/* shared_css: Global Styles for MyWebApp */

/* Variables */
: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;
    --text-light-color: #666;
    --bg-light-color: #f4f7f6;
    --border-color: #dee2e6;
    --font-family-sans: 'Roboto', sans-serif;
    --header-height: 70px;
    --footer-height: auto; /* dynamic */
    --spacing-sm: 10px;
    --spacing-md: 20px;
    --spacing-lg: 40px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family-sans);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-light-color);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

#main-content {
    flex: 1; /* Ensures main content takes available space, pushing footer down */
    padding-top: var(--header-height); /* Adjust for sticky header */
}

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

a:hover {
    color: #0056b3; /* Darker shade of primary-color */
    text-decoration: underline;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    margin-bottom: var(--spacing-md);
    font-weight: 700;
    color: var(--dark-color);
    line-height: 1.2;
}

h1 { font-size: 2.8em; }
h2 { font-size: 2.2em; }
h3 { font-size: 1.8em; }
h4 { font-size: 1.4em; }
h5 { font-size: 1.2em; }
h6 { font-size: 1em; }

p {
    margin-bottom: var(--spacing-sm);
}

ul, ol {
    margin-left: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

ul li, ol li {
    margin-bottom: calc(var(--spacing-sm) / 2);
}

/* Utility Classes */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }

.py-sm { padding-top: var(--spacing-sm); padding-bottom: var(--spacing-sm); }
.py-md { padding-top: var(--spacing-md); padding-bottom: var(--spacing-md); }
.py-lg { padding-top: var(--spacing-lg); padding-bottom: var(--spacing-lg); }

.px-sm { padding-left: var(--spacing-sm); padding-right: var(--spacing-sm); }
.px-md { padding-left: var(--spacing-md); padding-right: var(--spacing-md); }
.px-lg { padding-left: var(--spacing-lg); padding-right: var(--spacing-lg); }

.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: #fff;
    padding: 10px 20px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 500;
    transition: background-color 0.3s ease, transform 0.2s ease;
    border: none;
    cursor: pointer;
    font-size: 1em;
}

.btn:hover {
    background-color: #0056b3; /* Darker shade of primary-color */
    transform: translateY(-2px);
    color: #fff; /* Ensure text color remains white on hover */
}

.btn-outline {
    background-color: transparent;
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}

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

.card {
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

/* Forms */
.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    margin-bottom: calc(var(--spacing-sm) / 2);
    font-weight: 500;
}

.form-group input[type="text"],
.form-group input[type="email"],
.form-group input[type="password"],
.form-group input[type="number"],
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-family: var(--font-family-sans);
    font-size: 1em;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    border-color: var(--primary-color);
    outline: none;
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.25);
}

textarea {
    resize: vertical;
    min-height: 80px;
}

/* Header & Footer specific styles (can be moved if desired, but good for shared) */
.main-header {
    background-color: #ffffff;
    padding: 15px 30px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #eee;
    position: fixed; /* Changed from sticky for fixed header */
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    height: var(--header-height);
}

.main-header .logo {
    font-size: 1.8em;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    display: flex;
    align-items: center;
}
.main-header .logo i {
    margin-right: 10px;
    color: var(--success-color);
}
.main-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
}
.main-nav ul li {
    margin-left: 25px;
}
.main-nav ul li a {
    text-decoration: none;
    color: var(--text-light-color);
    font-weight: 500;
    padding: 5px 0;
    transition: color 0.3s ease;
}
.main-nav ul li a:hover,
.main-nav ul li a.active {
    color: var(--primary-color);
    border-bottom: 2px solid var(--primary-color);
}
.user-actions {
    display: flex;
    align-items: center;
}
.user-actions .search-bar {
    margin-right: 20px;
    position: relative;
}
.user-actions .search-bar input {
    border: 1px solid var(--border-color);
    padding: 8px 12px;
    border-radius: 20px;
    font-size: 0.9em;
    width: 200px;
    transition: width 0.3s ease, border-color 0.3s ease;
}
.user-actions .search-bar input:focus {
    width: 250px;
    border-color: var(--primary-color);
    outline: none;
}
.user-actions .auth-links a {
    margin-left: 15px;
    text-decoration: none;
    color: var(--primary-color);
    font-weight: 500;
    padding: 8px 15px;
    border: 1px solid var(--primary-color);
    border-radius: 20px;
    transition: background-color 0.3s ease, color 0.3s ease;
}
.user-actions .auth-links a:hover {
    background-color: var(--primary-color);
    color: #fff;
}
.user-actions .auth-links a:first-child {
    border: none;
    color: var(--text-light-color);
}
.user-actions .auth-links a:first-child:hover {
     color: var(--primary-color);
     background-color: transparent;
}

.main-footer {
    background-color: var(--dark-color);
    color: var(--light-color);
    padding: var(--spacing-lg) 0 var(--spacing-md);
    font-size: 0.9em;
    margin-top: var(--spacing-lg);
}

