:root {
  --header-offset: 122px;
  --primary: #E53935;
  --primary-dark: #C62828;
  --secondary: #FF5A4F;
  --bg: #F5F7FA;
  --text-main: #333333;
  --border-color: #E0E0E0;
  --card-bg: #FFFFFF;
}

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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--bg);
  color: var(--text-main);
  padding-top: var(--header-offset);
  overflow-x: hidden;
}

/* ===== Header ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  min-height: auto;
  z-index: 1000;
  background-color: #FFFFFF;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

/* Header Top */
.header-top {
  background-color: #FFFFFF;
  width: 100%;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-height: 68px;
  padding: 0 30px;
}

.logo {
  font-size: 28px;
  font-weight: 900;
  color: var(--primary) !important;
  text-decoration: none;
  letter-spacing: 1px;
  text-transform: uppercase;
  display: inline-block;
  line-height: 1.2;
}

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

.btn {
  display: inline-block;
  padding: 10px 22px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  text-align: center;
  transition: all 0.3s ease;
  border: none;
  cursor: pointer;
  line-height: 1.4;
}

.btn-register {
  background: linear-gradient(180deg, #FF5A4F 0%, #E53935 100%);
  color: #FFFFFF !important;
  box-shadow: 0 2px 8px rgba(229, 57, 53, 0.3);
}

.btn-register:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(229, 57, 53, 0.4);
}

.btn-download {
  background: var(--bg);
  color: var(--text-main) !important;
  border: 1px solid var(--border-color);
}

.btn-download:hover {
  background: var(--border-color);
}

/* Main Nav */
.main-nav {
  background-color: #FFFFFF;
  width: 100%;
  display: flex;
  border-top: 2px solid var(--primary);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  min-height: 52px;
  padding: 0 20px;
}

.nav-menu {
  list-style: none;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  gap: 4px;
  flex-wrap: wrap;
}

.nav-menu li {
  position: relative;
}

.nav-menu li a {
  display: block;
  padding: 10px 16px;
  color: var(--text-main);
  text-decoration: none;
  font-size: 15px;
  font-weight: 600;
  border-radius: 4px;
  transition: all 0.3s ease;
  white-space: nowrap;
}

.nav-menu li a:hover,
.nav-menu li a.active {
  color: var(--primary);
  background-color: rgba(229, 57, 53, 0.08);
}

/* Mobile elements hidden */
.hamburger-menu {
  display: none;
}

.mobile-menu-overlay {
  display: none;
}

.mobile-nav-buttons {
  display: none;
}

/* ===== Footer ===== */
.site-footer {
  background-color: #FFFFFF;
  border-top: 4px solid var(--primary);
  margin-top: 60px;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: 40px;
  padding: 40px 20px 30px;
}

.footer-brand .footer-logo {
  font-size: 28px;
  font-weight: 900;
  color: var(--primary) !important;
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.footer-desc {
  color: var(--text-main);
  font-size: 14px;
  line-height: 1.7;
  margin-top: 12px;
  max-width: 350px;
}

.footer-title {
  color: var(--primary);
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--primary);
  display: inline-block;
}

.footer-nav ul {
  list-style: none;
}

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

.footer-nav ul li a {
  color: var(--text-main);
  text-decoration: none;
  font-size: 14px;
  transition: color 0.3s ease;
  line-height: 1.6;
}

.footer-nav ul li a:hover {
  color: var(--primary);
  padding-left: 4px;
}

.footer-bottom {
  background-color: #FFFFFF;
  border-top: 1px solid var(--border-color);
  text-align: center;
  padding: 18px 20px;
}

.footer-bottom p {
  color: var(--text-main);
  font-size: 14px;
}

/* ===== Tablet Styles ===== */
@media (max-width: 992px) {
  .footer-container {
    grid-template-columns: 1fr 1fr;
    gap: 30px;
  }
}

