/* ============================================================
   Driiiip 万词通官网 - 公共样式
   主色 #1A6EFF · 苹果风格留白 · Inter + PingFang SC
   ============================================================ */

:root {
  --primary: #1A6EFF;
  --primary-dark: #0051D0;
  --primary-light: #EFF6FF;
  --text-main: #1D1D1F;
  --text-sub: #86868B;
  --text-muted: #A1A1A6;
  --bg-main: #FFFFFF;
  --bg-soft: #F5F5F7;
  --bg-blue: #EFF6FF;
  --border: #E5E5E7;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 8px 30px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 20px 60px rgba(26, 110, 255, 0.12);
  --radius-sm: 12px;
  --radius-md: 20px;
  --radius-lg: 32px;
  --max-width: 1180px;
}

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

html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Helvetica Neue', sans-serif;
  background: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  font-size: 16px;
  letter-spacing: -0.01em;
}

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

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

/* ============ 顶部导航 ============ */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
}
.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-brand {
  font-size: 26px;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: 2px;
  letter-spacing: 1px;
}
.nav-brand span { color: var(--primary); font-weight: 600; }
/* Driiiip 品牌文字动画 */
.brand-text {
  display: inline-flex;
  align-items: baseline;
}
.brand-dot {
  display: inline-block;
  transform-origin: bottom center;
  color: var(--primary);
}
/* 默认自动跳动，hover 时停止并平滑复原 */
.nav-brand .brand-dot-1 { animation: dotDance1 2.3s ease-in-out infinite; }
.nav-brand .brand-dot-2 { animation: dotDance2 3.1s ease-in-out infinite; animation-delay: 0.4s; }
.nav-brand .brand-dot-3 { animation: dotDance3 2.7s ease-in-out infinite; animation-delay: 0.9s; }
.nav-brand .brand-dot-4 { animation: dotDance4 3.5s ease-in-out infinite; animation-delay: 0.2s; }
/* hover 时：动画停止，颜色用 transition 平滑过渡回蓝色 */
.nav-brand:hover .brand-dot {
  animation-play-state: paused;
  color: var(--primary);
  transition: color 0.5s ease, transform 0.5s ease, opacity 0.5s ease;
}
.nav-brand:hover .brand-char-d { color: var(--primary); transition: color 0.5s; }
@keyframes dotDance1 {
  0%,100% { transform: translateY(0) scaleY(1); opacity: 1; color: var(--primary); }
  20% { transform: translateY(-4px) scaleY(1.1); opacity: .85; color: #22D3EE; }
  45% { transform: translateY(1px) scaleY(0.95); color: #06B6D4; }
  70% { transform: translateY(-2px) scaleY(1.05); opacity: .9; color: #22D3EE; }
}
@keyframes dotDance2 {
  0%,100% { transform: translateY(0) scale(1); color: var(--primary); }
  25% { transform: translateY(3px) scale(0.92); opacity: .75; color: #A78BFA; }
  55% { transform: translateY(-5px) scale(1.08); opacity: 1; color: #8B5CF6; }
  80% { transform: translateY(0) scale(1); color: #A78BFA; }
}
@keyframes dotDance3 {
  0%,100% { transform: translateY(0) rotate(0deg); color: var(--primary); }
  30% { transform: translateY(-3px) rotate(4deg); opacity: .9; color: #34D399; }
  60% { transform: translateY(2px) rotate(-2deg); color: #10B981; }
}
@keyframes dotDance4 {
  0%,100% { transform: translateY(0) scaleY(1); opacity: 1; color: var(--primary); }
  15% { transform: translateY(2px) scaleY(0.9); opacity: .7; color: #F472B6; }
  40% { transform: translateY(-6px) scaleY(1.12); opacity: 1; color: #EC4899; }
  65% { transform: translateY(0) scaleY(1); color: #F472B6; }
  85% { transform: translateY(-1px); opacity: .9; color: #F472B6; }
}
.nav-links {
  display: flex;
  gap: 32px;
  list-style: none;
}
.nav-links a {
  font-size: 15px;
  color: var(--text-sub);
  font-weight: 500;
}
.nav-links a:hover { color: var(--text-main); }
.nav-cta {
  background: var(--primary);
  color: #fff !important;
  padding: 8px 18px;
  border-radius: 980px;
  font-size: 14px;
  font-weight: 500;
  transition: background 0.2s, transform 0.2s;
}
.nav-cta:hover { background: var(--primary-dark); transform: scale(0.97); }
@media (max-width: 640px) {
  .nav-links { display: none; }
}

/* ============ 通用容器 ============ */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}
.section { padding: 100px 0; }
.section-soft { background: var(--bg-soft); }
.section-blue { background: var(--bg-blue); }
@media (max-width: 768px) {
  .section { padding: 64px 0; }
}

