 20px 16px; }
  .feature-card__icon { width: 40px; height: 40px; font-size: 20px; margin-bottom: 12px; }
  .feature-card__title { font-size: 14px; margin-bottom: 8px; }
  .feature-card__desc { font-size: 12px; line-height: 1.6; }
  .models__grid { grid-template-columns: repeat(2, 1fr); }
  .how__steps { grid-template-columns: 1fr; gap: 12px; }
  .step {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    text-align: left;
    background: var(--bg-card);
    border-radius: var(--radius-sm);
    padding: 18px 20px;
    border: 1px solid var(--border);
  }
  .step__num { flex-shrink: 0; width: 44px; height: 44px; font-size: 16px; margin: 0; }
  .step__body { flex: 1; }
  .step__title { font-size: 15px; margin-bottom: 4px; }
  .step__desc { font-size: 13px; }
  .pricing__grid { grid-template-columns: 1fr; }
  .prompt-tools__grid { grid-template-columns: 1fr; gap: 16px; }
  .gallery-showcase__grid { grid-template-columns: repeat(2, 1fr); gap: 14px; }
  .footer__top { grid-template-columns: 1fr 1fr; gap: 20px 28px; }
  .footer__top > div:first-child { grid-column: 1 / -1; }
  .footer__bottom { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 480px) {
  .features__grid { grid-template-columns: 1fr; }
  .btn--lg { padding: 13px 20px; font-size: 15px; }
  .hero__title { font-size: 28px; }
  .hero__actions {
    flex-direction: column;
    align-items: stretch;
  }
  .hero__primary,
  .hero__secondary {
    width: 100%;
    flex-basis: auto;
  }
  .cta-band__actions { gap: 12px; }
  .gallery-showcase__grid { grid-template-columns: 1fr; }
  .hero__gallery {
    grid-template-columns: 1fr 1fr;
  }
  .hero__gallery-item {
    min-height: 112px;
  }
}

/* ================================================================
   LIGHT THEME (prefers-color-scheme)
   ================================================================ */
@media (prefers-color-scheme: light) {
  :root {
    --brand: #2563eb;
    --brand-dark: #1d4ed8;
    --brand-light: rgba(37, 99, 235, 0.1);
    --accent: #3b82f6;
    --text-main: #0f172a;
    --text-sub: #475569;
    --text-inv: #ffffff;
    --text-tertiary: #64748b;
    --bg: #f8fafc;
    --bg-soft: #f1f5f9;
    --bg-section: #f1f5f9;
    --bg-card: #ffffff;
    --bg-card-hover: #f8fafc;
    --bg-hero: #0f172a;
    --border: #e2e8f0;
    --border-strong: #cbd5e1;
    --radius: 16px;
    --radius-sm: 8px;
    --shadow: 0 4px 24px rgba(15, 23, 42, 0.08);
    --shadow-md: 0 8px 40px rgba(15, 23, 42, 0.12);
  }

  body { background: var(--bg); color: var(--text-main); }

  .navbar {
    background: rgba(248, 250, 252, 0.88);
    border-bottom-color: rgba(226, 232, 240, 0.6);
  }
  .navbar--hero-top {
    background: transparent;
    border-bottom-color: transparent;
  }

  /* Hero 在浅色主题下保持深色 */
  .hero {
    background:
      radial-gradient(circle at 18% 14%, rgba(45, 212, 191, 0.16), transparent 28%),
      radial-gradient(circle at 88% 8%, rgba(96, 165, 250, 0.18), transparent 30%),
      linear-gradient(135deg, #081326 0%, #0b1020 52%, #15112a 100%);
  }

  .section-label { background: var(--brand-light); color: var(--brand); }
  .btn--primary { box-shadow: 0 4px 14px rgba(37, 99, 235, 0.25); }
  .btn--primary:hover { box-shadow: 0 6px 20px rgba(37, 99, 235, 0.35); }
  .btn--white { color: var(--brand); box-shadow: 0 4px 20px rgba(0,0,0,0.12); }
  .feature-card:hover { box-shadow: var(--shadow), inset 3px 0 0 var(--brand); }
  .gallery-card__overlay { background: rgba(37, 99, 235, 0.45); }

  .social-proof { background: linear-gradient(135deg, #1e40af 0%, #2563eb 100%) !important; }
  .cta-band { background: linear-gradient(135deg, #1e3a5f 0%, #1e40af 100%); }
  .cta-band::before { background: radial-gradient(ellipse at 50% 50%, rgba(96,165,250,0.1), transparent 70%); }
  .footer { background: #0f172a; }

  .qq-float__preview { background: var(--bg-card); border-color: var(--border); box-shadow: 0 8px 32px rgba(0,0,0,0.12); }
  .qq-float__btn { box-shadow: 0 4px 16px rgba(37, 99, 235, 0.2); }

  .navbar.mobile-open .navbar__links { background: rgba(15, 23, 42, 0.97); }
  .navbar.mobile-open .navbar__links a { color: rgba(255,255,255,0.82); border-bottom-color: rgba(255,255,255,0.06); }
  .navbar.mobile-open .navbar__links a:hover { color: #fff; }
}