/* ==========================================================================
   项目名称: 上海金桥农产品有限公司 - 官方一页式 Landing Page
   文件说明: style.css (核心样式表)
   视觉调性: 品牌绿 + 大地色深沉质感 / 留白艺术 / 响应式布局 / 现代平滑交互
   ========================================================================== */

/* --- 1. CSS 变量定义 (Design Tokens) --- */
:root {
  /* 品牌色彩系统 */
  --primary-color: #1a5e3a;        /* 森林深绿 - 代表专业、沉稳与源头生鲜 */
  --primary-hover: #13472c;        /* 深绿 Hover 态 */
  --accent-color: #2e7d32;         /* 鲜活生态绿 - 用于高亮与核心 CTA */
  --accent-glow: rgba(46, 125, 50, 0.35); /* 按钮微发光效果 */
  --secondary-color: #f4f7f4;      /* 极浅灰绿 - 区块背景交替用 */
  
  --earth-dark: #1c251f;          /* 大地深绿/接近黑 - 主文字与深色背景 */
  --earth-mid: #4a554d;           /* 灰绿 - 次级文字与描述文本 */
  --earth-light: #e8eee9;         /* 浅大地色 - 边框与分割线 */
  
  --bg-white: #ffffff;
  --bg-light: #f8faf8;
  --text-primary: #1c251f;
  --text-muted: #667068;
  --text-light: #f4f7f4;

  /* 阴影与发光系统 */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 16px 32px rgba(26, 94, 58, 0.12);
  --shadow-hover: 0 12px 28px rgba(26, 94, 58, 0.2);

  /* 布局与间距 (留白控制) */
  --container-max: 1200px;
  --section-padding-desktop: 100px 0;
  --section-padding-mobile: 60px 0;
  --border-radius-sm: 8px;
  --border-radius-md: 16px;
  --border-radius-lg: 24px;

  /* 动画平滑度 */
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

/* --- 2. 基础重置与全局设置 --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-white);
  scroll-behavior: smooth; /* 全局平滑滚动 */
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  overflow-x: hidden;
  width: 100%;
}

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

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

ul, ol {
  list-style: none;
}

/* --- 3. 布局容器与通用类 --- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: var(--section-padding-desktop);
  position: relative;
}

.section-bg-light {
  background-color: var(--secondary-color);
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 60px;
}

.section-subtitle {
  display: inline-block;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--accent-color);
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 12px;
  background-color: rgba(46, 125, 50, 0.08);
  padding: 6px 16px;
  border-radius: 50px;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--earth-dark);
  line-height: 1.3;
  margin-bottom: 16px;
  letter-spacing: -0.5px;
}

.section-description {
  font-size: 1.1rem;
  color: var(--earth-mid);
  line-height: 1.7;
}

/* --- 4. 按钮与交互系统 (CTA Buttons) --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--border-radius-sm);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition-normal);
  text-align: center;
  white-space: nowrap;
}

/* 主 CTA 按钮 - 微发光 + 轻微放大 */
.btn-primary {
  background-color: var(--primary-color);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(26, 94, 58, 0.3);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 8px 24px var(--accent-glow);
}

.btn-secondary {
  background-color: transparent;
  color: var(--primary-color);
  border-color: var(--primary-color);
}

.btn-secondary:hover {
  background-color: var(--primary-color);
  color: #ffffff;
  transform: translateY(-3px);
}

.btn-accent {
  background-color: var(--accent-color);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(46, 125, 50, 0.3);
}

.btn-accent:hover {
  background-color: #236327;
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 8px 24px var(--accent-glow);
}

/* --- 5. 吸顶导航栏 (Sticky Header) --- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 80px;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  z-index: 1000;
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.04);
  transition: all var(--transition-normal);
}

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

/* 纯文字排版 Logo (结合 CSS 高质感渲染) */
.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--primary-color);
  letter-spacing: -0.5px;
}

.brand-logo-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  color: #ffffff;
  border-radius: 10px;
  font-size: 1.2rem;
  font-weight: 900;
  box-shadow: 0 4px 10px var(--accent-glow);
}

.brand-logo-text span {
  color: var(--accent-color);
  font-weight: 400;
  font-size: 0.85rem;
  display: block;
  letter-spacing: 1px;
  line-height: 1;
  margin-top: 2px;
}

/* 导航链接 */
.nav-menu {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--earth-dark);
  position: relative;
  padding: 8px 0;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--accent-color);
  transition: width var(--transition-fast);
}

.nav-link:hover {
  color: var(--accent-color);
}

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

/* 汉堡菜单 (移动端) */
.hamburger-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 28px;
  height: 20px;
  background: transparent;
  border: none;
  cursor: pointer;
  z-index: 1001;
}

