/* shared_css.css */

/* Basic Reset & Box-sizing */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --primary-color: #007bff;
    --secondary-color: #6c757d;
    --accent-color: #28a745;
    --dark-color: #343a40;
    --light-color: #f8f9fa;
    --text-color: #212529;
    --heading-color: #343a40;
    --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";
    --font-family-monospace: SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

body {
    font-family: var(--font-family-sans-serif);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--light-color);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

#main-content-wrapper {
    flex: 1;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    color: var(--heading-color);
    margin-bottom: 0.5em;
    font-weight: 700;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: 1em;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: #0056b3;
    text-decoration: underline;
}

/* Buttons */
.btn {
    display: inline-block;
    font-weight: 400;
    color: var(--light-color);
    text-align: center;
    vertical-align: middle;
    user-select: none;
    background-color: transparent;
    border: 1px solid transparent;
    padding: 0.6rem 1.2rem;
    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;
}

/* Header */
.main-header {
    background-color: var(--dark-color);
    color: var(--light-color);
    padding: 1rem 0;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

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

.main-header .logo img {
    height: 40px;
    width: auto;
}

.main-nav .nav-links {
    list-style: none;
    display: flex;
    gap: 1.5rem;
    margin: 0;
    padding: 0;
}

.main-nav .nav-links a {
    color: var(--light-color);
    font-weight: 500;
    padding: 0.5rem 0;
    display: block;
    position: relative;
}

.main-nav .nav-links a:hover {
    color: var(--primary-color);
    text-decoration: none;
}

.main-nav .dropdown {
    position: relative;
}

.main-nav .dropdown-toggle {
    display: flex;
    align-items: center;
}

.main-nav .dropdown-toggle i {
    margin-left: 5px;
    font-size: 0.8em;
    transition: transform 0.3s ease;
}

.main-nav .dropdown:hover .dropdown-toggle i {
    transform: rotate(180deg);
}

.main-nav .dropdown-menu {
    display: none;
    position: absolute;
    background-color: var(--dark-color);
    min-width: 180px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    z-index: 1;
    list-style: none;
    padding: 0.5rem 0;
    border-radius: 0.25rem;
    top: 100%; /* Position below the parent link */
    left: 0;
    transform: translateY(10px);
    opacity: 0;
    transition: transform 0.3s ease, opacity 0.3s ease;
}

.main-nav .dropdown:hover .dropdown-menu {
    display: block;
    transform: translateY(0);
    opacity: 1;
}

.main-nav .dropdown-menu li a {
    color: var(--light-color);
    padding: 0.75rem 1rem;
    text-decoration: none;
    display: block;
    white-space: nowrap;
}

.main-nav .dropdown-menu li a:hover {
    background-color: #495057;
    color: var(--primary-color);
}

.main-header .auth-buttons {
    display: flex;
    gap: 10px;
}

.main-header .menu-toggle {
    display: none; /* Hidden on desktop */
    background: none;
    border: none;
    color: var(--light-color);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
}

/* Footer */
.main-footer {
    background-color: var(--dark-color);
    color: var(--light-color);
    padding: 3rem 0;
    margin-top: 50px; /* Space above footer */
}

.main-footer .footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.main-footer .footer-col h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.25rem;
}

.main-footer .footer-col p {
    font-size: 0.9rem;
    line-height: 1.8;
    color: rgba(255,255,255,0.7);
}

.main-footer .footer-logo img {
    margin-bottom: 1rem;
}

.main-footer .social-links {
    margin-top: 1.5rem;
}

.main-footer .social-links a {
    color: var(--light-color);
    font-size: 1.5rem;
    margin-right: 1rem;
    transition: color 0.3s ease;
}

.main-footer .social-links a:hover {
    color: var(--primary-color);
}

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

.main-footer ul li {
    margin-bottom: 0.75rem;
}

.main-footer ul li a {
    color: rgba(255,255,255,0.7);
    font-size: 0.95rem;
    transition: color 0.3s ease;
}

