/* ============================================
   My Aviation - Timeline CSS
   航空历史时间线
   ============================================ */

/* —— 页面头部 —— */
.timeline-page {
    padding: var(--spacing-xl) 0 var(--spacing-lg);
}

.timeline-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.timeline-header-icon {
    font-size: 3.5rem;
    color: var(--color-sky-1);
    margin-bottom: var(--spacing-md);
    animation: bounce-soft 3s ease-in-out infinite;
}

.timeline-header .page-title {
    font-size: 2.5rem;
    color: var(--color-sky-deep);
    margin-bottom: var(--spacing-sm);
}

.timeline-header .page-subtitle {
    font-size: 1.15rem;
    color: var(--color-text-2);
}

/* —— 年代筛选 —— */
.timeline-filter {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    padding: var(--spacing-lg) 0;
}

.timeline-filter-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 0.6rem 1.4rem;
    border-radius: var(--radius-full);
    background: var(--color-white);
    color: var(--color-text-2);
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 700;
    border: 3px solid var(--color-cloud-3);
    transition: all var(--transition-base);
    cursor: pointer;
}

.timeline-filter-btn small {
    font-size: 0.75rem;
    font-weight: 600;
    opacity: 0.7;
    margin-top: 2px;
}

.timeline-filter-btn:hover {
    border-color: var(--color-sky-1);
    color: var(--color-sky-1);
    transform: translateY(-3px);
}

.timeline-filter-btn.active {
    background: var(--color-sky-1);
    color: var(--color-white);
    border-color: var(--color-sky-1);
}

/* —— 时间线容器 —— */
.timeline-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: var(--spacing-lg) var(--spacing-lg) var(--spacing-3xl);
    position: relative;
}

/* 中央竖线 */
.timeline-container::before {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    left: 50%;
    width: 5px;
    background: linear-gradient(180deg,
        #FF6B6B 0%, #FF6B6B 20%,
        #4DA6FF 20%, #4DA6FF 35%,
        #51CF66 35%, #51CF66 60%,
        #9775FA 60%, #9775FA 80%,
        #FFB940 80%, #FFB940 100%);
    border-radius: var(--radius-full);
    transform: translateX(-50%);
    z-index: 0;
}

/* —— 年代横幅 —— */
.timeline-era {
    position: relative;
    z-index: 1;
    margin-bottom: var(--spacing-2xl);
}

.timeline-era-banner {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    background: var(--era-color, var(--color-sky-1));
    color: var(--color-white);
    padding: 0.8rem 2rem;
    border-radius: var(--radius-full);
    margin: var(--spacing-2xl) auto var(--spacing-xl);
    max-width: 320px;
    font-family: var(--font-heading);
    font-weight: 800;
    box-shadow: 0 6px 20px color-mix(in srgb, var(--era-color, var(--color-sky-1)) 30%, transparent);
    position: relative;
    z-index: 2;
}

.era-icon { font-size: 1.4rem; }
.era-title { font-size: 1.2rem; }
.era-years { font-size: 0.9rem; opacity: 0.85; }

/* —— 时间线条目 —— */
.timeline-items {
    position: relative;
}

.timeline-item {
    position: relative;
    width: 50%;
    padding: 0 3rem 2rem 0;
    opacity: 0;
    transform: translateX(-30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.timeline-item.visible {
    opacity: 1;
    transform: translateX(0);
}

/* 奇数项在右侧 */
.timeline-item:nth-child(odd) {
    margin-left: 50%;
    padding: 0 0 2rem 3rem;
    transform: translateX(30px);
}

.timeline-item:nth-child(odd).visible {
    transform: translateX(0);
}

/* —— 时间线标记点 —— */
.timeline-marker {
    position: absolute;
    top: 1.5rem;
    right: -10px;
    width: 20px;
    height: 20px;
    z-index: 3;
}

.timeline-item:nth-child(odd) .timeline-marker {
    right: auto;
    left: -10px;
}

.marker-dot {
    display: block;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--era-color, var(--color-sky-1));
    border: 4px solid var(--color-white);
    box-shadow: 0 0 0 4px color-mix(in srgb, var(--era-color, var(--color-sky-1)) 30%, transparent);
    animation: bounce-soft 2s ease-in-out infinite;
}