/* ============ 标题层级 ============ */
.eyebrow {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  color: var(--primary);
  background: var(--primary-light);
  padding: 6px 14px;
  border-radius: 980px;
  margin-bottom: 20px;
  letter-spacing: 0.02em;
}
.h1 {
  font-size: clamp(36px, 5.5vw, 56px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--text-main);
}
.h2 {
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.025em;
  color: var(--text-main);
}
.h3 {
  font-size: clamp(22px, 2.5vw, 28px);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text-main);
}
.lead {
  font-size: clamp(18px, 2vw, 24px);
  color: var(--text-sub);
  line-height: 1.5;
  font-weight: 400;
  margin-top: 16px;
}
.text-center { text-align: center; }
.mt-16 { margin-top: 16px; } .mt-24 { margin-top: 24px; } .mt-40 { margin-top: 40px; } .mt-64 { margin-top: 64px; }

/* ============ 按钮 ============ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 980px;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.25s;
  border: none;
  font-family: inherit;
}
.btn-primary {
  background: var(--primary);
  color: #fff;
}
.btn-primary:hover { background: var(--primary-dark); color: #fff; transform: scale(0.97); }
.btn-ghost {
  background: transparent;
  color: var(--primary);
  border: 1px solid var(--primary);
}
.btn-ghost:hover { background: var(--primary-light); }
.btn-white {
  background: #fff;
  color: var(--text-main);
  box-shadow: var(--shadow-sm);
}
.btn-white:hover { transform: scale(0.97); }
.btn-lg { padding: 16px 36px; font-size: 17px; }

/* ============ 卡片 ============ */
.card {
  background: #fff;
  border-radius: var(--radius-md);
  padding: 44px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.04), 0 1px 3px rgba(0, 0, 0, 0.03);
  transition: transform 0.35s cubic-bezier(0.2, 0.8, 0.2, 1), box-shadow 0.35s ease;
  border: 1px solid var(--border);
  position: relative;
}
.card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.10), 0 4px 12px rgba(26, 110, 255, 0.08);
  border-color: rgba(26, 110, 255, 0.20);
}
/* 卡片数字编号 */
.card-num {
  position: absolute;
  top: 24px;
  right: 28px;
  font-size: 48px;
  font-weight: 800;
  color: var(--primary-light);
  letter-spacing: -0.04em;
  line-height: 1;
  z-index: 0;
}
.card > * { position: relative; z-index: 1; }
.card-icon {
  width: 72px;
  height: 72px;
  border-radius: 20px;
  background: var(--primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--primary);
  box-shadow: 0 8px 20px rgba(26, 110, 255, 0.18), 0 2px 6px rgba(26, 110, 255, 0.10);
}
.card-icon svg { width: 52px; height: 52px; }
/* 小图标（用于 .tag 内） */
.tag svg { width: 32px; height: 32px; vertical-align: -6px; margin-right: 8px; }
/* 步骤数字旁的图标 */
.step-icon { width: 72px; height: 72px; border-radius: 20px; background: var(--primary-light); display: inline-flex; align-items: center; justify-content: center; color: var(--primary); margin-bottom: 16px; box-shadow: 0 8px 20px rgba(26, 110, 255, 0.18), 0 2px 6px rgba(26, 110, 255, 0.10); }
.step-icon svg { width: 52px; height: 52px; }
.card-title {
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--text-main);
}
.card-desc {
  color: var(--text-sub);
  font-size: 16px;
  line-height: 1.55;
}

/* ============ 网格 ============ */
.grid {
  display: grid;
  gap: 28px;
}
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 900px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}

/* ============ Hero ============ */
.hero {
  padding: 140px 0 100px;
  text-align: center;
  background: linear-gradient(180deg, var(--bg-blue) 0%, #fff 100%);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: -200px;
  left: 50%;
  transform: translateX(-50%);
  width: 900px;
  height: 600px;
  background: radial-gradient(ellipse at center, rgba(26, 110, 255, 0.18) 0%, rgba(26, 110, 255, 0.06) 40%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}
.hero .container { position: relative; z-index: 1; }
.hero h1 { margin-bottom: 0; }
.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  margin-top: 40px;
  flex-wrap: wrap;
}
.hero-shot {
  margin: 72px auto 0;
  max-width: 720px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 30px 80px rgba(26, 110, 255, 0.20), 0 10px 30px rgba(0, 0, 0, 0.08);
  background: var(--bg-soft);
}
.hero-shot img { width: 100%; }

/* ============ 数据展示 ============ */
.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
  text-align: center;
}
.stat-num {
  font-size: clamp(40px, 5vw, 64px);
  font-weight: 700;
  color: var(--primary);
  letter-spacing: -0.03em;
  line-height: 1;
}
.stat-label {
  margin-top: 12px;
  color: var(--text-sub);
  font-size: 16px;
}
@media (max-width: 600px) {
  .stats { grid-template-columns: 1fr; gap: 32px; }
}

/* ============ 功能截图展示 ============ */
.shot-frame {
  background: var(--bg-soft);
  border-radius: var(--radius-lg);
  padding: 40px;
  text-align: center;
  margin: 0 auto;
}
.shot-frame img {
  max-width: 380px;
  margin: 0 auto;
  border-radius: 24px;
  box-shadow: var(--shadow-md);
}

