/* 公共样式：基础变量 / 头部导航 / 底部 Footer
   视觉来源：Heckman_Homepage_Visual_Redesign.html（header / footer） */

/* CSS Reset & Base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

:root {
  /* 站群通用变量 */
  --primary-blue: #3a5f7a;
  --secondary-blue: #4e6e8c;
  --accent-red: #b27a7a;
  --accent-yellow: #c9b37a;
  --light-yellow: #f0e8d0;
  --text-light: #f8f9fa;
  --text-dark: #1e293b;
  --text-muted: #64748b;
  --bg-light: #f1f5f9;
  --border-light: #e2e8f0;
  --shadow-sm: 0 4px 20px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 10px 40px rgba(0, 0, 0, 0.08);
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-serif: 'Playfair Display', serif;

  /* Redesign 调色板（头尾公共） */
  --red: #9b2525;
  --orange: #e08a08;
  --blue: #1684c7;
  --ink: #202326;
  --muted: #687078;
  --cream: #fbfaf7;
  --paper: #ffffff;
  --pale: #f3f4f2;
  --line: #e2e4e3;
  --header-bg: #17191b;
  --footer-bg: #17191b;
  --footer-text: #aeb3b6;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--text-dark);
  background: #ffffff;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  /* 撑满高度链的基准：配合 .main-content 的 flex:1 */
  min-height: 100vh;

  display: flex;
  flex-direction: column;
}

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

.container {
  /* max-width: 1280px; */
  margin-left:15%;
  margin-right:15%;
  padding: 0 2rem;
}

/* 正文容器：为固定吸顶 Header 预留顶部间距（仅作用于带 main-container 的元素） */
.main-container {
  margin-top: 92px;
  flex:1;
}

/* 主内容区（版型标准类名）：自带纵向 flex，默认 flex:1，
   占满固定吸顶 Header 与 Footer 之间的区域；
   派生页面只需把内容写进 <div class="main-content">，无需再写高度样式 */
.main-content {
  display: flex;
  flex-direction: column;
  flex: 1;
  /* header 为 fixed 吸顶，脱离文档流，为其预留高度 */
  margin-top: 92px;
}

@media (max-width: 768px) {
  /* 移动端 header 高度为 78px */
  .main-content {
    margin-top: 78px;
  }
}

/* ========== Header（固定吸顶，不透明；渐变方向与 about 区块一致） ========== */
header {
  position: fixed;
  z-index: 1000;
  top: 0;
  left: 0;
  right: 0;
  width: 100%;
  color: #fff;
  background: linear-gradient(118deg, #17191b 0%, #202326 56%, #25282b 100%);
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  transition: box-shadow 0.3s ease;
}

/* 头部右下角彩条（同 hero-stripe） */
header::after {
  content: '';
  position: absolute;
  right: 0;
  bottom: -1px;
  width: 48%;
  height: 8px;
  background: linear-gradient(90deg, var(--red), var(--orange), var(--blue));
  pointer-events: none;
}

header.is-scrolled {
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
}

.nav {
  height: 92px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 92px;
  padding-top: 10px;
  padding-bottom: 10px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  text-decoration: none;
  flex-shrink: 0;
  /* 高度撑满 .nav-container 的内容区（92px - 上下 10px padding = 72px） */
  height: 100%;
}

.logo img {
  display: block;
  /* 高度撑满 .logo，宽度按图片原始比例等比缩放 */
  height: 100%;
  width: auto;
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: var(--orange);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.2rem;
  color: #fff;
  font-family: var(--font-serif);
}

.logo-text {
  font-weight: 700;
  font-size: 1.1rem;
  color: #fff;
  letter-spacing: -0.3px;
}
.logo-text span {
  color: var(--orange);
  font-weight: 300;
}

/* 一级导航：Redesign 观感 + 站群 ul/li 结构 */
.nav-links,
.navlinks {
  display: flex;
  align-items: center;
  gap: 34px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 14px;
  letter-spacing: 0.02em;
}

.nav-links a,
.navlinks a {
  color: #fff;
  text-decoration: none;
  font-size: 14px;
  font-weight: 400;
  opacity: 0.88;
  transition: opacity 0.2s, color 0.2s;
  position: relative;
  white-space: nowrap;
}

.nav-links a:hover,
.navlinks a:hover,
.nav-links .active a,
.navlinks .active {
  opacity: 1;
  color: #fff;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--orange);
  transition: width 0.3s;
}
.nav-links a:hover::after {
  width: 100%;
}

.menu-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--orange);
  display: inline-block;
  margin-left: 7px;
  vertical-align: 1px;
}

