/*
 * RIVER TIMELINE COMPONENT
 * ========================
 * A scroll-animated timeline with a river that fills as user scrolls
 *
 * Customization variables at the top - adjust colors, sizes, etc.
 */

:root {
    /* Colors - matching site's design system */
    --river-color-unfilled: #dee2e6;
    --river-color-filled: #0077b6;
    --river-color-glow: rgba(0, 119, 182, 0.3);
    --event-bg-left: #ffffff;
    --event-bg-right: #ffffff;
    --event-border: #dee2e6;
    --event-title-color: #1a1a2e;
    --event-text-color: #495057;
    --event-year-color: #0077b6;
    --event-active-border: #0077b6;

    /* Sizing */
    --river-width: 8px;
    --river-dot-size: 26px;
    --column-gap: 32px;
    --event-padding: 2rem;
    --event-border-radius: 12px;
    --timeline-max-width: 1400px;
}

/* Reset for component */
.river-timeline {
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    line-height: 1.6;
}

.river-timeline *,
.river-timeline *::before,
.river-timeline *::after {
    box-sizing: inherit;
}

/* Main container */
.river-timeline {
    width: 100%;
    padding: 60px 20px;
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
}

.river-timeline__container {
    display: grid;
    grid-template-columns: 1fr 80px 1fr;
    gap: var(--column-gap);
    max-width: var(--timeline-max-width);
    margin: 0 auto;
    position: relative;
}

/* Columns */
.river-timeline__column {
    display: flex;
    flex-direction: column;
    gap: 40px;
}

.river-timeline__column--left {
    padding-top: 0;
}

.river-timeline__column--right {
    padding-top: 150px; /* Offset for alternating effect */
}

.river-timeline__column--middle {
    position: relative;
    display: flex;
    justify-content: center;
    padding: 0;
    gap: 0;
}

/* The River */
.river-timeline__river {
    position: absolute;
    top: 0;
    bottom: 0;
    width: 100%;
    height: 100%;
}

.river-timeline__svg {
    width: 100%;
    height: 100%;
    overflow: visible;
}

.river-timeline__path {
    fill: none;
    stroke-width: var(--river-width);
    stroke-linecap: round;
    stroke-linejoin: round;
}

.river-timeline__path--bg {
    stroke: var(--river-color-unfilled);
}

.river-timeline__path--fill {
    stroke: var(--river-color-filled);
    filter: drop-shadow(0 0 6px var(--river-color-glow)) drop-shadow(0 0 12px var(--river-color-glow));
    transition: stroke-dashoffset 0.15s ease-out;
}

/* Event dots on the river */
.river-timeline__dot {
    position: absolute;
    width: var(--river-dot-size);
    height: var(--river-dot-size);
    background: #fff;
    border: 3px solid var(--river-color-unfilled);
    border-radius: 50%;
    transform: translate(-50%, -50%) scale(1);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 10;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.river-timeline__dot--active {
    background: var(--river-color-filled);
    border-color: var(--river-color-filled);
    transform: translate(-50%, -50%) scale(1.3);
}

/* Event cards */
.river-timeline__event {
    background: var(--event-bg-left);
    border: 2px solid var(--event-border);
    border-radius: var(--event-border-radius);
    padding: var(--event-padding);
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    opacity: 0.4;
    transform: translateY(30px) scale(0.98);
    position: relative;
}

.river-timeline__event--active {
    opacity: 1;
    transform: translateY(0) scale(1);
    border-color: var(--event-active-border);
    box-shadow: 0 8px 30px rgba(37, 99, 235, 0.2);
    background: #fff;
}

/* Left events - arrow pointing right toward the river center */
.river-timeline__column--left .river-timeline__event::after {
    content: '';
    position: absolute;
    right: -32px;
    top: 22px;
    width: 32px;
    height: 2px;
    background: var(--event-border);
    transition: background-color 0.3s ease;
}

.river-timeline__column--left .river-timeline__event::before {
    content: '';
    position: absolute;
    right: -32px;
    top: 18px;
    width: 0;
    height: 0;
    border-top: 6px solid transparent;
    border-bottom: 6px solid transparent;
    border-left: 8px solid var(--event-border);
    transition: border-left-color 0.3s ease;
}

