/*
==================================================
河南元达科耐火材料 - 三代传承严肃横向时间轴
厚重历史感 | 分层动画 | 视差效果
==================================================
*/

/* =============================================================================
   1. 设计系统变量
============================================================================= */
:root {
    /* 严肃历史色彩体系 */
    --heritage-dark: #1a1a1a;
    --heritage-darker: #0f0f0f;
    --heritage-charcoal: #2a2a2a;
    --heritage-steel: #3a3a3a;

    /* 企业强调色 */
    --accent-red: #d42c28;
    --accent-red-bright: #e74c3c;
    --accent-red-dark: #b71c1c;

    /* 时间轴专用文字色彩层级 */
    --timeline-text-primary: #ffffff;
    --timeline-text-secondary: #e0e0e0;
    --timeline-text-tertiary: #cccccc;
    --timeline-text-muted: #999999;

    /* 间距和尺寸 */
    --timeline-height: 420px;
    --section-padding: 80px 0;
    --container-max-width: 1400px;
    --timeline-line-height: 4px;

    /* 字体大小 - 优化年份大小避免布局冲突 */
    --font-year: clamp(2.5rem, 4vw, 3.5rem);
    --font-title: clamp(1.5rem, 3vw, 2.2rem);
    --font-description: clamp(1rem, 2vw, 1.2rem);

    /* 动画时序 */
    --animation-duration: 0.8s;
    --animation-delay-increment: 0.3s;
    --animation-easing: cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

/* =============================================================================
   2. 时间轴主容器
============================================================================= */
.heritage-timeline {
    background: linear-gradient(135deg,
        var(--heritage-darker) 0%,
        var(--heritage-dark) 25%,
        var(--heritage-charcoal) 75%,
        var(--heritage-dark) 100%);
    padding: var(--section-padding);
    position: relative;
    overflow: hidden;
    min-height: var(--timeline-height);
}

/* 深度纹理背景 */
.heritage-timeline::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background-image:
        linear-gradient(45deg, transparent 45%, rgba(255,255,255,0.02) 50%, transparent 55%),
        radial-gradient(circle at 20% 20%, rgba(212,44,40,0.05) 1px, transparent 1px),
        radial-gradient(circle at 80% 80%, rgba(255,255,255,0.03) 1px, transparent 1px);
    background-size: 100px 100px, 50px 50px, 30px 30px;
    pointer-events: none;
    opacity: 0.6;
}

/* 顶部装饰线 */
.heritage-timeline::after {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 2px;
    background: linear-gradient(90deg,
        transparent 0%,
        var(--accent-red-dark) 20%,
        var(--accent-red) 50%,
        var(--accent-red-dark) 80%,
        transparent 100%);
}

/* =============================================================================
   3. 标题区域
============================================================================= */
.timeline-header {
    text-align: center;
    margin-bottom: 60px;
    position: relative;
    z-index: 10;
}

.heritage-timeline h3 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    color: var(--timeline-text-primary);
    margin-bottom: 20px;
    font-family: 'Noto Serif SC', serif;
    letter-spacing: 2px;
    line-height: 1.2;
    position: relative;
}

.heritage-timeline .section-subtitle {
    font-size: var(--font-description);
    color: var(--timeline-text-primary);
    font-weight: 300;
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
    font-family: 'Noto Sans SC', sans-serif;
}

/* =============================================================================
   4. 横向时间轴布局
============================================================================= */
.timeline-container {
    position: relative;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 40px 20px;
}

/* 主时间线 */
.timeline-container::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 5%;
    right: 5%;
    height: var(--timeline-line-height);
    background: linear-gradient(90deg,
        transparent 0%,
        var(--heritage-steel) 5%,
        var(--accent-red-dark) 15%,
        var(--accent-red) 50%,
        var(--accent-red-dark) 85%,
        var(--heritage-steel) 95%,
        transparent 100%);
    transform: translateY(-50%);
    z-index: 1;
    border-radius: 2px;
    box-shadow: 0 0 20px rgba(212,44,40,0.3);
}