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

.main-footer .newsletter-form {
    display: flex;
    margin-top: 1rem;
}

.main-footer .newsletter-form input[type="email"] {
    flex-grow: 1;
    padding: 0.75rem 1rem;
    border: 1px solid rgba(255,255,255,0.3);
    border-radius: 0.25rem 0 0 0.25rem;
    background-color: rgba(255,255,255,0.1);
    color: var(--light-color);
    font-size: 0.9rem;
}

.main-footer .newsletter-form input[type="email"]::placeholder {
    color: rgba(255,255,255,0.5);
}

.main-footer .newsletter-form button {
    border-radius: 0 0.25rem 0.25rem 0;
    padding: 0.75rem 1.2rem;
    font-size: 0.9rem;
    white-space: nowrap;
}

.main-footer .footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding-top: 1.5rem;
    margin-top: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    font-size: 0.85rem;
    color: rgba(255,255,255,0.6);
}

.main-footer .footer-bottom .legal-links {
    display: flex;
    gap: 1.5rem;
    margin-top: 0;
}

.main-footer .footer-bottom .legal-links a {
    color: rgba(255,255,255,0.6);
}

.main-footer .footer-bottom .legal-links a:hover {
    color: var(--primary-color);
}

/* Responsive adjustments */
@media (max-width: 992px) {
    .main-nav .nav-links {
        gap: 1rem;
    }
}

@media (max-width: 768px) {
    .main-header .container {
        flex-direction: column;
        align-items: flex-start;
    }

    .main-header .logo {
        margin-bottom: 1rem;
        width: 100%;
        text-align: center;
    }

    .main-header .logo img {
        height: 35px;
    }

    .main-nav {
        width: 100%;
        display: flex;
        justify-content: flex-end;
        align-items: center;
    }

    .main-nav .menu-toggle {
        display: block;
        order: 1; /* Puts toggle button to the right */
        margin-left: auto;
    }

    .main-nav .nav-links {
        display: none; /* Hidden by default */
        flex-direction: column;
        width: 100%;
        background-color: var(--dark-color);
        position: absolute;
        top: 100%; /* Below header */
        left: 0;
        right: 0;
        padding: 1rem 0;
        box-shadow: 0 4px 8px rgba(0,0,0,0.2);
        z-index: 10;
        transition: max-height 0.3s ease-out, opacity 0.3s ease-out;
        max-height: 0;
        overflow: hidden;
        opacity: 0;
    }

    .main-nav .nav-links.active {
        display: flex; /* Show when active */
        max-height: 500px; /* Arbitrary large value */
        opacity: 1;
    }

    .main-nav .nav-links li {
        width: 100%;
        text-align: center;
    }

    .main-nav .nav-links a {
        padding: 0.75rem 0;
        border-bottom: 1px solid rgba(255,255,255,0.1);
    }

    .main-nav .nav-links li:last-child a {
        border-bottom: none;
    }

    .main-nav .dropdown-menu {
        position: static; /* Make dropdowns expand inline */
        width: 100%;
        background-color: #495057; /* Slightly different background */
        box-shadow: none;
        padding: 0;
        border-radius: 0;
        transform: none;
        opacity: 1;
        max-height: 0; /* Initially collapsed */
        overflow: hidden;
        transition: max-height 0.3s ease-out;
    }

    .main-nav .dropdown.active .dropdown-menu {
        max-height: 300px; /* Expand dropdown */
    }

    .main-nav .dropdown-menu li a {
        padding-left: 2rem; /* Indent dropdown items */
    }

    .main-header .auth-buttons {
        width: 100%;
        justify-content: center;
        margin-top: 1rem;
    }

    .main-footer .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .main-footer .footer-col {
        margin-bottom: 1.5rem;
    }

    .main-footer .footer-col ul {
        display: flex;
        flex-direction: column;
        align-items: center;
    }

    .main-footer .newsletter-form {
        max-width: 300px;
        margin-left: auto;
        margin-right: auto;
    }

    .main-footer .footer-bottom {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .main-footer .footer-bottom .legal-links {
        flex-direction: column;
        gap: 0.5rem;
    }
}

@media (max-width: 480px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.5rem; }
    .btn {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }
}
/* 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;
  }
}