/* Basic Reset & Typography */
:root {
    --primary-color: #007bff;
    --secondary-color: #6c757d;
    --text-color: #333;
    --heading-color: #222;
    --background-color: #f8f9fa;
    --border-color: #dee2e6;
    --font-family-base: 'Arial', sans-serif;
}

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

body {
    font-family: var(--font-family-base);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

a:hover {
    text-decoration: underline;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--heading-color);
    margin-bottom: 0.5em;
    line-height: 1.2;
}

/* Layout & Containers */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* Buttons */
.btn {
    display: inline-block;
    font-weight: 400;
    color: #fff;
    text-align: center;
    vertical-align: middle;
    user-select: none;
    background-color: var(--primary-color);
    border: 1px solid var(--primary-color);
    padding: 0.625rem 1.25rem;
    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;
    cursor: pointer;
}

.btn:hover {
    background-color: #0056b3;
    border-color: #0056b3;
    text-decoration: none;
}

.btn-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-secondary {
    background-color: var(--secondary-color);
    border-color: var(--secondary-color);
}

.btn-secondary:hover {
    background-color: #5a6268;
    border-color: #545b62;
}

.btn-subscribe {
    background-color: #28a745;
    border-color: #28a745;
}

.btn-subscribe:hover {
    background-color: #218838;
    border-color: #1e7e34;
}

/* Forms */
input[type="text"],
input[type="email"],
input[type="search"],
input[type="password"],
textarea,
select {
    display: block;
    width: 100%;
    padding: 0.5rem 0.75rem;
    font-size: 1rem;
    line-height: 1.5;
    color: #495057;
    background-color: #fff;
    background-clip: padding-box;
    border: 1px solid var(--border-color);
    border-radius: 0.25rem;
    transition: border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
}

input[type="search"] {
    -webkit-appearance: none; /* Remove default search input styling */
}

input:focus,
textarea:focus,
select:focus {
    color: #495057;
    background-color: #fff;
    border-color: #80bdff;
    outline: 0;
    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}

/* Utility Classes */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-left { text-align: left; }
.d-flex { display: flex; }
.justify-content-between { justify-content: space-between; }
.align-items-center { align-items: center; }
.sr-only, .screen-reader-text {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Header Specifics */
.site-header {
    background-color: #fff;
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.header-top-bar {
    background-color: #f2f2f2;
    font-size: 0.875rem;
    padding: 8px 0;
    border-bottom: 1px solid #e0e0e0;
}

.header-top-bar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.top-bar-left a, .top-bar-right a {
    margin-right: 15px;
    color: #555;
}

.top-bar-left a:last-child, .top-bar-right a:last-child {
    margin-right: 0;
}

.language-selector select {
    border: none;
    background: transparent;
    padding: 0;
    font-size: 0.875rem;
    color: #555;
    cursor: pointer;
}

.social-links a {
    font-size: 1rem;
    margin-left: 10px;
}

.header-main {
    padding: 15px 0;
}

.header-main .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap; /* Allow wrapping on smaller screens */
}

.logo img {
    max-height: 40px;
    width: auto;
    vertical-align: middle;
}

.main-navigation ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.main-navigation > ul {
    display: flex;
    gap: 25px;
}

.main-navigation ul li {
    position: relative;
}

.main-navigation ul li a {
    display: block;
    padding: 10px 0;
    color: var(--heading-color);
    font-weight: 500;
    white-space: nowrap;
}

.main-navigation ul li a:hover {
    color: var(--primary-color);
    text-decoration: none;
}

.main-navigation ul ul { /* Sub-menu styles */
    position: absolute;
    top: 100%;
    left: 0;
    background-color: #fff;
    border: 1px solid var(--border-color);
    min-width: 200px;
    z-index: 1000;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    display: none; /* Hidden by default */
    padding: 10px 0;
    border-radius: 0.25rem;
}

.main-navigation ul li:hover > ul {
    display: block;
}

.main-navigation ul ul li a {
    padding: 8px 15px;
    font-size: 0.95rem;
}

.main-navigation .menu-toggle {
    display: none; /* Hidden on desktop */
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 5px;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 20px;
}

.search-box {
    position: relative;
}

.search-box input[type="search"] {
    padding-right: 40px; /* Make space for the button */
    width: 200px;
}

