/* Letters页面专用样式 */

/* 容器样式 */
.letters-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 6rem 2rem 4rem;
}

.letters-content {
    max-width: 1000px;
    width: 100%;
    text-align: center;
    color: white;
    animation: fadeInUp 1.2s ease-out;
}

/* 标题样式 */
.letters-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    letter-spacing: 0.1em;
    text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    line-height: 1.2;
}

.letters-subtitle {
    font-size: 1.3rem;
    font-weight: 300;
    margin-bottom: 4rem;
    opacity: 0.9;
    letter-spacing: 0.02em;
}

/* 年份网格 */
.years-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 2rem;
    margin-bottom: 4rem;
}

/* 年份卡片 */
.year-card {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 16px;
    padding: 2rem 1.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    position: relative;
    overflow: hidden;
}

.year-card:hover {
    transform: translateY(-8px);
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.3);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2);
}

.year-card:active {
    transform: translateY(-4px);
}

/* 年份标题 */
.year-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: white;
    letter-spacing: 0.05em;
}

/* 年份描述 */
.year-description {
    font-size: 1rem;
    font-weight: 300;
    opacity: 0.8;
    line-height: 1.5;
    margin-bottom: 0;
}

/* 返回链接 */
.back-link {
    margin-top: 3rem;
}

.back-btn {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-size: 1.1rem;
    font-weight: 400;
    letter-spacing: 0.02em;
    transition: all 0.3s ease;
    padding: 0.8rem 1.5rem;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    display: inline-block;
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.05);
}

.back-btn:hover {
    color: rgba(255, 255, 255, 1);
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(60px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 响应式设计 */
@media (max-width: 768px) {
    .letters-container {
        padding: 5rem 1rem 3rem;
    }
    
    .letters-title {
        font-size: 2.5rem;
        margin-bottom: 0.8rem;
    }
    
    .letters-subtitle {
        font-size: 1.1rem;
        margin-bottom: 3rem;
    }
    
    .years-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
        margin-bottom: 3rem;
    }
    
    .year-card {
        padding: 1.5rem 1rem;
    }
    
    .year-title {
        font-size: 2rem;
    }
    
    .year-description {
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .letters-container {
        padding: 4rem 1rem 2rem;
    }
    
    .letters-title {
        font-size: 2rem;
    }
    
    .letters-subtitle {
        font-size: 1rem;
        margin-bottom: 2.5rem;
    }
    
    .year-card {
        padding: 1.2rem 0.8rem;
    }
    
    .year-title {
        font-size: 1.8rem;
        margin-bottom: 0.8rem;
    }
    
    .year-description {
        font-size: 0.85rem;
    }
    
    .back-btn {
        font-size: 1rem;
        padding: 0.7rem 1.2rem;
    }
}

/* 减少动画偏好 */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* 高对比度支持 */
@media (prefers-contrast: high) {
    .letters-title {
        text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.8);
    }
    
    .year-card {
        border-color: rgba(255, 255, 255, 0.5);
    }
    
    .letters-subtitle,
    .year-description {
        opacity: 1;
    }
}