/* ========================================
   内蒙古荣煜商贸有限公司 - 官网样式
   ======================================== */

:root {
  --color-primary: #1a5f4a;
  --color-primary-light: #2d8a6e;
  --color-primary-dark: #0f3d2f;
  --color-accent: #c9a227;
  --color-accent-light: #e8c547;
  --color-bg: #fafbfa;
  --color-bg-alt: #f0f4f2;
  --color-text: #1a1a1a;
  --color-text-muted: #5a6b63;
  --color-white: #ffffff;
  --color-border: #e2e8e5;
  --shadow-sm: 0 2px 8px rgba(26, 95, 74, 0.08);
  --shadow-md: 0 8px 24px rgba(26, 95, 74, 0.12);
  --shadow-lg: 0 16px 48px rgba(26, 95, 74, 0.16);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  --header-height: 72px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
  overflow-x: hidden;
}

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

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

ul {
  list-style: none;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ========== 按钮 ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
  color: var(--color-white);
  box-shadow: var(--shadow-sm);
}

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

.btn-outline {
  background: transparent;
  color: var(--color-white);
  border-color: rgba(255, 255, 255, 0.6);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--color-white);
}

.btn-full {
  width: 100%;
}

/* ========== 导航栏 ========== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition);
}

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

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

.nav-logo {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
  color: var(--color-white);
  font-size: 20px;
  font-weight: 700;
  border-radius: var(--radius-sm);
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.3;
}

.logo-text strong {
  font-size: 18px;
  color: var(--color-primary-dark);
}

.logo-text small {
  font-size: 11px;
  color: var(--color-text-muted);
  font-weight: 400;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  padding: 10px 18px;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text-muted);
  border-radius: var(--radius-sm);
  position: relative;
}

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

.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: 4px;
  left: 18px;
  right: 18px;
  height: 2px;
  background: var(--color-accent);
  border-radius: 1px;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--color-primary);
  border-radius: 1px;
  transition: var(--transition);
}

/* ========== Hero 区域 ========== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: calc(var(--header-height) + 40px) 0 80px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-gradient {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    var(--color-primary-dark) 0%,
    var(--color-primary) 40%,
    var(--color-primary-light) 100%
  );
}

.hero-pattern {
  position: absolute;
  inset: 0;
  opacity: 0.08;
  background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='1'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  color: var(--color-white);
}

.hero-badge {
  display: inline-block;
  padding: 8px 20px;
  background: rgba(255, 255, 255, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 50px;
  font-size: 14px;
  letter-spacing: 2px;
  margin-bottom: 24px;
  animation: fadeInUp 0.8s ease-out;
}

.hero-title {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 24px;
}

.hero-title-main {
  font-size: clamp(32px, 6vw, 52px);
  font-weight: 700;
  letter-spacing: 2px;
  line-height: 1.2;
  animation: fadeInUp 0.8s ease-out 0.1s both;
}

.hero-title-sub {
  font-size: clamp(18px, 3vw, 24px);
  font-weight: 400;
  opacity: 0.9;
  letter-spacing: 8px;
  animation: fadeInUp 0.8s ease-out 0.2s both;
}

.hero-desc {
  max-width: 640px;
  margin: 0 auto 40px;
  font-size: 17px;
  line-height: 1.8;
  opacity: 0.9;
  animation: fadeInUp 0.8s ease-out 0.3s both;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 60px;
  animation: fadeInUp 0.8s ease-out 0.4s both;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 48px;
  flex-wrap: wrap;
  animation: fadeInUp 0.8s ease-out 0.5s both;
}

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

.stat-number {
  font-size: 42px;
  font-weight: 700;
  color: var(--color-accent-light);
}

.stat-suffix {
  font-size: 28px;
  font-weight: 600;
  color: var(--color-accent-light);
}

.stat-label {
  display: block;
  font-size: 14px;
  opacity: 0.85;
  margin-top: 4px;
}

.hero-scroll {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: rgba(255, 255, 255, 0.7);
  font-size: 12px;
  animation: bounce 2s infinite;
}

.scroll-arrow {
  width: 20px;
  height: 20px;
  border-right: 2px solid rgba(255, 255, 255, 0.6);
  border-bottom: 2px solid rgba(255, 255, 255, 0.6);
  transform: rotate(45deg);
  margin-top: -4px;
}

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

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-tag {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(28px, 4vw, 36px);
  font-weight: 700;
  color: var(--color-primary-dark);
  margin-bottom: 12px;
}

.section-desc {
  font-size: 16px;
  color: var(--color-text-muted);
  max-width: 560px;
  margin: 0 auto;
}

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

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

.about-content h3 {
  font-size: 24px;
  color: var(--color-primary-dark);
  margin-bottom: 20px;
}

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

.about-features {
  margin-top: 32px;
}

.about-features li {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--color-border);
}

.about-features li:last-child {
  border-bottom: none;
}

.feature-icon {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-alt);
  color: var(--color-primary);
  font-weight: 700;
  border-radius: 50%;
  flex-shrink: 0;
}

