/* === 地铁逃生辅助 - Clay 设计系统 === */

:root {
  /* Clay 核心色 */
  --cream: #faf9f7;
  --black: #000000;
  --white: #ffffff;
  --silver: #9f9b93;
  --charcoal: #55534e;

  /* 色块调色板 */
  --ube-800: #43089f;
  --ube-900: #32037d;
  --ube-300: #c1b0ff;
  --pomegranate-400: #fc7981;
  --slushie-500: #3bd3fd;
  --slushie-800: #0089ad;
  --matcha-600: #078a52;
  --matcha-800: #02492a;
  --lemon-400: #f8cc65;
  --lemon-500: #fbbd41;
  --blueberry-800: #01418d;

  /* 边框 */
  --oat: #dad4c8;
  --oat-light: #eee9df;

  /* 阴影 */
  --shadow-clay: rgba(0,0,0,0.1) 0px 1px 1px,
                rgba(0,0,0,0.04) 0px -1px 1px inset,
                rgba(0,0,0,0.05) 0px -0.5px 1px;
  --shadow-hard: rgb(0,0,0) -7px 7px;

  /* 圆角 */
  --r-btn: 12px;
  --r-card: 24px;
  --r-section: 40px;
  --r-pill: 1584px;
}

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

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

html:not(.dpdo) body {
            filter: blur(10px);
            -webkit-filter: blur(10px);
        }
        body {
            transition: filter 0.5s ease, opacity 0.5s ease;
        }

body {
  font-family: 'DM Sans', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  font-size: 18px;
  font-weight: 400;
  line-height: 1.6;
  letter-spacing: -0.36px;
  color: var(--black);
  background: var(--cream);
}

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

/* === 导航 === */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 249, 247, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--oat);
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 14px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.36px;
  color: var(--black);
}

/* === 按钮系统 === */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 22px;
  border-radius: var(--r-btn);
  font-size: 16px;
  font-weight: 500;
  letter-spacing: -0.16px;
  cursor: pointer;
  border: none;
  transition: all 0.25s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  position: relative;
}

.btn:hover {
  transform: rotateZ(-2deg) translateY(-2px);
  box-shadow: var(--shadow-hard);
}

.btn:active {
  transform: rotateZ(0) translateY(0);
  box-shadow: var(--shadow-clay);
}

.btn-primary {
  background: var(--lemon-500);
  color: var(--black);
}

.btn-primary:hover {
  background: var(--lemon-400);
}

.btn-dark {
  background: var(--ube-800);
  color: var(--white);
}

.btn-dark:hover {
  background: var(--ube-900);
}

.btn-red {
  background: var(--pomegranate-400);
  color: var(--white);
}

.btn-red:hover {
  background: #e85d66;
}

.btn-outline {
  background: transparent;
  color: var(--black);
  border: 2px solid var(--black);
}

.btn-outline:hover {
  background: var(--black);
  color: var(--white);
}

.btn-outline-white {
  background: transparent;
  color: var(--white);
  border: 2px solid rgba(255,255,255,0.5);
}

.btn-outline-white:hover {
  background: var(--white);
  color: var(--black);
}

.btn-lg {
  padding: 14px 32px;
  font-size: 20px;
  letter-spacing: -0.4px;
}

/* === 章节 === */
.section {
  padding: 100px 0;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 28px;
}

/* === Hero（奶油底 + 色块装饰） === */
.hero {
  padding: 100px 0 80px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -120px;
  right: -80px;
  width: 500px;
  height: 500px;
  background: var(--ube-300);
  border-radius: 50%;
  opacity: 0.2;
  filter: blur(80px);
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -60px;
  left: -40px;
  width: 300px;
  height: 300px;
  background: var(--slushie-500);
  border-radius: 50%;
  opacity: 0.15;
  filter: blur(60px);
}

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

.hero-badge {
  display: inline-block;
  padding: 4px 14px;
  border-radius: var(--r-pill);
  background: var(--white);
  border: 1px solid var(--oat);
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1.08px;
  color: var(--charcoal);
  margin-bottom: 32px;
  box-shadow: var(--shadow-clay);
}

