/* ===============================================
   Blog Page Specific Styles
   =============================================== */

/* ===============================================
   Blog Header Section
   =============================================== */

.blog-header {
    padding: var(--spacing-3xl) 0;
    text-align: center;
    background: linear-gradient(135deg, var(--primary-container) 0%, var(--secondary-container) 100%);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-3xl);
    animation: fadeInDown 0.6s ease-out;
}

.blog-header h1 {
    font-size: 2.5rem;
    font-weight: var(--font-weight-bold);
    color: var(--on-background);
    margin-bottom: var(--spacing-md);
}

.blog-subtitle {
    font-size: 1.125rem;
    color: var(--on-surface-variant);
    line-height: 1.6;
}

/* ===============================================
   Blog Controls (Search & Filter)
   =============================================== */

.blog-controls {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-3xl);
    animation: fadeInUp 0.6s ease-out 0.1s both;
}

/* Search Container */
.search-container {
    position: relative;
    max-width: 400px;
}

.blog-search {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    padding-right: var(--spacing-xl);
    border: 1px solid var(--surface-variant);
    border-radius: var(--radius-lg);
    font-size: 1rem;
    background-color: var(--surface);
    color: var(--on-background);
    transition: all var(--transition-short);
}

.blog-search:focus {
    outline: none;
    border-color: var(--primary);
    background-color: var(--primary-container);
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
}

.search-icon {
    position: absolute;
    right: var(--spacing-lg);
    top: 50%;
    transform: translateY(-50%);
    color: var(--on-surface-variant);
    pointer-events: none;
}

/* Category Filters */
.category-filters {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.filter-btn {
    padding: var(--spacing-sm) var(--spacing-lg);
    border: 1.5px solid var(--surface-variant);
    background-color: var(--surface);
    color: var(--on-background);
    border-radius: var(--radius-full);
    cursor: pointer;
    font-weight: var(--font-weight-medium);
    font-size: 0.875rem;
    transition: all var(--transition-short);
}

.filter-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.filter-btn.active {
    background-color: var(--primary);
    border-color: var(--primary);
    color: var(--on-primary);
}

/* ===============================================
   Blog Posts Grid
   =============================================== */

.blog-posts {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-3xl);
}

/* Blog Card */
.blog-card {
    background-color: var(--surface);
    border: 1px solid var(--surface-variant);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    display: flex;
    flex-direction: column;
    transition: all var(--transition-standard);
    cursor: pointer;
    animation: fadeInUp 0.6s ease-out;
    overflow: hidden;
    position: relative;
}

.blog-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary) 0%, var(--secondary) 100%);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-short);
}

.blog-card:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-3);
    transform: translateY(-4px);
}

.blog-card:hover::before {
    transform: scaleX(1);
}

/* Associate staggered animations */
.blog-card:nth-child(1) { animation-delay: 0s; }
.blog-card:nth-child(2) { animation-delay: 0.05s; }
.blog-card:nth-child(3) { animation-delay: 0.1s; }
.blog-card:nth-child(4) { animation-delay: 0.15s; }
.blog-card:nth-child(5) { animation-delay: 0.2s; }
.blog-card:nth-child(6) { animation-delay: 0.25s; }

/* Blog Card Header */
.blog-card-header {
    margin-bottom: var(--spacing-lg);
    flex-grow: 1;
}

.blog-meta {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.blog-date {
    font-size: 0.8125rem;
    color: var(--on-surface-variant);
    font-weight: var(--font-weight-medium);
}

/* Category Tags */
.blog-category {
    display: inline-block;
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: var(--font-weight-semibold);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.research-tag {
    background-color: rgba(0, 102, 204, 0.1);
    color: var(--primary);
}

.tutorial-tag {
    background-color: rgba(127, 104, 100, 0.1);
    color: var(--tertiary);
}

.reflection-tag {
    background-color: rgba(90, 107, 138, 0.1);
    color: var(--secondary);
}

