/**
 * DripSafe Design System - Micro-interactions & States CSS
 * Version: 1.0.0
 * Round 8: Visual Details Polish
 * 
 * Includes: hover effects, loading states, empty states
 * Uses existing CSS variables from variables.css
 */

/* ============================
   1. POST CARD HOVER ENHANCEMENTS
   ============================ */

/* 整体可点击 + cursor变化 */
.ds-post-card {
    cursor: pointer;
}

.ds-post-card:hover .ds-post-card__thumbnail img {
    transform: scale(1.05);
}

/* 图片容器保持overflow hidden */
.ds-post-card__thumbnail {
    overflow: hidden;
}

/* 标题hover颜色过渡 */
.ds-post-card__title a {
    transition: color 0.2s ease;
}

/* 标签hover效果 */
.ds-post-card__tag {
    transition: background-color 0.2s ease, color 0.2s ease, transform 0.15s ease;
}

.ds-post-card__tag:hover {
    transform: translateY(-1px);
}

/* ============================
   2. FEATURED LINK CARD HOVER
   ============================ */

/* 整卡hover联动效果 */
.ds-featured-link-card {
    cursor: pointer;
}

.ds-featured-link-card:hover {
    transform: translateY(-4px) translateX(2px);
}

/* 箭头移入效果 */
.ds-featured-link-card__arrow {
    flex-shrink: 0;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--card-icon, #0066CC);
    opacity: 0.6;
    transition: 
        transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1),
        opacity 0.2s ease,
        color 0.2s ease;
}

.ds-featured-link-card:hover .ds-featured-link-card__arrow {
    transform: translateX(6px);
    opacity: 1;
    color: var(--card-icon, #0066CC);
}

/* 箭头SVG图标旋转进入 */
.ds-featured-link-card:hover .ds-featured-link-card__arrow svg {
    transform: scaleX(1);
}

.ds-featured-link-card__arrow svg {
    transform: scaleX(0.7);
    transition: transform 0.25s ease;
}

/* ============================
   3. BUTTON RIPPLE EFFECT
   ============================ */

.ds-btn {
    position: relative;
    overflow: hidden;
}

/* 涟漪效果 */
.ds-btn::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.4s ease, height 0.4s ease, opacity 0.4s ease;
    opacity: 0;
    pointer-events: none;
}

.ds-btn:not(:disabled):active::after {
    width: 200%;
    height: 200%;
    opacity: 0;
}

/* 点击时触发涟漪 */
@keyframes ds-ripple {
    0% {
        width: 0;
        height: 0;
        opacity: 0.5;
    }
    100% {
        width: 250%;
        height: 250%;
        opacity: 0;
    }
}

.ds-btn.ripple::after {
    animation: ds-ripple 0.5s ease-out;
}

/* ============================
   4. LOADING ANIMATIONS
   ============================ */

/* 文章列表加载中spinner */
.ds-loading-spinner {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
}

.ds-loading-spinner__circle {
    width: 40px;
    height: 40px;
    border: 3px solid var(--ds-border, #E2E8F0);
    border-top-color: var(--ds-primary, #0066CC);
    border-radius: 50%;
    animation: ds-spin 0.8s linear infinite;
}

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

/* 加载文案 */
.ds-loading-text {
    text-align: center;
    padding: 16px;
    color: var(--ds-text-muted, #94A3B8);
    font-size: var(--ds-text-sm, 14px);
}

/* 按钮提交loading态 */
.ds-btn--loading-submit {
    position: relative;
    pointer-events: none;
}

.ds-btn--loading-submit .ds-btn__text {
    visibility: hidden;
}

.ds-btn--loading-submit::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 18px;
    height: 18px;
    margin: -9px 0 0 -9px;
    border: 2px solid rgba(255, 255, 255, 0.4);
    border-right-color: #ffffff;
    border-radius: 50%;
    animation: ds-spin 0.7s linear infinite;
}

/* 骨架屏加载 */
.ds-skeleton {
    background: linear-gradient(
        90deg,
        var(--ds-bg-secondary, #F1F5F9) 25%,
        var(--ds-bg-tertiary, #E2E8F0) 50%,
        var(--ds-bg-secondary, #F1F5F9) 75%
    );
    background-size: 200% 100%;
    animation: ds-shimmer 1.5s infinite;
    border-radius: var(--ds-radius, 8px);
}

@keyframes ds-shimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

.ds-skeleton--text {
    height: 16px;
    margin-bottom: 8px;
    border-radius: 4px;
}