.footer-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.footer-section {
    flex: 1;
    min-width: 200px;
    margin-bottom: var(--spacing-md);
    padding: 0 var(--spacing-sm);
}

.footer-section h3 {
    color: #fff;
    margin-bottom: var(--spacing-md);
    font-size: 1.1em;
    display: flex;
    align-items: center;
}

.footer-section h3 .footer-icon {
    margin-right: 8px;
    color: var(--success-color);
}

.footer-section p {
    color: #ccc;
    line-height: 1.8;
}

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

.footer-section ul li {
    margin-bottom: calc(var(--spacing-sm) / 2);
}

.footer-section ul li a {
    color: #ccc;
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.social-links {
    margin-top: var(--spacing-md);
}

.social-links a {
    display: inline-block;
    color: #fff;
    font-size: 1.2em;
    margin-right: var(--spacing-sm);
    transition: color 0.3s ease, transform 0.2s ease;
}

.social-links a:hover {
    color: var(--primary-color);
    transform: translateY(-3px);
}

.newsletter-form {
    display: flex;
    margin-top: var(--spacing-md);
}

.newsletter-form input {
    flex: 1;
    padding: 10px 15px;
    border: none;
    border-radius: 5px 0 0 5px;
    font-size: 0.9em;
}

.newsletter-form button {
    background-color: var(--primary-color);
    color: #fff;
    border: none;
    padding: 10px 15px;
    border-radius: 0 5px 5px 0;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.newsletter-form button:hover {
    background-color: #0056b3; /* Darker shade of primary-color */
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    margin-top: var(--spacing-md);
    border-top: 1px solid rgba(255,255,255,0.1);
    color: #aaa;
}

.footer-bottom p {
    margin-bottom: calc(var(--spacing-sm) / 2);
    color: #aaa;
}

.footer-bottom .footer-note, .tech-stack-note {
    font-style: italic;
    font-size: 0.85em;
    color: #888;
}

/* Responsive Design */
@media (max-width: 992px) {
    .main-header .main-nav ul li {
        margin-left: 15px;
    }
    .user-actions .search-bar input {
        width: 150px;
    }
    .user-actions .search-bar input:focus {
        width: 200px;
    }
    .footer-section {
        min-width: 45%;
    }
}

@media (max-width: 768px) {
    .main-header {
        flex-direction: column;
        align-items: flex-start;
        height: auto; /* Allow header to expand */
        padding: 15px 20px;
    }
    .main-header .logo {
        margin-bottom: 10px;
    }
    .main-nav {
        width: 100%;
        margin-bottom: 10px;
    }
    .main-nav ul {
        flex-direction: column;
        align-items: flex-start;
        width: 100%;
    }
    .main-nav ul li {
        margin: 5px 0;
        width: 100%;
    }
    .main-nav ul li a {
        display: block;
        padding: 8px 0;
        border-bottom: 1px solid rgba(255,255,255,0.1); /* For better visibility */
    }
    .main-nav ul li:last-child a {
        border-bottom: none;
    }
    .user-actions {
        margin-top: 15px;
        width: 100%;
        justify-content: space-between;
    }
    .user-actions .search-bar {
        margin-right: 0;
        flex: 1;
    }
    .user-actions .search-bar input {
        width: 100%;
        margin-right: 10px;
    }
    .user-actions .auth-links {
        display: flex;
        flex-shrink: 0;
        margin-left: 10px;
    }
    .user-actions .auth-links a {
        margin-left: 10px;
        padding: 6px 12px;
    }
    .user-actions .auth-links a:first-child {
        margin-left: 0;
    }

    #main-content {
        padding-top: 0; /* Adjust as header is no longer fixed height */
    }

    .footer-container {
        flex-direction: column;
        align-items: center;
    }
    .footer-section {
        width: 90%;
        min-width: unset;
        text-align: center;
        margin-bottom: calc(var(--spacing-md) * 1.5);
    }
    .footer-section h3 {
        justify-content: center;
    }
    .social-links {
        display: flex;
        justify-content: center;
    }
    .newsletter-form {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    h1 { font-size: 2em; }
    h2 { font-size: 1.8em; }
    .container { padding: 0 var(--spacing-sm); }
    .main-header { padding: 10px 15px; }
    .user-actions { flex-direction: column; align-items: stretch; }
    .user-actions .search-bar { width: 100%; margin-bottom: 10px; }
    .user-actions .search-bar input { width: 100%; }
    .user-actions .auth-links { width: 100%; justify-content: space-around; margin-left: 0; }
    .user-actions .auth-links a { margin: 0 5px; }
    .newsletter-form { flex-direction: column; }
    .newsletter-form input { border-radius: 5px; margin-bottom: 10px; }
    .newsletter-form button { border-radius: 5px; }
}

/* Scroll to top button (example) */
.scroll-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background-color: var(--primary-color);
    color: #fff;
    width: 45px;
    height: 45px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5em;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease;
    z-index: 999;
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

.scroll-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(-5px);
}
/* 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;
  }
}