/* ===================== 设计 Token ===================== */
:root {
  /* 主色 */
  --c-primary: #7C3AED;
  --c-primary-2: #8B5CF6;
  --c-primary-3: #6D28D9;
  /* 辅色 */
  --c-accent: #EC4899;
  --c-accent-2: #6366F1;
  /* 背景层 */
  --bg-1: #FAF5FF;
  --bg-2: #FDF4FF;
  --bg-3: #F5F3FF;
  --bg-alt: #FFFFFF;
  /* 文字 */
  --text-1: #1F2937;
  --text-2: #334155;
  --text-3: #64748B;
  --text-4: #94A3B8;
  --text-inv: #FFFFFF;
  /* 渐变 */
  --grad-primary: linear-gradient(135deg, #7C3AED, #8B5CF6);
  --grad-logo: linear-gradient(135deg, #6366F1, #EC4899);
  --grad-cta: linear-gradient(135deg, #6D28D9, #7C3AED 55%, #EC4899);
  /* 圆角 */
  --r-sm: 8px;
  --r-md: 16px;
  --r-lg: 24px;
  --r-pill: 9999px;
  /* 阴影 */
  --shadow-sm: 0 4px 14px rgba(124, 58, 237, 0.08);
  --shadow-md: 0 8px 30px rgba(124, 58, 237, 0.12);
  --shadow-lg: 0 20px 50px rgba(124, 58, 237, 0.18);
  /* 玻璃 */
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-blur: blur(20px);
  /* 布局 */
  --container: 1140px;
  --nav-h: 68px;
}

/* ===================== 全局重置 ===================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: var(--nav-h); }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text-2);
  background: var(--bg-1);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
img, svg { display: block; max-width: 100%; }
button { font: inherit; cursor: pointer; border: none; background: none; }

.container { width: 100%; max-width: var(--container); margin: 0 auto; padding: 0 24px; }

/* ===================== 按钮 ===================== */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 24px; border-radius: var(--r-pill); font-weight: 600; font-size: 15px;
  transition: transform .25s ease, box-shadow .25s ease, background .25s ease;
  white-space: nowrap;
}
.btn-sm { padding: 8px 18px; font-size: 14px; }
.btn-lg { padding: 14px 32px; font-size: 16px; }
.btn-primary { background: var(--grad-primary); color: var(--text-inv); box-shadow: var(--shadow-md); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.btn-ghost { background: rgba(255,255,255,0.85); color: var(--c-primary); border: 1.5px solid rgba(124,58,237,0.25); }
.btn-ghost:hover { background: #fff; border-color: var(--c-primary); transform: translateY(-2px); }
.btn-light { background: #fff; color: var(--c-primary-3); box-shadow: var(--shadow-md); }
.btn-light:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.btn-outline-light { background: transparent; color: #fff; border: 1.5px solid rgba(255,255,255,0.6); }
.btn-outline-light:hover { background: rgba(255,255,255,0.12); border-color: #fff; }

