/* ============================================
   智慧时间轴组件 - 横向展开式
   Smart Timeline Component - Horizontal Expansion
   ============================================ */

:root {
    --tl-bg-color: #f8fafc;
    --tl-line-color: rgba(20, 129, 255, 0.3);
    --tl-active-color: #1481ff;
    --tl-text-color: #2a3e5d;
    --tl-year-color: #102541;
    --tl-transition-speed: 0.5s;
    --tl-font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
        "Noto Sans CJK SC", "Source Han Sans SC", sans-serif;
    --tl-font-display: "DIN Alternate", "Arial Narrow", "Helvetica Neue",
        Arial, sans-serif;
}

/* Section 容器 */
.timeline-section {
    width: 100%;
    background-image:
        radial-gradient(circle at 10% 20%, rgba(20, 129, 255, 0.08) 0%, transparent 20%),
        radial-gradient(circle at 90% 80%, rgba(20, 129, 255, 0.05) 0%, transparent 20%);
    font-family: var(--tl-font-sans);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 60px 0;
    position: relative;
}

/* 标题样式 */
.timeline-title {
    color: var(--tl-year-color);
    letter-spacing: 4px;
     font-weight: bold;
    text-transform: uppercase;
    font-size: 36px;
    opacity: 0.9;
    margin-bottom: 10px;
    text-align: center;
}

/* 主容器 */
.timeline-container {
    display: flex;
    width: 100%;
    height: 20vh;
    min-height: 500px;
    align-items: stretch;
    position: relative;
}

/* 主轴线 */
.timeline-line {
    position: absolute;
    top: 66.67%;
    left: 0;
    width: 100%;
    height: 1px;
    background: linear-gradient(90deg,
        transparent 0%,
        var(--tl-line-color) 5%,
        var(--tl-line-color) 95%,
        transparent 100%);
    z-index: 0;
    pointer-events: none;
}

/* 时间节点 */
.timeline-item {
    position: relative;
    flex: 1;
    transition: flex var(--tl-transition-speed) cubic-bezier(0.25, 0.1, 0.25, 1);
    border-right: 1px solid rgba(20, 129, 255, 0.1);
    cursor: pointer;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    justify-content: center;
    z-index: 1;
}

.timeline-item:last-child {
    border-right: none;
}

.timeline-item:hover {
    flex: 10;
    background: linear-gradient(90deg, rgba(20, 129, 255, 0.08) 0%, transparent 100%);
}

.timeline-container:hover .timeline-item:not(:hover) {
    opacity: 0.4;
}

/* 节点圆点 */
.dot {
    width: 8px;
    height: 8px;
    background-color: var(--tl-active-color);
    border-radius: 50%;
    position: absolute;
    top: 66.67%;
    left: 50%;
    transform: translate(-50%, -50%);
    box-shadow: 0 0 10px var(--tl-active-color);
    transition: all var(--tl-transition-speed);
    z-index: 2;
}

.timeline-item:hover .dot {
    background-color: var(--tl-active-color);
    transform: translate(-50%, -50%) scale(1.5);
    box-shadow: 0 0 20px rgba(20, 129, 255, 0.6);
}

/* 竖向年份标签 */
.year-label {
    position: absolute;
    top: calc(66.67% + 15px);
    left: 50%;
    transform-origin: 0 0;
    transform: rotate(90deg);

    font-family: var(--tl-font-display);
    font-size: 14px;
    color: var(--tl-year-color);
    white-space: nowrap;
    transition: all 0.3s;
    letter-spacing: 1px;
    opacity: 0.8;

    display: flex;
    align-items: center;
    gap: 12px;
    pointer-events: none;
}

/* 竖向文字中的简短描述 */
.short-desc {
    font-family: var(--tl-font-sans);
    font-size: 12px;
    opacity: 0.6;
    font-weight: 300;
    letter-spacing: 1px;
}

/* Hover 状态下：标签变大并移到底部背景 */
.timeline-item:hover .year-label {
    top: auto;
    bottom: -10px;
    left: 20px;
    transform: rotate(0deg);
    font-size: 4rem;
    font-weight: 700;
    opacity: 0.08;
    color: var(--tl-active-color);
    pointer-events: none;
}

/* Hover时隐藏简述 */
.timeline-item:hover .short-desc {
    display: none;
}

/* 内容区域 - 固定在时间轴线上方 */
.content {
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.4s ease 0.1s;
    padding: 0 40px;
    color: var(--tl-text-color);
    position: absolute;

    bottom: 36%;
    left: 0;
    width: 100%;

    text-align: left;
    pointer-events: none;

    display: flex;
    flex-direction: column;
    justify-content: flex-end;
}

.timeline-item:hover .content {
    opacity: 1;
    transform: translateY(0);
}

.content-date {
    display: block;
    color: var(--tl-active-color);
    font-family: var(--tl-font-display);
    font-size: 2rem;
    margin-bottom: 15px;
    font-weight: bold;
    text-shadow: 0 0 20px rgba(20, 129, 255, 0.2);
}

