:root {
    --primary-color: #007bff;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --info-color: #17a2b8;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
    --text-color: #333;
    --bg-color: #fff;
    --border-color: #dee2e6;
    --font-family-sans-serif: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
    --header-height: 80px;
}

body {
    font-family: var(--font-family-sans-serif);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    margin-top: 0;
    margin-bottom: 0.5rem;
    font-weight: 600;
    line-height: 1.2;
    color: var(--dark-color);
}

p {
    margin-top: 0;
    margin-bottom: 1rem;
}

a {
    color: var(--primary-color);
    text-decoration: none;
}
a:hover {
    text-decoration: underline;
}

/* Buttons */
.btn {
    display: inline-block;
    font-weight: 400;
    color: #fff;
    text-align: center;
    vertical-align: middle;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    background-color: transparent;
    border: 1px solid transparent;
    padding: 0.5rem 1rem;
    font-size: 1rem;
    line-height: 1.5;
    border-radius: 0.25rem;
    transition: color 0.15s ease-in-out, background-color 0.15s ease-in-out, border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
}
.btn-primary {
    color: #fff;
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}
.btn-primary:hover {
    color: #fff;
    background-color: #0056b3;
    border-color: #0056b3;
}
.btn-secondary {
    color: #fff;
    background-color: var(--secondary-color);
    border-color: var(--secondary-color);
}
.btn-secondary:hover {
    color: #fff;
    background-color: #545b62;
    border-color: #545b62;
}
.btn-outline {
    color: var(--primary-color);
    border-color: var(--primary-color);
    background-color: transparent;
}
.btn-outline:hover {
    color: #fff;
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}
.btn-lg {
    padding: 0.75rem 1.5rem;
    font-size: 1.25rem;
    border-radius: 0.3rem;
}

/* Header */
.site-header {
    background-color: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 2px 4px rgba(0,0,0,.05);
    position: sticky;
    top: 0;
    z-index: 1000;
}
.header-top-bar {
    background-color: var(--dark-color);
    color: var(--light-color);
    padding: 8px 0;
    font-size: 0.875rem;
    text-align: center;
}
.header-top-bar a {
    color: var(--primary-color);
    font-weight: bold;
}
.main-header-content {
    padding: 15px 0;
}
.main-header-content .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.branding .logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--dark-color);
    text-decoration: none;
}
.branding .logo svg {
    margin-right: 8px;
}
.main-nav .nav-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
}
.main-nav .nav-item {
    position: relative;
    margin-left: 25px;
}
.main-nav .nav-link {
    color: var(--dark-color);
    font-weight: 500;
    padding: 5px 0;
    display: block;
}
.main-nav .nav-link:hover {
    color: var(--primary-color);
    text-decoration: none;
}
.main-nav .dropdown-menu {
    display: none;
    position: absolute;
    background-color: var(--bg-color);
    box-shadow: 0 8px 16px rgba(0,0,0,0.1);
    min-width: 180px;
    z-index: 1;
    list-style: none;
    padding: 10px 0;
    border-radius: 0.25rem;
    margin-top: 10px;
    left: 0;
}
.main-nav .dropdown:hover .dropdown-menu,
.main-nav .dropdown .dropdown-menu.active {
    display: block;
}
.main-nav .dropdown-menu li a {
    color: var(--text-color);
    padding: 8px 20px;
    display: block;
    white-space: nowrap;
}
.main-nav .dropdown-menu li a:hover {
    background-color: var(--light-color);
    text-decoration: none;
}
.header-actions {
    display: flex;
    align-items: center;
    gap: 15px;
}
.search-bar {
    position: relative;
    display: flex;
    align-items: center;
}
.search-input {
    border: 1px solid var(--border-color);
    padding: 8px 12px;
    border-radius: 20px;
    font-size: 0.9rem;
    outline: none;
    width: 180px;
    transition: width 0.3s ease, border-color 0.3s ease;
}
.search-input:focus {
    width: 220px;
    border-color: var(--primary-color);
}
.search-button {
    background: none;
    border: none;
    cursor: pointer;
    position: absolute;
    right: 10px;
    padding: 0;
}
.search-button svg {
    color: var(--secondary-color);
}
.menu-toggle {
    display: none; /* Hidden on desktop */
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
    width: 30px;
    height: 20px;
    position: relative;
    flex-direction: column;
    justify-content: space-between;
}
.menu-toggle .icon-bar {
    display: block;
    width: 100%;
    height: 3px;
    background-color: var(--dark-color);
    border-radius: 2px;
    transition: all 0.3s ease;
}

.hero-section {
    background: linear-gradient(135deg, var(--primary-color), #0056b3);
    color: #fff;
    padding: 100px 0;
    text-align: center;
}
.hero-section h1 {
    color: #fff;
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}
.hero-section p {
    font-size: 1.35rem;
    margin-bottom: 2.5rem;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.5;
}
.hero-actions .btn {
    margin: 0 10px;
    min-width: 160px;
}