/* 时间轴项目容器 */
.timeline-items-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 80px;
    position: relative;
    z-index: 2;
    align-items: flex-start; /* 改为顶部对齐确保水平一致 */
    min-height: 500px;
    padding: 0 40px; /* 增加左右内边距 */
}

/* =============================================================================
   5. 时间轴项目设计
============================================================================= */
.timeline-item {
    position: relative;
    text-align: center;
    padding: 20px 15px;
    display: flex;
    flex-direction: column;
    align-items: center;

    /* 初始状态 - 隐藏 */
    opacity: 0;
    transform: translateY(30px);
    transition: none; /* 将通过JavaScript控制动画 */
}

/* 时间节点标记 */
.timeline-marker {
    position: relative;
    z-index: 3;
    margin-bottom: 25px;
    display: flex;
    flex-direction: column;
    align-items: center;
    height: 120px; /* 固定高度确保对齐 */
    justify-content: space-between;
}

.timeline-dot {
    width: 20px;
    height: 20px;
    background: var(--accent-red);
    border: 4px solid var(--heritage-dark);
    border-radius: 50%;
    box-shadow:
        0 0 0 4px var(--timeline-text-primary),
        0 0 20px rgba(212,44,40,0.5);
    position: relative;
    margin-bottom: 20px;

    /* 确保完全圆形 */
    flex-shrink: 0;
    display: block;

    /* 动画初始状态 */
    opacity: 0;
    transform: scale(0);
}

.timeline-dot::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 8px;
    height: 8px;
    background: var(--timeline-text-primary);
    border-radius: 50%;
    transform: translate(-50%, -50%);
}

/* =============================================================================
   6. 文字内容层级设计
============================================================================= */

/* 代际标识 - 放大字体 */
.generation-number {
    font-size: clamp(1.2rem, 2.5vw, 1.8rem);
    font-weight: 700;
    color: var(--accent-red-bright);
    font-family: 'Noto Sans SC', sans-serif;
    margin-bottom: 15px;
    letter-spacing: 1px;
}

/* 强力移除任何可能的emoji和视觉干扰元素 */
.generation-number::before,
.generation-number::after,
.timeline-marker::before,
.timeline-marker::after,
.timeline-item::before,
.timeline-item::after,
.timeline-dot::before,
.timeline-year::before,
.timeline-year::after,
.generation-title::before,
.generation-title::after,
.description-line::before,
.description-line::after {
    content: "" !important;
    display: none !important;
    visibility: hidden !important;
}

/* 保持timeline-dot内部圆点正常显示 */
.timeline-dot::after {
    content: '' !important;
    display: block !important;
    visibility: visible !important;
    position: absolute;
    top: 50%;
    left: 50%;
    width: 8px;
    height: 8px;
    background: var(--timeline-text-primary);
    border-radius: 50%;
    transform: translate(-50%, -50%);
}

/* 移除可能的Font Awesome图标和伪元素 */
.generation-number i,
.timeline-marker i,
.timeline-item i,
.timeline-dot i,
.timeline-year i,
.generation-title i,
.description-line i {
    display: none !important;
    visibility: hidden !important;
}

/* 强制字体设置，避免emoji回退显示 */
.heritage-timeline,
.heritage-timeline * {
    font-family: 'Noto Sans SC', 'Microsoft YaHei', 'PingFang SC', sans-serif !important;
    text-rendering: optimizeLegibility !important;
    -webkit-font-feature-settings: "kern" 1, "liga" 0, "calt" 0 !important;
    font-feature-settings: "kern" 1, "liga" 0, "calt" 0 !important;
    font-variant-emoji: text !important;
}

/* 禁用任何可能的Unicode emoji显示 */
.heritage-timeline {
    font-variant-emoji: text !important;
    -webkit-font-variant-emoji: text !important;
}

