.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: 12px 28px;
    border-radius: var(--radius-full);
    font-weight: var(--font-weight-semibold);
    font-size: 0.95rem;
    transition: all var(--transition-base);
    border: 2px solid transparent;
    line-height: 1.2;
    min-height: 52px;
    position: relative;
    white-space: nowrap;
}

.btn-primary {
    background-color: var(--color-accent);
    color: var(--color-text-inverse);
    border-color: var(--color-accent);
}
.btn-primary:hover,
.btn-primary:focus-visible {
    background-color: var(--color-accent-hover);
    border-color: var(--color-accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px var(--color-shadow-lg);
}
.btn-primary:active {
    transform: translateY(0);
}

.btn-outline {
    background-color: transparent;
    color: var(--color-text-primary);
    border-color: var(--color-border);
}
.btn-outline:hover,
.btn-outline:focus-visible {
    background-color: var(--color-bg-hover);
    border-color: var(--color-border);
}

.btn-sm {
    padding: 8px 18px;
    font-size: 0.85rem;
    min-height: 40px;
}

.btn-block {
    width: 100%;
    justify-content: center;
}

.btn:disabled {
    opacity: 0.5;
    pointer-events: none;
    transform: none !important;
}

/* ---- Cards ---- */
.feature-card,
.prompt-card {
    background-color: var(--color-bg-surface);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-border);
    transition: all var(--transition-base);
    contain: layout paint;
}

.feature-card:hover,
.prompt-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

/* ---- Image pair (before/after) ---- */
.img-pair {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0;
    background-color: var(--color-bg-surface-alt);
    aspect-ratio: 16 / 10;
    position: relative;
    overflow: hidden;
}
.img-pair > div {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.4rem;
    font-weight: var(--font-weight-medium);
    color: var(--color-text-muted);
    position: relative;
    overflow: hidden;
    background-color: var(--color-bg-surface-alt);
    min-height: 80px;
    filter: grayscale(1);
}
.img-pair .before {
    border-right: 2px solid var(--color-border);
}
.img-pair .after {
    background-color: var(--color-accent-light);
}
.img-pair .label {
    position: absolute;
    bottom: var(--spacing-sm);
    left: var(--spacing-sm);
    background-color: rgba(26, 24, 22, 0.65);
    color: #f6f4f0;
    padding: 1px 10px;
    border-radius: var(--radius-full);
    font-size: 0.6rem;
    font-weight: var(--font-weight-semibold);
    letter-spacing: 0.03em;
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    filter: none !important;
}

/* ---- Card body ---- */
.card-body {
    padding: var(--spacing-lg) var(--spacing-lg) var(--spacing-lg);
    flex: 1;
    display: flex;
    flex-direction: column;
}
.card-body .category-tag {
    display: inline-block;
    font-size: 0.65rem;
    font-weight: var(--font-weight-semibold);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--color-accent-text);
    background-color: var(--color-accent-light);
    padding: 2px 12px;
    border-radius: var(--radius-full);
    align-self: flex-start;
    margin-bottom: var(--spacing-sm);
}
.card-body h3 {
    font-size: 1.05rem;
    font-weight: var(--font-weight-semibold);
    margin-bottom: var(--spacing-xs);
    cursor: pointer;
}
.card-body h3:hover {
    color: var(--color-accent-text);
}
.card-body p {
    color: var(--color-text-secondary);
    font-size: 0.9rem;
    flex: 1;
    margin-bottom: var(--spacing-md);
}
.card-body .card-actions {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: auto;
}
.card-body .card-actions .btn {
    flex: 1;
    min-height: 40px;
    padding: 8px 16px;
    font-size: 0.85rem;
}

/* ---- Access box ---- */
.access-box {
    max-width: 480px;
    margin: 0 auto;
    background-color: var(--color-bg-surface);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl) var(--spacing-xl);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--color-border);
    text-align: center;
}
.access-box h2 {
    font-size: 1.8rem;
    font-weight: var(--font-weight-bold);
    margin-bottom: var(--spacing-sm);
}
.access-box p {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
}
.access-box .input-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}
.access-box input {
    padding: 14px 18px;
    border-radius: var(--radius-full);
    border: 2px solid var(--color-border);
    font-size: var(--font-size-base);
    font-family: var(--font-family);
    background-color: var(--color-bg-input);
    color: var(--color-text-primary);
    transition: all var(--transition-base);
    outline: none;
    width: 100%;
}
.access-box input:focus {
    border-color: var(--color-border-focus);
    box-shadow: 0 0 0 4px var(--color-accent-light);
}
.access-box .error-msg {
    color: var(--color-error);
    font-size: 0.9rem;
    margin-top: var(--spacing-sm);
    min-height: 28px;
    font-weight: var(--font-weight-medium);
}
.access-box .success-msg {
    color: var(--color-success);
    font-size: 0.9rem;
    margin-top: var(--spacing-sm);
    font-weight: var(--font-weight-medium);
}
.access-footer {
    margin-top: var(--spacing-lg);
    font-size: 0.85rem;
    color: var(--color-text-muted);
}
.access-link {
    color: var(--color-accent-text);
    font-weight: var(--font-weight-medium);
}
.access-link:hover {
    text-decoration: underline;
}

