/* ========== LAYOUT PRINCIPAL ========== */
body {
    display: flex;
    flex-direction: column;
    height: 100vh;
    max-height: 100vh;
}

/* Header fijo */
.header {
    flex-shrink: 0;
    height: var(--header-height);
    background-color: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    z-index: 100;
}

/* Body scrollable */
.chat-container {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    position: relative;
}

/* Footer fijo */
.input-section {
    flex-shrink: 0;
    background-color: var(--color-surface);
    border-top: 1px solid var(--color-border);
    z-index: 100;
}