/* ==========================================================================
   BLOCK TIMELINE / HISTORY JOURNEY - PURE BEM STANDARD
   ========================================================================== */

.block-timeline {
    max-width: 1200px;
    margin: 0 auto clamp(60px, 8vw, 90px) auto;
    padding: 0 20px;
    box-sizing: border-box;
}

.block-timeline__container {
    width: 100%;
    margin: 0 auto;
}

.block-timeline__header {
    text-align: center;
    margin-bottom: 30px;
}

.block-timeline__header h2 {
    font-family: var(--font-serif);
    font-weight: 600;
    color: var(--color-accent, #456C35);
    margin: 0 0 var(--space-heading-bottom, 8px) 0;
}

.block-timeline__header p {
    font-family: var(--font-serif);
    font-weight: 400;
    color: var(--color-accent, #456C35);
    margin: 0;
}

.block-timeline__body {
    display: flex;
    justify-content: space-between;
}

/* === CỘT NAV (BÊN TRÁI) === */
.block-timeline__nav {
    border-top: 1px solid var(--border-light, #dddddd);
    flex: 0 0 46%;
    max-width: 46%;
    display: flex;
    flex-wrap: wrap;
    align-content: flex-start;
    gap: 15px 25px;
    padding: 25px 40px 25px 0;
    height: 600px;
    box-sizing: border-box;
    position: relative;
}

.block-timeline__nav-btn {
    font-family: var(--font-sans);
    font-size: 16px;
    font-weight: 400;
    color: var(--text-grey, #999999);
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
    transition: color 0.3s ease;
}

.block-timeline__nav-btn:hover {
    color: var(--color-accent, #456C35);
}

.block-timeline__nav-btn.active {
    color: var(--color-accent, #456C35);
    font-weight: 600;
}

/* === CỘT NỘI DUNG (BÊN PHẢI) === */
.block-timeline__content {
    border-top: 1px solid var(--border-light, #dddddd);
    flex: 0 0 45%;
    max-width: 45%;
    height: 600px;
    overflow-y: auto;
    padding: 25px 0 25px 40px;
    scroll-behavior: smooth;
    box-sizing: border-box;
}

.block-timeline__content::-webkit-scrollbar {
    width: 6px;
}

.block-timeline__content::-webkit-scrollbar-thumb {
    background: var(--border-light, #cccccc);
    border-radius: 3px;
}

.block-timeline__item {
    display: flex;
    gap: 25px;
    margin-bottom: 50px;
}

.block-timeline__year {
    font-family: var(--font-serif);
    font-size: 28px;
    font-weight: 600;
    color: var(--color-accent, #456C35);
    min-width: 60px;
}

.block-timeline__item-body {
    flex: 1;
}

.block-timeline__item-body h3 {
    font-family: var(--font-serif);
    font-weight: 600;
    color: var(--text-dark, #333333);
    margin: 0 0 10px 0;
}

.block-timeline__item-body p {
    color: var(--text-dark, #333333);
    margin: 0 0 12px 0;
    line-height: 1.6;
}

.block-timeline__item-image {
    margin-top: 15px;
    border-radius: var(--radius-card, 6px);
    overflow: hidden;
}

.block-timeline__item-image img {
    width: 100%;
    height: auto;
    display: block;
}

/* === RESPONSIVE MOBILE (< 768px) === */
@media (max-width: 767px) {
    .block-timeline__body {
        flex-direction: column;
    }

    .block-timeline__nav,
    .block-timeline__content {
        flex: none;
        max-width: 100%;
        height: auto;
        padding: 15px 0;
    }

    .block-timeline__nav {
        overflow-x: auto;
        flex-wrap: nowrap;
        height: auto;
        position: sticky;
        top: 85px;
        z-index: 99;
        background-color: var(--color-primary, #ffffff);
        border-bottom: 1px solid var(--border-light, #dddddd);
        gap: 24px;
        display: flex;
        align-items: center;
        -webkit-overflow-scrolling: touch;
        scroll-behavior: smooth;
    }

    .block-timeline__nav::-webkit-scrollbar {
        display: none;
    }

    .block-timeline__nav-btn {
        flex-shrink: 0;
    }
}