.b64-container {
    max-width: 900px;
    margin: 0 auto;
}

.tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    border-bottom: 1px solid var(--line);
}

.tab-btn {
    padding: 12px 20px;
    background: transparent;
    border: none;
    border-bottom: 2px solid transparent;
    font-weight: 600;
    color: var(--muted);
    cursor: pointer;
    font-size: 15px;
    transition: all 0.2s;
}

.tab-btn.active {
    color: var(--brand);
    border-bottom-color: var(--brand);
}

.tab-btn:hover {
    color: var(--ink);
}

.tab-content.hidden {
    display: none;
}

.result-area {
    margin-top: 24px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 16px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
}

.result-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.code-box {
    width: 100%;
    min-height: 250px;
    padding: 14px;
    background: #f8f9fc;
    border: 1px solid var(--line);
    border-radius: 8px;
    font-family: monospace;
    font-size: 13px;
    color: #333;
    resize: vertical;
    word-break: break-all;
}

.input-box {
    background: #fff;
}

.info-row {
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    color: var(--muted);
    margin-top: 8px;
}

/* Decode Layout */
.decode-layout {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 30px;
}

@media (max-width: 768px) {
    .decode-layout {
        grid-template-columns: 1fr;
    }
}

.img-preview-box {
    width: 100%;
    height: 250px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    position: relative;
    background-image: linear-gradient(45deg, #f0f0f0 25%, transparent 25%), linear-gradient(-45deg, #f0f0f0 25%, transparent 25%), linear-gradient(45deg, transparent 75%, #f0f0f0 75%), linear-gradient(-45deg, transparent 75%, #f0f0f0 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
}

.img-preview-box img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.mt-2 { margin-top: 10px; }
.actions-right { display: flex; gap: 8px; }