/* ---- Library controls ---- */
.library-controls {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    flex: 1 1 100%;
}
.library-controls .search-wrap {
    flex: 1 1 240px;
    position: relative;
}
.library-controls .search-wrap input {
    width: 100%;
    padding: 12px 18px 12px 44px;
    border-radius: var(--radius-full);
    border: 2px solid var(--color-border);
    font-size: 0.95rem;
    font-family: var(--font-family);
    background-color: var(--color-bg-surface);
    color: var(--color-text-primary);
    transition: all var(--transition-base);
    outline: none;
}
.library-controls .search-wrap input:focus {
    border-color: var(--color-border-focus);
    box-shadow: 0 0 0 4px var(--color-accent-light);
}
.library-controls .search-wrap .search-icon {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--color-text-muted);
    font-size: 1.1rem;
    pointer-events: none;
}

.library-controls .filter-wrap {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}
.library-controls .filter-wrap .filter-btn {
    padding: 8px 18px;
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    font-weight: var(--font-weight-medium);
    border: 2px solid var(--color-border);
    background-color: var(--color-bg-surface);
    color: var(--color-text-secondary);
    transition: all var(--transition-base);
}
.library-controls .filter-wrap .filter-btn:hover {
    background-color: var(--color-bg-hover);
}
.library-controls .filter-wrap .filter-btn.active {
    background-color: var(--color-accent);
    color: var(--color-text-inverse);
    border-color: var(--color-accent);
}

/* ---- Detail page ---- */
.detail-back {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--color-text-secondary);
    font-weight: var(--font-weight-medium);
    margin-bottom: var(--spacing-lg);
    transition: color var(--transition-base);
    padding: var(--spacing-sm) 0;
}
.detail-back:hover {
    color: var(--color-text-primary);
}

.detail-container {
    background-color: var(--color-bg-surface);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--color-border);
}

.detail-images {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0;
    background-color: var(--color-bg-surface-alt);
    aspect-ratio: 16 / 9;
}
.detail-images > div {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3.6rem;
    font-weight: var(--font-weight-medium);
    color: var(--color-text-muted);
    position: relative;
    overflow: hidden;
    background-color: var(--color-bg-surface-alt);
    min-height: 120px;
    filter: grayscale(1);
}
.detail-images .before {
    border-right: 2px solid var(--color-border);
}
.detail-images .after {
    background-color: var(--color-accent-light);
}
.detail-images .label {
    position: absolute;
    bottom: var(--spacing-md);
    left: var(--spacing-md);
    background-color: rgba(26, 24, 22, 0.65);
    color: #f6f4f0;
    padding: 4px 14px;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: var(--font-weight-semibold);
    letter-spacing: 0.03em;
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    filter: none !important;
}

.detail-content {
    padding: var(--spacing-xl) var(--spacing-xl);
}
.detail-content .category-tag {
    display: inline-block;
    font-size: 0.7rem;
    font-weight: var(--font-weight-semibold);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--color-accent-text);
    background-color: var(--color-accent-light);
    padding: 2px 14px;
    border-radius: var(--radius-full);
    margin-bottom: var(--spacing-sm);
}
.detail-content h2 {
    font-size: 1.8rem;
    font-weight: var(--font-weight-bold);
    margin-bottom: var(--spacing-xs);
}
.detail-content .detail-desc {
    color: var(--color-text-secondary);
    font-size: 1.05rem;
    margin-bottom: var(--spacing-lg);
}

.detail-content .prompt-box {
    background-color: var(--color-bg-code);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg) var(--spacing-lg);
    border: 1px solid var(--color-border);
    margin-bottom: var(--spacing-md);
}
.detail-content .prompt-box .prompt-label {
    font-size: 0.7rem;
    font-weight: var(--font-weight-semibold);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-sm);
}
.detail-content .prompt-box pre {
    font-family: var(--font-family);
    font-size: 0.95rem;
    white-space: pre-wrap;
    word-break: break-word;
    color: var(--color-text-primary);
    line-height: 1.7;
}

.detail-content .copy-wrap {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
    flex-wrap: wrap;
}
.detail-content .copy-wrap .btn {
    min-height: 44px;
}
.detail-content .copy-feedback {
    font-size: 0.9rem;
    color: var(--color-success);
    font-weight: var(--font-weight-medium);
    min-height: 28px;
}

.detail-content .tip-box {
    margin-top: var(--spacing-lg);
    background-color: var(--color-bg-tip);
    border-radius: var(--radius-md);
    padding: var(--spacing-md) var(--spacing-lg);
    border: 1px solid var(--color-border);
}
.detail-content .tip-box .tip-label {
    font-size: 0.7rem;
    font-weight: var(--font-weight-semibold);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--color-accent-text);
}
.detail-content .tip-box p {
    color: var(--color-text-secondary);
    font-size: 0.95rem;
    margin-top: var(--spacing-xs);
}

/* ---- Empty state ---- */
.empty-state {
    text-align: center;
    padding: var(--spacing-3xl) var(--spacing-lg);
    color: var(--color-text-muted);
    grid-column: 1 / -1;
}
.empty-state h3 {
    font-size: 1.2rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xs);
}