/* ============ 适合人群标签 ============ */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}
.tag {
  display: inline-block;
  padding: 8px 16px;
  background: var(--bg-soft);
  color: var(--text-sub);
  border-radius: 980px;
  font-size: 14px;
  font-weight: 500;
}

/* ============ 扫码区（深色背景） ============ */
.cta {
  background: linear-gradient(135deg, #0A1929 0%, #0F2942 50%, #0A1929 100%);
  border-radius: var(--radius-lg);
  padding: 80px 48px;
  text-align: center;
  color: #fff;
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(26, 110, 255, 0.25);
}
.cta::before {
  content: '';
  position: absolute;
  top: -100px;
  left: 50%;
  transform: translateX(-50%);
  width: 700px;
  height: 400px;
  background: radial-gradient(ellipse at center, rgba(26, 110, 255, 0.35) 0%, transparent 70%);
  pointer-events: none;
}
.cta > * { position: relative; z-index: 1; }
.cta h2 { color: #fff; }
.cta p { color: rgba(255, 255, 255, 0.78); margin-top: 16px; font-size: 18px; }
.cta-qr {
  width: 180px;
  height: 180px;
  background: #fff;
  border-radius: 24px;
  padding: 14px;
  margin: 36px auto 16px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
}
.cta-qr img { width: 100%; height: 100%; border-radius: 14px; }
.cta-hint { font-size: 14px; color: rgba(255, 255, 255, 0.65); }

/* ============ FAQ ============ */
.faq-list { max-width: 820px; margin: 0 auto; }
.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 24px 0;
}
.faq-q {
  font-size: 19px;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 12px;
  display: flex;
  gap: 12px;
  align-items: flex-start;
}
.faq-q::before {
  content: 'Q';
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  background: var(--primary);
  color: #fff;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 700;
}
.faq-a {
  color: var(--text-sub);
  font-size: 16px;
  line-height: 1.7;
  padding-left: 40px;
}

/* ============ 页脚 ============ */
.footer {
  background: var(--bg-soft);
  padding: 48px 0 32px;
  border-top: 1px solid var(--border);
}
.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}
.footer-brand {
  font-weight: 800;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 2px;
  font-size: 24px;
  letter-spacing: 1px;
}
.footer-brand span { color: var(--primary); font-weight: 600; }
.footer-brand .brand-dot { color: var(--primary); }
.footer-brand .brand-dot-1 { animation: dotDance1 2.3s ease-in-out infinite; }
.footer-brand .brand-dot-2 { animation: dotDance2 3.1s ease-in-out infinite; animation-delay: 0.4s; }
.footer-brand .brand-dot-3 { animation: dotDance3 2.7s ease-in-out infinite; animation-delay: 0.9s; }
.footer-brand .brand-dot-4 { animation: dotDance4 3.5s ease-in-out infinite; animation-delay: 0.2s; }
.footer-brand:hover .brand-dot {
  animation-play-state: paused;
  color: var(--primary);
  transition: color 0.5s ease, transform 0.5s ease, opacity 0.5s ease;
}
.footer-copy {
  color: var(--text-muted);
  font-size: 14px;
}
.footer-links {
  display: flex;
  gap: 24px;
  font-size: 14px;
}
.footer-links a { color: var(--text-sub); }

/* ============ 动画 ============ */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}
.fade-up { animation: fadeUp 0.7s ease-out both; }
.fade-up-1 { animation-delay: 0.1s; }
.fade-up-2 { animation-delay: 0.2s; }
.fade-up-3 { animation-delay: 0.3s; }

/* 滚动淡入 */
.reveal { opacity: 0; transform: translateY(30px); transition: opacity 0.8s ease, transform 0.8s ease; }
.reveal.in { opacity: 1; transform: translateY(0); }

/* ============ 居中卡片（完整生态区） ============ */
.card-center {
  text-align: center;
}
.card-center .card-icon {
  margin-left: auto;
  margin-right: auto;
}

/* ============ 移动端优化 ============ */
@media (max-width: 768px) {
  .card { padding: 28px; }
  .card-icon { width: 56px; height: 56px; border-radius: 16px; margin-bottom: 16px; }
  .card-icon svg { width: 40px; height: 40px; }
  .card-num { font-size: 36px; top: 16px; right: 20px; }
  .card-title { font-size: 19px; }
  .card-desc { font-size: 15px; }
  .hero { padding: 80px 0 60px; }
  .hero::before { width: 600px; height: 400px; top: -150px; }
  .hero-shot { margin: 48px auto 0; }
  .cta { padding: 56px 24px; }
  .cta::before { width: 500px; height: 300px; }
  .nav-inner { padding: 12px 16px; }
  .nav-brand { font-size: 20px; }
  .footer-brand { font-size: 20px; }
  .section { padding: 56px 0; }
  .grid { gap: 16px; }
  .footer-inner { flex-direction: column; text-align: center; }
}
@media (max-width: 480px) {
  .container { padding: 0 16px; }
  .card { padding: 22px; }
  .card-icon { width: 48px; height: 48px; }
  .card-icon svg { width: 32px; height: 32px; }
  .btn-lg { padding: 14px 28px; font-size: 15px; }
}