/* layout.css — Page structure */
* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    height: 100vh;
    overflow: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.app-layout {
    display: flex;
    height: 100vh;
}

.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.chat-header {
    height: var(--header-height);
    padding: 0 24px;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-shrink: 0;
    background: var(--bg-secondary);
}

.chat-header h2 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.model-selector {
    display: flex;
    align-items: center;
    gap: 10px;
}

.model-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-weight: 600;
}

.model-selector select {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border);
    padding: 6px 12px;
    border-radius: var(--radius-xs);
    font-size: 0.8rem;
    font-family: var(--font-sans);
    cursor: pointer;
    outline: none;
    transition: border-color var(--transition-normal);
}

.model-selector select:hover {
    border-color: var(--border-light);
}

.model-selector select:focus {
    border-color: var(--accent);
}