/* ===== Base64 编解码 ===== */
/* 站点变量别名映射（自动跟随黑夜模式） */
:root {
    --card-bg: var(--c-bg-card);
    --border-color: var(--c-border);
    --text-primary: var(--c-text);
    --text-secondary: var(--c-text-sub);
    --text-tertiary: var(--c-text-muted);
    --bg-hover: var(--c-bg-soft);
    --input-bg: var(--c-surface-soft);
    --accent-color: var(--c-primary);
    --card-shadow: var(--shadow-md);
}

.b64-topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
    margin: 16px 0 20px;
}

.b64-title {
    font-size: 26px;
    font-weight: 800;
    margin: 0;
    letter-spacing: -0.3px;
}

.b64-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 14px;
    padding: 18px;
    margin-bottom: 18px;
    box-shadow: var(--card-shadow);
}

.b64-block-title {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 17px;
    margin: 0 0 14px;
}

/* 顶部 Tab */
.b64-tabs {
    display: inline-flex;
    background: var(--bg-hover);
    border-radius: 10px;
    padding: 4px;
    margin-bottom: 16px;
    gap: 4px;
}

.b64-tab {
    border: none;
    background: none;
    padding: 8px 22px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.15s;
}

.b64-tab.active {
    background: var(--accent-color);
    color: #fff;
}

.b64-panel {
    display: none;
}

.b64-panel.active {
    display: block;
}

/* 方向切换 */
.b64-switch {
    display: inline-flex;
    background: var(--bg-hover);
    border-radius: 10px;
    padding: 4px;
    margin-bottom: 14px;
    gap: 4px;
}

.b64-dir {
    border: none;
    background: none;
    padding: 8px 20px;
    border-radius: 8px;
    font-size: 13.5px;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.15s;
}

.b64-dir.active {
    background: var(--accent-color);
    color: #fff;
}

/* 编辑区 */
.b64-panes {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
}

.b64-pane {
    border: 1px solid var(--border-color);
    border-radius: 10px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    background: var(--input-bg);
    min-width: 0;
}

.b64-pane-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 14px;
    font-size: 13px;
    font-weight: 600;
    color: var(--text-secondary);
    background: var(--bg-hover);
    border-bottom: 1px solid var(--border-color);
}

.b64-len {
    font-size: 12px;
    font-weight: 400;
    color: var(--text-tertiary);
}

.b64-textarea {
    width: 100%;
    height: 240px;
    padding: 14px;
    border: none;
    outline: none;
    resize: vertical;
    background: transparent;
    color: var(--text-primary);
    font-family: 'JetBrains Mono', Consolas, 'Courier New', monospace;
    font-size: 13px;
    line-height: 1.7;
    word-break: break-all;
}

.b64-textarea[readonly] {
    background: rgba(128, 128, 128, 0.04);
}

.b64-textarea--sm {
    height: 140px;
}

.b64-pane-foot {
    display: flex;
    gap: 8px;
    padding: 10px 14px;
    border-top: 1px solid var(--border-color);
}

.b64-tip {
    margin-top: 12px;
    font-size: 13px;
    color: var(--text-tertiary);
    line-height: 1.6;
}

/* 图片拖拽区 */
.b64-drop {
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    padding: 36px 20px;
    text-align: center;
    cursor: pointer;
    transition: border-color 0.15s, background 0.15s;
}

.b64-drop:hover,
.b64-drop.dragover {
    border-color: var(--accent-color);
    background: rgba(99, 102, 241, 0.06);
}

.b64-drop-icon {
    font-size: 40px;
    margin-bottom: 8px;
}

.b64-drop-text {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0 0 4px;
}

.b64-drop-sub {
    font-size: 12.5px;
    color: var(--text-tertiary);
    margin: 0;
}

/* 图片结果 */
.b64-img-result {
    display: grid;
    grid-template-columns: 180px 1fr;
    gap: 16px;
    margin-top: 16px;
}

.b64-img-preview {
    border: 1px solid var(--border-color);
    border-radius: 10px;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-hover);
    padding: 8px;
}

.b64-img-preview img {
    max-width: 100%;
    max-height: 180px;
    object-fit: contain;
    border-radius: 6px;
}

.b64-img-info {
    display: flex;
    flex-direction: column;
    gap: 8px;
    min-width: 0;
}

.b64-info-row {
    display: flex;
    justify-content: space-between;
    gap: 10px;
    font-size: 13px;
    color: var(--text-secondary);
}

.b64-info-row b {
    color: var(--text-primary);
    font-weight: 600;
    text-align: right;
    word-break: break-all;
    font-family: 'JetBrains Mono', Consolas, monospace;
    font-size: 12.5px;
}

.b64-img-actions {
    grid-column: 1 / -1;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

/* 解码图片 */
.b64-img-decode-result {
    margin-top: 14px;
    text-align: center;
}

.b64-img-decode-result img {
    max-width: 100%;
    max-height: 320px;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    margin-bottom: 12px;
    object-fit: contain;
    background: var(--bg-hover);
}

.b64-img-decode-result .b64-img-actions {
    justify-content: center;
}

/* 移动端 */
@media (max-width: 768px) {
    .b64-title { font-size: 21px; }
    .b64-panes { grid-template-columns: 1fr; }
    .b64-img-result { grid-template-columns: 1fr; }
    .b64-tabs, .b64-switch { width: 100%; }
    .b64-tab, .b64-dir { flex: 1; }
}