/* ===== Mobile Styles ===== */
@media (max-width: 768px) {
  :root {
    --header-offset: 110px;
  }

  body {
    padding-top: var(--header-offset);
  }

  .site-header {
    background-color: #FFFFFF;
  }

  .header-top {
    min-height: 60px;
  }

  .header-container {
    width: 100%;
    max-width: none;
    min-height: 60px;
    padding: 0 15px;
    position: relative;
  }

  .logo {
    font-size: 24px;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1003;
  }

  .desktop-nav-buttons {
    display: none;
  }

  .main-nav {
    background-color: #FFFFFF;
    display: none;
    flex-direction: column;
    position: fixed;
    top: 60px;
    left: 0;
    width: 88%;
    max-width: 320px;
    height: auto;
    max-height: calc(100vh - 60px);
    overflow-y: auto;
    z-index: 1002;
    border-top: 2px solid var(--primary);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
    transform: translateX(-105%);
    transition: transform 0.35s ease;
  }

  .main-nav.active {
    display: block;
    transform: translateX(0);
  }

  .nav-container {
    width: 100%;
    max-width: none;
    min-height: auto;
    padding: 12px;
  }

  .nav-menu {
    list-style: none;
    display: flex;
    flex-direction: column;
    width: 100%;
  }

  .nav-menu li {
    width: 100%;
    border-bottom: 1px solid var(--border-color);
  }

  .nav-menu li:last-child {
    border-bottom: none;
  }

  .nav-menu li a {
    padding: 14px 12px;
    font-size: 16px;
    font-weight: 500;
    border-radius: 0;
    display: block;
    width: 100%;
  }

  .nav-menu li a:hover,
  .nav-menu li a.active {
    background-color: rgba(229, 57, 53, 0.08);
    color: var(--primary);
  }

  .mobile-nav-buttons {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    width: 100%;
    min-height: 48px;
    padding: 6px 15px;
    background-color: #FFFFFF;
    border-top: 1px solid var(--border-color);
    z-index: 1001;
  }

  .mobile-nav-buttons .btn {
    flex: 1;
    max-width: 180px;
    padding: 9px 14px;
    font-size: 13px;
  }

  .hamburger-menu {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 42px;
    height: 42px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
    margin-left: -6px;
    z-index: 1003;
    position: relative;
  }

  .hamburger-menu span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--text-main);
    margin: 3px auto;
    transition: all 0.35s ease;
    border-radius: 1px;
  }

  .hamburger-menu.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
    background-color: var(--primary);
  }

  .hamburger-menu.active span:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
  }

  .hamburger-menu.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
    background-color: var(--primary);
  }

  .mobile-menu-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1001;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.35s ease, visibility 0.35s ease;
  }

  .mobile-menu-overlay.active {
    display: block;
    opacity: 1;
    visibility: visible;
  }

  .footer-container {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 30px 16px 20px;
  }

  .footer-brand .footer-logo {
    font-size: 24px;
  }

  .footer-desc {
    font-size: 13px;
    max-width: 100%;
  }

  .footer-title {
    font-size: 15px;
    margin-bottom: 12px;
  }

  .footer-nav ul li {
    margin-bottom: 6px;
  }

  .footer-nav ul li a {
    font-size: 13px;
  }

  .footer-bottom {
    padding: 14px 16px;
  }

  .footer-bottom p {
    font-size: 13px;
  }

  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }

  .page-content {
    overflow-x: hidden;
    max-width: 100%;
  }

  body {
    overflow-x: hidden;
  }
}

@media (max-width: 480px) {
  .header-container {
    padding: 0 12px;
  }

  .logo {
    font-size: 22px;
  }

  .mobile-nav-buttons {
    padding: 5px 12px;
    gap: 8px;
  }

  .mobile-nav-buttons .btn {
    padding: 8px 10px;
    font-size: 12px;
    flex: 1;
  }

  .main-nav {
    top: 60px;
    width: 90%;
    max-width: 280px;
  }

  .nav-menu li a {
    padding: 12px 10px;
    font-size: 15px;
  }

  .footer-container {
    padding: 24px 12px 16px;
    gap: 20px;
  }
}
/* 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;
}