/* --- Base Styles --- */
        :root {
            --bg-light: #f7f7f7;
            --bg-white: #ffffff;
            --text-primary: #333;
            --text-secondary: #555;
            --text-tertiary: #888;
            --trail-inactive: #e0e0e0;
            --trail-active: #4CAF50; /* Green for progress */
            --shadow-light: 0 4px 10px rgba(0, 0, 0, 0.05);
            --shadow-active: 0 0 12px rgba(76, 175, 80, 0.5);
            --glow-complete: 0 0 20px 5px rgba(76, 175, 80, 0.7);
            --ease-cubic: cubic-bezier(0.4, 0, 0.2, 1);
            --ease-elastic: cubic-bezier(0.77, 0, 0.175, 1);
        }

        *, *::before, *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
            background-color: var(--bg-light);
            color: var(--text-secondary);
            line-height: 1.6;
            /* Example min-height to ensure scrolling is possible */
            min-height: 150vh; 
        }

        /* --- Keyframe Animations --- */
        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        @keyframes popIn {
            from {
                transform: scale(0.8);
                /* Opacity is handled by .visible transition */
            }
            to {
                transform: scale(1.05); /* Slightly larger on pop */
            }
        }

        /* --- Process Section Styles --- */
        .process-trail-section {
            width: 100%;
            /* Mobile padding */
            padding: 60px 20px;
        }

        .process-container {
            max-width: 1200px;
            margin: 0 auto;
            position: relative;
        }

        /* --- Trail Line (Progress Bar) --- */
        .trail-wrapper {
            position: absolute;
            z-index: 1;
            /* Mobile (Vertical) Layout */
            top: 0;
            bottom: 0;
            left: 30px; /* Aligns to center of 64px icon */
            width: 4px;
        }

        .trail-line {
            width: 100%;
            height: 100%;
            background-color: var(--trail-inactive);
            border-radius: 2px;
            position: relative;
        }
        
        .trail-line-active {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: var(--trail-active);
            border-radius: 2px;
            
            /* JS will control this */
            transform: scaleY(0);
            transform-origin: top;
            transition: transform 0.3s var(--ease-elastic), box-shadow 0.4s var(--ease-cubic);
        }
        
        /* Completion glow effect (Mobile-only) */
        @media (max-width: 767px) {
            .trail-line-active.complete {
                box-shadow: var(--glow-complete);
            }
        }

        /* --- Steps Grid --- */
        .steps-grid {
            position: relative;
            z-index: 2; /* Sits on top of the trail */
            display: flex;
            flex-direction: column;
            gap: 40px;
        }

        .step-item {
            display: flex;
            gap: 20px;
            align-items: flex-start;
            /* Start hidden for animation */
            opacity: 0;
            /* Add a transition for the .visible class */
            transition: opacity 0.5s var(--ease-cubic);
        }
        
        .step-item.visible {
            opacity: 1; /* Made visible by IntersectionObserver */
        }

        .step-icon-wrapper {
            flex-shrink: 0;
            width: 64px;
            height: 64px;
            border-radius: 50%;
            background-color: var(--bg-white);
            border: 4px solid var(--trail-inactive);
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: var(--shadow-light);
            transition: all 0.5s var(--ease-cubic);
            will-change: transform, border-color, box-shadow, background-color;
        }

        .step-icon-wrapper svg {
            width: 32px;
            height: 32px;
            stroke: var(--text-tertiary);
            stroke-width: 1.5;
            fill: none;
            stroke-linecap: round;
            stroke-linejoin: round;
            transition: stroke 0.5s var(--ease-cubic);
        }

        .step-text {
            padding-top: 8px; /* Align text nicely with icon */
        }

        .step-text h3,
        .step-text .subtitle,
        .step-text p {
            /* Prepare for animation */
            opacity: 0;
            transform: translateY(20px);
            will-change: opacity, transform;
        }

        .step-text h3 {
            font-size: 1.25rem;
            font-weight: 700;
            color: var(--text-primary);
            margin-bottom: 4px;
        }

        .step-text .subtitle {
            font-size: 0.8rem;
            font-weight: 500;
            color: var(--text-tertiary);
            text-transform: uppercase;
            letter-spacing: 1px;
            display: block;
            margin-bottom: 12px;
        }

        .step-text p {
            font-size: 0.9rem;
            color: var(--text-secondary);
            max-width: 320px;
        }

        /* --- Active Step State --- */
        .step-item.active .step-icon-wrapper {
            border-color: var(--trail-active);
            box-shadow: var(--shadow-active);
            animation: popIn 0.5s var(--ease-cubic) forwards;
            background-color: var(--trail-active); /* Fill bubble with green */
        }

        .step-item.active .step-icon-wrapper svg {
            stroke: var(--bg-white); /* Switch icon to white */
        }
        
        /* Staggered text animation */
        .step-item.active .step-text h3 {
            animation: fadeInUp 0.6s var(--ease-cubic) 0.1s forwards;
        }
        .step-item.active .step-text .subtitle {
            animation: fadeInUp 0.6s var(--ease-cubic) 0.2s forwards;
        }
        .step-item.active .step-text p {
            animation: fadeInUp 0.6s var(--ease-cubic) 0.3s forwards;
        }


        /* --- Tablet Layout (768px - 1023px) --- */
        @media (min-width: 768px) {
            .process-trail-section {
                padding: 80px 32px;
            }

            /* 2x2 Grid layout */
            .steps-grid {
                display: grid;
                grid-template-columns: 1fr 1fr;
                gap: 50px 40px;
            }

            .step-item {
                /* Center-align content within each grid cell */
                flex-direction: column;
                align-items: center;
                text-align: center;
                gap: 16px;
            }

            .step-text {
                padding-top: 0;
            }
            
            .step-text p {
                margin: 0 auto; /* Center text block */
            }

            /* Hide trail line on tablet - 2x2 grid is too complex for a clean line */
            .trail-wrapper {
                display: none;
            }
        }

        /* --- Desktop Layout (1024px+) --- */
        @media (min-width: 1024px) {
            .steps-grid {
                /* 4-column layout */
                grid-template-columns: repeat(4, 1fr);
                gap: 32px;
                /* Align items to the start of the grid cell (top) */
                align-items: flex-start;
            }

            /* Re-enable and re-orient the trail line */
            .trail-wrapper {
                display: block;
                /* Horizontal Layout */
                top: 30px; /* Aligns to center of 64px icon */
                bottom: auto;
                /* left, width are set by JS */
                height: 4px;
            }
            
            .trail-line-active {
                /* JS will set transform-origin: left */
                transform: scaleX(0); 
                /* Add a transition for the desktop auto-play */
                transition: transform 1.8s var(--ease-cubic);
            }
            
            .step-item {
                /* Already column/center aligned from tablet, which is correct */
                text-align: center;
            }
        }