/* Footer */
.site-footer {
    background-color: var(--dark-color);
    color: var(--light-color);
    padding: 60px 0 20px;
    font-size: 0.9rem;
}
.site-footer h3 {
    color: #fff;
    margin-bottom: 1.5rem;
    font-size: 1.15rem;
    font-weight: 600;
}
.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
    padding-bottom: 20px;
    border-bottom: 1px solid #444;
}
.footer-col ul {
    list-style: none;
    padding: 0;
    margin: 0;
}
.footer-col ul li {
    margin-bottom: 10px;
}
.footer-col ul li a {
    color: var(--light-color);
    transition: color 0.2s ease;
}
.footer-col ul li a:hover {
    color: var(--primary-color);
    text-decoration: none;
}
.footer-col.about-us p {
    margin-bottom: 20px;
}
.social-links {
    display: flex;
    gap: 15px;
    margin-top: 20px;
}
.social-links a {
    color: var(--light-color);
    font-size: 1.3rem;
    transition: color 0.2s ease;
}
.social-links a:hover {
    color: var(--primary-color);
}
.newsletter-form {
    display: flex;
    margin-top: 15px;
}
.newsletter-form input[type="email"] {
    flex-grow: 1;
    padding: 10px 15px;
    border: 1px solid #555;
    border-radius: 0.25rem 0 0 0.25rem;
    background-color: #444;
    color: #fff;
    outline: none;
    font-size: 0.9rem;
}
.newsletter-form input[type="email"]::placeholder {
    color: #bbb;
}
.newsletter-form button {
    border-radius: 0 0.25rem 0.25rem 0;
    padding: 10px 20px;
    white-space: nowrap;
    font-size: 0.9rem;
}
.footer-bottom {
    padding-top: 20px;
    margin-top: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}
.footer-bottom p {
    margin-bottom: 0;
    font-size: 0.85rem;
}
.footer-bottom .bottom-nav {
    display: flex;
    gap: 20px;
    list-style: none;
    padding: 0;
    margin: 0;
}
.footer-bottom .bottom-nav li a {
    color: var(--light-color);
    font-size: 0.85rem;
}
.footer-bottom .bottom-nav li a:hover {
    color: var(--primary-color);
}

/* Responsive adjustments */
@media (max-width: 992px) {
    .main-nav {
        display: none; /* Hidden main nav on smaller screens initially */
        flex-direction: column;
        position: absolute;
        top: var(--header-height);
        left: 0;
        width: 100%;
        background-color: var(--bg-color);
        box-shadow: 0 8px 16px rgba(0,0,0,0.1);
        padding: 20px 0;
        border-top: 1px solid var(--border-color);
        z-index: 999;
    }
    .main-nav.active {
        display: flex;
    }
    .main-nav .nav-list {
        flex-direction: column;
        align-items: center;
        width: 100%;
    }
    .main-nav .nav-item {
        margin: 10px 0;
        width: 100%;
        text-align: center;
    }
    .main-nav .nav-link {
        padding: 10px 0;
        border-bottom: 1px solid var(--light-color);
    }
    .main-nav .dropdown-menu {
        position: static;
        box-shadow: none;
        border: none;
        margin-top: 0;
        padding: 0;
        background-color: var(--light-color);
        width: 100%;
    }
    .main-nav .dropdown-menu li a {
        padding: 8px 0 8px 40px;
    }
    .header-actions {
        order: 1; 
        width: auto; /* Adjust width as needed */
        justify-content: flex-end;
        flex-grow: 1;
    }
    .header-actions .menu-toggle {
        display: flex; /* Show toggle button */
    }
    .main-header-content .container {
        flex-wrap: wrap;
        justify-content: space-between;
        gap: 15px;
    }
    .branding {
        flex-grow: 1;
    }
    .search-bar {
        display: none; /* Hide search bar on mobile for simplicity */
    }
    .hero-section {
        padding: 60px 0;
    }
    .hero-section h1 {
        font-size: 2.5rem;
    }
    .hero-section p {
        font-size: 1.1rem;
    }
}

@media (max-width: 768px) {
    .hero-actions {
        flex-direction: column;
        gap: 15px;
    }
    .hero-actions .btn {
        width: 80%;
        max-width: 300px;
    }
    .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }
    .footer-col ul {
        text-align: center;
        margin-bottom: 20px;
    }
    .footer-col.about-us .social-links {
        justify-content: center;
    }
    .newsletter-form {
        max-width: 350px;
        margin-left: auto;
        margin-right: auto;
    }
    .footer-bottom {
        flex-direction: column;
        gap: 15px;
    }
    .footer-bottom .bottom-nav {
        flex-direction: column;
        align-items: center;
    }
}
/* 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;
  }
}