/* ===== 变量与重置 ===== */
:root {
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-primary-light: #3b82f6;
  --color-accent: #06b6d4;
  --color-bg: #ffffff;
  --color-bg-alt: #f8fafc;
  --color-bg-dark: #0f172a;
  --color-text: #1e293b;
  --color-text-muted: #64748b;
  --color-border: #e2e8f0;
  --font: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.12);
  --radius: 12px;
  --radius-lg: 20px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a {
  text-decoration: none;
  color: inherit;
}

ul {
  list-style: none;
}

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

.container {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  font-family: var(--font);
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.35);
}

.btn-outline {
  background: transparent;
  color: var(--color-text);
  border: 1.5px solid var(--color-border);
}

.btn-outline:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn-full {
  width: 100%;
}

/* ===== 导航 ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: var(--transition);
}

.header.scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 17px;
}

.logo-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: #fff;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 700;
}

.nav-links {
  display: flex;
  gap: 36px;
}

.nav-links a {
  font-size: 15px;
  color: var(--color-text-muted);
  transition: var(--transition);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-primary);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: var(--transition);
}

/* ===== 首屏轮播 ===== */
.carousel-section {
  padding-top: 72px;
}

.carousel {
  position: relative;
  height: clamp(480px, 72vh, 640px);
  overflow: hidden;
  background: var(--color-bg-dark);
}

.carousel-track {
  position: relative;
  height: 100%;
}

.carousel-slide {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.8s ease, visibility 0.8s ease;
}

.carousel-slide.active {
  opacity: 1;
  visibility: visible;
  z-index: 1;
}

.slide-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  transform: scale(1.05);
  transition: transform 6s ease;
}

.carousel-slide.active .slide-bg {
  transform: scale(1);
}

.slide-bg-1 {
  background-image: url('images/banner1.jpg');
}

.slide-bg-2 {
  background-image: url('images/banner2.jpg');
}

.slide-bg-3 {
  background-image: url('images/banner3.jpg');
}

.slide-bg-4 {
  background-image: url('images/banner4.jpg');
}

.slide-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    90deg,
    rgba(15, 23, 42, 0.82) 0%,
    rgba(15, 23, 42, 0.55) 55%,
    rgba(15, 23, 42, 0.25) 100%
  );
}

.slide-content {
  position: relative;
  z-index: 2;
  max-width: 640px;
  color: #fff;
  transform: translateY(30px);
  opacity: 0;
  transition: transform 0.8s ease 0.2s, opacity 0.8s ease 0.2s;
}

.carousel-slide.active .slide-content {
  transform: translateY(0);
  opacity: 1;
}

.slide-tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 4px;
  color: var(--color-accent);
  margin-bottom: 16px;
}

.slide-title {
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 20px;
  letter-spacing: -0.5px;
}

.slide-desc {
  font-size: 16px;
  color: rgba(255, 255, 255, 0.75);
  margin-bottom: 32px;
  max-width: 520px;
  line-height: 1.8;
}

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

.btn-white {
  background: #fff;
  color: var(--color-primary);
}

.btn-white:hover {
  background: #f1f5f9;
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(255, 255, 255, 0.25);
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  border: 1.5px solid rgba(255, 255, 255, 0.35);
  backdrop-filter: blur(4px);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.6);
  color: #fff;
}

.carousel-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 10;
  width: 48px;
  height: 48px;
  border: none;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(8px);
  color: #fff;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  opacity: 0;
}

.carousel:hover .carousel-btn {
  opacity: 1;
}

.carousel-btn:hover {
  background: rgba(255, 255, 255, 0.25);
}

.carousel-btn svg {
  width: 22px;
  height: 22px;
}

.carousel-prev {
  left: 24px;
}

.carousel-next {
  right: 24px;
}

.carousel-dots {
  position: absolute;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 10;
  display: flex;
  gap: 10px;
}

.carousel-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: none;
  background: rgba(255, 255, 255, 0.35);
  cursor: pointer;
  padding: 0;
  transition: var(--transition);
}

.carousel-dot.active {
  background: #fff;
  width: 28px;
  border-radius: 5px;
}

.carousel-progress {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 3px;
  background: var(--color-accent);
  z-index: 10;
  width: 0;
  transition: width 0.1s linear;
}

.hero-stats-bar {
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.hero-stats {
  display: flex;
  justify-content: space-around;
  gap: 24px;
  padding: 28px 0;
}

.stat {
  text-align: center;
}

.stat-num {
  display: block;
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.2;
}

.stat-label {
  font-size: 13px;
  color: var(--color-text-muted);
  margin-top: 4px;
}

.gradient-text {
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ===== 通用区块 ===== */
.section {
  padding: 100px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 64px;
}

.section-tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 3px;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(28px, 3.5vw, 38px);
  font-weight: 700;
  margin-bottom: 12px;
}

.section-desc {
  font-size: 16px;
  color: var(--color-text-muted);
}

/* ===== 关于我们 ===== */
.about {
  background: var(--color-bg-alt);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
}

.about-text h3 {
  font-size: 22px;
  margin-bottom: 20px;
}

.about-text p {
  color: var(--color-text-muted);
  margin-bottom: 16px;
}

.about-features {
  margin-top: 28px;
}

.about-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 0;
  font-size: 15px;
  color: var(--color-text);
}

