:root {
  --header-offset: 166px;
  --primary-color: #FF8C1A;
  --secondary-color: #FFA53A;
  --card-bg: #17191F;
  --bg-color: #0D0E12;
  --text-main: #FFF3E6;
  --border-color: #A84F0C;
  --glow-color: #FFB04D;
  --deep-orange: #D96800;
}

body {
  padding-top: var(--header-offset);
  background-color: var(--bg-color);
  color: var(--text-main);
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  margin: 0;
  overflow-x: hidden;
}

/* ========== SITE HEADER ========== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background-color: var(--bg-color);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5), 0 2px 8px rgba(255, 140, 26, 0.3);
  z-index: 1000;
  min-height: auto;
}

/* Header Top */
.header-top {
  background: linear-gradient(135deg, #0D0E12 0%, #17191F 100%);
  border-bottom: 1px solid var(--border-color);
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 30px;
}

/* Logo */
.logo {
  display: inline-block;
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--text-main);
  text-decoration: none;
  letter-spacing: 1px;
  background: linear-gradient(135deg, var(--glow-color) 0%, var(--deep-orange) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: 0 0 20px rgba(255, 176, 77, 0.3);
}

/* Desktop Nav Buttons */
.desktop-nav-buttons {
  display: flex;
  gap: 10px;
  align-items: center;
}

.btn {
  display: inline-block;
  padding: 10px 22px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.3s ease;
  cursor: pointer;
  border: none;
  white-space: nowrap;
  color: #fff;
}

.btn-primary {
  background: linear-gradient(180deg, #FFA53A 0%, #D96800 100%);
  color: #fff;
  box-shadow: 0 4px 15px rgba(255, 140, 26, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(255, 140, 26, 0.6);
}

.btn-secondary {
  background: transparent;
  color: var(--text-main);
  border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
  background: var(--primary-color);
  color: #fff;
}

.btn-download {
  background: var(--card-bg);
  color: var(--glow-color);
  border: 2px solid var(--glow-color);
}

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

/* Main Navigation */
.main-nav {
  background: var(--card-bg);
  border-top: 1px solid var(--border-color);
  border-bottom: 2px solid var(--primary-color);
  display: flex;
  flex-direction: row;
  position: static;
  width: 100%;
}

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

.nav-link {
  color: var(--text-main);
  text-decoration: none;
  padding: 10px 16px;
  font-size: 0.95rem;
  font-weight: 500;
  transition: all 0.3s ease;
  border-radius: 6px;
  position: relative;
}

.nav-link:hover {
  color: var(--glow-color);
  background: rgba(255, 140, 26, 0.15);
  text-shadow: 0 0 10px rgba(255, 176, 77, 0.5);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: var(--primary-color);
  transition: width 0.3s ease;
  border-radius: 2px;
}

.nav-link:hover::after {
  width: 60%;
}

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

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

/* ========== SITE FOOTER ========== */
.site-footer {
  background: var(--card-bg);
  border-top: 2px solid var(--primary-color);
  margin-top: 40px;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 30px;
  padding: 50px 30px 30px;
}

.footer-column {
  min-width: 0;
}

.footer-logo {
  display: inline-block;
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-main);
  text-decoration: none;
  background: linear-gradient(135deg, var(--glow-color) 0%, var(--deep-orange) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 15px;
}

.footer-description {
  color: #aaa;
  font-size: 0.9rem;
  line-height: 1.6;
  margin: 0;
}

.footer-heading {
  color: var(--text-main);
  font-size: 1.1rem;
  margin-bottom: 18px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--primary-color);
  display: inline-block;
}

.footer-nav {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-link {
  color: #aaa;
  text-decoration: none;
  font-size: 0.9rem;
  transition: all 0.3s ease;
  padding: 3px 0;
}

.footer-link:hover {
  color: var(--glow-color);
  padding-left: 5px;
}

.footer-contact-text {
  color: #aaa;
  font-size: 0.9rem;
  margin: 8px 0;
  display: flex;
  align-items: center;
  gap: 8px;
}

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

.copyright-text {
  color: #aaa;
  font-size: 0.85rem;
  margin: 0;
}

/* ========== RESPONSIVE ========== */
@media (max-width: 768px) {
  :root {
    --header-offset: 146px;
  }
  
  .header-container {
    width: 100%;
    max-width: none;
    padding: 8px 15px;
  }
  
  .logo {
    font-size: 1.4rem;
    margin: 0 auto;
    display: block;
    text-align: center;
    flex: 1;
  }
  
  .desktop-nav-buttons {
    display: none;
  }
  
  .main-nav {
    display: none;
    flex-direction: column;
    position: fixed;
    top: 0;
    left: 0;
    width: 260px !important;
    height: 100vh;
    background: var(--card-bg);
    z-index: 1002;
    padding-top: 60px;
    overflow-y: auto;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    border-right: 2px solid var(--primary-color);
    border-top: none;
    border-bottom: none;
  }
  
  .main-nav.active,
  .main-nav.open {
    display: block;
    transform: translateX(0);
  }
  
  .nav-container {
    width: 100%;
    max-width: none;
    flex-direction: column;
    gap: 4px;
    padding: 10px 0;
  }
  
  .nav-link {
    display: block;
    padding: 12px 20px;
    font-size: 1rem;
    border-radius: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    color: var(--text-main);
  }
  
  .nav-link:hover {
    background: rgba(255, 140, 26, 0.1);
    color: var(--glow-color);
  }
  
  .mobile-nav-buttons {
    display: flex;
    justify-content: center;
    gap: 8px;
    padding: 8px 10px;
    background: var(--bg-color);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
    min-height: 48px;
    align-items: center;
  }
  
  .mobile-nav-buttons .btn {
    flex: 1;
    max-width: 130px;
    padding: 8px 12px;
    font-size: 0.82rem;
    text-align: center;
  }
  
  .mobile-menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1001;
    display: none;
  }
  
  .mobile-menu-overlay.visible {
    display: block;
  }
  
  .hamburger-menu {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 32px;
    height: 32px;
    cursor: pointer;
    z-index: 1003;
    background: none;
    border: none;
    padding: 0;
  }
  
  .hamburger-menu span {
    display: block;
    height: 3px;
    width: 100%;
    background: var(--text-main);
    border-radius: 3px;
    transition: all 0.3s ease;
  }
  
  .hamburger-menu.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 5px);
  }
  
  .hamburger-menu.active span:nth-child(2) {
    opacity: 0;
  }
  
  .hamburger-menu.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
  }
  
  .footer-container {
    width: 100%;
    max-width: none;
    grid-template-columns: 1fr;
    gap: 25px;
    padding: 40px 20px 20px;
  }
  
  .footer-column {
    text-align: center;
  }
  
  .footer-heading {
    font-size: 1rem;
  }
  
  .footer-nav {
    align-items: center;
  }
  
  .footer-link:hover {
    padding-left: 0;
  }
  
  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }
  
  .page-content {
    overflow-x: hidden;
    max-width: 100%;
  }
  
  body {
    overflow-x: hidden;
  }
}

/* Hamburger Menu - hidden on desktop */
.hamburger-menu {
  display: none;
}
/* 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;
}