/* ============================================
   BIMOBIMO - AI语音互动社交平台
   主色 #ff92ba / 次色 #ffbcd5 / 背景 #ffffff
   ============================================ */

:root {
  /* Colors */
  --primary: #ff92ba;
  --primary-hover: #ff7ba8;
  --primary-light: #ffbcd5;
  --primary-lighter: #fff0f6;
  --primary-soft: #ffe4ef;
  --bg: #ffffff;
  --bg-alt: #faf5f8;
  --text: #1a1520;
  --text-secondary: #6b6577;
  --text-tertiary: #9b95a8;
  --border: #f0e8ee;
  --border-hover: #e0d4de;
  --shadow-sm: 0 1px 3px rgba(255, 146, 186, 0.06);
  --shadow: 0 2px 12px rgba(255, 146, 186, 0.08);
  --shadow-lg: 0 8px 32px rgba(255, 146, 186, 0.12);
  --shadow-hover: 0 12px 40px rgba(255, 146, 186, 0.16);

  /* Typography */
  --font-sans: "Noto Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;

  /* Layout */
  --container-max: 1140px;
  --header-height: 64px;
  --radius: 12px;
  --radius-sm: 8px;
  --radius-lg: 20px;
  --radius-full: 999px;

  /* Transitions */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

/* ============================================
   Reset & Base
   ============================================ */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background-color: var(--bg);
  background-image:
    radial-gradient(ellipse 1000px 600px at 50% -100px, rgba(255, 146, 186, 0.08) 0%, transparent 60%),
    radial-gradient(ellipse 800px 500px at 90% 20%, rgba(255, 188, 213, 0.05) 0%, transparent 50%);
  background-repeat: no-repeat;
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

a:hover {
  color: var(--primary-hover);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.3;
  color: var(--text);
}

ul {
  list-style: none;
}

/* ============================================
   Layout
   ============================================ */

.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 80px 0;
}

.section-alt {
  background-color: var(--bg-alt);
}

.section-title {
  font-size: 32px;
  font-weight: 800;
  text-align: center;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.section-desc {
  text-align: center;
  color: var(--text-secondary);
  font-size: 16px;
  margin-bottom: 48px;
}

/* ============================================
   Buttons
   ============================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: inherit;
  font-size: 15px;
  font-weight: 600;
  line-height: 1;
  padding: 12px 24px;
  border-radius: var(--radius-full);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all 0.25s var(--ease);
  white-space: nowrap;
  text-decoration: none;
}

.btn-primary {
  background-color: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  border-color: var(--primary-hover);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
}

.btn-outline {
  background-color: transparent;
  color: var(--primary);
  border-color: var(--primary-light);
}

.btn-outline:hover {
  background-color: var(--primary-lighter);
  border-color: var(--primary);
  color: var(--primary-hover);
}

.btn-sm {
  font-size: 14px;
  padding: 8px 18px;
}

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

/* ============================================
   Header
   ============================================ */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  z-index: 1000;
  transition: border-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.site-header.scrolled {
  border-bottom-color: var(--border);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  gap: 16px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 20px;
  color: var(--text);
  letter-spacing: -0.01em;
  flex-shrink: 0;
}

.logo img {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
}

.logo:hover {
  color: var(--text);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 28px;
  margin-left: auto;
}

.main-nav a {
  font-size: 15px;
  font-weight: 500;
  color: var(--text-secondary);
  position: relative;
  transition: color 0.2s var(--ease);
}

.main-nav a::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
  transition: width 0.25s var(--ease);
}

.main-nav a:hover {
  color: var(--primary);
}

.main-nav a:hover::after {
  width: 100%;
}

.header-download {
  flex-shrink: 0;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 24px;
  color: var(--text);
  cursor: pointer;
  padding: 8px;
  border-radius: var(--radius-sm);
  transition: background 0.2s var(--ease);
}

.menu-toggle:hover {
  background: var(--primary-lighter);
}

/* ============================================
   Hero
   ============================================ */

.hero-section {
  padding-top: calc(var(--header-height) + 60px);
  padding-bottom: 60px;
  overflow: hidden;
}

.hero-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 48px;
}

.hero-content {
  flex: 1;
  max-width: 560px;
}

.hero-content h1 {
  font-size: 48px;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
  color: var(--text);
}

.hero-subtitle {
  font-size: 17px;
  line-height: 1.8;
  color: var(--text-secondary);
  margin-bottom: 28px;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 32px;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  background: var(--primary-lighter);
  border: 1px solid var(--primary-soft);
  border-radius: var(--radius-full);
  font-size: 14px;
  font-weight: 500;
  color: var(--primary-hover);
}

