/* =============================================
   Kaiyun APP下载中心 — 独家设计系统
   风格：暖土有机 · 柔和大地色系
   ============================================= */

/* 基础重置 */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --cream: #faf7f2;
  --warm-white: #fefcf9;
  --terracotta: #e07b5e;
  --terracotta-dark: #c96a4f;
  --terracotta-light: #fbe8e2;
  --sage: #7a9e7e;
  --sage-light: #e8f0e9;
  --sage-dark: #5f7d62;
  --sand: #e8dccf;
  --sand-light: #f5f1ea;
  --warm-brown: #3d322b;
  --warm-brown-light: #6b5d54;
  --warm-gray: #8c8279;
  --border-soft: #e8e2d9;
  --shadow-soft: 0 2px 16px rgba(61, 50, 43, 0.06);
  --shadow-hover: 0 8px 32px rgba(61, 50, 43, 0.10);
  --shadow-card: 0 1px 4px rgba(61, 50, 43, 0.04), 0 4px 20px rgba(61, 50, 43, 0.05);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --transition: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

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

body {
  font-family: system-ui, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  overflow-x: hidden;
  background: var(--warm-white);
  color: var(--warm-brown);
  line-height: 1.6;
  font-size: 16px;
}

::selection {
  background: var(--terracotta-light);
  color: var(--terracotta-dark);
}

/* 核心布局 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 80px 0;
  position: relative;
}

.section:nth-child(even) {
  background: #f7f3ec;
}

.section:nth-child(odd) {
  background: var(--warm-white);
}

/* 导航 */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(254, 252, 249, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-soft);
  transition: var(--transition);
}

.site-header.scrolled {
  box-shadow: 0 1px 20px rgba(61, 50, 43, 0.06);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.25rem;
  text-decoration: none;
  color: var(--warm-brown);
  letter-spacing: -0.3px;
  transition: var(--transition);
}

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

.logo-icon {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  background: linear-gradient(135deg, var(--terracotta-light), #fce4dc);
  color: var(--terracotta);
  font-weight: 700;
  letter-spacing: -0.5px;
  box-shadow: 0 2px 8px rgba(224, 123, 94, 0.15);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.main-nav a {
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--warm-brown-light);
  transition: var(--transition);
  position: relative;
  padding: 4px 0;
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--terracotta);
  border-radius: 4px;
  transition: width 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

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

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

.nav-cta {
  padding: 10px 22px !important;
  border-radius: 50px !important;
  color: #fff !important;
  font-weight: 700 !important;
  background: linear-gradient(135deg, var(--terracotta), #d97054);
  box-shadow: 0 4px 14px rgba(224, 123, 94, 0.3);
  transition: var(--transition) !important;
  letter-spacing: 0.2px;
}

.nav-cta::after {
  display: none !important;
}

.nav-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(224, 123, 94, 0.4);
  color: #fff !important;
}

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 6px;
  background: none;
  border: none;
  z-index: 1001;
}

.menu-toggle span {
  display: block;
  width: 26px;
  height: 2.5px;
  background: var(--warm-brown);
  border-radius: 3px;
  transition: var(--transition);
}

.menu-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.menu-toggle.active span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* Hero */
.hero {
  min-height: 70vh;
  display: flex;
  align-items: center;
  padding-top: 68px;
  background: linear-gradient(180deg, #fefcf9 0%, #faf7f2 40%, #f7f2eb 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -120px;
  right: -80px;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(224, 123, 94, 0.06) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -100px;
  left: -60px;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(122, 158, 126, 0.05) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-content {
  max-width: 720px;
}

.hero-eyebrow {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 700;
  padding: 6px 16px;
  border-radius: 50px;
  margin-bottom: 20px;
  background: var(--terracotta-light);
  color: var(--terracotta-dark);
  letter-spacing: 1.5px;
  text-transform: uppercase;
}

.hero h1 {
  font-size: 3rem;
  line-height: 1.15;
  margin-bottom: 20px;
  font-weight: 900;
  letter-spacing: -1px;
  color: var(--warm-brown);
}

