:root {
  --primary-color: #E53935;
  --secondary-color: #FF5A4F;
  --header-offset: 122px;
  --card-bg: #FFFFFF;
  --background: #F5F7FA;
  --text-main: #333333;
  --border-color: #E0E0E0;
  --bg-primary-dark: #b71c1c;
  --bg-primary-light: #ffcdd2;
}
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--background);
  padding-top: var(--header-offset);
  overflow-x: hidden;
}
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  display: block;
  box-shadow: 0 2px 15px rgba(0, 0, 0, 0.2);
  background-color: var(--bg-primary-dark);
}
.header-top {
  width: 100%;
  background: linear-gradient(90deg, #b71c1c 0%, var(--primary-color) 100%);
  border-bottom: 2px solid var(--secondary-color);
}
.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 24px;
  min-height: 44px;
}
.logo {
  font-size: 28px;
  font-weight: 900;
  color: #ffffff;
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 1px;
  display: block;
  line-height: 1.2;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}
.logo:hover {
  color: #ffffff;
  opacity: 0.9;
}
.desktop-nav-buttons {
  display: flex;
  align-items: center;
  gap: 10px;
}
.mobile-nav-buttons {
  display: none;
}
.btn {
  display: inline-block;
  padding: 8px 18px;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  border-radius: 25px;
  text-align: center;
  outline: none;
  border: none;
  cursor: pointer;
  line-height: 1.4;
  white-space: nowrap;
  box-shadow: 0 3px 10px rgba(229, 57, 53, 0.3);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.btn:active {
  transform: scale(0.95);
}
.btn-register {
  background: linear-gradient(180deg, #FF5A4F 0%, #E53935 100%);
  color: #ffffff;
}
.btn-login {
  background: linear-gradient(180deg, #FF5A4F 0%, #E53935 100%);
  color: #ffffff;
}
.btn-download {
  background: linear-gradient(180deg, #FF5A4F 0%, #E53935 100%);
  color: #ffffff;
}
.btn-download {
  background: linear-gradient(180deg, #FF5A4F 0%, #E53935 100%);
  color: #ffffff;
}
.main-nav {
  width: 100%;
  background-color: #ffffff;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  flex-direction: row;
  position: static;
}
.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  gap: 6px;
  flex-wrap: nowrap;
  width: 100%;
  padding: 8px 20px;
  min-height: 36px;
}
.nav-link {
  display: inline-block;
  color: var(--text-main);
  font-size: 13px;
  font-weight: 500;
  text-decoration: none;
  padding: 6px 12px;
  border-radius: 4px;
  line-height: 1.2;
  white-space: nowrap;
  transition: background-color 0.3s, color 0.3s;
}
.nav-link:hover,
.nav-link.active {
  background-color: var(--primary-color);
  color: #ffffff;
}
.hamburger-menu {
  display: none;
}
.mobile-menu-overlay {
  display: none;
}
@media (max-width: 768px) {
  :root {
    --header-offset: 110px;
  }
  .site-header {
    background-color: var(--bg-primary-dark);
  }
  .header-container {
    width: 100%;
    max-width: none;
    min-height: 36px;
    padding: 8px 15px;
    flex-wrap: nowrap;
  }
  .header-top {
    width: 100%;
  }
  .logo {
    font-size: 22px;
    letter-spacing: 0.5px;
    margin: 0 auto;
    text-align: center;
  }
  .desktop-nav-buttons {
    display: none;
  }
  .mobile-nav-buttons {
    display: flex;
    width: 100%;
    justify-content: center;
    align-items: center;
    gap: 8px;
    background: #b71c1c;
    padding: 5px 10px;
    min-height: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    overflow-x: auto;
  }
  .mobile-nav-buttons .btn {
    padding: 5px 12px;
    font-size: 12px;
    flex-shrink: 0;
  }
  .main-nav {
    display: block;
    flex-direction: column;
    position: fixed;
    top: 0;
    left: 0;
    width: 85%;
    max-width: 360px;
    height: 100vh;
    max-height: 100vh;