/* 二级菜单（下拉） */
.nav-links li,
.navlinks li {
  position: relative;
}

.nav-links li dl,
.navlinks li dl {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 200px;
  background: var(--header-bg);
  padding: 0.5rem 0;
  border-radius: 10px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.35);
  border: 1px solid rgba(255, 255, 255, 0.1);
  margin: 0;
  z-index: 100;
  list-style: none;
  backdrop-filter: blur(4px);
  transition: opacity 0.25s ease, transform 0.25s ease;
  opacity: 0;
  transform: translateY(6px);
  pointer-events: none;
}

.nav-links li:hover dl,
.navlinks li:hover dl {
  display: block;
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.nav-links li dl dd,
.navlinks li dl dd {
  display: block;
  padding: 0.2rem 1.5rem;
  margin: 0;
}

.nav-links li dl dd a,
.navlinks li dl dd a {
  color: rgba(255, 255, 255, 0.85);
  text-decoration: none;
  font-size: 0.82rem;
  font-weight: 400;
  display: block;
  padding: 0.4rem 0;
  border-radius: 4px;
  transition: color 0.2s, background 0.2s;
  white-space: nowrap;
  opacity: 1;
}

.nav-links li dl dd a::after,
.navlinks li dl dd a::after {
  display: none;
}

.nav-links li dl dd a:hover,
.navlinks li dl dd a:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
}

.lang-toggle {
  background: rgba(255, 255, 255, 0.1);
  padding: 0.4rem 1rem;
  border-radius: 40px;
  color: #fff;
  font-size: 0.8rem;
  border: 1px solid rgba(255, 255, 255, 0.15);
  cursor: pointer;
  transition: 0.2s;
}
.lang-toggle:hover {
  background: var(--orange);
  border-color: var(--orange);
  color: var(--ink);
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
  z-index: 1001;
}
.hamburger span {
  width: 28px;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: 0.3s;
}

/* ========== Footer（与 about 同款不透明深色渐变） ========== */
footer {
  background: linear-gradient(118deg, #17191b 0%, #202326 56%, #25282b 100%);
  color: var(--footer-text);
  padding: 42px 0;
  border-top: none;
}

.footer-grid {
  display: grid;
}

.footer-grid h4,
.footer-brand {
  color: #fff;
  margin-bottom: 1.2rem;
  font-size: 1rem;
}

.footer-brand {
  font-family: Georgia, 'Times New Roman', serif;
  font-size: 22px;
  font-weight: 400;
  margin-bottom: 0;
  line-height: 1.3;
}

.footer-row {
  display: flex;
  justify-content: space-between;
  gap: 30px;
  align-items: end;
}

.footer-small {
  font-size: 12px;
  line-height: 1.7;
}

.footer-line {
  height: 1px;
  background: #33383c;
  margin: 28px 0 20px;
  border: none;
}

footer p {
  color: var(--footer-text);
}

.footer-grid a {
  color: var(--footer-text);
  text-decoration: none;
  display: block;
  margin-bottom: 0.5rem;
  font-size: 0.9rem;
}
.footer-grid a:hover {
  color: #fff;
}

.footer-bottom {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  text-align: center;
  font-size: 0.85rem;
  color: var(--footer-text);
}

/* ========== Responsive - Nav & Footer ========== */
@media (max-width: 900px) {
  .nav,
  .nav-container {
    height: 78px;
  }
  .nav-links,
  .navlinks {
    gap: 16px;
    font-size: 12px;
  }
}

@media (max-width: 768px) {
  .nav-links,
  .navlinks {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 78px;
    left: 0;
    width: 100%;
    background: rgba(23, 25, 27, 0.98);
    padding: 2rem;
    gap: 1.5rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    align-items: flex-start;
  }
  .nav-links.active,
  .navlinks.active {
    display: flex;
  }
  .hamburger {
    display: flex;
  }

  .nav-links li dl,
  .navlinks li dl {
    display: block !important;
    position: static;
    background: transparent;
    box-shadow: none;
    border: none;
    padding: 0.3rem 0 0.3rem 1rem;
    border-radius: 0;
    opacity: 1 !important;
    transform: none !important;
    pointer-events: auto !important;
    min-width: auto;
    backdrop-filter: none;
  }
  .nav-links li dl dd,
  .navlinks li dl dd {
    padding: 0.15rem 0;
  }
  .nav-links li dl dd a,
  .navlinks li dl dd a {
    color: rgba(255, 255, 255, 0.75);
    font-size: 0.8rem;
    padding: 0.2rem 0;
    white-space: normal;
    background: transparent !important;
  }
  .nav-links li dl dd a:hover,
  .navlinks li dl dd a:hover {
    color: #fff;
    background: transparent !important;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .footer-row {
    display: block;
  }
  .footer-brand {
    margin-bottom: 12px;
  }
  .footer-small {
    margin-top: 12px;
  }
  .footer-bottom {
    text-align: center;
    margin-top: 2rem;
    padding-top: 1.5rem;
  }
  .container {
    /* 只收窄左右 padding，保留 .nav-container 的上下 10px */
    padding-left: 1.5rem;
    padding-right: 1.5rem;
  }
}