.ds-skeleton--title {
    height: 24px;
    width: 60%;
    margin-bottom: 12px;
    border-radius: 4px;
}

.ds-skeleton--image {
    width: 100%;
    aspect-ratio: 16 / 9;
    border-radius: var(--ds-radius-lg, 12px);
}

.ds-skeleton--card {
    background: var(--ds-bg-card, #ffffff);
    border-radius: var(--ds-radius-lg, 12px);
    padding: 20px;
    border: 1px solid var(--ds-border, #E2E8F0);
}

/* 加载完成状态 */
.ds-load-complete {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 24px 16px;
    color: var(--ds-text-muted, #94A3B8);
    font-size: var(--ds-text-sm, 14px);
}

.ds-load-complete__icon {
    color: var(--ds-success, #10B981);
}

/* ============================
   5. EMPTY STATE DESIGNS
   ============================ */

/* 基础空状态容器 */
.ds-empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 60px 24px;
    text-align: center;
}

.ds-empty-state__icon {
    width: 80px;
    height: 80px;
    margin-bottom: 24px;
    color: var(--ds-text-muted, #94A3B8);
    opacity: 0.6;
}

.ds-empty-state__title {
    font-size: var(--ds-text-xl, 20px);
    font-weight: var(--ds-font-semibold, 600);
    color: var(--ds-text-primary, #1E293B);
    margin-bottom: 8px;
}

.ds-empty-state__desc {
    font-size: var(--ds-text-base, 15px);
    color: var(--ds-text-secondary, #64748B);
    max-width: 400px;
    line-height: 1.6;
    margin-bottom: 24px;
}

.ds-empty-state__action {
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

/* 搜索无结果 */
.ds-empty-state--search {
    padding: 48px 24px;
}

.ds-empty-state--search .ds-empty-state__icon {
    width: 64px;
    height: 64px;
}

/* 无文章显示 */
.ds-empty-state--posts .ds-empty-state__icon {
    width: 72px;
    height: 72px;
}

/* 加载失败 */
.ds-empty-state--error .ds-empty-state__icon {
    color: var(--ds-error, #EF4444);
    opacity: 0.8;
}

/* 空状态按钮变体 */
.ds-empty-state__btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 20px;
    font-size: var(--ds-text-sm, 14px);
    font-weight: var(--ds-font-medium, 500);
    color: var(--ds-primary, #0066CC);
    background: transparent;
    border: 1.5px solid var(--ds-primary, #0066CC);
    border-radius: var(--ds-radius, 8px);
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
}

.ds-empty-state__btn:hover {
    background: var(--ds-primary, #0066CC);
    color: #ffffff;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 102, 204, 0.2);
}

/* ============================
   DARK MODE SUPPORT
   ============================ */

[data-theme="dark"] .ds-loading-spinner__circle {
    border-color: var(--ds-border, #334155);
    border-top-color: var(--ds-secondary, #00D4FF);
}

[data-theme="dark"] .ds-skeleton {
    background: linear-gradient(
        90deg,
        var(--ds-bg-secondary, #1E293B) 25%,
        var(--ds-bg-tertiary, #334155) 50%,
        var(--ds-bg-secondary, #1E293B) 75%
    );
    background-size: 200% 100%;
}

[data-theme="dark"] .ds-empty-state__title {
    color: var(--ds-text-primary, #F1F5F9);
}

[data-theme="dark"] .ds-empty-state__desc {
    color: var(--ds-text-secondary, #94A3B8);
}

[data-theme="dark"] .ds-empty-state__icon {
    color: var(--ds-text-muted, #64748B);
}

[data-theme="dark"] .ds-btn--loading-submit::before {
    border-color: rgba(255, 255, 255, 0.3);
    border-right-color: #ffffff;
}

[data-theme="dark"] .ds-featured-link-card:hover {
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
}

[data-theme="dark"] .ds-post-card:hover {
    box-shadow: var(--ds-shadow-xl, 0 20px 40px rgba(0, 0, 0, 0.3));
    border-color: var(--ds-secondary, #00D4FF);
}

/* ============================
   RESPONSIVE
   ============================ */

@media (max-width: 767px) {
    .ds-empty-state {
        padding: 40px 16px;
    }
    
    .ds-empty-state__icon {
        width: 64px;
        height: 64px;
    }
    
    .ds-empty-state__title {
        font-size: var(--ds-text-lg, 18px);
    }
    
    .ds-loading-spinner {
        padding: 32px 16px;
    }
    
    .ds-btn {
        min-height: var(--ds-btn-height, 44px);
    }
}