/* 小清新风格CSS - 单词岛 */

:root {
    --primary-color: #6ECEDA;
    --secondary-color: #FFB3C6;
    --accent-color: #A8E6CF;
    --text-primary: #2C3E50;
    --text-secondary: #7F8C8D;
    --background-light: #F8F9FA;
    --background-gradient: linear-gradient(135deg, #f5f7fa 0%, #e4edf9 100%);
    --card-background: rgba(255, 255, 255, 0.9);
    --shadow-light: 0 4px 20px rgba(110, 206, 218, 0.15);
    --border-radius: 16px;
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Noto Sans SC', sans-serif;
    background: var(--background-gradient);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* 导航栏 */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 1rem 2rem;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: var(--shadow-light);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.logo-icon {
    font-size: 1.8rem;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

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

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

.nav-links a:hover::after {
    width: 100%;
}

.login-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 0.5rem 1.5rem;
    border-radius: 25px;
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
    box-shadow: var(--shadow-light);
}

.login-btn:hover {
    background: #5bc0de;
    transform: translateY(-2px);
}

/* 主页横幅 */
.hero {
    padding: 8rem 2rem 4rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    min-height: 80vh;
}

.hero-content {
    max-width: 800px;
    margin-bottom: 3rem;
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-primary, .btn-secondary {
    padding: 0.8rem 2rem;
    border-radius: 25px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    box-shadow: var(--shadow-light);
}

.btn-primary:hover {
    background: #5bc0de;
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(110, 206, 218, 0.25);
}

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

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

.hero-image {
    max-width: 600px;
    margin: 0 auto;
}

.illustration {
    width: 100%;
    height: auto;
    filter: drop-shadow(0 10px 20px rgba(0, 0, 0, 0.1));
}

/* 特色功能 */
.features {
    padding: 4rem 2rem;
    background: var(--background-light);
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.2rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.section-header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.feature-card {
    background: var(--card-background);
    padding: 2rem;
    border-radius: var(--border-radius);
    text-align: center;
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    backdrop-filter: blur(10px);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(110, 206, 218, 0.2);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    display: inline-block;
}

.feature-card h3 {
    font-size: 1.4rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.feature-card p {
    color: var(--text-secondary);
}

/* 学习方法 */
.how-it-works {
    padding: 4rem 2rem;
    background: var(--accent-color);
    background: linear-gradient(135deg, #f0f9ff 0%, #e8f4f8 100%);
}

.steps-container {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
    max-width: 1200px;
    margin: 0 auto;
}

.step {
    background: var(--card-background);
    padding: 2rem;
    border-radius: var(--border-radius);
    text-align: center;
    min-width: 250px;
    box-shadow: var(--shadow-light);
    backdrop-filter: blur(10px);
}

.step-number {
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0 auto 1rem;
}

.step h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

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

/* 用户评价 */
.testimonials {
    padding: 4rem 2rem;
    background: var(--background-light);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.testimonial-card {
    background: var(--card-background);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
    backdrop-filter: blur(10px);
}

.user-avatar {
    font-size: 3rem;
    margin-bottom: 1rem;
    display: inline-block;
}

.testimonial-card h4 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.testimonial-card p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-style: italic;
}

.rating {
    color: #FFD700;
    font-size: 1.2rem;
}

/* 页脚 */
.footer {
    background: var(--text-primary);
    color: white;
    padding: 3rem 2rem 1rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.5rem;
    font-weight: 700;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    margin-right: 1rem;
    transition: var(--transition);
}

.footer-links a:hover {
    color: white;
}

.footer-social span {
    font-weight: 500;
}

.copyright {
    text-align: center;
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9rem;
}

/* 模态框 */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
}

.modal-content {
    background: var(--card-background);
    margin: 5% auto;
    padding: 2rem;
    border-radius: var(--border-radius);
    width: 90%;
    max-width: 500px;
    position: relative;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    backdrop-filter: blur(10px);
}

.close {
    position: absolute;
    right: 1.5rem;
    top: 1rem;
    font-size: 1.5rem;
    font-weight: bold;
    cursor: pointer;
    color: var(--text-secondary);
    transition: var(--transition);
}

.close:hover {
    color: var(--text-primary);
}

.modal-content h2 {
    text-align: center;
    margin-bottom: 2rem;
    color: var(--primary-color);
    font-size: 1.8rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-primary);
}

.form-group input {
    width: 100%;
    padding: 0.8rem;
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(110, 206, 218, 0.2);
}

.form-footer {
    text-align: center;
    margin-top: 1rem;
}

.form-footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

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

/* 下载模态框样式 */
.download-options {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.download-card {
    text-align: center;
    padding: 1rem;
}

.store-badge {
    width: 150px;
    height: auto;
    cursor: pointer;
    transition: var(--transition);
}

.store-badge:hover {
    transform: scale(1.05);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .steps-container, .features-grid, .testimonials-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
    
    .modal-content {
        width: 95%;
        margin: 10% auto;
    }
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feature-card, .step, .testimonial-card {
    animation: fadeInUp 0.6s ease-out;
}

.feature-card:nth-child(2) { animation-delay: 0.1s; }
.feature-card:nth-child(3) { animation-delay: 0.2s; }
.step:nth-child(2) { animation-delay: 0.1s; }
.step:nth-child(3) { animation-delay: 0.2s; }
.testimonial-card:nth-child(2) { animation-delay: 0.1s; }
.testimonial-card:nth-child(3) { animation-delay: 0.2s; }