/**
 * 按钮组件样式
 *
 * 通用按钮样式，包括主要、次要、危险等变体
 */

/* 基础按钮 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    min-height: var(--tap-btn-min-h);
    padding: 10px 20px;
    font-size: 14px;
    font-weight: 500;
    border-radius: var(--radius-sm);
    border: none;
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
    text-decoration: none;
    touch-action: manipulation;
}

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

/* 主要按钮 */
.btn-primary {
    background: var(--brand-primary);
    color: white;
}

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

/* 次要按钮 */
.btn-secondary {
    background: white;
    color: var(--neutral-600);
    border: 1px solid var(--neutral-200);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--neutral-50);
    border-color: var(--neutral-300);
}

/* 危险按钮 */
.btn-danger {
    background: var(--color-danger);
    color: white;
}

.btn-danger:hover:not(:disabled) {
    background: #dc2626;
}

/* 成功按钮 */
.btn-success {
    background: var(--color-success);
    color: white;
}

.btn-success:hover:not(:disabled) {
    background: #059669;
}

/* 幽灵按钮 */
.btn-ghost {
    background: transparent;
    color: var(--text-sub);
}

.btn-ghost:hover:not(:disabled) {
    background: var(--neutral-100);
    color: var(--text-main);
}

/* 链接按钮 */
.btn-link {
    background: transparent;
    color: var(--brand-primary);
    padding: 0;
}

.btn-link:hover:not(:disabled) {
    text-decoration: underline;
}

/* 尺寸变体 */
.btn-sm {
    min-height: var(--tap-btn-sm-min-h);
    padding: 6px 12px;
    font-size: 13px;
}

.btn-lg {
    padding: 14px 28px;
    font-size: 16px;
}

/* 图标按钮 */
.btn-icon {
    width: var(--tap-icon);
    height: var(--tap-icon);
    padding: 0;
    border-radius: 50%;
}

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

.btn-icon.btn-lg {
    width: 48px;
    height: 48px;
}

/* 加载状态 */
.btn.loading {
    position: relative;
    color: transparent !important;
}

.btn.loading::after {
    content: "";
    position: absolute;
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255, 255, 255, 0.72);
    border-right-color: transparent;
    border-radius: 50%;
    animation: btn-spin 0.6s linear infinite;
}

.btn-secondary.loading::after,
.btn-ghost.loading::after,
.btn-link.loading::after {
    border-color: rgba(99, 102, 241, 0.45);
    border-right-color: transparent;
}

@keyframes btn-spin {
    to { transform: rotate(360deg); }
}

/* 开始按钮（特殊大按钮） */
.btn-start {
    width: 100%;
    max-width: 320px;
    min-height: 52px;
    padding: 16px 24px;
    font-size: 1rem;
    font-weight: 600;
    color: white;
    background: linear-gradient(135deg, #6366f1, #8b5cf6);
    border-radius: var(--radius-md);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
    transition: all 0.2s;
    margin-top: 20px;
}

.btn-start:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 16px rgba(99, 102, 241, 0.4);
}

.btn-start:active {
    transform: translateY(0);
}

.btn-start:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
    box-shadow: 0 2px 8px rgba(99, 102, 241, 0.2);
}