/**
 * DripSafe Design System - Button Components
 * Version: 1.0.0
 * 基于杨过的视觉设计规范
 */

/* ============================
   Button Variables
   ============================ */

:root {
    --ds-btn-height: 44px;
    --ds-btn-height-sm: 36px;
    --ds-btn-height-lg: 52px;
    --ds-btn-radius: 8px;
    --ds-btn-padding-x: 20px;
    --ds-btn-font-size: 15px;
    --ds-btn-font-weight: 600;
    --ds-btn-transition: all 0.2s ease;
}

/* ============================
   Base Button Styles
   ============================ */

.ds-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    height: var(--ds-btn-height);
    padding: 0 var(--ds-btn-padding-x);
    font-family: var(--ds-font-sans);
    font-size: var(--ds-btn-font-size);
    font-weight: var(--ds-btn-font-weight);
    line-height: 1;
    text-decoration: none;
    border: none;
    border-radius: var(--ds-btn-radius);
    cursor: pointer;
    transition: var(--ds-btn-transition);
    white-space: nowrap;
    user-select: none;
}

.ds-btn:focus-visible {
    outline: 2px solid var(--ds-border-focus, var(--ds-primary));
    outline-offset: 2px;
}

.ds-btn:disabled,
.ds-btn.ds-btn-disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

/* ============================
   Primary Button (蓝青渐变)
   ============================ */

.ds-btn--primary {
    background: linear-gradient(135deg, var(--ds-primary), var(--ds-secondary));
    color: #ffffff;
    box-shadow: var(--ds-shadow-md);
}

.ds-btn--primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 14px rgba(0, 102, 204, 0.35);
}

.ds-btn--primary:active {
    transform: translateY(0);
    box-shadow: var(--ds-shadow-sm);
}

/* ============================
   Secondary Button (边框型)
   ============================ */

.ds-btn--secondary {
    background: transparent;
    color: var(--ds-primary);
    border: 2px solid var(--ds-primary);
}

.ds-btn--secondary:hover {
    background: var(--ds-primary);
    color: #ffffff;
    transform: translateY(-2px);
}

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

/* ============================
   Ghost Button (幽灵按钮)
   ============================ */

.ds-btn--ghost {
    background: transparent;
    color: var(--ds-text-primary);
}

.ds-btn--ghost:hover {
    background: var(--ds-bg-secondary, #F9FAFB);
    color: var(--ds-primary);
}

/* ============================
   Danger Button (危险按钮)
   ============================ */

.ds-btn--danger {
    background: var(--ds-error, #EF4444);
    color: #ffffff;
}

.ds-btn--danger:hover {
    background: #DC2626;
    transform: translateY(-2px);
    box-shadow: 0 4px 14px rgba(239, 68, 68, 0.4);
}

/* ============================
   Icon Button (图标按钮)
   ============================ */

.ds-btn--icon {
    width: 40px;
    height: 40px;
    padding: 0;
    background: var(--ds-bg-secondary, #F9FAFB);
    color: var(--ds-primary);
    border-radius: 8px;
}

.ds-btn--icon:hover {
    background: var(--ds-primary);
    color: #ffffff;
}

/* ============================
   Size Variants
   ============================ */

.ds-btn--sm {
    height: var(--ds-btn-height-sm);
    font-size: 13px;
    padding: 0 16px;
}

.ds-btn--lg {
    height: var(--ds-btn-height-lg);
    font-size: 17px;
    padding: 0 28px;
}

/* ============================
   Block Button
   ============================ */

.ds-btn--block {
    display: flex;
    width: 100%;
}

/* ============================
   Loading State
   ============================ */

.ds-btn--loading {
    position: relative;
    color: transparent !important;
}

.ds-btn--loading::after {
    content: '';
    position: absolute;
    width: 16px;
    height: 16px;
    top: 50%;
    left: 50%;
    margin-left: -8px;
    margin-top: -8px;
    border: 2px solid currentColor;
    border-right-color: transparent;
    border-radius: 50%;
    animation: ds-spin 0.75s linear infinite;
}

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

/* ============================
   Link Button (链接型按钮)
   ============================ */

.ds-btn--link {
    background: none;
    padding: 0;
    height: auto;
    color: var(--ds-link-color);
    border: none;
    border-radius: 0;
}

.ds-btn--link:hover {
    color: var(--ds-link-hover-color);
    text-decoration: underline;
    transform: none;
    box-shadow: none;
}

/* ============================
   Dark Mode Support
   ============================ */

[data-theme="dark"] .ds-btn--primary {
    background: linear-gradient(135deg, var(--ds-primary), var(--ds-secondary));
}

[data-theme="dark"] .ds-btn--ghost {
    background: transparent;
}

[data-theme="dark"] .ds-btn--ghost:hover {
    background: var(--ds-bg-secondary);
}

[data-theme="dark"] .ds-btn--icon {
    background: var(--ds-bg-secondary);
}

[data-theme="dark"] .ds-btn--secondary {
    border-color: var(--ds-primary);
    color: var(--ds-primary);
}

[data-theme="dark"] .ds-btn--secondary:hover {
    background: var(--ds-primary);
    color: #ffffff;
}

/* ============================
   Responsive
   ============================ */

@media (max-width: 767px) {
    :root {
        --ds-btn-height: 40px;
        --ds-btn-height-sm: 32px;
        --ds-btn-height-lg: 48px;
        --ds-btn-padding-x: 16px;
        --ds-btn-font-size: 14px;
    }
}