/* ============================================
   夜色AI聊天 - APP下载引流页样式
   移动端优先 | SEO友好 | 响应式设计
   ============================================ */

/* ---- Reset & Base ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --primary: #7C3AED;
  --primary-dark: #6D28D9;
  --primary-light: #A78BFA;
  --bg-dark: #0F0A1E;
  --bg-card: #1A1333;
  --bg-card-hover: #231B40;
  --text-primary: #F3F0FF;
  --text-secondary: #B4A9D6;
  --text-muted: #7C6DA6;
  --accent: #F472B6;
  --accent2: #60A5FA;
  --gradient-hero: linear-gradient(135deg, #1A0A3E 0%, #2D1160 40%, #1E0A45 100%);
  --gradient-btn: linear-gradient(135deg, #7C3AED 0%, #A855F7 50%, #C084FC 100%);
  --gradient-card: linear-gradient(145deg, #1A1333 0%, #231B45 100%);
  --shadow-glow: 0 0 40px rgba(124, 58, 237, 0.3);
  --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.4);
  --radius: 16px;
  --radius-sm: 10px;
  --radius-xs: 6px;
  --max-width: 1200px;
  --header-height: 60px;
  --btn-bottom-height: 64px;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  padding-bottom: calc(var(--btn-bottom-height) + 20px);
}

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

/* ---- Utility ---- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 16px;
}

.section-title {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 1rem;
  position: relative;
  padding-left: 14px;
}
.section-title::before {
  content: '';
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 4px;
  background: var(--gradient-btn);
  border-radius: 2px;
}

/* ---- Header ---- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(15, 10, 30, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(124, 58, 237, 0.15);
  height: var(--header-height);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
}
.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--gradient-btn);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  color: #fff;
  flex-shrink: 0;
}

.nav-links {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  justify-content: flex-end;
}
.nav-links a {
  font-size: 0.8rem;
  color: var(--text-secondary);
  padding: 4px 10px;
  border-radius: 20px;
  transition: all 0.2s;
  white-space: nowrap;
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--primary-light);
  background: rgba(124, 58, 237, 0.12);
}

/* ---- Hero Section ---- */
.hero {
  background: var(--gradient-hero);
  padding: 40px 0 36px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 50% 50%, rgba(124, 58, 237, 0.08) 0%, transparent 60%);
  animation: heroPulse 6s ease-in-out infinite;
}
@keyframes heroPulse {
  0%, 100% { transform: scale(1); opacity: 0.5; }
  50% { transform: scale(1.05); opacity: 1; }
}

.hero .container { position: relative; z-index: 1; }

.hero-badge {
  display: inline-block;
  background: rgba(124, 58, 237, 0.2);
  border: 1px solid rgba(124, 58, 237, 0.3);
  color: var(--primary-light);
  font-size: 0.8rem;
  padding: 4px 14px;
  border-radius: 20px;
  margin-bottom: 16px;
}

.hero h1 {
  font-size: 1.8rem;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 10px;
  background: linear-gradient(135deg, #E9D5FF 0%, #C084FC 40%, #A78BFA 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}

.hero-tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 20px;
}
.hero-tags span {
  font-size: 0.75rem;
  color: var(--text-muted);
  background: rgba(255, 255, 255, 0.05);
  padding: 3px 10px;
  border-radius: 12px;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--gradient-btn);
  color: #fff;
  font-size: 1.05rem;
  font-weight: 700;
  padding: 14px 40px;
  border-radius: 50px;
  box-shadow: 0 4px 24px rgba(124, 58, 237, 0.45);
  transition: all 0.3s;
  cursor: pointer;
  border: none;
}
.hero-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 32px rgba(124, 58, 237, 0.6);
}
.hero-cta .arrow {
  display: inline-block;
  transition: transform 0.3s;
}
.hero-cta:hover .arrow { transform: translateX(3px); }

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 32px;
  margin-top: 24px;
  flex-wrap: wrap;
}
.hero-stat {
  text-align: center;
}
.hero-stat .num {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--primary-light);
}
.hero-stat .label {
  font-size: 0.72rem;
  color: var(--text-muted);
}

/* ---- Feature Cards ---- */
.features {
  padding: 36px 0;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 12px;
}
.feature-card {
  background: var(--bg-card);
  border-radius: var(--radius-sm);
  padding: 20px 14px;
  text-align: center;
  transition: all 0.3s;
  border: 1px solid rgba(124, 58, 237, 0.08);
}
.feature-card:hover {
  background: var(--bg-card-hover);
  transform: translateY(-3px);
  box-shadow: var(--shadow-card);
}
.feature-icon {
  font-size: 2rem;
  margin-bottom: 10px;
}
.feature-card h3 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 4px;
}
.feature-card p {
  font-size: 0.72rem;
  color: var(--text-muted);
  line-height: 1.4;
}