.hero h1 {
  font-size: 72px;
  font-weight: 600;
  line-height: 1.04;
  letter-spacing: -2.4px;
  color: var(--black);
  max-width: 650px;
  margin-bottom: 24px;
}

.hero p {
  font-size: 20px;
  font-weight: 400;
  line-height: 1.5;
  color: var(--silver);
  max-width: 480px;
  margin-bottom: 40px;
}

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

/* === 色块章节（ub purple 暗底） === */
.section-dark {
  background: var(--ube-800);
  color: var(--white);
  border-radius: var(--r-section);
  margin: 0 20px;
  padding: 100px 40px;
}

.section-dark .section-label {
  color: var(--ube-300);
}

.section-dark .section-title {
  color: var(--white);
}

.section-dark .section-lead {
  color: rgba(255,255,255,0.65);
}

/* === 色块章节（slushie 青底） === */
.section-cyan {
  background: var(--slushie-800);
  color: var(--white);
  border-radius: var(--r-section);
  margin: 0 20px;
  padding: 100px 40px;
}

.section-cyan .section-label {
  color: var(--slushie-500);
}

.section-cyan .section-title {
  color: var(--white);
}

.section-cyan .section-lead {
  color: rgba(255,255,255,0.65);
}

/* === 区块标题 === */
.section-header {
  margin-bottom: 56px;
}

.section-label {
  display: block;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1.08px;
  color: var(--ube-800);
  margin-bottom: 12px;
}

.section-title {
  font-size: 44px;
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -1.32px;
  margin-bottom: 16px;
}

.section-lead {
  font-size: 18px;
  font-weight: 400;
  line-height: 1.6;
  color: var(--silver);
  max-width: 480px;
}

/* === 功能卡片 === */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.feature-card {
  background: var(--white);
  border: 1px solid var(--oat);
  border-radius: var(--r-card);
  padding: 40px 28px;
  box-shadow: var(--shadow-clay);
  transition: transform 0.25s cubic-bezier(0.25, 0.46, 0.45, 0.94),
              box-shadow 0.25s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: rgba(0,0,0,0.15) 0px 4px 8px,
              rgba(0,0,0,0.04) 0px -1px 1px inset;
}

.feature-icon {
  font-size: 40px;
  margin-bottom: 20px;
  width: 64px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 16px;
  background: var(--cream);
  border: 1px dashed var(--oat);
}

.feature-card h3 {
  font-size: 24px;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.48px;
  margin-bottom: 10px;
}

.feature-card p {
  font-size: 16px;
  font-weight: 400;
  line-height: 1.55;
  color: var(--silver);
}

/* === 展示图（暗色块内） === */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.gallery-item {
  border-radius: var(--r-card);
  overflow: hidden;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.1);
}

.gallery-item img {
  width: 100%;
  height: 230px;
  object-fit: cover;
}

.gallery-caption {
  padding: 14px 20px;
  font-size: 14px;
  font-weight: 500;
  color: rgba(255,255,255,0.55);
}

/* === 下载网格 === */
.download-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.download-card {
  background: var(--white);
  border: 1px solid var(--oat);
  border-radius: var(--r-card);
  padding: 36px 20px;
  text-align: center;
  box-shadow: var(--shadow-clay);
  transition: transform 0.25s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.download-card:hover {
  transform: translateY(-3px);
}

.download-card .device-icon {
  font-size: 44px;
  margin-bottom: 16px;
}

.download-card h4 {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.4px;
  margin-bottom: 6px;
}

.download-card .device-req {
  font-size: 13px;
  color: var(--silver);
  margin-bottom: 22px;
}

/* === 使用步骤 === */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  width: 100%;
}

.step-card {
  text-align: center;
  padding: 32px 24px;
  position: relative;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--ube-800);
  color: var(--white);
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 20px;
}

.step-card h3 {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.44px;
  margin-bottom: 8px;
}