.about-features strong {
  display: block;
  color: var(--color-text);
  margin-bottom: 4px;
}

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

.about-visual {
  display: grid;
  gap: 20px;
}

.about-card {
  background: var(--color-bg-alt);
  border-radius: var(--radius-md);
  padding: 28px;
  border-left: 4px solid var(--color-accent);
  transition: all var(--transition);
}

.about-card:hover {
  transform: translateX(8px);
  box-shadow: var(--shadow-md);
}

.about-icon {
  font-size: 32px;
  margin-bottom: 12px;
}

.about-card h4 {
  font-size: 18px;
  color: var(--color-primary-dark);
  margin-bottom: 8px;
}

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

/* ========== 业务范围 ========== */
.services {
  background: var(--color-bg-alt);
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.service-card {
  background: var(--color-white);
  padding: 36px 28px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  border: 1px solid transparent;
}

.service-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary-light);
}

.service-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
  color: var(--color-white);
  border-radius: var(--radius-sm);
  margin-bottom: 20px;
}

.service-icon svg {
  width: 28px;
  height: 28px;
}

.service-card h3 {
  font-size: 20px;
  color: var(--color-primary-dark);
  margin-bottom: 12px;
}

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

/* ========== 核心优势 ========== */
.advantages {
  background: linear-gradient(180deg, var(--color-white) 0%, var(--color-bg-alt) 100%);
}

.advantages-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.advantage-item {
  background: var(--color-white);
  padding: 32px 24px;
  border-radius: var(--radius-md);
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.advantage-item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  transform: scaleX(0);
  transition: transform var(--transition);
}

.advantage-item:hover::before {
  transform: scaleX(1);
}

.advantage-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.advantage-number {
  font-size: 36px;
  font-weight: 700;
  color: var(--color-accent);
  opacity: 0.5;
  margin-bottom: 12px;
}

.advantage-item h3 {
  font-size: 18px;
  color: var(--color-primary-dark);
  margin-bottom: 12px;
}

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

/* ========== 联系我们 ========== */
.contact {
  background: var(--color-white);
}

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

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.contact-item {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}

.contact-icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-alt);
  color: var(--color-primary);
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

.contact-icon svg {
  width: 24px;
  height: 24px;
}

.contact-item h4 {
  font-size: 16px;
  color: var(--color-primary-dark);
  margin-bottom: 4px;
}

.contact-item p {
  font-size: 15px;
  color: var(--color-text-muted);
}

.contact-form {
  background: var(--color-bg-alt);
  padding: 40px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.contact-form h3 {
  font-size: 22px;
  color: var(--color-primary-dark);
  margin-bottom: 28px;
}

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

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

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 14px 16px;
  font-size: 15px;
  font-family: inherit;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-white);
  transition: border-color var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-primary);
}

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

/* ========== 页脚 ========== */
.footer {
  background: var(--color-primary-dark);
  color: rgba(255, 255, 255, 0.85);
  padding: 60px 0 0;
}

.footer-main {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 48px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand p {
  margin-top: 16px;
  font-size: 14px;
  opacity: 0.8;
  max-width: 320px;
}

.footer .logo-text strong {
  color: var(--color-white);
}

.footer .logo-text small {
  color: rgba(255, 255, 255, 0.6);
}

.footer-links h4 {
  font-size: 16px;
  color: var(--color-white);
  margin-bottom: 20px;
}

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

.footer-links a {
  font-size: 14px;
  opacity: 0.8;
  transition: opacity var(--transition);
}

.footer-links a:hover {
  opacity: 1;
  color: var(--color-accent-light);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 24px 0;
  font-size: 13px;
  opacity: 0.7;
}

/* ========== 返回顶部 ========== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary);
  color: var(--color-white);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all var(--transition);
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--color-primary-light);
  transform: translateY(-4px);
}

.back-to-top svg {
  width: 24px;
  height: 24px;
}

/* ========== 动画 ========== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translateX(-50%) translateY(0);
  }
  40% {
    transform: translateX(-50%) translateY(-8px);
  }
  60% {
    transform: translateX(-50%) translateY(-4px);
  }
}

.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

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

/* ========== 响应式 ========== */
@media (max-width: 1024px) {
  .services-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .about-grid,
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

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

@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }

  .nav-menu {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--color-white);
    flex-direction: column;
    padding: 24px;
    gap: 0;
    box-shadow: var(--shadow-md);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition);
  }

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

  .nav-link {
    display: block;
    padding: 16px;
    width: 100%;
    text-align: center;
    border-bottom: 1px solid var(--color-border);
  }

  .nav-toggle {
    display: flex;
  }

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

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

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

  .hero-stats {
    gap: 32px;
  }

  .stat-number {
    font-size: 32px;
  }

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

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

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

  .footer-brand p {
    margin-left: auto;
    margin-right: auto;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 8px;
    text-align: center;
  }

  .section {
    padding: 60px 0;
  }
}

@media (max-width: 480px) {
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }

  .hero-actions .btn {
    width: 100%;
  }

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