/* ============================================
TREINIO BUTTON COMPONENT
5 типов: Primary, Secondary, Danger, Ghost, Icon
2 размера: MD (44px), SM (36px)
============================================ */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    height: var(--control-height-md);
    padding: 0 var(--space-4);
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: var(--font-button);
    font-weight: var(--weight-medium);
    line-height: 1;
    cursor: pointer;
    transition: all var(--transition-hover) var(--transition-ease);
    border: 1px solid transparent;
    white-space: nowrap;
    text-decoration: none;
    background: none;
    color: inherit;
    -webkit-tap-highlight-color: transparent;
}

.btn:disabled,
.btn.disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.btn svg {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
    stroke-width: 2;
}

/* === Primary === */
.btn-primary {
    background: var(--color-primary);
    color: var(--text-on-primary);
    border-color: var(--color-primary);
}

.btn-primary:hover:not(:disabled) {
    background: var(--color-primary-hover);
    border-color: var(--color-primary-hover);
}

.btn-primary:active:not(:disabled) {
    transform: scale(0.98);
    transition-duration: var(--transition-click);
}

/* === Secondary === */
.btn-secondary {
    background: var(--bg-surface);
    color: var(--text-primary);
    border-color: var(--border-default);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--bg-page);
    border-color: var(--border-focus);
    color: var(--color-primary);
}

.btn-secondary:active:not(:disabled) {
    transform: scale(0.98);
    transition-duration: var(--transition-click);
}

/* === Danger === */
.btn-danger {
    background: var(--color-danger);
    color: var(--text-on-danger);
    border-color: var(--color-danger);
}

.btn-danger:hover:not(:disabled) {
    background: var(--color-danger-hover);
    border-color: var(--color-danger-hover);
}

.btn-danger:active:not(:disabled) {
    transform: scale(0.98);
    transition-duration: var(--transition-click);
}

/* === Ghost === */
.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
    border-color: transparent;
}

.btn-ghost:hover:not(:disabled) {
    background: var(--bg-surface);
    color: var(--text-primary);
    border-color: var(--border-default);
}

.btn-ghost:active:not(:disabled) {
    background: var(--bg-elevated);
    transition-duration: var(--transition-click);
}

/* === Icon === */
.btn-icon {
    width: var(--control-height-md);
    height: var(--control-height-md);
    padding: 0;
    border-radius: var(--radius-full);
    background: transparent;
    color: var(--text-secondary);
    border-color: transparent;
}

.btn-icon:hover:not(:disabled) {
    background: var(--bg-surface);
    color: var(--text-primary);
}

.btn-icon:active:not(:disabled) {
    background: var(--bg-elevated);
    transition-duration: var(--transition-click);
}

/* === Small === */
.btn-sm {
    height: var(--control-height-sm);
    padding: 0 var(--space-3);
    font-size: var(--font-sm);
    border-radius: var(--radius-sm);
}

.btn-sm svg {
    width: 16px;
    height: 16px;
}

.btn-sm.btn-icon {
    width: var(--control-height-sm);
    height: var(--control-height-sm);
}