/* 主体容器，让三栏布局占满视口 */
.main-container {
    position: relative;
    display: flex;
    flex-direction: row;
    height: var(--app-viewport, 100vh);
    align-items: stretch;
    background: var(--claude-bg);
    color: var(--claude-text);
}

.main-container.utility-panel-hidden {
    background: var(--claude-bg);
}

.main-container.utility-panel-hidden .chat-container {
    background: rgba(255, 255, 255, 0.92);
}

#app {
    min-height: var(--app-viewport, 100vh);
    background: var(--claude-bg);
}