:root {
  --primary: #2F6BFF;
  --primary-light: #6FA3FF;
  --primary-dark: #1E4FCC;
  --btn-gradient: linear-gradient(180deg, #4A8BFF 0%, #2F6BFF 100%);
  --card-bg: #FFFFFF;
  --bg-main: #F4F7FB;
  --text-main: #1F2D3D;
  --text-dark: #000000;
  --border-color: #D6E2FF;
  --glow-color: #A5C4FF;
  --header-offset: 122px;
}

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

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

/* ===== Header Styles ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background-color: #FFFFFF;
  box-shadow: 0 4px 20px rgba(47, 107, 255, 0.15);
  border-bottom: 2px solid var(--border-color);
  min-height: auto;
}

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

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  min-height: 68px;
}

/* Logo Styles */
.logo {
  display: block;
  text-decoration: none;
  font-size: 2rem;
  font-weight: 800;
  color: var(--primary);
  letter-spacing: -0.5px;
  line-height: 1.2;
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  background: var(--btn-gradient);
  color: #FFFFFF;
  border-radius: 10px;
  font-size: 1.4rem;
  font-weight: 800;
  box-shadow: 0 4px 12px rgba(47, 107, 255, 0.3);
}

.logo-text {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--primary);
}

/* Desktop Nav Buttons */
.desktop-nav-buttons {
  display: flex;
  align-items: center;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  border-radius: 50px;
  font-size: 0.9rem;
  font-weight: 700;
  text-decoration: none;
  transition: all 0.3s ease;
  white-space: nowrap;
  cursor: pointer;
  border: none;
  box-shadow: 0 4px 10px rgba(47, 107, 255, 0.2);
}

.btn-register {
  background: var(--btn-gradient);
  color: #FFFFFF;
}

.btn-register:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(47, 107, 255, 0.35);
}

.btn-login {
  background: #FFFFFF;
  color: var(--primary);
  border: 2px solid var(--primary);
  box-shadow: none;
}

.btn-login:hover {
  background: var(--primary);
  color: #FFFFFF;
}

.btn-download {
  background: var(--primary-light);
  color: #FFFFFF;
}

.btn-download:hover {
  background: var(--primary);
  transform: translateY(-2px);
}

/* Main Navigation */
.main-nav {
  background-color: var(--primary);
  width: 100%;
  display: flex;
  position: static;
  min-height: 52px;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  padding: 10px 20px;
  width: 100%;
}

.nav-list {
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  list-style: none;
  gap: 28px;
  flex-wrap: wrap;
}

.nav-item {
  position: relative;
}

.nav-link {
  display: block;
  color: #FFFFFF;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  padding: 6px 4px;
  position: relative;
  transition: color 0.3s ease;
  white-space: nowrap;
}

.nav-link:hover {
  color: #FFFFFF;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: #FFFFFF;
  transition: width 0.3s ease;
}

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

/* Hamburger Menu - Hidden on Desktop */
.hamburger-menu {
  display: none;
}

/* Mobile Nav Buttons - Hidden on Desktop */
.mobile-nav-buttons {
  display: none;
}

/* Mobile Menu Overlay - Hidden on Desktop */
.mobile-menu-overlay {
  display: none;
}

/* ===== Footer Styles ===== */
.site-footer {
  background-color: var(--primary);
  color: #FFFFFF;
  padding-top: 50px;
  margin-top: 60px;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: 40px;
  padding: 0 24px 40px;
}

.footer-logo {
  display: block;
  font-size: 1.8rem;
  font-weight: 800;
  color: #FFFFFF;
  text-decoration: none;
  margin-bottom: 16px;
}

.footer-desc {
  font-size: 0.9rem;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: 12px;
  text-align: left;
}

.footer-note {
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.7);
  font-weight: 500;
}

.footer-title {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 18px;
  position: relative;
  padding-bottom: 8px;
}

.footer-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 32px;
  height: 3px;
  background-color: #FFFFFF;
  border-radius: 2px;
}

.footer-nav {
  list-style: none;
  padding: 0;
}

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

.footer-nav a {
  color: rgba(255, 255, 255, 0.9);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.3s ease, padding-left 0.3s ease;
}