.hero h1 .highlight {
  background: linear-gradient(135deg, var(--terracotta), #e8916f);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.15rem;
  opacity: 0.7;
  max-width: 560px;
  margin-bottom: 36px;
  line-height: 1.7;
  color: var(--warm-brown-light);
}

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

.hero-image {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(61, 50, 43, 0.1);
  position: relative;
}

.hero-image::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  box-shadow: inset 0 0 0 1px rgba(224, 123, 94, 0.08);
  pointer-events: none;
}

.hero-image img {
  width: 100%;
  height: auto;
  display: block;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 30px;
  border-radius: 50px;
  font-weight: 700;
  cursor: pointer;
  border: none;
  text-decoration: none;
  transition: var(--transition);
  font-size: 0.95rem;
  letter-spacing: 0.2px;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  color: #fff;
  background: linear-gradient(135deg, var(--terracotta), #d97054);
  box-shadow: 0 6px 20px rgba(224, 123, 94, 0.3);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 28px rgba(224, 123, 94, 0.4);
  background: linear-gradient(135deg, #e8876d, #e07b5e);
}

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

.btn-outline:hover {
  border-color: var(--terracotta);
  color: var(--terracotta);
  background: var(--terracotta-light);
}

.btn-secondary {
  background: var(--sage-light);
  color: var(--sage-dark);
  border: 2px solid transparent;
}

.btn-secondary:hover {
  background: #dce8dd;
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(122, 158, 126, 0.2);
}

/* 标签/标题 */
.section-label {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 2.5px;
  margin-bottom: 14px;
  text-transform: uppercase;
  color: var(--sage-dark);
  background: var(--sage-light);
  padding: 6px 14px;
  border-radius: 50px;
}

.section-title {
  font-size: 2.2rem;
  margin-bottom: 16px;
  font-weight: 900;
  letter-spacing: -0.6px;
  color: var(--warm-brown);
  line-height: 1.25;
}

.section-desc {
  max-width: 600px;
  opacity: 0.7;
  margin-bottom: 44px;
  line-height: 1.7;
  color: var(--warm-brown-light);
  font-size: 1.05rem;
}

/* 卡片网格 */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px;
}

.category-card {
  border-radius: var(--radius-md);
  padding: 32px 28px;
  border: 1px solid var(--border-soft);
  background: #fff;
  transition: var(--transition);
  position: relative;
  cursor: pointer;
  box-shadow: var(--shadow-card);
}

.category-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--terracotta), var(--sage));
  border-radius: var(--radius-md) var(--radius-md) 0 0;
  opacity: 0;
  transition: var(--transition);
}

.category-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
  border-color: transparent;
}

.category-card:hover::before {
  opacity: 1;
}

.card-icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
  font-size: 1.4rem;
  background: var(--sand-light);
  color: var(--terracotta);
  transition: var(--transition);
}

.category-card:hover .card-icon {
  background: var(--terracotta-light);
  transform: scale(1.05);
}

.category-card h3 {
  font-size: 1.15rem;
  font-weight: 800;
  margin-bottom: 8px;
  color: var(--warm-brown);
}

.category-card p {
  font-size: 0.9rem;
  color: var(--warm-gray);
  line-height: 1.6;
  margin-bottom: 16px;
}

.card-link {
  font-weight: 700;
  font-size: 0.85rem;
  text-decoration: none;
  color: var(--terracotta);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: gap 0.3s ease;
}

.card-link::after {
  content: '→';
  transition: var(--transition);
}

.card-link:hover {
  gap: 10px;
  color: var(--terracotta-dark);
}

/* 特性块 */
.feature-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: center;
}

.feature-image {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 16px 48px rgba(61, 50, 43, 0.08);
  position: relative;
}

.feature-image::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  box-shadow: inset 0 0 0 1px rgba(122, 158, 126, 0.06);
  pointer-events: none;
}

