/* Basic Reset & Base Styles */
:root {
    --primary-color: #007bff;
    --secondary-color: #6c757d;
    --text-color: #333;
    --background-color: #f8f9fa;
    --border-color: #dee2e6;
    --font-family: 'Arial', sans-serif;
}
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}
a {
    color: var(--primary-color);
    text-decoration: none;
}
a:hover {
    text-decoration: underline;
}
ul {
    list-style: none;
}
/* Main Header Styles */
.main-header {
    background-color: #fff;
    border-bottom: 1px solid var(--border-color);
    padding: 15px 0;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}
.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
    flex-wrap: wrap;
}
.logo img {
    display: block;
    max-height: 40px;
}
.search-bar {
    flex-grow: 1;
    margin: 0 20px;
    max-width: 400px;
}
.search-bar form {
    display: flex;
}
.search-bar input {
    flex-grow: 1;
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: 4px 0 0 4px;
    outline: none;
}
.search-bar button {
    padding: 8px 15px;
    background-color: var(--primary-color);
    color: #fff;
    border: 1px solid var(--primary-color);
    border-radius: 0 4px 4px 0;
    cursor: pointer;
    transition: background-color 0.3s ease;
}
.search-bar button:hover {
    background-color: #0056b3;
}
.user-actions {
    display: flex;
    align-items: center;
    gap: 10px;
}
.btn {
    display: inline-block;
    padding: 8px 15px;
    border-radius: 4px;
    text-align: center;
    transition: background-color 0.3s ease, color 0.3s ease;
    white-space: nowrap;
}
.btn-primary {
    background-color: var(--primary-color);
    color: #fff;
    border: 1px solid var(--primary-color);
}
.btn-primary:hover {
    background-color: #0056b3;
    border-color: #0056b3;
    text-decoration: none;
}
.btn-secondary {
    background-color: var(--secondary-color);
    color: #fff;
    border: 1px solid var(--secondary-color);
}
.btn-secondary:hover {
    background-color: #5a6268;
    border-color: #5a6268;
    text-decoration: none;
}
.language-selector select {
    padding: 7px 10px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background-color: #fff;
    cursor: pointer;
}
.main-nav {
    position: relative;
}
.nav-list {
    display: flex;
    justify-content: flex-start;
    gap: 20px;
}
.nav-item {
    position: relative;
}
.nav-item a {
    display: block;
    padding: 10px 0;
    color: var(--text-color);
    font-weight: bold;
    transition: color 0.3s ease;
}
.nav-item a:hover {
    color: var(--primary-color);
    text-decoration: none;
}
.submenu, .submenu-level2 {
    position: absolute;
    top: 100%;
    left: 0;
    background-color: #fff;
    border: 1px solid var(--border-color);
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    min-width: 200px;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s;
}
.nav-item.has-submenu:hover > .submenu,
.has-submenu-level2:hover > .submenu-level2 {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.submenu li a, .submenu-level2 li a {
    padding: 10px 15px;
    white-space: nowrap;
    font-weight: normal;
}
.submenu-level2 {
    left: 100%;
    top: 0;
}
.menu-toggle {
    display: none; /* Hidden on desktop */
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
}
.icon-bar {
    display: block;
    width: 25px;
    height: 3px;
    background-color: var(--text-color);
    margin: 5px 0;
    transition: all 0.3s ease;
}
/* Main Footer Styles */
.main-footer {
    background-color: #343a40;
    color: #f8f9fa;
    padding: 40px 0;
    font-size: 0.9em;
}
.main-footer a {
    color: #adb5bd;
}
.main-footer a:hover {
    color: #fff;
    text-decoration: underline;
}
.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-bottom: 30px;
}
.footer-column h3 {
    color: #fff;
    margin-bottom: 15px;
    font-size: 1.1em;
}
.footer-column p {
    margin-bottom: 10px;
}
.footer-column ul {
    list-style: none;
    padding: 0;
}
.footer-column ul li {
    margin-bottom: 8px;
}
.social-links {
    margin-top: 20px;
    display: flex;
    gap: 15px;
}
.social-links img {
    filter: invert(80%); /* Make icons visible on dark background */
    transition: filter 0.3s ease;
}
.social-links a:hover img {
    filter: invert(100%);
}
.newsletter form {
    display: flex;
    margin-top: 15px;
}
.newsletter input[type="email"] {
    flex-grow: 1;
    padding: 10px 15px;
    border: 1px solid #6c757d;
    border-radius: 4px 0 0 4px;
    background-color: #495057;
    color: #fff;
    outline: none;
}
.newsletter input[type="email"]::placeholder {
    color: #ced4da;
}
.btn-subscribe {
    background-color: var(--primary-color);
    color: #fff;
    border: 1px solid var(--primary-color);
    padding: 10px 20px;
    border-radius: 0 4px 4px 0;
    cursor: pointer;
    transition: background-color 0.3s ease;
}
.btn-subscribe:hover {
    background-color: #0056b3;
    border-color: #0056b3;
}
.privacy-policy-note {
    font-size: 0.8em;
    margin-top: 10px;
    color: #adb5bd;
}
.footer-bottom {
    border-top: 1px solid #495057;
    padding-top: 20px;
    margin-top: 30px;
    text-align: center;
    color: #adb5bd;
}
.footer-bottom p {
    margin-bottom: 8px;
}
/* Responsive Adjustments */
@media (max-width: 992px) {
    .header-top {
        flex-direction: column;
        align-items: flex-start;
    }
    .search-bar {
        width: 100%;
        margin: 15px 0;
        max-width: none;
    }
    .user-actions {
        width: 100%;
        justify-content: flex-start;
        margin-top: 10px;
    }
    .main-nav .nav-list {
        display: none; /* Hide by default on mobile */
        flex-direction: column;
        width: 100%;
        background-color: #fff;
        border-top: 1px solid var(--border-color);
        position: absolute;
        left: 0;
        top: 100%;
        box-shadow: 0 2px 5px rgba(0,0,0,0.1);
        z-index: 999;
    }
    .main-nav .nav-list.active {
        display: flex; /* Show when active */
    }
    .nav-item {
        width: 100%;
        border-bottom: 1px solid #eee;
    }
    .nav-item a {
        padding: 12px 15px;
    }
    .submenu, .submenu-level2 {
        position: static;
        border: none;
        box-shadow: none;
        background-color: #f2f2f2;
        min-width: unset;
        opacity: 1;
        visibility: visible;
        transform: none;
        display: none; /* Hidden by default on mobile */
    }
    .nav-item.has-submenu.active > .submenu,
    .has-submenu-level2.active > .submenu-level2 {
        display: block; /* Show when active */
    }
    .submenu li a, .submenu-level2 li a {
        padding-left: 30px;
    }
    .submenu-level2 li a {
        padding-left: 45px;
    }
    .menu-toggle {
        display: block; /* Show toggle button on mobile */
    }
}
@media (max-width: 768px) {
    .footer-grid {
        grid-template-columns: 1fr;
    }
    .footer-column {
        text-align: center;
    }
    .social-links {
        justify-content: center;
    }
    .newsletter form {
        flex-direction: column;
        max-width: 300px;
        margin-left: auto;
        margin-right: auto;
    }
    .newsletter input[type="email"] {
        border-radius: 4px;
        margin-bottom: 10px;
    }
    .btn-subscribe {
        border-radius: 4px;
    }
}
/* 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;
  }
}