.hero-tag i {
  font-size: 16px;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-image {
  flex-shrink: 0;
  position: relative;
}

.hero-image img {
  width: 280px;
  height: auto;
  border-radius: 24px;
  box-shadow: var(--shadow-hover);
}

/* ============================================
   Screenshot Carousel
   ============================================ */

.screenshot-scroll {
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  -ms-overflow-style: none;
  padding-bottom: 8px;
}

.screenshot-scroll::-webkit-scrollbar {
  display: none;
}

.screenshot-track {
  display: flex;
  gap: 24px;
  padding: 8px 4px;
  width: max-content;
}

.screenshot-item {
  flex-shrink: 0;
  width: 280px;
}

.screenshot-item img {
  width: 100%;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 0.3s var(--ease-out);
}

.screenshot-item:hover img {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
}

.screenshot-item figcaption {
  text-align: center;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-top: 12px;
}

.screenshot-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  margin-top: 24px;
}

.screenshot-btn {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 2px solid var(--border);
  background: var(--bg);
  color: var(--text-secondary);
  font-size: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s var(--ease);
}

.screenshot-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-lighter);
}

.screenshot-dots {
  display: flex;
  gap: 8px;
}

.screenshot-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--border-hover);
  border: none;
  cursor: pointer;
  padding: 0;
  transition: all 0.25s var(--ease);
}

.screenshot-dot.active {
  width: 24px;
  border-radius: var(--radius-full);
  background: var(--primary);
}

/* ============================================
   Feature Grid
   ============================================ */

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

.feature-grid-2 {
  grid-template-columns: repeat(2, 1fr);
}

.feature-card-wide {
  grid-column: 1 / -1;
}

.feature-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  transition: all 0.3s var(--ease);
}

.feature-card:hover {
  border-color: var(--primary-light);
  box-shadow: var(--shadow);
  transform: translateY(-4px);
}

.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-sm);
  background: var(--primary-lighter);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  color: var(--primary);
  margin-bottom: 20px;
}

.feature-card h3 {
  font-size: 19px;
  font-weight: 700;
  margin-bottom: 10px;
}

.feature-card p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ============================================
   Review Grid
   ============================================ */

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

.review-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  transition: all 0.3s var(--ease);
}

.review-card:hover {
  border-color: var(--primary-light);
  box-shadow: var(--shadow);
  transform: translateY(-4px);
}

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

.review-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--primary-lighter);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  color: var(--primary);
  flex-shrink: 0;
}

.review-meta {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.review-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
}

.review-card__time {
  font-size: 13px;
  color: var(--text-tertiary);
}

.review-content {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ============================================
   Scene Grid
   ============================================ */

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

.scene-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 28px;
  text-align: center;
  transition: all 0.3s var(--ease);
}

.scene-card:hover {
  border-color: var(--primary-light);
  box-shadow: var(--shadow);
  transform: translateY(-4px);
}

.scene-icon {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary-lighter), var(--primary-soft));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 30px;
  color: var(--primary);
  margin: 0 auto 24px;
}

.scene-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
}

.scene-card p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ============================================
   FAQ
   ============================================ */

.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  border-bottom: 1px solid var(--border);
}

.faq-item:first-child {
  border-top: 1px solid var(--border);
}

.faq-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 4px;
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  list-style: none;
  transition: color 0.2s var(--ease);
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary:hover {
  color: var(--primary);
}

.faq-item summary i {
  font-size: 20px;
  color: var(--text-tertiary);
  transition: transform 0.25s var(--ease), color 0.2s var(--ease);
  flex-shrink: 0;
}

.faq-item[open] summary i {
  transform: rotate(180deg);
  color: var(--primary);
}

.faq-answer {
  padding: 0 4px 20px;
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
  animation: faqSlide 0.3s var(--ease-out);
}

@keyframes faqSlide {
  from {
    opacity: 0;
    transform: translateY(-8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============================================
   Download CTA
   ============================================ */

.download-section {
  text-align: center;
  background: linear-gradient(180deg, var(--bg) 0%, var(--primary-lighter) 100%);
}

.download-inner {
  max-width: 600px;
}

.download-section h2 {
  font-size: 32px;
  font-weight: 800;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.download-desc {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

.download-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ============================================
   Footer
   ============================================ */

.site-footer {
  background: var(--bg);
  border-top: 1px solid var(--border);
  padding: 40px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 16px;
  color: var(--text);
}

.footer-brand img {
  width: 24px;
  height: 24px;
  border-radius: 4px;
}

.footer-nav {
  display: flex;
  gap: 24px;
}

.footer-nav a {
  font-size: 14px;
  color: var(--text-secondary);
}

.footer-nav a:hover {
  color: var(--primary);
}

.footer-copyright {
  font-size: 13px;
  color: var(--text-tertiary);
}

/* ============================================
   Privacy Page
   ============================================ */