/* ===================== 导航 ===================== */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  height: var(--nav-h);
  background: rgba(250, 245, 255, 0.72);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid rgba(124,58,237,0.08);
  transition: box-shadow .3s ease;
}
.nav.scrolled { box-shadow: var(--shadow-sm); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 100%; }
.brand { display: flex; align-items: center; gap: 10px; }
.brand-logo { display: flex; filter: drop-shadow(0 4px 10px rgba(99,102,241,0.3)); }
.brand-text { font-weight: 800; font-size: 20px; color: var(--text-1); letter-spacing: -0.5px; }
.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-links a { font-weight: 500; color: var(--text-2); transition: color .2s; }
.nav-links a:not(.btn):hover { color: var(--c-primary); }
.nav-toggle { display: none; flex-direction: column; gap: 5px; padding: 6px; }
.nav-toggle span { width: 24px; height: 2px; background: var(--text-1); border-radius: 2px; transition: .3s; }
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===================== Hero ===================== */
.hero {
  position: relative; min-height: 100vh; display: flex; align-items: center; justify-content: center;
  text-align: center; padding: calc(var(--nav-h) + 40px) 24px 80px;
  background: var(--grad-primary);
  overflow: hidden;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(circle at 20% 30%, rgba(236,72,153,0.35), transparent 45%),
    radial-gradient(circle at 80% 70%, rgba(99,102,241,0.35), transparent 45%);
  pointer-events: none;
}
.hero-bg { position: absolute; inset: 0; pointer-events: none; }
.float-emoji {
  position: absolute; left: var(--x); top: -40px; font-size: 32px; opacity: 0.85;
  animation: floatUp var(--dur) var(--d) ease-in infinite;
}
@keyframes floatUp {
  0%   { transform: translateY(0) rotate(0deg); opacity: 0; }
  10%  { opacity: 0.85; }
  90%  { opacity: 0.85; }
  100% { transform: translateY(110vh) rotate(20deg); opacity: 0; }
}
.hero-inner { position: relative; z-index: 1; max-width: 760px; }
.hero-badge {
  display: inline-block; padding: 7px 16px; border-radius: var(--r-pill);
  background: rgba(255,255,255,0.18); border: 1px solid rgba(255,255,255,0.3);
  color: #fff; font-size: 13px; font-weight: 500; letter-spacing: 0.5px;
  backdrop-filter: blur(10px); margin-bottom: 28px;
}
.hero-title {
  font-size: clamp(56px, 12vw, 120px); font-weight: 800; color: #fff;
  letter-spacing: -2px; line-height: 1; margin-bottom: 12px;
  text-shadow: 0 8px 30px rgba(0,0,0,0.15);
}
.hero-tagline {
  font-size: clamp(20px, 4vw, 30px); font-weight: 600; color: rgba(255,255,255,0.95);
  margin-bottom: 24px; font-style: italic;
}
.hero-desc {
  font-size: clamp(15px, 2.2vw, 18px); color: rgba(255,255,255,0.88);
  max-width: 560px; margin: 0 auto 40px;
}
.hero-cta { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; margin-bottom: 48px; }
.hero-meta { display: flex; gap: 40px; justify-content: center; flex-wrap: wrap; }
.hero-meta span { color: rgba(255,255,255,0.85); font-size: 14px; }
.hero-meta strong { display: block; font-size: 28px; color: #fff; font-weight: 800; }
.scroll-hint {
  position: absolute; bottom: 28px; left: 50%; transform: translateX(-50%);
  width: 26px; height: 42px; border: 2px solid rgba(255,255,255,0.6); border-radius: 14px;
  display: flex; justify-content: center; padding-top: 8px;
}
.scroll-hint span {
  width: 4px; height: 8px; background: #fff; border-radius: 2px;
  animation: scrollDot 1.6s ease-in-out infinite;
}
@keyframes scrollDot { 0%,100% { transform: translateY(0); opacity: 1; } 50% { transform: translateY(12px); opacity: 0.3; } }

/* ===================== 通用 Section ===================== */
.section { padding: 100px 0; position: relative; }
.section-alt { background: var(--bg-alt); }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 64px; }
.section-tag {
  display: inline-block; padding: 5px 14px; border-radius: var(--r-pill);
  background: rgba(124,58,237,0.1); color: var(--c-primary); font-size: 13px; font-weight: 600;
  letter-spacing: 0.5px; margin-bottom: 18px;
}
.section-title { font-size: clamp(28px, 4vw, 40px); font-weight: 800; color: var(--text-1); letter-spacing: -0.5px; margin-bottom: 16px; }
.section-sub { font-size: 16px; color: var(--text-3); }

/* ===================== 功能卡 ===================== */
.feature-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
}
.feature-card {
  background: #fff; border-radius: var(--r-lg); padding: 36px 30px;
  border: 1px solid rgba(124,58,237,0.06);
  box-shadow: var(--shadow-sm);
  transition: transform .3s ease, box-shadow .3s ease, border-color .3s ease;
}
.feature-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: rgba(124,58,237,0.18); }
.feature-icon {
  width: 56px; height: 56px; border-radius: var(--r-md);
  background: var(--grad-primary); color: #fff;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 22px; box-shadow: 0 8px 20px rgba(124,58,237,0.25);
}
.feature-card h3 { font-size: 19px; font-weight: 700; color: var(--text-1); margin-bottom: 10px; }
.feature-card p { font-size: 15px; color: var(--text-3); line-height: 1.65; }

/* ===================== 使用流程 ===================== */
.steps { display: flex; align-items: stretch; justify-content: center; gap: 12px; flex-wrap: wrap; }
.step {
  flex: 1; min-width: 220px; max-width: 280px;
  background: #fff; border-radius: var(--r-lg); padding: 36px 28px; text-align: center;
  box-shadow: var(--shadow-sm); border: 1px solid rgba(124,58,237,0.06);
  position: relative;
}
.step-num {
  width: 48px; height: 48px; border-radius: 50%; margin: 0 auto 20px;
  background: var(--grad-logo); color: #fff; font-size: 20px; font-weight: 800;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 6px 16px rgba(236,72,153,0.3);
}
.step h3 { font-size: 18px; font-weight: 700; color: var(--text-1); margin-bottom: 8px; }
.step p { font-size: 14px; color: var(--text-3); }
.step-arrow { display: flex; align-items: center; color: var(--c-primary); opacity: 0.5; }