.hamburger-toggle span {
  width: 100%;
  height: 2.5px;
  background-color: var(--earth-dark);
  border-radius: 2px;
  transition: all var(--transition-fast);
}

/* --- 6. 英雄区 (Hero Section) --- */
.hero-section {
  padding-top: 160px;
  padding-bottom: 110px;
  background: linear-gradient(135deg, rgba(26, 94, 58, 0.92) 0%, rgba(28, 37, 31, 0.88) 100%),
              url('/images/hero-banner.jpg') center/cover no-repeat;
  color: #ffffff;
  position: relative;
  overflow: hidden;
}

.hero-content {
  max-width: 800px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 18px;
  background-color: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 50px;
  font-size: 0.9rem;
  font-weight: 500;
  margin-bottom: 24px;
}

.hero-title {
  font-size: 3.25rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 24px;
  letter-spacing: -1px;
}

.hero-title span {
  color: #81c784; /* 高亮嫩绿 */
}

.hero-description {
  font-size: 1.2rem;
  color: rgba(255, 255, 255, 0.9);
  line-height: 1.7;
  margin-bottom: 40px;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  margin-top: 70px;
  padding-top: 40px;
  border-top: 1px solid rgba(255, 255, 255, 0.15);
}

.stat-number {
  font-size: 2.25rem;
  font-weight: 800;
  color: #81c784;
  line-height: 1;
  margin-bottom: 8px;
}

.stat-label {
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.8);
}

/* --- 7. B端客户痛点区块 (Pain Points) --- */
.pain-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 30px;
}

.pain-card {
  background-color: var(--bg-white);
  border-radius: var(--border-radius-md);
  padding: 36px 30px;
  border: 1px solid var(--earth-light);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
}

.pain-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
  border-color: rgba(26, 94, 58, 0.2);
}

.pain-icon {
  width: 56px;
  height: 56px;
  background-color: #feebe8;
  color: #e53935;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 20px;
}

.pain-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--earth-dark);
  margin-bottom: 12px;
}

.pain-desc {
  font-size: 0.95rem;
  color: var(--earth-mid);
  line-height: 1.6;
}

/* --- 8. 解决方案与优势 (Solutions & Services) --- */
.solutions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 30px;
}

.solution-card {
  background-color: var(--bg-white);
  border-radius: var(--border-radius-md);
  padding: 40px 30px;
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(0, 0, 0, 0.03);
  position: relative;
  overflow: hidden;
  transition: all var(--transition-normal);
}

.solution-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.solution-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-hover);
}

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

.solution-icon {
  width: 64px;
  height: 64px;
  background-color: rgba(46, 125, 50, 0.08);
  color: var(--accent-color);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  margin-bottom: 24px;
}

.solution-title {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--earth-dark);
  margin-bottom: 12px;
}

.solution-desc {
  font-size: 0.95rem;
  color: var(--earth-mid);
  line-height: 1.6;
}

/* --- 9. 信任背书与资质认证 (Social Proof / E-E-A-T) --- */
.trust-badges {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 40px;
  flex-wrap: wrap;
  margin-bottom: 60px;
}

.trust-badge-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 28px;
  background-color: var(--bg-white);
  border: 1px solid var(--earth-light);
  border-radius: var(--border-radius-sm);
  box-shadow: var(--shadow-sm);
}

.trust-badge-icon {
  font-size: 1.8rem;
  color: var(--accent-color);
}

.trust-badge-text {
  font-size: 1rem;
  font-weight: 700;
  color: var(--earth-dark);
}

/* 合作客户 Logo 展台 */
.clients-wrapper {
  text-align: center;
  padding-top: 30px;
}

.clients-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 24px;
  letter-spacing: 1px;
}

.clients-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 20px;
  align-items: center;
}

.client-logo-box {
  background: var(--bg-white);
  padding: 20px;
  border-radius: var(--border-radius-sm);
  border: 1px solid var(--earth-light);
  font-weight: 700;
  color: var(--earth-mid);
  transition: all var(--transition-fast);
}

.client-logo-box:hover {
  border-color: var(--accent-color);
  color: var(--primary-color);
}

/* --- 10. 关于金桥与实体园区 (About Us) --- */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-image-wrapper {
  position: relative;
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.about-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-normal);
}

.about-image-wrapper:hover .about-img {
  transform: scale(1.03);
}

.about-experience-badge {
  position: absolute;
  bottom: 24px;
  left: 24px;
  background-color: var(--primary-color);
  color: #ffffff;
  padding: 20px 28px;
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-lg);
}

.about-exp-years {
  font-size: 2rem;
  font-weight: 800;
  line-height: 1;
}

.about-exp-text {
  font-size: 0.85rem;
  opacity: 0.9;
}

.about-content-list {
  margin-top: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.about-list-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  font-size: 1rem;
  color: var(--earth-mid);
}

