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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    "Helvetica Neue", Helvetica, Arial, sans-serif;
  color: #1c1e21;
  line-height: 1.7;
  background: #fff;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  position: relative;
}

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

/* =============================
   Global background orbs (ByteDance-like)
   - Animated in modern browsers
   - Static fallback in IE/compat mode
   ============================= */
.bg-orbs {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}

.bg-orb {
  position: absolute;
  left: 0;
  top: 0;
  width: 720px;
  height: 720px;
  border-radius: 50%;
  opacity: 0.85;
  transform: translate3d(0, 0, 0);
}

/* 边缘范围(B)：更靠近四周，不遮挡正文 */
.bg-orb--1 {
  left: -260px;
  top: -260px;
  background: radial-gradient(circle at 35% 35%, rgba(0, 102, 255, 0.28), rgba(0, 102, 255, 0) 62%);
}

.bg-orb--2 {
  right: -300px;
  bottom: -300px;
  left: auto;
  top: auto;
  width: 780px;
  height: 780px;
  background: radial-gradient(circle at 60% 60%, rgba(111, 66, 193, 0.22), rgba(111, 66, 193, 0) 64%);
}

/* 页面内容层级在光斑之上 */
.header,
.slider-section,
.section,
.footer {
  position: relative;
  z-index: 1;
}

@media (max-width: 900px) {
  .bg-orb {
    width: 520px;
    height: 520px;
    opacity: 0.7;
  }

  .bg-orb--2 {
    width: 560px;
    height: 560px;
  }
}

a {
  text-decoration: none;
  color: inherit;
  transition: opacity 0.2s ease;
}

a:hover {
  opacity: 0.8;
}

.container {
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

:root {
  --header-h: 100px;
  --brand-primary: #0066ff;
  --brand-dark: #001d3d;
  --text-primary: #1c1e21;
  --text-secondary: #5f6368;
  --bg-light: #f8f9fa;
  --border-light: rgba(0, 0, 0, 0.08);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
}

/* Enhanced header with ByteDance-style minimal design */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100px;
  height: var(--header-h);
  background: #4790f9;
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
  border-bottom: 1px solid var(--border-light);
  z-index: 1000;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), background 0.3s ease;
  will-change: transform;
}

.header.is-scrolled {
  background: rgba(71, 144, 249, 0.95);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
  box-shadow: var(--shadow-sm);
}

.header.is-collapsed {
  transform: translateY(-100px);
  transform: translateY(calc(-1 * var(--header-h)));
}

.header__inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo img {
  height: 80px;
  transition: transform 0.3s ease;
}

.logo:hover img {
  transform: scale(1.05);
}

/* Refined navigation with ByteDance-style hover effects */
.nav {
  display: flex;
  gap: 32px;
  color: #1c1e21;
  color: var(--text-primary);
  font-size: 15px;
  font-weight: 500;
}

.nav a {
  position: relative;
  padding: 8px 4px;
  transition: color 0.2s ease;
  color: #ffffff;
}

.nav a::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 0;
  height: 2px;
  background: #ffffff;
  transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1), left 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.nav a:hover {
  color: #ffffff;
  opacity: 1;
}

.nav a:hover::after {
  width: 100%;
  left: 0;
}

.menu-toggle {
  display: none;
  font-size: 24px;
  background: none;
  border: none;
  cursor: pointer;
  color: #1c1e21;
  color: #ffffff;
  padding: 8px;
}

/* 全新幻灯片样式：简洁设计，支持图片完整显示 */
.slider-section {
  padding-top: 100px;
  padding-top: var(--header-h);
  background: #fff;
}

.slider {
  position: relative;
  width: 100%;
  overflow: hidden;
  background: #fff;
  cursor: grab;
  user-select: none;
}

.slider:active {
  cursor: grabbing;
}

.slider-track {
  display: flex;
  transition: transform 0.5s ease-in-out;
  will-change: transform;
}

.slider-track.no-transition {
  transition: none;
}

.slider-image {
  width: 100%;
  height: auto;
  flex-shrink: 0;
  object-fit: contain;
  display: block;
}

/* 长条按钮样式 */
.slider-dots {
  position: absolute;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 12px;
  z-index: 10;
}

.slider-dot {
  width: 60px;
  height: 4px;
  background: rgba(255, 255, 255, 0.4);
  border: none;
  border-radius: 2px;
  cursor: pointer;
  transition: all 0.3s ease;
  padding: 0;
}

.slider-dot:hover {
  background: rgba(255, 255, 255, 0.6);
}

.slider-dot.active {
  background: rgba(255, 255, 255, 0.95);
  width: 80px;
}

/* Modern button design inspired by ByteDance */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  border-radius: 6px;
  font-weight: 600;
  font-size: 16px;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  border: none;
  white-space: nowrap;
}

.btn--primary {
  background: #0066ff;
  background: var(--brand-primary);
  color: #fff;
  box-shadow: 0 2px 8px rgba(0, 102, 255, 0.3);
}

