.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-family: var(--font-sans);
    font-size: 0.85rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    border: none;
    box-shadow: 0 4px 15px rgba(220, 38, 38, 0.3);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 
        0 8px 25px rgba(220, 38, 38, 0.4),
        0 0 30px rgba(220, 38, 38, 0.3);
}

.btn-primary:active {
    transform: translateY(-1px);
    box-shadow: 
        0 4px 15px rgba(220, 38, 38, 0.3),
        0 0 20px rgba(220, 38, 38, 0.2);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-card);
    border-color: var(--primary);
    color: var(--primary);
    transform: translateY(-3px);
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
    border: none;
}

.btn-ghost:hover {
    color: var(--primary);
    background: rgba(220, 38, 38, 0.1);
}

.btn-icon {
    width: 18px;
    height: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-icon svg {
    width: 100%;
    height: 100%;
}

.btn-sm {
    padding: 0.6rem 1.2rem;
    font-size: 0.85rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1rem;
}

.btn-block {
    width: 100%;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
}

.btn:disabled::before {
    display: none;
}

.btn-loading {
    pointer-events: none;
}

.btn-loading .btn-text {
    opacity: 0;
}

.btn-loading::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    border: 2px solid transparent;
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}