/* ── Main content shell ── */
.main-content { flex: 1; display: flex; flex-direction: column; background: var(--bg-primary); overflow: hidden; min-width: 0; }

/* ── Header ── */
.header {
    height: var(--header-height); flex-shrink: 0;
    border-bottom: 1px solid var(--border-color);
    display: flex; align-items: center; justify-content: space-between;
    padding: 0 20px; background: var(--bg-primary);
}

.model-selector {
    display: flex; align-items: center; gap: 8px;
    padding: 8px 16px; background: var(--bg-secondary);
    border: 1px solid var(--border-color); border-radius: 8px;
    cursor: pointer; font-size: 14px; color: var(--text-primary); transition: all 0.2s;
}
.model-selector:hover { background: var(--bg-hover); }
.model-selector svg { width: 16px; height: 16px; color: var(--text-secondary); }

.header-actions { display: flex; align-items: center; gap: 8px; }
.icon-btn {
    width: 36px; height: 36px; display: flex; align-items: center; justify-content: center;
    background: transparent; border: none; color: var(--text-secondary);
    cursor: pointer; border-radius: 6px; transition: all 0.2s;
}
.icon-btn:hover { background: var(--bg-hover); color: var(--text-primary); }