.feature-image img {
  width: 100%;
  height: auto;
  display: block;
}

.feature-text h3 {
  font-size: 1.6rem;
  font-weight: 900;
  margin-bottom: 12px;
  color: var(--warm-brown);
  letter-spacing: -0.4px;
}

.feature-text p {
  color: var(--warm-brown-light);
  line-height: 1.7;
  margin-bottom: 20px;
}

.feature-list {
  list-style: none;
}

.feature-list li {
  padding: 8px 0;
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 500;
  color: var(--warm-brown);
}

.feature-list li::before {
  content: '✓';
  font-weight: 800;
  color: var(--sage-dark);
  background: var(--sage-light);
  width: 26px;
  height: 26px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  flex-shrink: 0;
}

/* 数据条 */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}

.stat-item {
  padding: 28px 20px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-soft);
  background: #fff;
  transition: var(--transition);
  box-shadow: var(--shadow-card);
}

.stat-item:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-hover);
  border-color: var(--terracotta-light);
}

.stat-number {
  font-size: 2.6rem;
  font-weight: 900;
  letter-spacing: -1px;
  background: linear-gradient(135deg, var(--terracotta), #e8916f);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}

.stat-label {
  font-size: 0.9rem;
  opacity: 0.6;
  margin-top: 8px;
  font-weight: 500;
  color: var(--warm-gray);
}

/* 内容墙 */
.content-wall {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.content-wall-item {
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border-soft);
  background: #fff;
  transition: var(--transition);
  box-shadow: var(--shadow-card);
}

.content-wall-item:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
}

.content-wall-item img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  display: block;
}

.content-wall-body {
  padding: 22px 20px;
}

.content-wall-body h4 {
  font-weight: 800;
  font-size: 1rem;
  margin-bottom: 6px;
  color: var(--warm-brown);
}

.content-wall-body p {
  font-size: 0.85rem;
  color: var(--warm-gray);
  line-height: 1.6;
}

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

.faq-item {
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  margin-bottom: 10px;
  overflow: hidden;
  cursor: pointer;
  background: #fff;
  transition: var(--transition);
  box-shadow: 0 1px 3px rgba(61, 50, 43, 0.02);
}

.faq-item:hover {
  border-color: var(--terracotta-light);
  box-shadow: 0 2px 8px rgba(224, 123, 94, 0.06);
}

.faq-item .faq-question {
  padding: 18px 22px;
  font-weight: 700;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--warm-brown);
  transition: var(--transition);
  font-size: 0.98rem;
}

.faq-item .faq-question::after {
  content: '+';
  font-size: 1.3rem;
  font-weight: 300;
  color: var(--terracotta);
  transition: transform 0.3s ease;
}

.faq-item.open .faq-question::after {
  content: '−';
  transform: rotate(180deg);
}

.faq-item .faq-answer {
  padding: 0 22px 18px;
  display: none;
  opacity: 0.7;
  color: var(--warm-brown-light);
  line-height: 1.7;
  font-size: 0.93rem;
}

.faq-item.open .faq-answer {
  display: block;
  animation: fadeSlideIn 0.35s ease;
}

.faq-item.open {
  border-color: var(--terracotta-light);
  background: #fffdfb;
}

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

/* CTA横幅 */
.cta-banner {
  padding: 60px 24px;
  text-align: center;
  border-radius: var(--radius-xl);
  color: #fff;
  background: linear-gradient(135deg, #e07b5e 0%, #d46b4d 30%, #c96042 70%, #b8553a 100%);
  position: relative;
  overflow: hidden;
}

.cta-banner::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(255,255,255,0.08) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.cta-banner::after {
  content: '';
  position: absolute;
  bottom: -40%;
  left: -10%;
  width: 350px;
  height: 350px;
  background: radial-gradient(circle, rgba(255,255,255,0.05) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

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

.cta-banner h2 {
  color: #fff;
  font-size: 2rem;
  font-weight: 900;
  letter-spacing: -0.5px;
  margin-bottom: 16px;
}