/* ===================== 产品预览 ===================== */
.preview-inner { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: center; }
.preview-text .section-tag,
.preview-text .section-title,
.preview-text .section-sub { text-align: left; }
.preview-text .section-sub { margin-bottom: 28px; }
.preview-list { margin-bottom: 32px; }
.preview-list li { display: flex; align-items: center; gap: 12px; padding: 10px 0; color: var(--text-2); font-size: 15px; }
.dot { width: 8px; height: 8px; border-radius: 50%; background: var(--grad-primary); flex-shrink: 0; }

/* 手机框 */
.phone-wrap { position: relative; display: flex; justify-content: center; }
.phone-glow {
  position: absolute; inset: -40px; border-radius: 50%;
  background: radial-gradient(circle, rgba(139,92,246,0.35), transparent 70%);
  filter: blur(30px); z-index: 0;
}
.phone {
  position: relative; z-index: 1; width: 320px; height: 640px;
  background: #1a1a2e; border-radius: 44px; padding: 12px;
  box-shadow: 0 30px 60px rgba(0,0,0,0.3), inset 0 0 0 2px rgba(255,255,255,0.05);
  transform: rotate(-3deg);
}
.phone-notch {
  position: absolute; top: 18px; left: 50%; transform: translateX(-50%);
  width: 120px; height: 22px; background: #1a1a2e; border-radius: 0 0 16px 16px; z-index: 3;
}
.phone-screen {
  width: 100%; height: 100%; background: var(--bg-1); border-radius: 34px;
  overflow: hidden; display: flex; flex-direction: column;
}
.chat-header {
  display: flex; align-items: center; gap: 8px; padding: 18px 18px 14px;
  background: var(--grad-primary); color: #fff;
}
.chat-back { font-size: 24px; line-height: 1; opacity: 0.9; }
.chat-title { font-weight: 700; font-size: 16px; flex: 1; }
.chat-room { font-size: 12px; background: rgba(255,255,255,0.2); padding: 3px 8px; border-radius: var(--r-pill); }
.chat-body { flex: 1; padding: 16px 14px; overflow: hidden; display: flex; flex-direction: column; gap: 12px; background: var(--bg-1); }
.sys-msg { text-align: center; font-size: 11px; color: var(--text-4); padding: 4px 0; }
.bubble { max-width: 78%; padding: 9px 13px; border-radius: 16px; font-size: 13px; line-height: 1.5; }
.bubble p { word-break: break-word; }
.bubble-left { align-self: flex-start; background: #fff; color: var(--text-1); border-bottom-left-radius: 4px; box-shadow: 0 2px 8px rgba(0,0,0,0.04); }
.bubble-right { align-self: flex-end; background: var(--grad-primary); color: #fff; border-bottom-right-radius: 4px; }
.bubble-author { display: block; font-size: 11px; color: var(--c-primary); margin-bottom: 2px; font-weight: 600; }
.bubble.sticker { background: none; padding: 4px; align-self: flex-start; box-shadow: none; }
.sticker-emoji { font-size: 36px; }
.ai-card {
  align-self: flex-start; max-width: 88%; background: #fff; border-radius: 14px; padding: 12px 14px;
  border: 1px solid rgba(124,58,237,0.15); box-shadow: 0 4px 14px rgba(124,58,237,0.08);
}
.ai-card-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 10px; }
.ai-tag { font-size: 11px; font-weight: 700; color: var(--c-primary); background: rgba(124,58,237,0.1); padding: 3px 8px; border-radius: var(--r-pill); }
.ai-conf { font-size: 11px; color: var(--text-4); }
.ai-emotion { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 8px; }
.emo-chip { font-size: 11px; padding: 3px 9px; border-radius: var(--r-pill); background: var(--bg-3); color: var(--text-3); }
.emo-accent { background: rgba(236,72,153,0.12); color: var(--c-accent); font-weight: 600; }
.ai-bar { height: 5px; background: var(--bg-3); border-radius: 3px; overflow: hidden; margin-bottom: 10px; }
.ai-bar span { display: block; height: 100%; background: var(--grad-logo); border-radius: 3px; }
.ai-suggest { font-size: 12px; color: var(--text-2); line-height: 1.5; }
.chat-input {
  display: flex; align-items: center; gap: 8px; padding: 12px 14px;
  background: #fff; border-top: 1px solid rgba(0,0,0,0.04);
}
.input-emoji { font-size: 20px; }
.input-field { flex: 1; font-size: 13px; color: var(--text-4); }
.input-send { font-size: 13px; font-weight: 600; color: var(--c-primary); padding: 6px 12px; background: rgba(124,58,237,0.1); border-radius: var(--r-pill); }