/* —— 时间线卡片 —— */
.timeline-card {
    background: var(--color-white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
    border: 3px solid transparent;
    transition: all var(--transition-base);
    position: relative;
}

.timeline-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: var(--era-color, var(--color-sky-1));
}

/* 卡片箭头（指向中心线） */
.timeline-card::before {
    content: '';
    position: absolute;
    top: 1.8rem;
    right: -12px;
    width: 0;
    height: 0;
    border-style: solid;
    border-width: 10px 0 10px 12px;
    border-color: transparent transparent transparent var(--color-white);
    filter: drop-shadow(2px 0 1px rgba(0,0,0,0.05));
}

.timeline-item:nth-child(odd) .timeline-card::before {
    right: auto;
    left: -12px;
    border-width: 10px 12px 10px 0;
    border-color: transparent var(--color-white) transparent transparent;
    filter: drop-shadow(-2px 0 1px rgba(0,0,0,0.05));
}

.timeline-year {
    display: inline-block;
    background: var(--era-color, var(--color-sky-1));
    color: var(--color-white);
    padding: 0.2rem 1rem;
    border-radius: var(--radius-full);
    font-family: var(--font-heading);
    font-size: 1.3rem;
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
    box-shadow: 0 3px 10px color-mix(in srgb, var(--era-color, var(--color-sky-1)) 25%, transparent);
}

.timeline-title {
    font-size: 1.2rem;
    color: var(--color-sky-deep);
    margin-bottom: var(--spacing-sm);
}

.timeline-image {
    width: 100%;
    height: 140px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: var(--spacing-md);
    position: relative;
    overflow: hidden;
}

.timeline-image i {
    animation: float-soft 4s ease-in-out infinite;
}

.timeline-image::after {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 70% 30%, rgba(255,255,255,0.2), transparent);
}

.timeline-text {
    color: var(--color-text-2);
    line-height: 1.8;
    font-size: 0.98rem;
    margin-bottom: var(--spacing-md);
}

.timeline-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.timeline-tag {
    display: inline-block;
    padding: 0.2rem 0.8rem;
    background: var(--color-cloud);
    border-radius: var(--radius-full);
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--color-text-2);
}

/* —— 未来条目特殊样式 —— */
.timeline-item.timeline-future .timeline-card {
    border: 3px dashed var(--color-sun);
    background: linear-gradient(135deg, #FFF9F0, var(--color-white));
}

.timeline-item.timeline-future .timeline-year {
    animation: bounce-soft 1.5s ease-in-out infinite;
}

/* ============================================
   响应式
   ============================================ */
@media (max-width: 768px) {
    /* 竖线移到左侧 */
    .timeline-container::before {
        left: 24px;
        transform: none;
    }

    .timeline-era-banner {
        margin-left: 50px;
        max-width: calc(100% - 50px);
    }

    /* 所有条目在右侧 */
    .timeline-item {
        width: 100%;
        margin-left: 0 !important;
        padding: 0 0 2rem 50px !important;
        transform: translateX(0);
    }

    .timeline-item:nth-child(odd) {
        margin-left: 0;
    }

    /* 标记点移到左侧 */
    .timeline-marker {
        left: 14px !important;
        right: auto !important;
    }

    /* 卡片箭头移到左侧 */
    .timeline-card::before {
        left: -12px !important;
        right: auto !important;
        border-width: 10px 12px 10px 0 !important;
        border-color: transparent var(--color-white) transparent transparent !important;
        filter: drop-shadow(-2px 0 1px rgba(0,0,0,0.05)) !important;
    }

    .timeline-filter-btn {
        font-size: 0.9rem;
        padding: 0.5rem 1rem;
    }
}

@media (max-width: 480px) {
    .timeline-header .page-title {
        font-size: 1.8rem;
    }

    .timeline-card {
        padding: var(--spacing-md);
    }

    .timeline-image {
        height: 100px;
        font-size: 2.2rem;
    }

    .timeline-era-banner {
        padding: 0.6rem 1.2rem;
        font-size: 0.95rem;
    }

    .era-icon { font-size: 1.1rem; }
    .era-title { font-size: 1rem; }
    .era-years { font-size: 0.8rem; }
}