.cta-banner p {
  color: rgba(255,255,255,0.85);
  margin-bottom: 28px;
  font-size: 1.05rem;
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

.cta-banner .btn-primary {
  background: #fff;
  color: var(--terracotta);
  box-shadow: 0 6px 24px rgba(0,0,0,0.15);
  font-weight: 800;
}

.cta-banner .btn-primary:hover {
  background: #fefcf9;
  box-shadow: 0 10px 30px rgba(0,0,0,0.2);
  transform: translateY(-3px);
}

/* 页脚 */
.site-footer {
  padding: 56px 0 28px;
  background: #f5f1ea;
  color: var(--warm-brown);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
}

.footer-brand .logo {
  margin-bottom: 14px;
}

.footer-brand p {
  font-size: 0.9rem;
  color: var(--warm-gray);
  line-height: 1.7;
}

.footer-col h4 {
  font-weight: 800;
  font-size: 0.95rem;
  margin-bottom: 14px;
  color: var(--warm-brown);
}

.footer-col ul {
  list-style: none;
}

.footer-col ul li {
  margin-bottom: 8px;
}

.footer-col ul li a {
  text-decoration: none;
  color: var(--warm-gray);
  font-size: 0.9rem;
  transition: var(--transition);
}

.footer-col ul li a:hover {
  color: var(--terracotta);
  padding-left: 4px;
}

.footer-bottom {
  border-top: 1px solid var(--border-soft);
  margin-top: 40px;
  padding-top: 20px;
  text-align: center;
  font-size: 0.85rem;
  color: var(--warm-gray);
}

/* 工具类 */
.text-accent {
  color: var(--terracotta);
  font-weight: 700;
}

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

.seo-description {
  max-width: 600px;
  margin: 0 auto 48px;
  opacity: 0.7;
  text-align: center;
  color: var(--warm-brown-light);
  line-height: 1.7;
}

.mt-0 {
  margin-top: 0;
}

.mb-0 {
  margin-bottom: 0;
}

/* 装饰分隔线 */
.section-divider {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin: 0 auto 40px;
  max-width: 400px;
}

.section-divider span {
  display: block;
  height: 2px;
  flex: 1;
  background: var(--border-soft);
  border-radius: 2px;
}

.section-divider .divider-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--terracotta-light);
  flex: none;
}

/* 响应式 */
@media (max-width: 1024px) {
  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-content {
    max-width: 100%;
  }
  .hero p {
    margin-left: auto;
    margin-right: auto;
  }
  .hero-buttons {
    justify-content: center;
  }
  .hero-image {
    max-width: 500px;
    margin: 0 auto;
  }
  .feature-block {
    gap: 36px;
  }
}

@media (max-width: 768px) {
  .feature-block {
    grid-template-columns: 1fr;
  }
  .stats-bar {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .hero h1 {
    font-size: 2.2rem;
  }
  .section-title {
    font-size: 1.7rem;
  }
  .main-nav {
    display: none;
  }
  .menu-toggle {
    display: flex;
  }
  .main-nav.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 68px;
    left: 0;
    width: 100%;
    background: rgba(254, 252, 249, 0.98);
    padding: 24px;
    border-bottom: 1px solid var(--border-soft);
    box-shadow: 0 20px 40px rgba(61, 50, 43, 0.08);
    gap: 16px;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
  }
  .main-nav.open a {
    font-size: 1rem;
    padding: 10px 0;
  }
  .nav-cta {
    text-align: center;
    display: block;
    width: 100%;
  }
}

@media (max-width: 480px) {
  .cards-grid,
  .content-wall,
  .stats-bar {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }
  .hero-buttons .btn {
    width: 100%;
    justify-content: center;
  }
  .hero h1 {
    font-size: 1.8rem;
  }
  .section {
    padding: 56px 0;
  }
  .cta-banner {
    padding: 44px 20px;
    border-radius: var(--radius-lg);
  }
  .cta-banner h2 {
    font-size: 1.5rem;
  }
  .stat-number {
    font-size: 2rem;
  }
}