.about-list-item check-icon {
  color: var(--accent-color);
  font-weight: bold;
}

/* --- 11. 常见问题 (FAQ) --- */
.faq-container {
  max-width: 840px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background-color: var(--bg-white);
  border: 1px solid var(--earth-light);
  border-radius: var(--border-radius-sm);
  overflow: hidden;
  transition: all var(--transition-fast);
}

.faq-item:hover {
  border-color: rgba(26, 94, 58, 0.3);
}

.faq-question {
  width: 100%;
  padding: 22px 28px;
  text-align: left;
  background: transparent;
  border: none;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--earth-dark);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-icon {
  font-size: 1.2rem;
  color: var(--accent-color);
  transition: transform var(--transition-fast);
}

.faq-answer {
  padding: 0 28px 22px 28px;
  color: var(--earth-mid);
  font-size: 0.98rem;
  line-height: 1.7;
  display: none; /* JS 控制展开 */
}

.faq-item.active .faq-answer {
  display: block;
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
}

/* --- 12. 终极呼吁与咨询表单 (Final CTA & Form) --- */
.cta-section {
  background: linear-gradient(135deg, var(--earth-dark) 0%, var(--primary-color) 100%);
  color: #ffffff;
}

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

.cta-info h2 {
  font-size: 2.25rem;
  font-weight: 800;
  margin-bottom: 20px;
  line-height: 1.3;
}

.cta-info p {
  font-size: 1.1rem;
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 36px;
  line-height: 1.6;
}

.direct-contact-card {
  display: flex;
  flex-direction: column;
  gap: 20px;
  background: rgba(255, 255, 255, 0.08);
  padding: 28px;
  border-radius: var(--border-radius-md);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.12);
}

.contact-row {
  display: flex;
  align-items: center;
  gap: 16px;
}

.contact-row-icon {
  width: 44px;
  height: 44px;
  background-color: var(--accent-color);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}

.contact-row-text .label {
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.7);
}

.contact-row-text .value {
  font-size: 1.15rem;
  font-weight: 700;
  color: #ffffff;
}

/* 表单样式 */
.cta-form-box {
  background-color: var(--bg-white);
  padding: 40px;
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-lg);
  color: var(--earth-dark);
}

.cta-form-box h3 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 24px;
  text-align: center;
  color: var(--earth-dark);
}

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

.form-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--earth-dark);
}

.form-input, .form-textarea, .form-select {
  width: 100%;
  padding: 14px 16px;
  font-size: 0.95rem;
  border: 1.5px solid var(--earth-light);
  border-radius: var(--border-radius-sm);
  background-color: var(--bg-light);
  transition: all var(--transition-fast);
  font-family: inherit;
}

.form-input:focus, .form-textarea:focus, .form-select:focus {
  outline: none;
  border-color: var(--accent-color);
  background-color: #ffffff;
  box-shadow: 0 0 0 4px rgba(46, 125, 50, 0.1);
}

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

.form-submit-btn {
  width: 100%;
  padding: 16px;
  font-size: 1.05rem;
}

/* --- 13. 页尾 (Footer) --- */
.site-footer {
  background-color: var(--earth-dark);
  color: var(--text-light);
  padding-top: 80px;
  padding-bottom: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 40px;
  margin-bottom: 60px;
}

.footer-brand p {
  margin-top: 16px;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.65);
  line-height: 1.6;
  max-width: 320px;
}

.footer-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 20px;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-links a {
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.7);
  transition: color var(--transition-fast);
}

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

.footer-contact-info {
  display: flex;
  flex-direction: column;
  gap: 12px;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.7);
}

.footer-bottom {
  padding-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.5);
}

/* 备案号跳转链接特定样式 */
.icp-link {
  color: rgba(255, 255, 255, 0.5);
  text-decoration: underline;
  transition: color var(--transition-fast);
}

.icp-link:hover {
  color: var(--accent-color);
}

/* --- 14. 响应式适配 (Responsive Media Queries) --- */
@media (max-width: 1024px) {
  .hero-title {
    font-size: 2.5rem;
  }
  
  .about-grid, .cta-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

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

  .hamburger-toggle {
    display: flex;
  }

  /* 移动端菜单抽屉 */
  .nav-menu {
    position: fixed;
    top: 80px;
    left: 0;
    width: 100%;
    background-color: #ffffff;
    flex-direction: column;
    padding: 30px;
    gap: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    clip-path: circle(0% at 100% 0);
    transition: clip-path 0.4s ease-in-out;
  }

  .nav-menu.active {
    clip-path: circle(140% at 100% 0);
  }

  .header-cta-btn {
    display: none; /* 移动端隐藏或移动至菜单内 */
  }

  .hero-title {
    font-size: 2rem;
  }

  .hero-stats {
    grid-template-columns: 1fr;
    gap: 20px;
  }

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

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