.river-timeline__column--left .river-timeline__event--active::after {
    background: var(--event-active-border);
}

.river-timeline__column--left .river-timeline__event--active::before {
    border-left-color: var(--event-active-border);
}

/* Right events - arrow pointing left toward the river center */
.river-timeline__column--right .river-timeline__event::after {
    content: '';
    position: absolute;
    left: -32px;
    top: 22px;
    width: 32px;
    height: 2px;
    background: var(--event-border);
    transition: background-color 0.3s ease;
}

.river-timeline__column--right .river-timeline__event::before {
    content: '';
    position: absolute;
    left: -40px;
    top: 18px;
    width: 0;
    height: 0;
    border-top: 6px solid transparent;
    border-bottom: 6px solid transparent;
    border-right: 8px solid var(--event-border);
    transition: border-right-color 0.3s ease;
}

.river-timeline__column--right .river-timeline__event--active::after {
    background: var(--event-active-border);
}

.river-timeline__column--right .river-timeline__event--active::before {
    border-right-color: var(--event-active-border);
}

/* Event content */
.river-timeline__year {
    display: inline-block;
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--event-year-color);
    background: rgba(37, 99, 235, 0.1);
    padding: 8px 16px;
    border-radius: 20px;
    margin-bottom: 16px;
}

.river-timeline__title {
    font-size: 2.75rem;
    font-weight: 700;
    color: var(--event-title-color);
    margin: 0 0 16px 0;
    line-height: 1.3;
    font-family: 'Roboto Slab', 'Georgia', serif;
}

.river-timeline__description {
    font-size: 1.75rem;
    color: var(--event-text-color);
    margin: 0;
    line-height: 1.9;
}

/* Scroll progress indicator (optional) */
.river-timeline__progress {
    position: fixed;
    top: 50%;
    right: 20px;
    transform: translateY(-50%);
    width: 4px;
    height: 100px;
    background: var(--river-color-unfilled);
    border-radius: 2px;
    z-index: 100;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.river-timeline__progress--visible {
    opacity: 1;
}

.river-timeline__progress-fill {
    width: 100%;
    height: 0%;
    background: var(--river-color-filled);
    border-radius: 2px;
    transition: height 0.1s ease-out;
}

/* Responsive Design */
@media (max-width: 900px) {
    .river-timeline__container {
        grid-template-columns: 1fr 60px 1fr;
        gap: 15px;
    }

    .river-timeline__column--right {
        padding-top: 100px;
    }

    .river-timeline__event {
        padding: 16px;
    }

    .river-timeline__title {
        font-size: 1.1rem;
    }

    /* Shorter connector lines for smaller gap */
    .river-timeline__column--left .river-timeline__event::after,
    .river-timeline__column--right .river-timeline__event::after {
        width: 20px;
    }

    .river-timeline__column--left .river-timeline__event::after {
        right: -20px;
    }

    .river-timeline__column--left .river-timeline__event::before {
        right: -20px;
    }

    .river-timeline__column--right .river-timeline__event::after {
        left: -20px;
    }

    .river-timeline__column--right .river-timeline__event::before {
        left: -28px;
    }
}

@media (max-width: 700px) {
    .river-timeline {
        padding: 40px 15px;
    }

    /* Single column layout on mobile */
    .river-timeline__container {
        display: flex;
        flex-direction: row;
        flex-wrap: wrap;
        gap: 0;
        position: relative;
        padding-left: 50px;
    }

    /* Hide the separate columns structure - children flow into parent */
    .river-timeline__column--left,
    .river-timeline__column--right {
        display: contents; /* Makes children act as if they're direct children of container */
    }

    .river-timeline__column--middle {
        position: absolute;
        left: 0;
        top: 0;
        bottom: 0;
        width: 40px;
        display: block;
    }

    /* All events in single flow - order set via data-index attribute */
    .river-timeline__event {
        width: 100%;
        flex: 0 0 100%;
        margin-bottom: 24px;
        padding: 16px;
    }