.btn--primary:hover {
  background: #0052cc;
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(0, 102, 255, 0.4);
  opacity: 1;
}

.btn--outline {
  border: 2px solid #0066ff;
  border: 2px solid var(--brand-primary);
  color: #0066ff;
  color: var(--brand-primary);
  background: transparent;
}

.btn--outline:hover {
  background: #0066ff;
  background: var(--brand-primary);
  color: #fff;
  transform: translateY(-2px);
  opacity: 1;
}

/* Improved section spacing and typography */
.section {
  padding: 100px 0;
  padding-top: 130px;
  position: relative;
}

/* 圆形渐变装饰背景（类似字节跳动官网的氛围光斑），不影响内容点击 */
.section--decor {
  overflow: hidden;
}

.section--decor::before,
.section--decor::after {
  content: "";
  position: absolute;
  z-index: 0;
  width: 680px;
  height: 680px;
  border-radius: 50%;
  pointer-events: none;
  opacity: 0.9;
}

.section--decor::before {
  left: -280px;
  top: -240px;
  background: radial-gradient(circle at 40% 40%, rgba(0, 102, 255, 0.12), rgba(0, 102, 255, 0) 65%);
}

.section--decor::after {
  right: -300px;
  bottom: -260px;
  background: radial-gradient(circle at 60% 60%, rgba(111, 66, 193, 0.1), rgba(111, 66, 193, 0) 65%);
}

/* 确保内容在装饰之上 */
.section--decor > .container {
  position: relative;
  z-index: 1;
}

@media (max-width: 900px) {
  .section--decor::before,
  .section--decor::after {
    width: 520px;
    height: 520px;
    opacity: 0.75;
  }

  .section--decor::before {
    left: -260px;
    top: -300px;
  }

  .section--decor::after {
    right: -280px;
    bottom: -320px;
  }
}

.section--alt {

}

.section__title {
  font-size: 42px;
  font-weight: 700;
  margin-bottom: 16px;
  color: #1c1e21;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  line-height: 1.3;
}

.section__desc {
  max-width: 720px;
  margin-bottom: 48px;
  color: #5f6368;
  color: var(--text-secondary);
  font-size: 18px;
  line-height: 1.7;
}

/* ============
   Culture / Code (ByteDance-like: wide layout, no card border)
   ============ */
.feature-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 72px;
  padding: 28px 0;
}

/* 用“细分割线”而不是卡片边框 */
.feature-row + .feature-row {
  margin-top: 100px;
  padding-top: 64px;
}

.feature-row__media {
  flex: 0 0 52%;
}

.feature-row__media img {
  width: 100%;
  height: auto;
  border-radius: 12px;
  display: block;
}

.feature-row__content {
  flex: 1;
  min-width: 0;
}

.feature-row__title {
  font-size: 44px;
  font-weight: 750;
  line-height: 1.12;
  letter-spacing: -0.02em;
  margin-bottom: 18px;
  color: #1c1e21;
  color: var(--text-primary);
}

.feature-row__desc {
  max-width: 560px;
  color: #5f6368;
  color: var(--text-secondary);
  font-size: 17px;
  line-height: 1.85;
  margin-bottom: 26px;
}

.feature-row__more {
  display: inline-flex;
  align-items: center;
  font-weight: 700;
  color: #0066ff;
  color: var(--brand-primary);
}

.feature-row__more::after {
  content: "→";
  margin-left: 10px;
  transform: translateX(0);
  transition: transform 0.25s ease;
}

.feature-row__more:hover::after {
  transform: translateX(4px);
}

/* 行为准则：反向布局（左文右图） */
.feature-row--reverse {
  flex-direction: row-reverse;
}

@media (max-width: 900px) {
  .feature-row {
    flex-direction: column;
    align-items: flex-start;
    gap: 24px;
    padding: 10px 0;
  }

  .feature-row + .feature-row {
    margin-top: 40px;
    padding-top: 40px;
  }

  .feature-row__media {
    width: 100%;
    flex-basis: auto;
  }

  .feature-row__title {
    font-size: 32px;
  }
}

/* Enhanced grid with better hover effects */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 28px;
}

.card {
  background: #fff;
  padding: 32px;
  border-radius: 12px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
  box-shadow: var(--shadow-sm);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  border: 1px solid rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-light);
}

.card:hover {
  transform: translateY(-8px);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}

.card h3 {
  margin-bottom: 12px;
  font-size: 22px;
  font-weight: 600;
  color: #1c1e21;
  color: var(--text-primary);
}

.card p {
  color: #5f6368;
  color: var(--text-secondary);
  line-height: 1.7;
  font-size: 15px;
}

/* Refined news section */
.news {
  display: grid;
  gap: 20px;
}

.news__item {
  padding: 28px;
  border-radius: 12px;
  background: #fff;
  border: 1px solid rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-light);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;

  /* 左图右文 */
  display: flex;
  gap: 18px;
  align-items: center;
}

.news__item:hover {
  border-color: #0066ff;
  border-color: var(--brand-primary);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
  box-shadow: var(--shadow-md);
  transform: translateX(4px);
}

