/**
 * FlowX4 Buttons
 * ==============
 */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    line-height: 1;
    color: var(--color-text-secondary);
    background: var(--color-surface-primary);
    border: 1px solid var(--color-border-default);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.btn:hover {
    color: var(--color-text-primary);
    background: var(--color-surface-hover);
    border-color: var(--color-border-strong);
}

.btn:active {
    transform: scale(0.98);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn svg {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
}

/* Primary Button */
.btn-primary {
    color: #fff;
    background: var(--color-accent-primary);
    border-color: var(--color-accent-primary);
}

.btn-primary:hover {
    color: #fff;
    background: var(--color-accent-primary-hover);
    border-color: var(--color-accent-primary-hover);
}

/* Secondary Button */
.btn-secondary {
    color: var(--color-text-secondary);
    background: transparent;
    border-color: var(--color-border-default);
}

.btn-secondary:hover {
    color: var(--color-text-primary);
    background: var(--color-surface-hover);
}

/* Danger Button */
.btn-danger {
    color: var(--color-error);
    background: var(--color-error-muted);
    border-color: transparent;
}

.btn-danger:hover {
    color: #fff;
    background: var(--color-error);
}

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

.btn-ghost:hover {
    color: var(--color-text-primary);
    background: var(--color-surface-hover);
}

/* Button Sizes */
.btn-sm {
    padding: var(--space-1) var(--space-2);
    font-size: var(--font-size-xs);
}

.btn-lg {
    padding: var(--space-3) var(--space-6);
    font-size: var(--font-size-lg);
}

.btn-full {
    width: 100%;
}

/* Icon Button */
.btn-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    padding: 0;
    color: var(--color-text-secondary);
    background: transparent;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-icon:hover {
    color: var(--color-text-primary);
    background: var(--color-surface-hover);
}

.btn-icon svg {
    width: 18px;
    height: 18px;
    min-width: 18px;
    min-height: 18px;
    flex-shrink: 0;
}

/* Button Loading State */
.btn--loading {
    pointer-events: none;
    position: relative;
    color: transparent !important;
}

.btn--loading::after {
    content: '';
    position: absolute;
    width: 16px;
    height: 16px;
    background: url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 48 48'><line x1='8' y1='38' x2='22' y2='10' stroke='%238B5CF6' stroke-width='5.5' stroke-linecap='round'/><line x1='16' y1='38' x2='30' y2='10' stroke='%238B5CF6' stroke-width='5.5' stroke-linecap='round'/><line x1='24' y1='38' x2='38' y2='10' stroke='%238B5CF6' stroke-width='5.5' stroke-linecap='round'/><line x1='32' y1='38' x2='40' y2='22' stroke='%238B5CF6' stroke-width='5.5' stroke-linecap='round'/></svg>") no-repeat center / contain;
    animation: logo-btn-pulse 1.5s ease-in-out infinite;
}

@keyframes logo-btn-pulse {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 1; }
}

/* Back Button Icon */
.btn-back-icon {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
}