/* ===================== CTA 区 ===================== */
.cta-section {
  padding: 100px 24px;
  background: var(--grad-cta);
  position: relative; overflow: hidden;
}
.cta-section::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(circle at 15% 20%, rgba(255,255,255,0.15), transparent 40%),
    radial-gradient(circle at 85% 80%, rgba(255,255,255,0.12), transparent 40%);
}
.cta-inner { position: relative; text-align: center; max-width: 680px; margin: 0 auto; }
.cta-title { font-size: clamp(28px, 4.5vw, 42px); font-weight: 800; color: #fff; margin-bottom: 16px; letter-spacing: -0.5px; }
.cta-sub { font-size: 17px; color: rgba(255,255,255,0.9); margin-bottom: 36px; }
.cta-buttons { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

/* ===================== 页脚 ===================== */
.footer { background: #1a1626; color: rgba(255,255,255,0.7); padding: 56px 0 40px; }
.footer-inner { text-align: center; }
.footer-brand { display: flex; align-items: center; justify-content: center; gap: 10px; margin-bottom: 14px; color: #fff; font-weight: 600; }
.footer-meta { font-size: 14px; color: rgba(255,255,255,0.5); margin-bottom: 8px; }
.footer-copy { font-size: 13px; color: rgba(255,255,255,0.4); }

/* ===================== 滚动入场动画 ===================== */
[data-reveal] {
  opacity: 0; transform: translateY(30px);
  transition: opacity .7s ease, transform .7s ease;
}
[data-reveal].in { opacity: 1; transform: translateY(0); }

/* ===================== 响应式 ===================== */
@media (max-width: 1024px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .preview-inner { grid-template-columns: 1fr; gap: 48px; }
  .preview-text { text-align: center; }
  .preview-text .section-tag,
  .preview-text .section-title,
  .preview-text .section-sub { text-align: center; }
  .preview-list { display: inline-block; text-align: left; }
}

@media (max-width: 768px) {
  .nav-links {
    position: fixed; top: var(--nav-h); left: 0; right: 0;
    flex-direction: column; gap: 0; background: rgba(255,255,255,0.96);
    backdrop-filter: var(--glass-blur); padding: 8px 24px 24px;
    border-bottom: 1px solid rgba(124,58,237,0.1);
    transform: translateY(-130%); transition: transform .35s ease; align-items: stretch;
  }
  .nav-links.open { transform: translateY(0); }
  .nav-links a { padding: 14px 0; border-bottom: 1px solid rgba(124,58,237,0.06); }
  .nav-links .btn { margin-top: 14px; border-bottom: none; }
  .nav-toggle { display: flex; }

  .section { padding: 70px 0; }
  .section-head { margin-bottom: 44px; }
  .feature-grid { grid-template-columns: 1fr; }

  .steps { flex-direction: column; align-items: center; }
  .step { width: 100%; max-width: 360px; }
  .step-arrow { transform: rotate(90deg); padding: 4px 0; }

  .hero-meta { gap: 24px; }
  .phone { width: 280px; height: 560px; transform: rotate(0deg); }
}

@media (max-width: 480px) {
  .hero-cta { flex-direction: column; width: 100%; }
  .hero-cta .btn { width: 100%; }
  .cta-buttons { flex-direction: column; width: 100%; }
  .cta-buttons .btn { width: 100%; }
}

/* 触发动画的逐项延迟（JS 会加 .in） */
.feature-card.in:nth-child(2) { transition-delay: .08s; }
.feature-card.in:nth-child(3) { transition-delay: .16s; }
.feature-card.in:nth-child(4) { transition-delay: .08s; }
.feature-card.in:nth-child(5) { transition-delay: .16s; }
.feature-card.in:nth-child(6) { transition-delay: .24s; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  [data-reveal] { opacity: 1; transform: none; }
}