:root {
    --text-dark: #333333;
    --text-light: #555555;
    --line-color: #888888;
    --bg-white: #ffffff;
    --bg-body: #f9f9f9;
    --mobile-item-divider: #e2e2e2;
}

/* --- Theme Classes (Gradient Start and End Colors) --- */
.theme-2026 { --grad-start: #C65320; --grad-end: #E58A4A; }
.theme-2023 { --grad-start: #0D477F; --grad-end: #287EAD; }
.theme-2018 { --grad-start: #84171A; --grad-end: #B52D2F; }
.theme-2012 { --grad-start: #256330; --grad-end: #478C4A; }
.theme-2005 { --grad-start: #806000; --grad-end: #B88D12; }
.theme-1990 { --grad-start: #086579; --grad-end: #168FA9; }
.theme-1985 { --grad-start: #725267; --grad-end: #96768D; }
.theme-1971 { --grad-start: #5D6B20; --grad-end: #849637; }

/* --- Layout & Containers --- */
.timeline-container {
    width: 100%;
    max-width: 1100px;
    padding: 0 20px;
    margin: 0 auto; /* Horizontal centering */
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.timeline-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    /* background: var(--bg-white); */
    padding: 4px 20px;
    border-radius: 12px;
}

.timeline-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    background: var(--bg-body);
}

.timeline-item-reverse {
    flex-direction: row-reverse;
}

/* --- Typography & Gradients --- */
/* Shared Gradient Text Utility */
.timeline-year,
.timeline-title {
    background: linear-gradient(135deg, var(--grad-start) 0%, var(--grad-end) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    color: var(--grad-start); /* Fallback */
}

.timeline-year {
    flex: 1;
    font-size: 5rem;
    font-weight: 900;
    letter-spacing: -2px;
    line-height: 1;
    z-index: 2;
    text-align: right;
}

.timeline-item-reverse .timeline-year {
    text-align: left;
}

.timeline-title {
    font-size: 2.7rem;
    font-weight: 700;
    margin-bottom: 8px;
    letter-spacing: -0.5px;
    line-height: 1.2;
}

.timeline-desc {
    font-size: 1.5rem;
    color: var(--text-light);
    line-height: 1.5;
}

.timeline-desc strong {
    color: var(--text-dark);
    font-weight: 700;
}

/* --- Content & Graphics Layout --- */
.timeline-content {
    flex: 1;
    z-index: 2;
    text-align: left;
}

.timeline-item-reverse .timeline-content {
    text-align: right;
}

.timeline-graphics {
    --scale: 0.75;
    position: relative;
    flex: 0 0 calc(320px * var(--scale));
    height: calc(180px * var(--scale));
    z-index: 1;
}

.timeline-svg {
    position: absolute;
    top: 0;
    left: 0;
    width: 320px;
    height: 180px;
    z-index: 1;
    transform: scale(var(--scale));
    transform-origin: top left;
}

.icon-ring {
    position: absolute;
    left: calc(100px * var(--scale));
    top: calc(30px * var(--scale));
    width: 120px;
    height: 120px;
    transform: scale(var(--scale));
    transform-origin: top left;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2;
    box-shadow: 0 4px 10px rgba(0,0,0,0.50);

    /* Shaded Gradient Border */
    background-image: linear-gradient(var(--bg-white), var(--bg-white)),
                      linear-gradient(135deg, var(--grad-start) 0%, var(--grad-end) 100%);
    background-clip: padding-box, border-box;
    background-origin: padding-box, border-box;
    border: 14px solid transparent;
}

.icon-ring i {
    font-size: 42px;
}

.timeline-custom-icon {
    width: 55px;
    height: 55px;
    display: block;
    object-fit: contain;
}

/* --- Bullet Lists --- */
.left-bullets,
.right-bullets {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
}

.left-bullets { align-items: flex-start; }
.right-bullets { align-items: flex-end; }

.left-bullets li,
.right-bullets li {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    margin-bottom: 2px;
    line-height: 1.3;
    font-size: 1.5rem;
    color: var(--text-light);
}

.right-bullets li {
    text-align: right;
}

.left-bullets li::before,
.right-bullets li::before {
    content: "•";
    color: var(--text-dark, #333);
    font-size: 1.8em;
    flex-shrink: 0;
    line-height: 0.6;
    height: 0.6em;
    padding-top: 4px;
}

/* --- Responsive Design --- */

/* Tablets (Max Width: 1024px) */
@media (max-width: 1024px) {
    .timeline-item,
    .timeline-item-reverse {
        padding: 15px;
    }

    .timeline-year {
        font-size: 3.8rem;
        padding-right: 15px;
    }

    .timeline-item-reverse .timeline-year {
        padding-left: 15px;
        padding-right: 0;
    }

    .timeline-content { padding-left: 15px; }
    .timeline-item-reverse .timeline-content { padding-right: 15px; padding-left: 0; }

    .timeline-title { font-size: 1.75rem; }
    .timeline-desc { font-size: 1.3rem; }

    .left-bullets li,
    .right-bullets li {
        font-size: 1rem;
        line-height: 1.3;
    }

    .timeline-graphics {
        --scale: 0.65;
    }
}

/* Mobile (Max Width: 768px) */
@media (max-width: 768px) {
    .timeline-item,
    .timeline-item-reverse {
        flex-direction: column;
        text-align: center;
        max-width: 100%;
        margin: 0 auto;
        padding: 20px 15px;
        gap: 20px;
    }

    .timeline-year,
    .timeline-item-reverse .timeline-year {
        flex: auto;
        width: 100%;
        text-align: center;
        padding: 0;
        font-size: 6rem;
    }

    .timeline-content,
    .timeline-item-reverse .timeline-content {
        flex: auto;
        width: 100%;
        text-align: left;
        padding: 0;
    }

    .timeline-title {
        text-align: center;
        font-size: 3rem;
    }

    .timeline-desc {
        font-size: 1.8rem;
    }

    /* Mobile Bullet Fix */
    .left-bullets,
    .right-bullets {
        align-items: flex-start;
        width: 100%;
    }

    .left-bullets li,
    .right-bullets li {
        text-align: left;
        justify-content: flex-start;
        width: 100%;
        font-size: 1.8rem;
    }

    /* Mobile Vertical SVG */
    .timeline-graphics {
        --scale: 0.8;
        flex: 0 0 calc(320px * var(--scale));
        height: calc(320px * var(--scale));
        width: 100%;
        margin: 10px 0;
        position: relative;
    }

    .timeline-svg {
        display: block;
        top: 50%;
        left: 50%;
        transform-origin: center center;
        transform: translate(-50%, -50%) scale(var(--scale)) rotate(90deg);
    }

    .timeline-item-reverse .timeline-svg {
        transform: translate(-50%, -50%) scale(var(--scale)) rotate(-90deg);
    }

    .icon-ring {
        left: 50%;
        top: 50%;
        transform-origin: center center;
        transform: translate(-50%, -50%) scale(var(--scale));
    }
}