/* Blog Title */
.blog-title {
    font-size: 1.25rem;
    font-weight: var(--font-weight-semibold);
    color: var(--on-background);
    line-height: 1.4;
    margin-bottom: 0;
    transition: color var(--transition-short);
}

.blog-card:hover .blog-title {
    color: var(--primary);
}

/* Blog Excerpt */
.blog-excerpt {
    font-size: 0.9375rem;
    color: var(--on-surface-variant);
    line-height: 1.6;
    margin-bottom: var(--spacing-lg);
    flex-grow: 1;
}

/* Blog Footer */
.blog-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--surface-variant);
}

.read-time {
    font-size: 0.8125rem;
    color: var(--on-surface-variant);
    font-weight: var(--font-weight-medium);
}

.read-more {
    color: var(--primary);
    text-decoration: none;
    font-weight: var(--font-weight-semibold);
    font-size: 0.9375rem;
    transition: all var(--transition-short);
    display: flex;
    align-items: center;
}

.read-more:hover {
    color: var(--secondary);
    transform: translateX(2px);
}

/* ===============================================
   No Results Message
   =============================================== */

.no-results {
    text-align: center;
    padding: var(--spacing-3xl) var(--spacing-xl);
    background-color: var(--neutral-90);
    border-radius: var(--radius-lg);
    color: var(--on-surface-variant);
    font-size: 1.0625rem;
}

/* ===============================================
   Load More Button
   =============================================== */

.load-more-container {
    display: flex;
    justify-content: center;
    padding: var(--spacing-2xl) 0;
    animation: fadeInUp 0.6s ease-out;
}

.load-more-btn {
    padding: var(--spacing-md) var(--spacing-xl);
    background-color: var(--primary);
    color: var(--on-primary);
    border: none;
    border-radius: var(--radius-full);
    font-size: 1rem;
    font-weight: var(--font-weight-semibold);
    cursor: pointer;
    transition: all var(--transition-short);
    box-shadow: var(--shadow-2);
}

.load-more-btn:hover {
    background-color: var(--on-primary-container);
    transform: translateY(-2px);
    box-shadow: var(--shadow-3);
}

.load-more-btn:active {
    transform: translateY(0);
    box-shadow: var(--shadow-1);
}

/* ===============================================
   Blog Grid Responsive Design
   =============================================== */

@media (max-width: 768px) {
    .blog-header {
        padding: var(--spacing-2xl) var(--spacing-lg);
    }

    .blog-header h1 {
        font-size: 1.875rem;
    }

    .blog-subtitle {
        font-size: 1rem;
    }

    .blog-controls {
        gap: var(--spacing-lg);
    }

    .blog-posts {
        grid-template-columns: 1fr;
    }

    .category-filters {
        justify-content: flex-start;
        overflow-x: auto;
        padding-bottom: var(--spacing-sm);
    }

    .filter-btn {
        white-space: nowrap;
    }
}

@media (max-width: 480px) {
    .blog-header h1 {
        font-size: 1.5rem;
    }

    .blog-subtitle {
        font-size: 0.9375rem;
    }

    .blog-card {
        padding: var(--spacing-lg);
    }

    .blog-title {
        font-size: 1.0625rem;
    }

    .blog-excerpt {
        font-size: 0.875rem;
    }

    .blog-footer {
        flex-direction: column;
        gap: var(--spacing-sm);
        align-items: flex-start;
    }

    .read-more {
        margin-top: var(--spacing-sm);
    }

    .search-container {
        max-width: 100%;
    }

    .category-filters {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }
}

/* ===============================================
   Animation Keyframes for Blog
   =============================================== */

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Fade transition state for hidden search results */
.blog-posts.filtering {
    opacity: 0.6;
    transition: opacity 0.3s ease-out;
}

.blog-posts.filtering.ready {
    opacity: 1;
}