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

:root {
  --primary-color: #f97316;
  --primary-dark: #ea580c;
  --primary-light: #fb923c;
  --secondary-color: #fbbf24;
  --accent-color: #06b6d4;
  --text-dark: #1f2937;
  --text-light: #6b7280;
  --text-muted: #9ca3af;
  --bg-light: #fffbeb;
  --bg-white: #ffffff;
  --border-color: #fde68a;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --transition: all 0.3s ease;
  --radius: 20px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Nunito', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  line-height: 1.7;
  color: var(--text-dark);
  background-color: var(--bg-white);
}

a {
  text-decoration: none;
  color: inherit;
  transition: var(--transition);
}

ul {
  list-style: none;
}

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

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

.section {
  padding: 80px 0;
}

.section-title {
  text-align: center;
  margin-bottom: 50px;
}

.section-title h2 {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--text-dark);
  margin-bottom: 15px;
}

.section-title p {
  font-size: 1.1rem;
  color: var(--text-light);
  max-width: 600px;
  margin: 0 auto;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 1rem;
  font-weight: 700;
  border-radius: 50px;
  cursor: pointer;
  transition: var(--transition);
  border: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: #fff;
  box-shadow: 0 4px 15px rgba(249, 115, 22, 0.4);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(249, 115, 22, 0.5);
}

.btn-outline {
  background: transparent;
  color: var(--primary-color);
  border: 3px solid var(--primary-color);
}

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

.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  transition: var(--transition);
}

.header.scrolled {
  box-shadow: var(--shadow-md);
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--primary-color);
}

.logo i {
  font-size: 2rem;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 35px;
}

.nav-menu a {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-dark);
  position: relative;
  padding: 8px 0;
}

.nav-menu a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  border-radius: 3px;
  transition: var(--transition);
}

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

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

.hamburger {
  display: none;
  flex-direction: column;
  gap: 6px;
  cursor: pointer;
  padding: 5px;
}

.hamburger span {
  width: 28px;
  height: 3px;
  background: var(--text-dark);
  border-radius: 3px;
  transition: var(--transition);
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(6px, 6px);
}

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

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(7px, -7px);
}

.footer {
  background: linear-gradient(135deg, #1f2937 0%, #374151 100%);
  color: #fff;
  padding: 80px 0 40px;
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 50px;
  margin-bottom: 50px;
}

.footer-brand h3 {
  font-size: 1.6rem;
  margin-bottom: 20px;
  color: #fff;
}

.footer-brand p {
  color: var(--text-muted);
  line-height: 1.9;
  margin-bottom: 25px;
}

.footer-social {
  display: flex;
  gap: 15px;
}

.footer-social a {
  width: 45px;
  height: 45px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  transition: var(--transition);
}

.footer-social a:hover {
  background: var(--primary-color);
}

.footer-links h4 {
  font-size: 1.1rem;
  margin-bottom: 25px;
  color: #fff;
}

.footer-links ul li {
  margin-bottom: 15px;
}

.footer-links ul li a {
  color: var(--text-muted);
  transition: var(--transition);
}

.footer-links ul li a:hover {
  color: var(--primary-light);
  padding-left: 5px;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 40px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.6);
  z-index: 2000;
  align-items: center;
  justify-content: center;
}

.modal.show {
  display: flex;
}

.modal-content {
  background: #fff;
  padding: 50px;
  border-radius: var(--radius);
  text-align: center;
  max-width: 420px;
  animation: modalIn 0.3s ease;
}

@keyframes modalIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.modal-content i {
  font-size: 4rem;
  color: var(--primary-color);
  margin-bottom: 25px;
}

.modal-content h3 {
  font-size: 1.5rem;
  margin-bottom: 15px;
}

.modal-content p {
  color: var(--text-light);
  margin-bottom: 25px;
}

@media (max-width: 992px) {
  .nav-menu {
    position: fixed;
    top: 80px;
    left: 0;
    right: 0;
    background: var(--bg-white);
    flex-direction: column;
    padding: 25px;
    gap: 0;
    box-shadow: var(--shadow-lg);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
  }

  .nav-menu.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav-menu a {
    padding: 18px 0;
    width: 100%;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
  }

  .hamburger {
    display: flex;
  }

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

@media (max-width: 768px) {
  .section {
    padding: 60px 0;
  }

  .section-title h2 {
    font-size: 2rem;
  }

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

  .footer-social {
    justify-content: center;
  }
}