.step-card p {
  font-size: 15px;
  color: var(--silver);
  line-height: 1.55;
}

.step-arrow {
  display: none;
}

@media (min-width: 769px) {
  .step-card:not(:last-child)::after {
    content: '→';
    position: absolute;
    right: -20px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 24px;
    color: var(--oat);
    font-weight: 300;
  }
}

/* === 优势数据 === */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  width: 100%;
}

.advantage-item {
  text-align: center;
  padding: 28px 16px;
}

.advantage-number {
  font-size: 40px;
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.8px;
  color: var(--ube-800);
  margin-bottom: 8px;
}

.advantage-label {
  font-size: 14px;
  font-weight: 500;
  color: var(--silver);
}

/* 深色块内的优势数据 */
.section-dark .advantage-number {
  color: var(--ube-300);
}

.section-dark .advantage-label {
  color: rgba(255,255,255,0.6);
}

/* === FAQ === */
.faq-list {
  max-width: 700px;
  width: 100%;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--white);
  border: 1px solid var(--oat);
  border-radius: var(--r-card);
  padding: 24px 28px;
  box-shadow: var(--shadow-clay);
  cursor: default;
  transition: border-color 0.2s;
}

.faq-item:hover {
  border-color: var(--ube-300);
}

.faq-item h4 {
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.36px;
  margin-bottom: 8px;
  color: var(--black);
}

.faq-item p {
  font-size: 15px;
  color: var(--silver);
  line-height: 1.6;
}

/* === CTA 色块章节（matcha 绿底） === */
.section-green {
  background: var(--matcha-800);
  color: var(--white);
  border-radius: var(--r-section);
  margin: 0 20px;
  padding: 100px 40px;
  text-align: center;
}

.section-green h2 {
  font-size: 44px;
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -1.32px;
  max-width: 500px;
  margin: 0 auto 18px;
}

.section-green p {
  font-size: 18px;
  color: rgba(255,255,255,0.65);
  margin-bottom: 36px;
}

.cta-actions {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

/* === 退款保障（奶油底白卡片） === */
.guarantee-box {
  max-width: 560px;
  margin: 0 auto;
  padding: 48px 40px;
  border-radius: var(--r-card);
  background: var(--white);
  border: 1px solid var(--oat);
  box-shadow: var(--shadow-clay);
  text-align: center;
}

.guarantee-box .icon-shield {
  font-size: 48px;
  margin-bottom: 20px;
}

.guarantee-box h3 {
  font-size: 28px;
  font-weight: 600;
  letter-spacing: -0.56px;
  margin-bottom: 14px;
}

.guarantee-box p {
  font-size: 16px;
  color: var(--silver);
  margin-bottom: 28px;
  line-height: 1.6;
}

/* === 页脚 === */
.footer {
  padding: 32px 0;
  text-align: center;
}

.footer p {
  font-size: 13px;
  color: var(--silver);
}

/* === 响应式 === */
@media (max-width: 768px) {
  .hero { padding: 64px 0 48px; }
  .hero h1 { font-size: 40px; letter-spacing: -1.2px; }
  .hero p { font-size: 17px; }

  .section { padding: 64px 0; }
  .section-title { font-size: 32px; letter-spacing: -0.64px; }

  .section-dark,
  .section-cyan,
  .section-green {
    margin: 0 12px;
    padding: 56px 24px;
    border-radius: 24px;
  }

  .section-dark .section-title,
  .section-cyan .section-title,
  .section-green h2 {
    font-size: 28px;
    letter-spacing: -0.56px;
  }

  .features-grid,
  .gallery-grid,
  .steps-grid { grid-template-columns: 1fr; }

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

  .download-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .download-card { padding: 24px 14px; }

  .faq-item { padding: 20px 20px; }
  .step-card:not(:last-child)::after { display: none; }

  .guarantee-box { padding: 32px 24px; }
  .guarantee-box h3 { font-size: 22px; }
}

@media (max-width: 480px) {
  .download-grid { grid-template-columns: 1fr; max-width: 280px; margin: 0 auto; }
  .hero h1 { font-size: 34px; }
  .nav-inner { padding: 14px 18px; }
}