.privacy-main {
  padding-top: calc(var(--header-height) + 48px);
  padding-bottom: 60px;
}

.privacy-main h1 {
  font-size: 32px;
  font-weight: 800;
  margin-bottom: 8px;
}

.privacy-update {
  font-size: 14px;
  color: var(--text-tertiary);
  margin-bottom: 32px;
}

.privacy-main h2 {
  font-size: 20px;
  font-weight: 700;
  margin-top: 36px;
  margin-bottom: 12px;
}

.privacy-main p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 12px;
}

.privacy-main ul {
  padding-left: 20px;
  margin-bottom: 16px;
}

.privacy-main li {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 6px;
}

.privacy-main strong {
  color: var(--text);
}

/* ============================================
   404 Page
   ============================================ */

.error-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(180deg, var(--primary-lighter) 0%, var(--bg) 70%);
}

.error-inner {
  text-align: center;
}

.error-icon {
  font-size: 72px;
  color: var(--primary);
  margin-bottom: 24px;
}

.error-page h1 {
  font-size: 72px;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 16px;
  line-height: 1;
}

.error-desc {
  font-size: 17px;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

/* ============================================
   Scroll Animations
   ============================================ */

.fade-up {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s var(--ease-out), transform 0.6s var(--ease-out);
}

.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger animation for grid items */
.feature-card.fade-up,
.highlight-card.fade-up {
  transition-delay: calc(var(--i, 0) * 60ms);
}

.scene-card.fade-up {
  transition-delay: calc(var(--i, 0) * 100ms);
}

/* ============================================
   Responsive - Tablet
   ============================================ */

@media (max-width: 968px) {
  .hero-content h1 {
    font-size: 38px;
  }

  .hero-image img {
    width: 220px;
  }

  .feature-grid,
  .review-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .scene-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .section-title {
    font-size: 28px;
  }
}

/* ============================================
   Responsive - Mobile
   ============================================ */

@media (max-width: 768px) {
  .main-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--bg);
    flex-direction: column;
    align-items: stretch;
    padding: 16px 24px;
    gap: 0;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s var(--ease);
    margin-left: 0;
  }

  .main-nav.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .main-nav a {
    padding: 14px 0;
    border-bottom: 1px solid var(--border);
    font-size: 16px;
  }

  .main-nav a:last-child {
    border-bottom: none;
  }

  .main-nav a::after {
    display: none;
  }

  .header-download {
    display: none;
  }

  .menu-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .menu-toggle.active i {
    transform: rotate(90deg);
  }

  .menu-toggle i {
    transition: transform 0.25s var(--ease);
  }

  .hero-section {
    padding-top: calc(var(--header-height) + 32px);
    padding-bottom: 40px;
  }

  .hero-inner {
    flex-direction: column;
    text-align: center;
    gap: 32px;
  }

  .hero-content {
    max-width: 100%;
  }

  .hero-content h1 {
    font-size: 32px;
  }

  .hero-subtitle {
    font-size: 15px;
  }

  .hero-tags {
    justify-content: center;
  }

  .hero-buttons {
    justify-content: center;
  }

  .hero-image img {
    width: 200px;
  }

  .section {
    padding: 56px 0;
  }

  .section-title {
    font-size: 24px;
  }

  .section-desc {
    font-size: 15px;
    margin-bottom: 36px;
  }

  .feature-grid,
  .review-grid,
  .scene-grid {
    grid-template-columns: 1fr;
  }

  .feature-card,
  .scene-card,
  .review-card {
    padding: 24px 20px;
  }

  .screenshot-item {
    width: 240px;
  }

  .download-buttons {
    flex-direction: column;
    align-items: stretch;
  }

  .download-buttons .btn {
    width: 100%;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }

  .footer-nav {
    justify-content: center;
    flex-wrap: wrap;
  }

  .privacy-main {
    padding-top: calc(var(--header-height) + 32px);
  }

  .privacy-main h1 {
    font-size: 26px;
  }
}

/* ============================================
   Responsive - Small Mobile
   ============================================ */

@media (max-width: 380px) {
  .hero-content h1 {
    font-size: 28px;
  }

  .hero-tag {
    font-size: 13px;
    padding: 6px 12px;
  }

  .btn {
    font-size: 14px;
    padding: 11px 20px;
  }
}

/* ============================================
   Reduced Motion
   ============================================ */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .fade-up {
    opacity: 1;
    transform: none;
  }
}