.news__thumb {
  flex: 0 0 120px;
  width: 120px;
  height: 78px;
  border-radius: 10px;
  overflow: hidden;
  background: #f2f3f5;
}

.news__thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.news__body {
  flex: 1;
  min-width: 0;
}

.news__item h3 {
  margin-bottom: 8px;
  font-size: 18px;
  font-weight: 650;
  color: #1c1e21;
  color: var(--text-primary);
  line-height: 1.35;
}

.news__item p {
  color: #5f6368;
  color: var(--text-secondary);
  line-height: 1.7;
  font-size: 14px;
}

/* Modern form design */
.form {
  display: grid;
  gap: 16px;
  max-width: 600px;
}

.form input,
.form textarea {
  margin-bottom: 20px;
  padding: 14px 16px;
  border-radius: 8px;
  border: 1px solid rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-light);
  font-size: 15px;
  font-family: inherit;
  transition: all 0.3s ease;
  background: #fff;
}

.form input:focus,
.form textarea:focus {
  outline: none;
  border-color: #0066ff;
  border-color: var(--brand-primary);
  box-shadow: 0 0 0 3px rgba(0, 102, 255, 0.1);
}

.form textarea {
  min-height: 140px;
  resize: vertical;
  line-height: 1.6;
}

.form .btn {
  justify-self: start;
  background: #0066ff;
  background: var(--brand-primary);
  color: #fff;
}

.form .btn:hover {
  background: #0052cc;
  opacity: 1;
}

/* Minimal footer design */
.footer {
  padding: 40px 0;
  background: #001d3d;
  background: var(--brand-dark);
  color: rgba(255, 255, 255, 0.8);
}

.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}

.footer p {
  font-size: 14px;
}

.back-to-top {
  font-weight: 600;
  font-size: 14px;
  padding: 8px 16px;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.1);
  transition: all 0.3s ease;
}

.back-to-top:hover {
  background: rgba(255, 255, 255, 0.2);
  opacity: 1;
}

/* =============================
   IE/旧内核兼容降级
   说明：360 兼容模式通常是 IE 内核，不支持 CSS Grid/CSS 变量等。
   这里提供 flex/float 的降级，让布局至少能“横向排列 + 有间距”。
   ============================= */

/* Grid 降级：用 flex 模拟卡片栅格 */
.grid {
  display: flex;
  flex-wrap: wrap;
  margin-left: -14px;
  margin-right: -14px;
}

.grid > .card {
  box-sizing: border-box;
  width: 33.3333%;
  padding-left: 14px;
  padding-right: 14px;
}

/* 卡片自身 padding 不能被上面的 padding 覆盖，给一层内边距 */
.grid > .card {
  margin-bottom: 28px;
}

@media (max-width: 900px) {
  .grid > .card {
    width: 100%;
  }
}

/* News / Form 在 IE 下用 block + 间距即可 */
.news,
.form {
  display: block;
}

.news__item {
  margin-bottom: 20px;
}

/* IE 下 flex 支持不稳定时，降级为上下结构 */
.news__thumb {
  margin-bottom: 12px;
}

.form input,
.form textarea,
.form button {
  width: 100%;
}

.form .btn {
  width: auto;
}

/* 头部导航间距兜底（gap 在旧内核可能不生效） */
.nav a {
  margin-left: 16px;
}



/* 让 slider 在旧内核也能横向排列（flex 可用时） */
.slider-track {
  font-size: 0; /* 防止图片间的空白字符影响 */
}

.slider-image {
  display: inline-block;
  vertical-align: top;
}

/* Responsive improvements */
@media (max-width: 900px) {
  .grid {
    margin-left: 0;
    margin-right: 0;
  }

  .section {
    padding: 60px 0;
  }

  .section__title {
    font-size: 32px;
  }

  .nav {
    position: absolute;
    top: 100px;
    top: var(--header-h);
    right: 0;
    background: rgba(71, 144, 249, 0.95);
    backdrop-filter: blur(10px);
    flex-direction: column;
    width: 240px;
    padding: 24px;
    gap: 20px;
    transform: translateX(100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
    box-shadow: var(--shadow-lg);
    border-left: 1px solid rgba(0, 0, 0, 0.08);
    border-left: 1px solid var(--border-light);
  }

  .nav.open {
    transform: translateX(0);
  }

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

  .menu-toggle {
    display: block;
  }

  .slider-dots {
    bottom: 20px;
  }

  .slider-dot {
    width: 50px;
  }

  .slider-dot.active {
    width: 65px;
  }
}

@media (max-width: 600px) {
  .container {
    width: 95%;
    padding: 0 15px;
  }

  .section__title {
    font-size: 28px;
  }

  .slider-dots {
    bottom: 15px;
    gap: 8px;
  }

  .slider-dot {
    width: 40px;
    height: 3px;
  }

  .slider-dot.active {
    width: 55px;
  }
}