.about-features svg {
  width: 20px;
  height: 20px;
  color: var(--color-primary);
  flex-shrink: 0;
}

.about-visual {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.about-card {
  background: var(--color-bg);
  padding: 28px;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  transition: var(--transition);
}

.about-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.about-card-icon {
  font-size: 28px;
  margin-bottom: 12px;
}

.about-card h4 {
  font-size: 17px;
  margin-bottom: 8px;
}

.about-card p {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ===== 核心业务 ===== */
.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.service-card {
  padding: 36px 28px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  transition: var(--transition);
  background: var(--color-bg);
}

.service-card:hover {
  border-color: transparent;
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

.service-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.1), rgba(6, 182, 212, 0.1));
  border-radius: 12px;
  margin-bottom: 20px;
}

.service-icon svg {
  width: 24px;
  height: 24px;
  color: var(--color-primary);
}

.service-card h3 {
  font-size: 18px;
  margin-bottom: 10px;
}

.service-card p {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ===== 解决方案 ===== */
.solutions {
  background: var(--color-bg-dark);
  color: #fff;
}

.solutions .section-tag {
  color: var(--color-accent);
}

.solutions .section-desc {
  color: rgba(255, 255, 255, 0.6);
}

.solutions-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.solution-item {
  display: flex;
  gap: 24px;
  padding: 32px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-lg);
  transition: var(--transition);
}

.solution-item:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.15);
}

.solution-num {
  font-size: 32px;
  font-weight: 700;
  color: var(--color-accent);
  opacity: 0.7;
  line-height: 1;
  flex-shrink: 0;
}

.solution-content h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

.solution-content p {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.7;
}

/* ===== 合作流程 ===== */
.process {
  background: var(--color-bg-alt);
}

.process-steps {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 0;
}

.process-step {
  text-align: center;
  flex: 1;
  max-width: 200px;
}

.step-circle {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  background: var(--color-primary);
  color: #fff;
  border-radius: 50%;
  font-size: 18px;
  font-weight: 600;
}

.process-step h4 {
  font-size: 16px;
  margin-bottom: 6px;
}

.process-step p {
  font-size: 13px;
  color: var(--color-text-muted);
}

.process-line {
  flex: 0 0 60px;
  height: 2px;
  background: var(--color-border);
  margin-top: 24px;
}

/* ===== 联系我们 ===== */
.contact-wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
}

.contact-desc {
  color: var(--color-text-muted);
  margin-bottom: 32px;
}

.contact-list li {
  display: flex;
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--color-border);
}

.contact-list li:last-child {
  border-bottom: none;
}

.contact-list svg {
  width: 22px;
  height: 22px;
  color: var(--color-primary);
  flex-shrink: 0;
  margin-top: 2px;
}

.contact-list strong {
  display: block;
  font-size: 14px;
  margin-bottom: 4px;
}

.contact-list span {
  font-size: 14px;
  color: var(--color-text-muted);
}

.contact-form {
  background: var(--color-bg-alt);
  padding: 36px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 8px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  font-size: 15px;
  font-family: var(--font);
  background: var(--color-bg);
  transition: var(--transition);
  outline: none;
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group textarea {
  resize: vertical;
  min-height: 100px;
}

/* ===== 页脚 ===== */
.footer {
  background: var(--color-bg-dark);
  color: rgba(255, 255, 255, 0.7);
  padding-top: 60px;
}

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

.footer-brand p {
  margin-top: 16px;
  font-size: 14px;
  line-height: 1.7;
}

.footer .logo-text {
  color: #fff;
}

.footer-links h4 {
  color: #fff;
  font-size: 15px;
  margin-bottom: 16px;
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  font-size: 14px;
  transition: var(--transition);
}

.footer-links a:hover {
  color: #fff;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 20px 0;
}

.footer-bottom p {
  font-size: 13px;
  text-align: center;
  color: rgba(255, 255, 255, 0.4);
}

/* ===== 动画 ===== */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 响应式 ===== */
@media (max-width: 968px) {
  .about-grid,
  .contact-wrapper {
    grid-template-columns: 1fr;
    gap: 40px;
  }

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

  .solutions-list {
    grid-template-columns: 1fr;
  }

  .footer-content {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(12px);
    flex-direction: column;
    padding: 24px;
    gap: 0;
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-120%);
    opacity: 0;
    transition: var(--transition);
    pointer-events: none;
  }

  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-links li {
    padding: 12px 0;
    border-bottom: 1px solid var(--color-border);
  }

  .nav-links li:last-child {
    border-bottom: none;
  }

  .hero-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

  .carousel-btn {
    opacity: 1;
    width: 40px;
    height: 40px;
  }

  .carousel-prev {
    left: 12px;
  }

  .carousel-next {
    right: 12px;
  }

  .slide-actions {
    flex-direction: column;
  }

  .slide-actions .btn {
    width: 100%;
    text-align: center;
  }

  .services-grid {
    grid-template-columns: 1fr;
  }

  .process-steps {
    flex-direction: column;
    align-items: center;
    gap: 8px;
  }

  .process-line {
    width: 2px;
    height: 32px;
    flex: none;
    margin: 0;
  }

  .footer-content {
    grid-template-columns: 1fr;
  }

}

@media (max-width: 480px) {
  .carousel {
    height: clamp(420px, 65vh, 520px);
  }

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

  .contact-form {
    padding: 24px;
  }
}