:root {
  --header-offset: 122px;
  --primary-color: #26A9E0;
  --secondary-color: #FFFFFF;
  --login-color: #EA7C07;
  --text-dark: #1a1a2e;
  --text-light: #ffffff;
  --bg-light: #f5f7fa;
}

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

body {
  padding-top: var(--header-offset);
  font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
  background-color: var(--secondary-color);
  color: var(--text-dark);
  overflow-x: hidden;
}

/* ==========================================
   SITE HEADER - FIXED TOP NAVIGATION
   ========================================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background-color: var(--secondary-color);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
  border-bottom: 2px solid rgba(38, 169, 224, 0.3);
  min-height: auto;
}

/* Desktop Header Top Bar */
.header-top {
  background: var(--secondary-color);
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 40px;
  min-height: 68px;
  gap: 20px;
}

/* Logo Styling */
.logo {
  font-size: 2.2rem;
  font-weight: 900;
  background: linear-gradient(135deg, #26A9E0, #1E7FA8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-decoration: none;
  letter-spacing: 1px;
  line-height: 1.2;
  display: inline-block;
  white-space: nowrap;
  position: relative;
}

.logo::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, #26A9E0, #EA7C07);
  border-radius: 2px;
}

/* Desktop Navigation Buttons */
.desktop-nav-buttons {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-left: auto;
  flex-shrink: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 22px;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.3s ease;
  cursor: pointer;
  border: 2px solid transparent;
  white-space: nowrap;
  letter-spacing: 0.3px;
}

.btn-login {
  background: linear-gradient(135deg, #EA7C07, #C96A06);
  color: #ffffff;
  border-color: #EA7C07;
}

.btn-login:hover {
  background: linear-gradient(135deg, #C96A06, #EA7C07);
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(234, 124, 7, 0.4);
}

.btn-register {
  background: linear-gradient(135deg, #26A9E0, #1E7FA8);
  color: #ffffff;
  border-color: #26A9E0;
}

.btn-register:hover {
  background: linear-gradient(135deg, #1E7FA8, #26A9E0);
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(38, 169, 224, 0.4);
}

.btn-primary {
  background: linear-gradient(135deg, #000000, #333333);
  color: #ffffff;
  border-color: #000000;
}

.btn-primary:hover {
  background: linear-gradient(135deg, #333333, #000000);
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

/* Main Navigation (Desktop) */
.main-nav {
  background: var(--primary-color);
  width: 100%;
  display: flex;
  justify-content: center;
  border-top: 1px solid rgba(255, 255, 255, 0.15);
}

.nav-container {
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  gap: 4px;
  padding: 8px 20px;
  min-height: 52px;
}

.nav-container a {
  color: var(--text-light);
  text-decoration: none;
  font-size: 0.82rem;
  font-weight: 500;
  padding: 6px 14px;
  border-radius: 6px;
  transition: background-color 0.3s ease, transform 0.2s ease;
  white-space: nowrap;
}

.nav-container a:hover {
  background-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-1px);
}

/* Hide mobile elements on desktop */
.hamburger-menu,
.mobile-menu-overlay,
.mobile-nav-buttons {
  display: none;
}

/* ==========================================
   SITE FOOTER
   ========================================== */
.site-footer {
  background: linear-gradient(180deg, #1a1a2e, #16213e);
  color: var(--text-light);
  padding-top: 60px;
  margin-top: 60px;
  border-top: 3px solid var(--primary-color);
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 40px;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 40px;
}

.footer-column h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--primary-color);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.footer-logo {
  font-size: 2rem;
  font-weight: 900;
  background: linear-gradient(135deg, #26A9E0, #EA7C07);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-decoration: none;
  display: inline-block;
  margin-bottom: 15px;
}

.footer-brand p {
  line-height: 1.7;
  font-size: 0.9rem;
  color: #b8c2cc;
  max-width: 300px;
}

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

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

.footer-nav a {
  color: #b8c2cc;
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.3s ease, padding-left 0.3s ease;
  display: inline-block;
}

.footer-nav a:hover {
  color: var(--primary-color);
  padding-left: 5px;
}

.footer-bottom {
  background: rgba(0, 0, 0, 0.4);
  padding: 20px;
  text-align: center;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
  font-size: 0.85rem;
  color: #b8c2cc;
}

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

  .site-header {
    background-color: var(--secondary-color);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  }

  .header-container {
    width: 100%;
    max-width: none;
    padding: 0 10px;
    min-height: 60px;
    display: flex;
    justify-content: flex-end;
    align-items: center;
    position: relative;
  }

  .logo {
    font-size: 1.6rem;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1;
  }

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

  /* Mobile Navigation Buttons */
  .mobile-nav-buttons {
    display: flex;
    justify-content: center;
    background: var(--secondary-color);
    border-top: 1px solid rgba(0, 0, 0, 0.08);
    padding: 6px 10px;
    gap: 8px;
    width: 100%;
    z-index: 1000;
  }

  .mobile-nav-buttons .btn {
    flex: 1;
    padding: 8px 12px;
    font-size: 0.78rem;
    max-width: 150px;
  }

  /* Main Nav - Mobile Sidebar */
  .main-nav {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 280px;
    height: 100vh;
    background: var(--primary-color);
    flex-direction: column;
    justify-content: flex-start;
    align-items: stretch;
    z-index: 1002;
    padding-top: 70px;
    padding-bottom: 20px;
    box-shadow: 4px 0 20px rgba(0, 0, 0, 0.2);
    overflow-y: auto;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
  }

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

  .nav-container {
    width: 100%;
    max-width: none;
    flex-direction: column;
    justify-content: flex-start;
    align-items: stretch;
    gap: 4px;
    padding: 0 16px;
    overflow-y: auto;
  }

  .nav-container a {
    color: var(--text-light);
    font-size: 1rem;
    padding: 12px 16px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 4px;
    text-align: left;
  }

  .nav-container a:last-child {
    border-bottom: none;
  }

  /* Hamburger Menu - Left Side */
  .hamburger-menu {
    display: block;
    position: absolute;
    left: 10px;
    top: 50%;
    transform: translateY(-50%);
    cursor: pointer;
    z-index: 1003;
    padding: 8px;
    border-radius: 4px;
  }

  .hamburger-menu span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--text-dark);
    margin: 5px 0;
    transition: all 0.3s ease;
    border-radius: 1px;
  }

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

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

  .hamburger-menu.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
    background: var(--primary-color);
  }

  /* Menu Overlay */
  .mobile-menu-overlay {
    display: block;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1001;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease;
  }

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

  body.no-scroll {
    overflow: hidden;
  }

  /* Footer Mobile */
  .footer-container {
    grid-template-columns: 1fr;
    padding: 0 20px;
    gap: 25px;
  }

  .footer-column h3 {
    margin-bottom: 12px;
    font-size: 1rem;
  }

  .footer-brand p {
    font-size: 0.85rem;
  }

  .footer-bottom {
    padding: 15px;
    font-size: 0.8rem;
  }
}

/* ==========================================
   MOBILE CONTENT PROTECTION
   ========================================== */
@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;
  }
}
/* 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;
}