/* 全局样式 */
:root {
    /* 主色调 */
    --primary-color: #4361ee;
    --primary-dark: #3a56d4;
    --primary-light: #6b86ff;
    
    /* 辅助色 */
    --secondary-color: #4cc9f0;
    --accent-color: #f72585;
    
    /* 中性色 */
    --dark: #2b2d42;
    --gray-dark: #5c5f73;
    --gray: #8d99ae;
    --gray-light: #edf2f4;
    --white: #ffffff;
    
    /* 功能色 */
    --success: #52b788;
    --warning: #ffb703;
    --error: #e63946;
    
    /* 字体 */
    --font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
    
    /* 圆角 */
    --border-radius: 8px;
    --border-radius-lg: 12px;
    
    /* 阴影 */
    --box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);

    /* 添加这些CSS变量 */
    --font-primary: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --color-primary: #4285f4;
    --color-primary-dark: #3367d6;
    --color-secondary: #34a853;
    --color-tertiary: #fbbc05;
    --color-accent: #ea4335;
    --color-background: #f4f6f9;
    --color-card: #ffffff;
    --color-text-primary: #333333;
    --color-text-secondary: #6c757d;
    --color-border: #e9ecef;
    --color-success: #28a745;
    --color-warning: #ffc107;
    --color-danger: #dc3545;
    --color-info: #17a2b8;
    --border-radius-sm: 4px;
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.15);
    --transition-speed: 0.3s;
}

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

body {
    font-family: var(--font-family);
    color: var(--dark);
    line-height: 1.6;
    background-color: var(--gray-light);
}

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

a:hover {
    color: var(--primary-dark);
}

h1, h2, h3, h4, h5, h6 {
    margin-bottom: 1rem;
    line-height: 1.3;
}

button, .button, .cta-button {
    cursor: pointer;
    border: none;
    border-radius: var(--border-radius);
    padding: 10px 20px;
    font-weight: 600;
    transition: all 0.3s ease;
}

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

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 落地页样式 */
.landing-container {
    width: 100%;
    overflow-x: hidden;
}

.landing-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 50px;
    background-color: var(--white);
    box-shadow: var(--box-shadow);
}

.logo {
    display: flex;
    align-items: center;
}

.logo-img {
    width: 50px;
    height: 50px;
    margin-right: 15px;
}

.logo h1 {
    font-size: 1.5rem;
    margin-bottom: 0;
    color: var(--primary-color);
}

.landing-nav {
    display: flex;
    gap: 30px;
}

.landing-nav a {
    color: var(--dark);
    font-weight: 500;
}

.landing-nav a:hover {
    color: var(--primary-color);
}

.hero-section {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 80px 50px;
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary-color) 100%);
    color: var(--white);
}

.hero-content {
    width: 50%;
    padding-right: 50px;
}

.hero-content h2 {
    font-size: 2.5rem;
    margin-bottom: 20px;
}

.hero-content p {
    font-size: 1.1rem;
    margin-bottom: 30px;
}

.cta-buttons {
    display: flex;
    gap: 20px;
}

.cta-button {
    display: inline-block;
    padding: 12px 30px;
    font-size: 1rem;
    text-align: center;
    border-radius: var(--border-radius);
    transition: all 0.3s ease;
}

.cta-button.student {
    background-color: var(--white);
    color: var(--primary-color);
}

.cta-button.student:hover {
    background-color: var(--gray-light);
}

.cta-button.admin {
    background-color: transparent;
    border: 2px solid var(--white);
    color: var(--white);
}

.cta-button.admin:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.hero-image {
    width: 45%;
}

.about-section, .features-section, .contact-section {
    padding: 80px 50px;
    text-align: center;
}

.about-section {
    background-color: var(--white);
}

.about-section h2, .features-section h2, .contact-section h2 {
    font-size: 2rem;
    margin-bottom: 40px;
}

.about-content {
    display: flex;
    justify-content: center;
    gap: 60px;
}

.about-item {
    width: 350px;
    padding: 30px;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--box-shadow);
    background-color: var(--white);
    transition: transform 0.3s ease;
}

.about-item:hover {
    transform: translateY(-10px);
}

.about-icon {
    font-size: 3rem;
    margin-bottom: 20px;
    color: var(--primary-color);
}

.features-section {
    background-color: var(--gray-light);
}

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

.feature {
    padding: 30px;
    border-radius: var(--border-radius);
    background-color: var(--white);
    box-shadow: var(--box-shadow);
    transition: transform 0.3s ease;
}

.feature:hover {
    transform: translateY(-5px);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: var(--primary-color);
}

.contact-section {
    background-color: var(--white);
}

.contact-form {
    max-width: 600px;
    margin: 0 auto;
    text-align: left;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
}

.form-group input, .form-group textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--gray);
    border-radius: var(--border-radius);
    font-family: var(--font-family);
    font-size: 1rem;
}

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

.submit-button {
    background-color: var(--primary-color);
    color: white;
    padding: 12px 30px;
    border-radius: var(--border-radius);
    font-size: 1rem;
    width: 100%;
}

.submit-button:hover {
    background-color: var(--primary-dark);
}

.landing-footer {
    background-color: var(--dark);
    color: var(--white);
    padding: 60px 50px 30px;
}

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

.footer-logo {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.logo-img-small {
    width: 40px;
    height: 40px;
    margin-bottom: 10px;
}

.footer-links {
    display: flex;
    gap: 60px;
}

.footer-column h4 {
    font-size: 1.1rem;
    margin-bottom: 20px;
}

.footer-column a, .footer-column p {
    display: block;
    margin-bottom: 10px;
    color: var(--gray-light);
}

.footer-column a:hover {
    color: var(--white);
}

.copyright {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.9rem;
    color: var(--gray);
}

/* 响应式设计 */
@media (max-width: 992px) {
    .hero-section {
        flex-direction: column;
        text-align: center;
        padding: 60px 30px;
    }
    
    .hero-content {
        width: 100%;
        padding-right: 0;
        margin-bottom: 50px;
    }
    
    .hero-image {
        width: 80%;
    }
    
    .cta-buttons {
        justify-content: center;
    }
    
    .about-content {
        flex-direction: column;
        align-items: center;
    }
    
    .about-item {
        width: 100%;
        max-width: 400px;
        margin-bottom: 30px;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 40px;
    }
    
    .footer-links {
        flex-direction: column;
        gap: 30px;
    }
}

@media (max-width: 768px) {
    .landing-header {
        flex-direction: column;
        padding: 20px;
    }
    
    .logo {
        margin-bottom: 20px;
    }
    
    .landing-nav {
        width: 100%;
        justify-content: center;
    }
    
    .about-section, .features-section, .contact-section {
        padding: 60px 20px;
    }
    
    .cta-buttons {
        flex-direction: column;
        gap: 15px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
}