/* ===============================================
   Buttons CSS
   =============================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-md);
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: var(--fs-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
    border: 1px solid transparent;
    position: relative;
    overflow: hidden;
    text-decoration: none;
}

/* Ripple Effect */
.btn::after {
    content: '';
    position: absolute;
    top: 50%; left: 50%;
    width: 5px; height: 5px;
    background: rgba(255, 255, 255, 0.5);
    opacity: 0;
    border-radius: 100%;
    transform: scale(1, 1) translate(-50%, -50%);
    transform-origin: 50% 50%;
}
.btn:focus:not(:active)::after {
    animation: ripple 0.6s ease-out;
}
@keyframes ripple {
    0% { transform: scale(0, 0); opacity: 0.5; }
    100% { transform: scale(40, 40); opacity: 0; }
}

/* Primary (Uses Navy or Brand Color) */
.btn-primary {
    background-color: var(--color-primary);
    color: #fff;
}
.btn-primary:hover { 
    background-color: var(--color-primary-dark); 
}

/* Secondary (Subtle background) */
.btn-secondary {
    background-color: var(--bg-input);
    color: var(--text-secondary);
    border-color: var(--border-color);
}
.btn-secondary:hover { 
    background-color: var(--bg-hover); 
}

/* Outline */
.btn-outline {
    background-color: transparent;
    border-color: var(--border-color);
    color: var(--text-secondary);
}
.btn-outline:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

/* Danger */
.btn-danger {
    background-color: var(--color-danger);
    color: #fff;
}
.btn-danger:hover { 
    filter: brightness(0.9); 
}

/* Warning */
.btn-warning {
    background-color: var(--color-warning);
    color: #fff;
}
.btn-warning:hover { 
    filter: brightness(0.9); 
}

/* Success */
.btn-success {
    background-color: var(--color-success);
    color: #fff;
}
.btn-success:hover { 
    filter: brightness(0.9); 
}

/* Sizes */
.btn-sm { 
    padding: var(--spacing-xs) var(--spacing-md); 
    font-size: var(--fs-xs); 
    border-radius: var(--radius-sm);
}
.btn-lg { 
    padding: var(--spacing-md) var(--spacing-xl); 
    font-size: var(--fs-base); 
}
.btn-block { 
    width: 100%; 
}

/* Icon Button */
.btn-icon {
    width: 36px; height: 36px;
    display: flex; align-items: center; justify-content: center;
    border-radius: var(--radius-md);
    color: var(--text-muted);
    transition: all var(--transition-fast);
    background: transparent;
    border: 1px solid transparent;
}
.btn-icon:hover { 
    background: var(--bg-hover); 
    color: var(--color-primary); 
}
.btn-icon--outline {
    border: 1px solid var(--border-color);
}

/* Spinner Animation (used in loading states) */
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}