.feature-card-icon.base64-icon {
    background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
}
.feature-card-btn.b64-main-btn {
    background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
    width: 100%;
    padding: 14px;
    font-size: 1rem;
}
.feature-card-btn.b64-main-btn:hover {
    box-shadow: 0 6px 20px rgba(14, 165, 233, 0.4);
    transform: translateY(-2px);
}
.b64-form-area { margin-top: 4px; }
.b64-tabs {
    display: flex;
    background: rgba(14, 165, 233, 0.08);
    border-radius: 10px;
    padding: 4px;
    margin-bottom: 8px;
}
.b64-tab {
    flex: 1;
    padding: 8px 12px;
    border: none;
    border-radius: 8px;
    background: transparent;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-gray);
    cursor: pointer;
    transition: all 0.2s ease;
}
.b64-tab:hover { background: rgba(14, 165, 233, 0.15); }
.b64-tab.active {
    background: linear-gradient(135deg, #0ea5e9, #0284c7);
    color: white;
    box-shadow: 0 2px 8px rgba(14, 165, 233, 0.3);
}
.b64-mode-hint {
    padding: 6px 12px;
    background: rgba(14, 165, 233, 0.06);
    border-radius: 6px;
    font-size: 0.82rem;
    color: #0284c7;
    margin-bottom: 10px;
}
.b64-text-row {
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.b64-text-block {
    background: white;
    border: 1px solid var(--border-light);
    border-radius: 10px;
    overflow: hidden;
    transition: border-color 0.3s;
}
.b64-text-block:focus-within {
    border-color: #0ea5e9;
    box-shadow: 0 0 0 3px rgba(14, 165, 233, 0.1);
}
.b64-text-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 12px;
    background: rgba(14, 165, 233, 0.04);
    border-bottom: 1px solid var(--border-light);
}
.b64-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: #0284c7;
}
.b64-actions {
    display: flex;
    gap: 4px;
}
.b64-action-btn {
    width: 26px;
    height: 26px;
    border: none;
    background: transparent;
    color: var(--text-gray);
    cursor: pointer;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}
.b64-action-btn:hover {
    background: rgba(14, 165, 233, 0.1);
    color: #0284c7;
}
.b64-textarea {
    width: 100%;
    border: none;
    border-radius: 0;
    padding: 10px 12px;
    font-size: 0.92rem;
    line-height: 1.6;
    resize: vertical;
    min-height: 90px;
    outline: none;
    background: transparent;
    font-family: 'Consolas', 'Monaco', monospace;
}
.b64-textarea:focus {
    border: none;
    box-shadow: none;
}
.b64-textarea[readonly] {
    background: #f8fafc;
    color: #0c4a6e;
}
.b64-count-row {
    display: flex;
    justify-content: space-between;
    padding: 4px 12px 8px;
    font-size: 0.78rem;
    color: var(--text-gray);
}
.b64-arrow-btn {
    width: 36px;
    height: 36px;
    margin: 0 auto;
    border: none;
    border-radius: 50%;
    background: linear-gradient(135deg, #0ea5e9, #0284c7);
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
}
.b64-arrow-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 4px 12px rgba(14, 165, 233, 0.4);
}
.b64-arrow-btn.flip {
    transform: rotate(180deg);
}
.b64-options {
    display: flex;
    gap: 16px;
    margin-top: 10px;
    flex-wrap: wrap;
}
.b64-opt {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.85rem;
    color: var(--text-dark);
    cursor: pointer;
}
.b64-opt input[type="checkbox"] {
    accent-color: #0ea5e9;
    width: 16px;
    height: 16px;
    cursor: pointer;
}
.b64-image-row {
    margin-top: 12px;
    padding: 12px;
    background: rgba(14, 165, 233, 0.04);
    border-radius: 10px;
    border: 1px dashed rgba(14, 165, 233, 0.3);
}
.b64-image-title {
    font-size: 0.85rem;
    font-weight: 600;
    color: #0284c7;
    margin-bottom: 8px;
}
.b64-image-actions {
    display: flex;
    gap: 8px;
}
.b64-img-btn {
    flex: 1;
    padding: 8px;
    font-size: 0.85rem;
}
.b64-output-preview {
    margin-top: 12px;
    padding: 12px;
    background: white;
    border: 1px solid var(--border-light);
    border-radius: 10px;
    text-align: center;
}
.b64-preview-img {
    max-width: 100%;
    max-height: 300px;
    border-radius: 8px;
    margin-bottom: 8px;
}
.b64-preview-info {
    font-size: 0.82rem;
    color: var(--text-gray);
}
.b64-download-btn {
    margin-top: 8px;
    padding: 6px 14px;
    background: linear-gradient(135deg, #0ea5e9, #0284c7);
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 0.85rem;
    cursor: pointer;
}