/* Left-Aligned Scroll Progress Timeline
   =====================================================
   A vertical progress line on the far left of content sections
   that fills as the user scrolls, with node markers for each card.
   
   Theme Colors (inherited from site):
   - Primary: #38bdf8 (Sky Blue)
   - Secondary: #818cf8 (Indigo)
   - Track: rgba(255, 255, 255, 0.1)
*/

/* --- Wrapper Container --- */
.scroll-timeline-wrapper {
    position: relative;
    padding-left: 60px;
    /* Space for the timeline on the left */
}

/* --- Progress Line Container (Track) --- */
.scroll-progress-line {
    position: absolute;
    left: 20px;
    top: 0;
    bottom: 0;
    width: 4px;
    z-index: 5;
}

/* --- Background Track (Muted) --- */
.scroll-progress-track {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
}

/* --- Active Fill (Animated on Scroll) --- */
.scroll-progress-fill {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 0;
    /* CRITICAL: Starts at 0, grows via JS only */
    background: linear-gradient(to bottom, #38bdf8, #818cf8);
    border-radius: 4px;
    box-shadow: 0 0 15px rgba(56, 189, 248, 0.6);
    transition: height 0.05s linear;
}

/* --- Timeline Nodes (Icon Bubbles) --- */
/* Fix 2: Icon centered on vertical track using transform */
.scroll-timeline-node {
    position: absolute;
    left: 22px;
    /* Center of 4px track at left: 20px = 20 + 2 = 22px */
    width: 28px;
    height: 28px;
    background: #0f172a;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    /* Center both horizontally and vertically on the point */
    z-index: 10;
    /* Sits on top of the line, hiding it behind */
    transition: all 0.4s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.scroll-timeline-node i {
    font-size: 11px;
    color: rgba(255, 255, 255, 0.5);
    transition: all 0.4s ease;
}

.scroll-timeline-node.active {
    background: linear-gradient(135deg, #38bdf8, #818cf8);
    border-color: #fff;
    box-shadow: 0 0 20px rgba(56, 189, 248, 0.6);
    transform: translate(-50%, -50%) scale(1.15);
}

.scroll-timeline-node.active i {
    color: #fff;
}

/* --- Horizontal Connector Lines (Bridge) --- */
/* Fix 1: Bridge snaps to icon center, no gap */
.timeline-connector {
    position: absolute;
    /* Left edge touches icon border: center(22px) + radius(14px) = 36px */
    left: 36px;
    height: 2px;
    width: 20px;
    background: rgba(255, 255, 255, 0.15);
    z-index: 4;
    /* Below icon */
    transform: translateY(-50%);
    /* Center vertically on the same top position as icon */
    transition: all 0.4s ease;
}

.timeline-connector.active {
    background: linear-gradient(to right, #38bdf8, rgba(56, 189, 248, 0.4));
    box-shadow: 0 0 8px rgba(56, 189, 248, 0.4);
}

/* --- Card Container (with node positioning) --- */
.scroll-timeline-wrapper .glass-card {
    position: relative;
}

/* --- Tablet Responsive --- */
@media (max-width: 768px) {
    .scroll-timeline-wrapper {
        padding-left: 50px;
    }

    .scroll-progress-line {
        left: 15px;
        width: 3px;
    }

    .scroll-timeline-node {
        left: 16.5px;
        /* 15 + 1.5 = center of 3px track */
        width: 24px;
        height: 24px;
    }

    .scroll-timeline-node i {
        font-size: 10px;
    }

    .scroll-timeline-node.active {
        transform: translate(-50%, -50%) scale(1.1);
    }

    .timeline-connector {
        left: 28.5px;
        /* 16.5 + 12 (radius) */
        width: 12px;
    }
}

/* --- Mobile Responsive (HIDE bridge lines) --- */
@media (max-width: 480px) {
    .scroll-timeline-wrapper {
        padding-left: 40px;
    }

    .scroll-progress-line {
        left: 10px;
        width: 2px;
    }

    .scroll-timeline-node {
        left: 11px;
        /* 10 + 1 = center of 2px track */
        width: 20px;
        height: 20px;
    }

    .scroll-timeline-node i {
        font-size: 8px;
    }

    .scroll-timeline-node.active {
        transform: translate(-50%, -50%) scale(1.1);
    }

    /* Fix 4: Completely hide bridge on mobile */
    .timeline-connector {
        display: none !important;
    }
}

/* --- Very Small Screens --- */
@media (max-width: 360px) {
    .scroll-timeline-wrapper {
        padding-left: 35px;
    }

    .scroll-progress-line {
        left: 8px;
    }

    .scroll-timeline-node {
        left: 9px;
        width: 18px;
        height: 18px;
    }

    .scroll-timeline-node i {
        font-size: 7px;
    }
}