.search-box button {
    position: absolute;
    right: 0;
    top: 0;
    height: 100%;
    background: none;
    border: none;
    color: var(--primary-color);
    padding: 0 10px;
    cursor: pointer;
    font-size: 1rem;
}

.user-auth a {
    margin-left: 10px;
}

/* Footer Specifics */
.site-footer {
    background-color: #222;
    color: #ccc;
    padding: 60px 0 30px;
    font-size: 0.9rem;
}

.site-footer a {
    color: #eee;
}

.site-footer a:hover {
    color: var(--primary-color);
    text-decoration: underline;
}

.footer-widgets {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    margin-bottom: 40px;
}

.footer-widget {
    flex: 1;
    min-width: 250px;
    margin-bottom: 30px;
    padding-right: 20px;
}

.footer-widget:last-child {
    padding-right: 0;
}

.footer-widget h3 {
    color: #fff;
    font-size: 1.2rem;
    margin-bottom: 20px;
}

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

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

.footer-widget address p {
    margin-bottom: 8px;
}

.newsletter-form {
    display: flex;
    margin-top: 15px;
}

.newsletter-form input[type="email"] {
    flex-grow: 1;
    border-top-right-radius: 0;
    border-bottom-right-radius: 0;
    border-color: #555;
    background-color: #333;
    color: #fff;
}

.newsletter-form button {
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
    white-space: nowrap;
}

.social-icons {
    margin-top: 20px;
}

.social-icons a {
    display: inline-block;
    width: 35px;
    height: 35px;
    line-height: 35px;
    text-align: center;
    background-color: #444;
    color: #fff;
    border-radius: 50%;
    margin-right: 10px;
    transition: background-color 0.3s ease;
}

.social-icons a:hover {
    background-color: var(--primary-color);
    text-decoration: none;
}

.footer-bottom {
    border-top: 1px solid #333;
    padding-top: 20px;
    text-align: center;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.footer-bottom p {
    margin: 0;
}

.back-to-top {
    margin-top: 10px; /* For smaller screens */
}

.back-to-top a {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 5px 10px;
    background-color: #444;
    border-radius: 5px;
    color: #fff;
}

.back-to-top a:hover {
    background-color: var(--primary-color);
    text-decoration: none;
}

/* Responsive Adjustments */
@media (max-width: 992px) {
    .main-navigation > ul {
        display: none; /* Hide main menu on smaller screens by default */
        flex-direction: column;
        width: 100%;
        position: absolute;
        top: 100%;
        left: 0;
        background-color: #fff;
        border-top: 1px solid var(--border-color);
        box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        z-index: 999;
    }

    .main-navigation > ul.active {
        display: flex; /* Show when active */
    }

    .main-navigation ul li {
        width: 100%;
        border-bottom: 1px solid #f0f0f0;
    }

    .main-navigation ul ul {
        position: static;
        border: none;
        box-shadow: none;
        padding-left: 20px;
        background-color: #f9f9f9;
    }

    .main-navigation .menu-toggle {
        display: block; /* Show hamburger icon */
    }

    .header-main .container {
        flex-wrap: wrap;
        justify-content: space-between;
    }

    .header-actions {
        order: 3; /* Move actions below logo/nav toggle */
        width: 100%;
        justify-content: center;
        margin-top: 15px;
    }

    .logo {
        flex-basis: auto;
    }

    .footer-widgets {
        flex-direction: column;
    }

    .footer-widget {
        min-width: unset;
        padding-right: 0;
        margin-bottom: 40px;
    }

    .footer-bottom {
        flex-direction: column;
    }
    .footer-bottom p {
        margin-bottom: 10px;
    }
    .back-to-top {
        margin-top: 15px;
    }
}

@media (max-width: 768px) {
    .header-top-bar .container {
        flex-direction: column;
        text-align: center;
    }
    .top-bar-left, .top-bar-right {
        margin-bottom: 10px;
    }
    .top-bar-right {
        display: flex;
        justify-content: center;
        align-items: center;
        width: 100%;
    }
    .language-selector {
        margin-right: 15px;
    }
    .social-links a {
        margin: 0 5px;
    }
    .search-box input[type="search"] {
        width: 100%;
    }
    .header-actions {
        flex-direction: column;
        gap: 10px;
    }
    .user-auth {
        display: flex;
        gap: 10px;
    }
    .user-auth a {
        margin-left: 0;
    }
}
/* 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;
  }
}