    overflow-y: auto;
    background-color: #ffffff;
    transform: translateX(-100%);
    transition: transform 0.3s ease-in-out;
    z-index: 1001;
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.2);
    border-right: 1px solid var(--border-color);
  }
  .main-nav.active {
    display: block;
    transform: translateX(0);
  }
  .nav-container {
    width: 100%;
    max-width: none;
    flex-direction: column;
    justify-content: flex-start;
    align-items: stretch;
    padding: 60px 15px 20px;
    gap: 0;
    height: auto;
    min-height: auto;
  }
  .nav-link {
    display: block;
    padding: 14px 12px;
    font-size: 16px;
    border-bottom: 1px solid #f0f0f0;
    color: var(--text-main);
    width: 100%;
    border-radius: 0;
  }
  .nav-link:hover,
  .nav-link.active {
    background-color: var(--primary-color);
    color: #ffffff;
  }
  .hamburger-menu {
    display: flex;
    position: fixed;
    top: 10px;
    left: 15px;
    z-index: 1002;
    background: none;
    border: none;
    cursor: pointer;
    width: 30px;
    height: 30px;
    flex-direction: column;
    justify-content: center;
    gap: 6px;
    padding: 0;
  }
  .hamburger-menu span {
    display: block;
    width: 28px;
    height: 3px;
    background-color: #ffffff;
    border-radius: 3px;
    transition: transform 0.3s ease, opacity 0.3s ease;
  }
  .hamburger-menu.active span:nth-child(1) {
    transform: translateY(9px) rotate(45deg);
  }
  .hamburger-menu.active span:nth-child(2) {
    opacity: 0;
  }
  .hamburger-menu.active span:nth-child(3) {
    transform: translateY(-9px) rotate(-45deg);
  }
  .mobile-menu-overlay.active {
    display: block;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 999;
  }
  body.no-scroll {
    overflow: hidden;
  }
  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }
  .page-content {
    overflow-x: hidden;
    max-width: 100%;
  }
  body {
    overflow-x: hidden;
  }
}
.site-footer {
  background-color: #1a1a1a;
  color: #cccccc;
  padding-top: 40px;
  margin-top: 60px;
}
.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: 30px;
  padding: 40px 20px;
}
.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 15px;
  padding-right: 30px;
}
.footer-logo {
  color: #ffffff;
  font-size: 24px;
  text-decoration: none;
  font-weight: 800;
}
.footer-description {
  font-size: 14px;
  line-height: 1.6;
  color: #999999;
}
.footer-copyright {
  font-size: 13px;
  color: #777777;
  padding-top: 20px;
  border-top: 1px solid #333;
}
.footer-heading {
  color: #ffffff;
  font-size: 16px;
  margin-bottom: 15px;
  font-weight: 600;
}
.footer-nav {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.footer-nav a {
  color: #aaaaaa;
  text-decoration: none;
  font-size: 14px;
  line-height: 1.6;
  transition: color 0.3s;
  display: inline-block;
}
.footer-nav a:hover {
  color: #ffffff;
}
@media (max-width: 768px) {
  .footer-container {
    grid-template-columns: 1fr;
    gap: 30px;
    padding: 30px 20px;
    width: 100%;
    max-width: none;
  }
  .footer-column {
    padding: 10px 0;
  }
  .footer-nav {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 5px 20px;
  }
  .footer-heading {
    margin-bottom: 10px;
    padding-bottom: 8px;
    border-bottom: 1px solid #333;
  }
  .footer-brand {
    padding-right: 0;
  }
}
/* 移动端内容区防溢出（系统追加，请勿删除） */
@media (max-width: 768px) {
  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }
  .page-content {
    overflow-x: hidden;
    max-width: 100%;
  }
  body {
    overflow-x: hidden;
  }
}
/* 内容保护（系统追加，请勿删除） */
body {
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}
input, textarea, select, [contenteditable="true"] {
  -webkit-user-select: text;
  -moz-user-select: text;
  user-select: text;
}