/* 基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #4a90e2;
    --primary-dark: #357abd;
    --secondary-color: #7b68ee;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --info-color: #17a2b8;
    --dark-color: #343a40;
    --light-color: #f8f9fa;
    --gray-color: #6c757d;
    --border-color: #dee2e6;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 5px 20px rgba(0, 0, 0, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.navbar {
    background: #fff;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

.navbar-brand a {
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-color);
    text-decoration: none;
}

.navbar-nav {
    display: flex;
    list-style: none;
    gap: 20px;
    align-items: center;
}

.navbar-nav a {
    color: var(--dark-color);
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 5px;
    transition: all 0.3s;
}

.navbar-nav a:hover {
    color: var(--primary-color);
    background: rgba(74, 144, 226, 0.1);
}

.navbar-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
}

/* 按钮 */
.btn {
    display: inline-block;
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.3s;
    font-size: 14px;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

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

.btn-block {
    display: block;
    width: 100%;
}

.btn-lg {
    padding: 15px 30px;
    font-size: 16px;
}

.btn-sm {
    padding: 5px 10px;
    font-size: 12px;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: #fff;
    padding: 100px 20px;
    text-align: center;
}

.hero h1 {
    font-size: 48px;
    margin-bottom: 20px;
}

.hero p {
    font-size: 20px;
    margin-bottom: 30px;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
}

/* Features Section */
.features {
    padding: 80px 20px;
    background: #fff;
}

.section-title {
    text-align: center;
    font-size: 36px;
    margin-bottom: 50px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.feature-card {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 10px;
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 24px;
    margin-bottom: 15px;
    color: var(--dark-color);
}

.feature-card p {
    color: var(--gray-color);
    line-height: 1.8;
}

/* How It Works */
.how-it-works {
    padding: 80px 20px;
    background: #f5f5f5;
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.step {
    text-align: center;
    padding: 30px;
}

.step-number {
    width: 60px;
    height: 60px;
    background: var(--primary-color);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: bold;
    margin: 0 auto 20px;
}

.step h3 {
    font-size: 20px;
    margin-bottom: 15px;
}

.step p {
    color: var(--gray-color);
}

/* CTA Section */
.cta {
    padding: 80px 20px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: #fff;
    text-align: center;
}

.cta h2 {
    font-size: 36px;
    margin-bottom: 20px;
}

.cta p {
    font-size: 18px;
    margin-bottom: 30px;
}

/* Footer */
.footer {
    background: var(--dark-color);
    color: #fff;
    padding: 50px 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.footer-section h3 {
    margin-bottom: 20px;
    font-size: 20px;
}

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

/* Auth Pages */
.auth-page {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.auth-container {
    width: 100%;
    max-width: 450px;
    padding: 20px;
}

.auth-card {
    background: #fff;
    border-radius: 10px;
    padding: 40px;
    box-shadow: var(--shadow-lg);
}

.auth-header {
    text-align: center;
    margin-bottom: 30px;
}

.auth-header .logo {
    font-size: 32px;
    font-weight: bold;
    color: var(--primary-color);
    text-decoration: none;
    display: block;
    margin-bottom: 10px;
}

.auth-header h2 {
    font-size: 24px;
    color: var(--dark-color);
}

.auth-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--dark-color);
}

.form-group input {
    padding: 12px 15px;
    border: 2px solid var(--border-color);
    border-radius: 5px;
    font-size: 14px;
    transition: border-color 0.3s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.checkbox-group {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 0;
    font-weight: normal;
}

.forgot-link {
    color: var(--primary-color);
    text-decoration: none;
}

.forgot-link:hover {
    text-decoration: underline;
}

.form-tip {
    color: var(--gray-color);
    font-size: 14px;
    text-align: center;
    margin-top: -10px;
}

.message {
    margin-top: 20px;
    padding: 15px;
    border-radius: 5px;
    display: none;
    text-align: center;
}

.message.success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.message.error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.auth-footer {
    text-align: center;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}

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

.auth-footer a:hover {
    text-decoration: underline;
}

/* Dashboard */
.dashboard-page {
    background: #f5f5f5;
}

.dashboard-nav {
    background: #fff;
    box-shadow: var(--shadow);
    padding: 15px 0;
}

.dashboard-nav .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 15px;
}

.dashboard-container {
    display: flex;
    min-height: calc(100vh - 70px);
}

.sidebar {
    width: 250px;
    background: #fff;
    box-shadow: var(--shadow);
    padding: 20px 0;
}

.sidebar-menu {
    list-style: none;
}

.sidebar-menu li a {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 15px 25px;
    color: var(--dark-color);
    text-decoration: none;
    transition: all 0.3s;
}

.sidebar-menu li a:hover,
.sidebar-menu li.active a {
    background: rgba(74, 144, 226, 0.1);
    color: var(--primary-color);
}

.menu-icon {
    font-size: 20px;
}

.dashboard-main {
    flex: 1;
    padding: 30px;
}

.dashboard-header {
    margin-bottom: 30px;
}

.dashboard-header h1 {
    font-size: 32px;
    margin-bottom: 10px;
}

.dashboard-header p {
    color: var(--gray-color);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.stat-card {
    background: #fff;
    padding: 25px;
    border-radius: 10px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 20px;
}

.stat-icon {
    font-size: 40px;
}

.stat-content h3 {
    font-size: 32px;
    color: var(--primary-color);
}

.stat-content p {
    color: var(--gray-color);
    font-size: 14px;
}

.quick-actions {
    background: #fff;
    padding: 25px;
    border-radius: 10px;
    box-shadow: var(--shadow);
    margin-bottom: 30px;
}

.quick-actions h2 {
    margin-bottom: 20px;
}

.action-buttons {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.action-buttons .btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.recent-items {
    background: #fff;
    padding: 25px;
    border-radius: 10px;
    box-shadow: var(--shadow);
}

.recent-items h2 {
    margin-bottom: 20px;
}

.list-container {
    min-height: 200px;
}

.empty-state {
    text-align: center;
    padding: 40px;
    color: var(--gray-color);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar-toggle {
        display: block;
    }

    .navbar-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: #fff;
        box-shadow: var(--shadow);
        padding: 20px;
    }

    .navbar-menu.active {
        display: block;
    }

    .navbar-nav {
        flex-direction: column;
    }

    .hero h1 {
        font-size: 32px;
    }

    .hero p {
        font-size: 16px;
    }

    .hero-buttons {
        flex-direction: column;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .steps {
        grid-template-columns: 1fr;
    }

    .dashboard-container {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        padding: 10px 0;
    }

    .sidebar-menu li a {
        padding: 10px 15px;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .action-buttons {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .auth-card {
        padding: 30px 20px;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }
}