/* Cover Section Styles */
.covers-section {
    margin-bottom: 48px;
}

.covers-section h2 {
    font: var(--md-sys-typescale-headline-medium);
    color: var(--md-sys-color-primary);
    margin-bottom: 24px;
    letter-spacing: 0;
}

.covers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 20px;
    margin-bottom: 32px;
}

.cover-item {
    position: relative;
    background: var(--md-sys-color-surface-container-high);
    border-radius: var(--md-sys-shape-corner-large);
    overflow: hidden;
    box-shadow: var(--md-sys-elevation-2);
    transition: all 0.3s cubic-bezier(0.2, 0, 0, 1);
    cursor: pointer;
    height: 300px;
}

.cover-item:hover {
    box-shadow: var(--md-sys-elevation-3);
    transform: translateY(-4px);
}

.cover-item:active {
    transform: translateY(-2px);
}

.cover-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: transform 0.4s cubic-bezier(0.2, 0, 0, 1);
}

.cover-item:hover img {
    transform: scale(1.05);
}

.cover-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 24px;
    background: linear-gradient(
        to top,
        rgba(28, 27, 31, 0.95) 0%,
        rgba(28, 27, 31, 0.85) 60%,
        rgba(28, 27, 31, 0.3) 85%,
        transparent 100%
    );
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    transform: translateY(0);
    transition: all 0.3s cubic-bezier(0.2, 0, 0, 1);
}

.cover-item:hover .cover-overlay {
    background: linear-gradient(
        to top,
        rgba(28, 27, 31, 0.98) 0%,
        rgba(28, 27, 31, 0.92) 70%,
        rgba(28, 27, 31, 0.5) 90%,
        transparent 100%
    );
}

.cover-overlay h3 {
    font: var(--md-sys-typescale-title-large);
    color: var(--md-sys-color-on-surface);
    margin-bottom: 8px;
    letter-spacing: 0.15px;
}

.cover-overlay p {
    font: var(--md-sys-typescale-body-medium);
    color: var(--md-sys-color-on-surface-variant);
    margin-bottom: 12px;
    line-height: 1.5;
}

.cover-tag {
    display: inline-block;
    background: var(--md-sys-color-primary-container);
    color: var(--md-sys-color-on-primary-container);
    padding: 8px 16px;
    border-radius: var(--md-sys-shape-corner-extra-large);
    font: var(--md-sys-typescale-label-medium);
    letter-spacing: 1px;
    text-transform: uppercase;
    box-shadow: var(--md-sys-elevation-1);
}

/* Cover Detail Modal */
.cover-modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.88);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    align-items: center;
    justify-content: center;
    overflow-y: auto;
    padding: 24px;
}

.cover-modal-content {
    position: relative;
    background: var(--md-sys-color-surface-container);
    border-radius: var(--md-sys-shape-corner-extra-large);
    max-width: 1200px;
    width: 100%;
    box-shadow: var(--md-sys-elevation-3);
    animation: modal-entrance 0.3s cubic-bezier(0.2, 0, 0, 1) forwards;
    overflow: hidden;
}

.cover-modal-close {
    position: absolute;
    top: 16px;
    right: 16px;
    color: var(--md-sys-color-on-surface);
    font-size: 32px;
    font-weight: 300;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.2, 0, 0, 1);
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--md-sys-shape-corner-extra-large);
    background: rgba(43, 41, 48, 0.7);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(202, 196, 208, 0.1);
    z-index: 10;
    box-shadow: var(--md-sys-elevation-2);
}

.cover-modal-close:hover {
    background: var(--md-sys-color-error-container);
    color: var(--md-sys-color-on-error-container);
    transform: scale(1.1);
}

.cover-modal-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    min-height: 500px;
}

.cover-modal-text {
    padding: 48px 40px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.cover-modal-tag-badge {
    display: inline-block;
    background: var(--md-sys-color-primary-container);
    color: var(--md-sys-color-on-primary-container);
    padding: 8px 16px;
    border-radius: var(--md-sys-shape-corner-extra-large);
    font: var(--md-sys-typescale-label-medium);
    letter-spacing: 1px;
    text-transform: uppercase;
    align-self: flex-start;
    box-shadow: var(--md-sys-elevation-1);
}

.cover-modal-text h2 {
    font: var(--md-sys-typescale-display-small);
    color: var(--md-sys-color-on-surface);
    margin: 8px 0;
    line-height: 1.2;
}

.modal-abstract {
    font: var(--md-sys-typescale-title-large);
    color: var(--md-sys-color-on-surface-variant);
    line-height: 1.5;
}

.modal-description {
    margin-top: 8px;
    padding-top: 16px;
    border-top: 1px solid var(--md-sys-color-outline-variant);
}

.modal-description h3 {
    font: var(--md-sys-typescale-title-medium);
    color: var(--md-sys-color-secondary);
    margin-bottom: 12px;
}

.modal-description p {
    font: var(--md-sys-typescale-body-large);
    color: var(--md-sys-color-on-surface);
    line-height: 1.8;
}

.btn-open-collection {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    padding: 16px 32px;
    margin-top: auto;
    background: var(--md-sys-color-primary);
    color: var(--md-sys-color-on-primary);
    border: none;
    border-radius: var(--md-sys-shape-corner-extra-large);
    font: var(--md-sys-typescale-label-large);
    letter-spacing: 0.5px;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.2, 0, 0, 1);
    box-shadow: var(--md-sys-elevation-2);
    align-self: flex-start;
}

.btn-open-collection:hover {
    background: var(--md-sys-color-primary-container);
    color: var(--md-sys-color-on-primary-container);
    box-shadow: var(--md-sys-elevation-3);
    transform: translateY(-2px);
}

.btn-open-collection:active {
    transform: translateY(0);
    box-shadow: var(--md-sys-elevation-1);
}

.btn-open-collection svg {
    transition: transform 0.2s cubic-bezier(0.2, 0, 0, 1);
}

.btn-open-collection:hover svg {
    transform: translateX(4px);
}

.cover-modal-image {
    position: relative;
    overflow: hidden;
    background: var(--md-sys-color-surface-container-highest);
}

.cover-modal-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* Responsive covers */
@media (max-width: 968px) {
    .cover-modal-layout {
        grid-template-columns: 1fr;
    }

    .cover-modal-image {
        order: -1;
        height: 350px;
    }

    .cover-modal-text {
        padding: 32px 24px;
    }

    .cover-modal-text h2 {
        font: var(--md-sys-typescale-headline-large);
    }
}

@media (max-width: 768px) {
    .covers-grid {
        grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
        gap: 16px;
    }

    .cover-item {
        height: 250px;
    }

    .covers-section h2 {
        font: var(--md-sys-typescale-headline-small);
        margin-bottom: 16px;
    }

    .cover-overlay {
        padding: 20px;
    }
}

@media (max-width: 480px) {
    .covers-grid {
        grid-template-columns: 1fr;
    }

    .cover-item {
        height: 280px;
    }

    .cover-modal {
        padding: 0;
    }

    .cover-modal-content {
        border-radius: 0;
        max-height: 100vh;
        overflow-y: auto;
    }

    .cover-modal-image {
        height: 300px;
    }

    .cover-modal-text {
        padding: 24px 20px;
    }

    .cover-modal-close {
        top: 12px;
        right: 12px;
        width: 44px;
        height: 44px;
        font-size: 28px;
    }
}