/* 年代 - 大字 */
.timeline-year {
    font-size: var(--font-year);
    font-weight: 900;
    color: var(--timeline-text-primary);
    font-family: 'Noto Serif SC', serif;
    letter-spacing: 3px;
    margin-bottom: 10px;
    line-height: 0.9;
    text-shadow: 0 4px 8px rgba(0,0,0,0.8);

    /* 动画初始状态 */
    opacity: 0;
    transform: translateY(20px);
}

/* 标题 - 中字 */
.generation-title {
    font-size: var(--font-title);
    font-weight: 600;
    color: var(--timeline-text-primary);
    font-family: 'Noto Sans SC', sans-serif;
    margin-bottom: 15px;
    line-height: 1.2;
    letter-spacing: 0.5px;
    max-width: 200px;
    word-wrap: break-word;

    /* 动画初始状态 */
    opacity: 0;
    transform: translateY(15px);
}

/* 重点词红色突出 */
.generation-title .highlight {
    color: var(--accent-red-bright);
    font-weight: 700;
}

/* 说明文字容器 */
.timeline-description {
    max-width: 250px;
    margin: 0 auto;
    line-height: 1.4;
}

/* 说明文字 - 小字 */
.description-line {
    font-size: var(--font-description);
    color: var(--timeline-text-primary);
    font-family: 'Noto Sans SC', sans-serif;
    line-height: 1.5;
    margin-bottom: 8px;
    font-weight: 300;
    letter-spacing: 0.3px;

    /* 动画初始状态 */
    opacity: 0;
    transform: translateY(10px);
}

.description-line:last-child {
    margin-bottom: 0;
}

/* 关键词突出 */
.description-line .keyword {
    color: var(--accent-red);
    font-weight: 500;
}

/* =============================================================================
   7. 动画状态类
============================================================================= */

/* 时间轴项目激活状态 */
.timeline-item.animate {
    opacity: 1;
    transform: translateY(0);
}

/* 各元素激活状态 */
.timeline-dot.animate {
    opacity: 1;
    transform: scale(1);
    transition: all var(--animation-duration) var(--animation-easing);
}

.timeline-year.animate {
    opacity: 1;
    transform: translateY(0);
    transition: all var(--animation-duration) var(--animation-easing);
}

.generation-title.animate {
    opacity: 1;
    transform: translateY(0);
    transition: all var(--animation-duration) var(--animation-easing);
}

.description-line.animate {
    opacity: 1;
    transform: translateY(0);
    transition: all var(--animation-duration) var(--animation-easing);
}

/* =============================================================================
   8. 结论区域
============================================================================= */
.heritage-conclusion {
    margin-top: 80px;
    text-align: center;
    position: relative;
    z-index: 10;
}

.conclusion-text {
    font-size: clamp(1.4rem, 3vw, 1.8rem) !important;
    color: var(--timeline-text-primary);
    font-family: 'Noto Serif SC', serif;
    font-weight: 400;
    max-width: 800px;
    margin: 0 auto;
    line-height: 1.8;
    letter-spacing: 1px;
    padding: 40px;
    background: rgba(255,255,255,0.05);
    backdrop-filter: blur(10px);
    border-radius: 8px;
    border: 1px solid rgba(255,255,255,0.1);
    position: relative;

    /* 动画初始状态 */
    opacity: 0;
    transform: translateY(30px);
}

.conclusion-text.animate {
    opacity: 1;
    transform: translateY(0);
    transition: all 1s var(--animation-easing);
}

.conclusion-text::before {
    content: '';
    position: absolute;
    top: 0; left: 50%;
    width: 80px;
    height: 2px;
    background: var(--accent-red);
    transform: translateX(-50%);
}

/* 结论文字中的关键词 - 增强优先级 */
.heritage-timeline .conclusion-text .highlight {
    color: var(--accent-red-bright) !important;
    font-weight: 600 !important;
    font-size: clamp(1.4rem, 3vw, 1.8rem) !important; /* 与主文字完全相同 */
    line-height: inherit !important;
}