.content-text {
    font-size:0.9rem;
    line-height: 1.8;
    border-left: 3px solid var(--tl-active-color);
    padding-left: 20px;
    max-width: 650px;
    background: linear-gradient(90deg, rgba(20, 129, 255, 0.08) 0%, transparent 100%);
    padding-top: 10px;
    padding-bottom: 10px;
    border-radius: 0 4px 4px 0;
}

.content-text p {
    margin: 0 0 8px 0;
}

.content-text p:last-child {
    margin-bottom: 0;
}

/* 重要节点高亮 */
.timeline-item.highlight .dot {
    width: 10px;
    height: 10px;
    box-shadow: 0 0 15px var(--tl-active-color), 0 0 30px var(--tl-active-color);
}

.timeline-item.highlight .year-label {
    color: var(--tl-active-color);
    opacity: 1;
}

/* ============================================
   自动轮播展开效果（与hover效果一致）
   ============================================ */
.timeline-item.auto-expanded {
    flex: 10;
    background: linear-gradient(90deg, rgba(20, 129, 255, 0.08) 0%, transparent 100%);
}

.timeline-container.has-auto-expanded .timeline-item:not(.auto-expanded) {
    opacity: 0.4;
}

.timeline-item.auto-expanded .dot {
    background-color: var(--tl-active-color);
    transform: translate(-50%, -50%) scale(1.5);
    box-shadow: 0 0 20px rgba(20, 129, 255, 0.6);
}

.timeline-item.auto-expanded .year-label {
    top: auto;
    bottom: -10px;
    left: 20px;
    transform: rotate(0deg);
    font-size: 4rem;
    font-weight: 700;
    opacity: 0.08;
    color: var(--tl-active-color);
    pointer-events: none;
}

.timeline-item.auto-expanded .short-desc {
    display: none;
}

.timeline-item.auto-expanded .content {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================
   响应式设计
   ============================================ */
@media (max-width: 1200px) {
    .timeline-container {
        width: 100%;
        height: 20vh;
        min-height: 500px;
    }

    .year-label {
        font-size: 12px;
        top: calc(66.67% + 15px);
    }

    .short-desc {
        font-size: 10px;
    }

    .content-text {
        font-size: 1rem;
        max-width: 500px;
    }

    .content-date {
        font-size: 1.6rem;
    }
}

@media (max-width: 991px) {
    .timeline-section {
        padding: 40px 0;
        min-height: auto;
        height: auto;
    }

    .timeline-container {
        width: 100%;
        height: 20vh;
        min-height: 500px;
        overflow-x: auto;
        overflow-y: visible;
        -webkit-overflow-scrolling: touch;
    }

    .timeline-item {
        min-width: 80px;
        flex: none;
    }

    .timeline-item:hover {
        flex: none;
        min-width: 350px;
    }

    .content {
        padding: 0 20px;
    }

    .content-text {
        font-size: 0.9rem;
        max-width: 300px;
    }
}

@media (max-width: 768px) {
    .timeline-title {
        font-size: 18px;
        letter-spacing: 2px;
        margin-bottom: 30px;
    }

    .timeline-container {
        height: 70vh;
    }

    .timeline-item {
        min-width: 60px;
    }

    .timeline-item:hover {
        min-width: 280px;
    }

    .year-label {
        font-size: 11px;
    }

    .short-desc {
        font-size: 9px;
        display: none;
    }

    .content {
        padding: 0 15px;
    }

    .content-date {
        font-size: 1.4rem;
        margin-bottom: 10px;
    }

    .content-text {
        font-size: 0.85rem;
        padding-left: 15px;
        max-width: 250px;
    }

    .dot {
        width: 6px;
        height: 6px;
    }
}

@media (max-width: 576px) {
    .timeline-section {
        padding: 30px 0;
    }

    .timeline-title {
        font-size: 16px;
        letter-spacing: 1px;
    }

    .timeline-container {
        height: 60vh;
    }

    .timeline-item {
        min-width: 50px;
    }

    .timeline-item:hover {
        min-width: 220px;
    }

    .year-label {
        font-size: 10px;
        top: calc(66.67% + 12px);
    }

    .content-date {
        font-size: 1.2rem;
    }

    .content-text {
        font-size: 0.8rem;
        line-height: 1.6;
    }

    .timeline-item:hover .year-label {
        font-size: 2.5rem;
        bottom: -30px;
        left: 10px;
    }
}