/* ---- App Preview ---- */
.app-preview {
  padding: 10px 0 36px;
}
.preview-mockup {
  background: var(--gradient-card);
  border-radius: var(--radius);
  padding: 24px 16px;
  text-align: center;
  border: 1px solid rgba(124, 58, 237, 0.1);
}
.preview-mockup .phone-frame {
  width: 180px;
  height: 320px;
  margin: 0 auto 16px;
  background: #111;
  border-radius: 20px;
  border: 3px solid #333;
  overflow: hidden;
  position: relative;
}
.phone-screen {
  width: 100%;
  height: 100%;
  background: linear-gradient(180deg, #1a1035 0%, #0d0620 100%);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--primary-light);
  font-size: 0.85rem;
  gap: 8px;
}
.phone-screen .chat-bubble {
  background: rgba(124, 58, 237, 0.2);
  padding: 8px 14px;
  border-radius: 12px 12px 12px 4px;
  font-size: 0.7rem;
  max-width: 80%;
  animation: floatBubble 3s ease-in-out infinite;
}
.phone-screen .chat-bubble:nth-child(2) {
  align-self: flex-end;
  border-radius: 12px 12px 4px 12px;
  background: rgba(244, 114, 182, 0.2);
  animation-delay: 0.5s;
}
.phone-screen .chat-bubble:nth-child(3) { animation-delay: 1s; }
@keyframes floatBubble {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-4px); }
}

/* ---- FAQ Section ---- */
.faq {
  padding: 36px 0;
}
.faq-list { display: flex; flex-direction: column; gap: 10px; }
.faq-item {
  background: var(--bg-card);
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid rgba(124, 58, 237, 0.08);
}
.faq-q {
  padding: 14px 16px;
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}
.faq-q::after {
  content: '+';
  font-size: 1.2rem;
  color: var(--text-muted);
  transition: transform 0.3s;
}
.faq-item.open .faq-q::after {
  content: '−';
  transform: rotate(180deg);
}
.faq-a {
  padding: 0 16px 14px;
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.6;
  display: none;
}
.faq-item.open .faq-a { display: block; }

/* ---- SEO Content ---- */
.seo-content {
  padding: 20px 0 36px;
}
.seo-text {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.8;
}
.seo-text h2 {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin: 16px 0 8px;
  font-weight: 700;
}
.seo-text h3 {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin: 12px 0 6px;
  font-weight: 600;
}
.seo-text p { margin-bottom: 8px; }

/* ---- Related Links ---- */
.related-section { padding: 10px 0 36px; }
.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  gap: 8px;
}
.related-card {
  display: block;
  background: var(--bg-card);
  border-radius: var(--radius-xs);
  padding: 12px;
  font-size: 0.8rem;
  color: var(--text-secondary);
  text-align: center;
  transition: all 0.2s;
  border: 1px solid rgba(124, 58, 237, 0.06);
}
.related-card:hover {
  background: var(--bg-card-hover);
  color: var(--primary-light);
}

/* ---- Breadcrumb ---- */
.breadcrumb {
  padding: 12px 0;
  font-size: 0.75rem;
  color: var(--text-muted);
}
.breadcrumb a { color: var(--text-secondary); }
.breadcrumb a:hover { color: var(--primary-light); }
.breadcrumb .sep { margin: 0 6px; }

/* ---- Floating Bottom Download Bar ---- */
.bottom-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 200;
  background: rgba(15, 10, 30, 0.95);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-top: 1px solid rgba(124, 58, 237, 0.2);
  padding: 10px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.bottom-bar-info {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}
.bottom-bar-icon {
  width: 40px;
  height: 40px;
  background: var(--gradient-btn);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  color: #fff;
  flex-shrink: 0;
}
.bottom-bar-text {
  min-width: 0;
}
.bottom-bar-text .bname {
  font-size: 0.85rem;
  font-weight: 700;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.bottom-bar-text .bdesc {
  font-size: 0.68rem;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.bottom-bar-btns {
  display: flex;
  gap: 8px;
  flex-shrink: 0;
}
.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: var(--gradient-btn);
  color: #fff;
  font-size: 0.85rem;
  font-weight: 700;
  padding: 10px 20px;
  border-radius: 50px;
  white-space: nowrap;
  transition: all 0.3s;
  box-shadow: 0 2px 12px rgba(124, 58, 237, 0.4);
}
.btn-download:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 20px rgba(124, 58, 237, 0.55);
}
.btn-download-secondary {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-primary);
  border: 1px solid rgba(255, 255, 255, 0.15);
  box-shadow: none;
}
.btn-download-secondary:hover {
  background: rgba(255, 255, 255, 0.15);
  box-shadow: none;
}