/* =============================================================================
   9. 响应式设计
============================================================================= */
@media (max-width: 1200px) {
    .timeline-items-container {
        gap: 40px;
    }

    .timeline-description {
        max-width: 240px;
    }
}

@media (max-width: 992px) {
    .heritage-timeline {
        padding: 60px 0;
    }

    .timeline-items-container {
        grid-template-columns: 1fr;
        gap: 80px;
        max-width: 500px;
        margin: 0 auto;
    }

    .timeline-container::before {
        top: 0;
        left: 50%;
        right: auto;
        bottom: 0;
        width: var(--timeline-line-height);
        height: auto;
        background: linear-gradient(180deg,
            transparent 0%,
            var(--heritage-steel) 5%,
            var(--accent-red-dark) 15%,
            var(--accent-red) 50%,
            var(--accent-red-dark) 85%,
            var(--heritage-steel) 95%,
            transparent 100%);
        transform: translateX(-50%);
    }

    .timeline-item {
        padding: 30px;
    }

    .timeline-description {
        max-width: 320px;
    }
}

@media (max-width: 768px) {
    .heritage-timeline {
        padding: 40px 0;
    }

    .timeline-header {
        margin-bottom: 40px;
    }

    .timeline-container {
        padding: 20px 15px;
    }

    .timeline-items-container {
        gap: 60px;
    }

    .timeline-item {
        padding: 20px 15px;
    }

    .timeline-description {
        max-width: 280px;
    }

    .heritage-conclusion {
        margin-top: 60px;
    }

    .conclusion-text {
        padding: 30px 20px;
    }
}

/* 中等屏幕优化 */
@media (max-width: 992px) {
    :root {
        --font-year: clamp(2rem, 5vw, 2.8rem);
        --font-title: clamp(1.3rem, 3.5vw, 1.8rem);
        --font-description: clamp(0.9rem, 2.5vw, 1.1rem);
    }
}

@media (max-width: 768px) {
    :root {
        --font-year: clamp(1.8rem, 6vw, 2.4rem);
        --font-title: clamp(1.2rem, 4vw, 1.6rem);
        --font-description: clamp(0.85rem, 3vw, 1rem);
    }
}

@media (max-width: 480px) {
    :root {
        --font-year: clamp(1.6rem, 8vw, 2rem);
        --font-title: clamp(1rem, 4.5vw, 1.4rem);
        --font-description: clamp(0.8rem, 3.5vw, 0.95rem);
    }

    .timeline-items-container {
        gap: 50px;
    }

    .timeline-marker {
        margin-bottom: 20px;
    }

    .timeline-year {
        margin-bottom: 10px;
        letter-spacing: 2px;
    }

    .generation-title {
        margin-bottom: 15px;
    }
}

/* =============================================================================
   10. 视差效果和性能优化
============================================================================= */

/* 为视差效果准备的变换层 */
.timeline-parallax-layer {
    will-change: transform;
    transform: translateZ(0); /* 硬件加速 */
}

/* 减少动画偏好支持 */
@media (prefers-reduced-motion: reduce) {
    .timeline-item,
    .timeline-dot,
    .timeline-year,
    .generation-title,
    .description-line,
    .conclusion-text {
        transition: none !important;
        animation: none !important;
    }

    .heritage-timeline::before {
        animation: none !important;
    }
}

/* 高对比度模式支持 */
@media (prefers-contrast: high) {
    :root {
        --timeline-text-primary: #ffffff;
        --timeline-text-secondary: #ffffff;
        --timeline-text-tertiary: #ffffff;
        --accent-red: #ff0000;
        --accent-red-bright: #ff0000;
        --heritage-dark: #000000;
    }

    .heritage-timeline {
        background: #000000;
    }

    .timeline-container::before {
        background: #ffffff;
    }
}