    /* Use data-index attribute for ordering (set by JS) */
    .river-timeline__event[data-index="0"] { order: 0; }
    .river-timeline__event[data-index="1"] { order: 1; }
    .river-timeline__event[data-index="2"] { order: 2; }
    .river-timeline__event[data-index="3"] { order: 3; }
    .river-timeline__event[data-index="4"] { order: 4; }
    .river-timeline__event[data-index="5"] { order: 5; }
    .river-timeline__event[data-index="6"] { order: 6; }
    .river-timeline__event[data-index="7"] { order: 7; }
    .river-timeline__event[data-index="8"] { order: 8; }
    .river-timeline__event[data-index="9"] { order: 9; }
    .river-timeline__event[data-index="10"] { order: 10; }
    .river-timeline__event[data-index="11"] { order: 11; }
    .river-timeline__event[data-index="12"] { order: 12; }

    .river-timeline__year {
        font-size: 1.125rem;
        padding: 6px 12px;
    }

    .river-timeline__title {
        font-size: 1.75rem;
    }

    .river-timeline__description {
        font-size: 1.125rem;
        line-height: 1.7;
    }

    /* Remove arrows on mobile */
    .river-timeline__column--left .river-timeline__event::after,
    .river-timeline__column--left .river-timeline__event::before,
    .river-timeline__column--right .river-timeline__event::after,
    .river-timeline__column--right .river-timeline__event::before {
        display: none;
    }

    /* Dots are positioned by JS to match the curved path */

    /* Hide progress indicator on mobile */
    .river-timeline__progress {
        display: none;
    }
}

/* Dot pulse animation when active */
@keyframes dotPulse {
    0%, 100% {
        box-shadow: 0 0 0 4px var(--river-color-glow), 0 2px 12px rgba(37, 99, 235, 0.3);
    }
    50% {
        box-shadow: 0 0 0 8px var(--river-color-glow), 0 2px 16px rgba(37, 99, 235, 0.5);
    }
}

.river-timeline__dot--active {
    animation: dotPulse 2s ease-in-out infinite;
}

/* CTA Section at bottom of timeline */
.river-timeline__cta {
    grid-column: 1 / -1;
    display: flex;
    justify-content: center;
    padding: 60px 20px;
    margin-top: 40px;
}

.river-timeline__cta-content {
    text-align: center;
    max-width: 600px;
    padding: 40px;
    background: linear-gradient(135deg, #f0f7ff 0%, #e8f4fd 100%);
    border-radius: 20px;
    border: 2px solid var(--river-color-filled);
    box-shadow: 0 10px 40px rgba(37, 99, 235, 0.15);
}

.river-timeline__cta-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 700;
    color: var(--event-title-color);
    margin: 0 0 20px 0;
    font-family: 'Roboto Slab', 'Georgia', serif;
    line-height: 1.3;
}

.river-timeline__cta-description {
    font-size: 1.75rem;
    color: var(--event-text-color);
    margin: 0 0 32px 0;
    line-height: 1.85;
}

.river-timeline__cta-button {
    display: inline-block;
    padding: 20px 48px;
    background: var(--river-color-filled);
    color: #fff;
    font-size: 2rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: 50px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
}

.river-timeline__cta-button:hover {
    background: #1d4ed8;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}

.river-timeline__cta-button:active {
    transform: translateY(0);
}

/* CTA responsive */
@media (max-width: 700px) {
    .river-timeline__cta {
        padding: 40px 15px;
        margin-top: 20px;
    }

    .river-timeline__cta-content {
        padding: 30px 20px;
    }

    .river-timeline__cta-title {
        font-size: 1.5rem;
    }

    .river-timeline__cta-description {
        font-size: 1.125rem;
    }

    .river-timeline__cta-button {
        padding: 16px 32px;
        font-size: 1.125rem;
        width: 100%;
        text-align: center;
    }
}

/* Dark mode support (optional) */
@media (prefers-color-scheme: dark) {
    .river-timeline--dark {
        --river-color-unfilled: #374151;
        --river-color-filled: #3b82f6;
        --event-bg-left: #1f2937;
        --event-bg-right: #1f2937;
        --event-border: #374151;
        --event-title-color: #f9fafb;
        --event-text-color: #d1d5db;
        --event-active-border: #3b82f6;
        background: linear-gradient(180deg, #111827 0%, #1f2937 100%);
    }
}