/* ---- Download Section (in-page) ---- */
.download-section {
  padding: 36px 0;
  text-align: center;
}
.download-cards {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 16px;
}
.download-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 24px 20px;
  flex: 1;
  min-width: 140px;
  max-width: 220px;
  text-align: center;
  border: 1px solid rgba(124, 58, 237, 0.1);
  transition: all 0.3s;
}
.download-card:hover {
  background: var(--bg-card-hover);
  transform: translateY(-3px);
  box-shadow: var(--shadow-card);
}
.download-card .dc-icon {
  font-size: 2.4rem;
  margin-bottom: 10px;
}
.download-card .dc-name {
  font-size: 0.9rem;
  font-weight: 700;
  margin-bottom: 12px;
}
.download-card .dc-btn {
  display: block;
  background: var(--gradient-btn);
  color: #fff;
  font-size: 0.85rem;
  font-weight: 700;
  padding: 10px 0;
  border-radius: 50px;
  transition: all 0.3s;
}
.download-card .dc-btn:hover {
  box-shadow: 0 4px 16px rgba(124, 58, 237, 0.5);
}

/* ---- Content Sections ---- */
.content-block {
  padding: 16px 0 28px;
}
.content-block p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 10px;
}
.content-block strong { color: var(--primary-light); }

/* ---- Steps ---- */
.steps {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 12px 0;
}
.step-item {
  display: flex;
  gap: 14px;
  align-items: flex-start;
}
.step-num {
  width: 32px;
  height: 32px;
  background: var(--gradient-btn);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
  color: #fff;
  flex-shrink: 0;
}
.step-info h3 {
  font-size: 0.88rem;
  font-weight: 600;
  margin-bottom: 2px;
}
.step-info p {
  font-size: 0.76rem;
  color: var(--text-muted);
  margin: 0;
}

/* ---- Footer ---- */
.site-footer {
  background: rgba(26, 19, 51, 0.6);
  border-top: 1px solid rgba(124, 58, 237, 0.1);
  padding: 24px 0 16px;
  text-align: center;
  font-size: 0.72rem;
  color: var(--text-muted);
}
.site-footer .footer-links {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 10px;
}
.site-footer .footer-links a { color: var(--text-muted); }
.site-footer .footer-links a:hover { color: var(--primary-light); }
.site-footer .footer-disclaimer {
  margin-top: 8px;
  font-size: 0.68rem;
  color: var(--text-muted);
  opacity: 0.6;
  line-height: 1.6;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* ---- Back to Top ---- */
.back-to-top {
  position: fixed;
  right: 16px;
  bottom: 90px;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: rgba(124, 58, 237, 0.3);
  border: 1px solid rgba(124, 58, 237, 0.4);
  color: var(--primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  cursor: pointer;
  z-index: 150;
  transition: all 0.3s;
  opacity: 0;
  pointer-events: none;
}
.back-to-top.visible {
  opacity: 1;
  pointer-events: auto;
}
.back-to-top:hover {
  background: rgba(124, 58, 237, 0.5);
}

/* ---- Responsive ---- */
@media (min-width: 600px) {
  .hero h1 { font-size: 2.2rem; }
  .hero-subtitle { font-size: 1rem; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .related-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (min-width: 768px) {
  html { font-size: 17px; }
  .container { padding: 0 24px; }
  .hero { padding: 56px 0 48px; }
  .hero h1 { font-size: 2.4rem; }
  .feature-grid { grid-template-columns: repeat(3, 1fr); }
  .related-grid { grid-template-columns: repeat(4, 1fr); }
  .bottom-bar { padding: 12px 24px; }
}

@media (min-width: 1024px) {
  .feature-grid { grid-template-columns: repeat(4, 1fr); }
  .related-grid { grid-template-columns: repeat(6, 1fr); }
  .hero h1 { font-size: 2.6rem; }
}

/* ---- Schema hidden ---- */
.schema-hidden { display: none; }