/* ============================================================
   AppxSAAS 餐饮管理系统 V3 — 官网落地页样式
   主色：深蓝 #1F497D / 辅色 #2E5C8A / 浅蓝 #EAF1FB
   纯静态、无外部依赖，使用系统字体栈
   ============================================================ */

:root {
  --color-primary: #1F497D;
  --color-secondary: #2E5C8A;
  --color-light: #EAF1FB;
  --color-white: #ffffff;
  --color-bg: #f7f9fc;
  --color-text: #2b3340;
  --color-muted: #6b7686;
  --color-border: #e3e9f2;
  --shadow-sm: 0 2px 8px rgba(31, 73, 125, 0.06);
  --shadow-md: 0 8px 24px rgba(31, 73, 125, 0.12);
  --radius: 12px;
  --container: 1160px;
  --header-h: 64px;
  --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

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

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

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

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

ul {
  list-style: none;
}

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

/* ---------------- 顶部导航栏 ---------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow 0.3s ease;
}

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

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

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 20px;
  color: var(--color-primary);
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 9px;
  background: var(--color-primary);
  color: var(--color-white);
  font-weight: 800;
}

.main-nav ul {
  display: flex;
  gap: 28px;
}

.main-nav a {
  font-size: 15px;
  color: var(--color-text);
  font-weight: 500;
  padding: 6px 2px;
  position: relative;
  transition: color 0.2s ease;
}

.main-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width 0.25s ease;
}

.main-nav a:hover {
  color: var(--color-primary);
}

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

/* 移动端汉堡按钮 */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: transparent;
  border: none;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-primary);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ---------------- Hero ---------------- */
.hero {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
  color: var(--color-white);
  padding: 96px 0 110px;
  text-align: center;
}

.hero-inner {
  max-width: 760px;
  margin: 0 auto;
}

.hero-title {
  font-size: 46px;
  font-weight: 800;
  letter-spacing: 0.5px;
  margin-bottom: 18px;
}

.hero-subtitle {
  font-size: 20px;
  font-weight: 500;
  opacity: 0.95;
  margin-bottom: 22px;
}

.hero-desc {
  font-size: 16px;
  opacity: 0.88;
  margin-bottom: 34px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ---------------- 按钮 ---------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 30px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
  border: 2px solid transparent;
}

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

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 22px rgba(0, 0, 0, 0.18);
}

.btn-outline {
  background: transparent;
  color: var(--color-white);
  border-color: rgba(255, 255, 255, 0.7);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.14);
  transform: translateY(-2px);
}

/* ---------------- 通用区块 ---------------- */
.section {
  padding: 84px 0;
}

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

.section-title {
  font-size: 32px;
  font-weight: 800;
  color: var(--color-primary);
  text-align: center;
  margin-bottom: 14px;
  position: relative;
}

.section-title.left {
  text-align: left;
}

.section-title.left::after {
  left: 0;
  transform: none;
}

.section-title::after {
  content: "";
  display: block;
  width: 56px;
  height: 4px;
  border-radius: 4px;
  background: var(--color-secondary);
  margin: 14px auto 0;
}

.section-lead {
  text-align: center;
  color: var(--color-muted);
  font-size: 16px;
  margin-bottom: 48px;
}

/* ---------------- 产品概述 ---------------- */
.overview-content {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.overview-content p {
  font-size: 16px;
  color: var(--color-text);
}

/* ---------------- 功能卡片网格 ---------------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 30px 24px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-secondary);
}

.feature-icon {
  width: 54px;
  height: 54px;
  border-radius: 14px;
  background: var(--color-light);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  margin-bottom: 18px;
}

.feature-card h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 10px;
}

.feature-card p {
  font-size: 14.5px;
  color: var(--color-muted);
}

/* ---------------- 技术优势 ---------------- */
.tech-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.tech-card {
  background: var(--color-light);
  border-radius: var(--radius);
  padding: 32px 26px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.tech-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
}

.tech-card h3 {
  font-size: 19px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.tech-card p {
  font-size: 15px;
  color: var(--color-text);
}

/* ---------------- 应用价值 ---------------- */
.value-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.value-item {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 30px 24px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.value-item:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
}

.value-num {
  font-size: 30px;
  font-weight: 800;
  color: var(--color-secondary);
  opacity: 0.85;
  margin-bottom: 10px;
}

.value-item h3 {
  font-size: 17px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 10px;
}

.value-item p {
  font-size: 14.5px;
  color: var(--color-muted);
}

/* ---------------- 关于 / 联系 ---------------- */
.about-contact {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
}

.about-text {
  font-size: 16px;
  color: var(--color-text);
  margin-top: 18px;
}

.contact-list {
  margin-top: 18px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.contact-list li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-bottom: 14px;
  border-bottom: 1px dashed var(--color-border);
}

.contact-label {
  font-size: 13px;
  color: var(--color-muted);
}

.contact-value {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-primary);
}

.contact-btn {
  margin-top: 24px;
  background: var(--color-primary);
  color: var(--color-white);
}

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

/* ---------------- 页脚 ---------------- */
.site-footer {
  background: var(--color-primary);
  color: rgba(255, 255, 255, 0.85);
  padding: 36px 0;
  text-align: center;
}

.footer-copy {
  font-size: 15px;
  font-weight: 500;
}

.footer-tag {
  font-size: 13px;
  opacity: 0.7;
  margin-top: 6px;
}

/* ---------------- 滚动淡入动画 ---------------- */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   响应式布局
   ============================================================ */

/* 桌面大屏（>=1280px）保持多列，已在上面定义 */

/* 平板（<1024px，覆盖约 768px 档） */
@media (max-width: 1024px) {
  .feature-grid,
  .tech-grid,
  .value-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .hero-title {
    font-size: 38px;
  }
}

/* 移动端（<768px） */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .main-nav {
    position: fixed;
    top: var(--header-h);
    right: 0;
    width: 70%;
    max-width: 300px;
    height: calc(100vh - var(--header-h));
    background: var(--color-white);
    box-shadow: var(--shadow-md);
    transform: translateX(100%);
    transition: transform 0.3s ease;
    padding: 24px;
  }

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

  .main-nav ul {
    flex-direction: column;
    gap: 4px;
  }

  .main-nav a {
    display: block;
    padding: 14px 8px;
    font-size: 16px;
    border-bottom: 1px solid var(--color-border);
  }

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

  .hero {
    padding: 70px 0 80px;
  }

  .hero-title {
    font-size: 30px;
  }

  .hero-subtitle {
    font-size: 17px;
  }

  .section {
    padding: 56px 0;
  }

  .section-title {
    font-size: 26px;
  }

  .about-contact {
    grid-template-columns: 1fr;
    gap: 36px;
  }
}

/* 小屏手机（375px 档） */
@media (max-width: 480px) {
  .container {
    padding: 0 18px;
  }

  .feature-grid,
  .tech-grid,
  .value-grid {
    grid-template-columns: 1fr;
  }

  .hero-title {
    font-size: 26px;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .btn {
    width: 100%;
  }
}

/* 尊重用户的减少动效偏好 */
@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
  html {
    scroll-behavior: auto;
  }
}