.footer-nav a:hover {
  color: #FFFFFF;
  padding-left: 4px;
}

.footer-contact-list {
  list-style: none;
  padding: 0;
}

.footer-contact-list li {
  margin-bottom: 10px;
}

.footer-contact-list a {
  color: rgba(255, 255, 255, 0.9);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.3s ease, padding-left 0.3s ease;
}

.footer-contact-list a:hover {
  color: #FFFFFF;
  padding-left: 4px;
}

/* Footer Bottom */
.footer-bottom {
  background-color: var(--primary-dark);
  padding: 16px 0;
}

.footer-bottom-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
}

.footer-copyright {
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.8);
}

.footer-policy-links {
  display: flex;
  gap: 20px;
  list-style: none;
}

.footer-policy-links a {
  color: rgba(255, 255, 255, 0.8);
  text-decoration: none;
  font-size: 0.85rem;
}

.footer-policy-links a:hover {
  color: #FFFFFF;
}

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

  /* Header Top */
  .header-container {
    width: 100%;
    max-width: none;
    padding: 12px 15px;
    min-height: 60px;
    justify-content: space-between;
  }

  /* Logo - Always visible on mobile */
  .logo {
    display: block;
    flex: 1;
    justify-content: center;
    text-align: center;
  }

  .logo-text {
    font-size: 1.5rem;
  }

  .logo-icon {
    width: 34px;
    height: 34px;
    font-size: 1.1rem;
  }

  /* Hide Desktop Buttons */
  .desktop-nav-buttons {
    display: none;
  }

  /* Mobile Buttons */
  .mobile-nav-buttons {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    padding: 8px 15px;
    background-color: #FFFFFF;
    border-bottom: 1px solid var(--border-color);
    min-height: 48px;
    flex-wrap: nowrap;
  }

  .mobile-nav-buttons .btn {
    padding: 8px 14px;
    font-size: 0.8rem;
    flex: 1;
    max-width: 120px;
  }

  /* Hamburger Menu */
  .hamburger-menu {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 40px;
    height: 40px;
    cursor: pointer;
    padding: 8px;
    z-index: 1001;
  }

  .hamburger-line {
    display: block;
    width: 100%;
    height: 2px;
    background-color: var(--primary);
    border-radius: 2px;
    transition: all 0.3s ease;
  }

  .hamburger-menu.active .line-1 {
    transform: translateY(7px) rotate(45deg);
  }

  .hamburger-menu.active .line-2 {
    opacity: 0;
  }

  .hamburger-menu.active .line-3 {
    transform: translateY(-7px) rotate(-45deg);
  }

  /* Main Navigation in Mobile */
  .main-nav {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 85%;
    max-width: 320px;
    height: 100vh;
    background-color: #FFFFFF;
    z-index: 1000;
    flex-direction: column;
    padding-top: 80px;
    box-shadow: 4px 0 20px rgba(0, 0, 0, 0.1);
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    overflow-y: auto;
  }

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

  .nav-container {
    width: 100%;
    max-width: none;
    padding: 20px;
    flex-direction: column;
    justify-content: flex-start;
    align-items: flex-start;
  }

  .nav-list {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
    width: 100%;
  }

  .nav-item {
    width: 100%;
  }

  .nav-link {
    color: var(--text-main);
    font-size: 1rem;
    padding: 12px 8px;
    border-bottom: 1px solid var(--border-color);
    width: 100%;
    display: block;
  }

  .nav-link::after {
    display: none;
  }

  .nav-link:hover {
    color: var(--primary);
    background-color: rgba(47, 107, 255, 0.05);
  }

  /* Overlay */
  .mobile-menu-overlay {
    display: block;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease;
  }

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

  /* Footer Mobile */
  .footer-container {
    grid-template-columns: 1fr;
    gap: 30px;
    padding: 0 20px 30px;
  }

  .footer-bottom-container {
    flex-direction: column;
    text-align: center;
    gap: 8px;
    padding: 0 15px;
  }

  .footer-policy-links {
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
  }

  /* Content area protection */
  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }

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

  body {
    overflow-x: hidden;
  }
}

/* ===== Extra Small Screens ===== */
@media (max-width: 480px) {
  .mobile-nav-buttons .btn {
    padding: 8px 10px;
    font-size: 0.75rem;
    max-width: 100px;
  }

  .logo-text {
    font-size: 1.3rem;
  }

  .logo-icon {
    width: 30px;
    height: 30px;
    font-size: 1rem;
  }
}
/* 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;
}