body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
            background-color: #f5f7fa;
            color: #1f2937;
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 20px;
            margin: 0;
            box-sizing: border-box;
        }

        h1, h2, h3, h4, h5, h6 { font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif; margin: 0; }
        * { box-sizing: border-box; }

        .timeline-wrapper {
            --nvd: #063046; /* Dark Blue */
            --nva: #063046; /* Accent Blue */
            --nvs: #2dcc70; /* Success Green */
            --nvi: #1f2937; /* Text Dark */
            --nvm: #64748b; /* Text Muted */
            --nvl: #e2e8f0; /* Light Border */
            
            width: 100%;
            max-width: 1000px;
            margin: 2rem auto;
            background: #fff;
            border: 1px solid #eef2f7;
            border-radius: 20px;
            box-shadow: 0 20px 40px -15px rgba(10,42,74,.12);
            overflow: hidden;
            display: flex;
            flex-direction: column;
        }

        .timeline-header {
            background: linear-gradient(135deg, var(--nvd), #0a4a6e);
            color: #fff;
            padding: 2.5rem 2.5rem;
            text-align: center;
            position: relative;
            overflow: hidden;
        }

        .timeline-header::after {
            content: '';
            position: absolute;
            top: -20%;
            right: -10%;
            width: 300px;
            height: 300px;
            background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 60%);
            border-radius: 50%;
        }

        .timeline-header h2 {
            font-size: 2.2rem;
            line-height: 1.2;
            margin-bottom: 0.75rem;
            position: relative;
            z-index: 1;
        }

        .timeline-header p {
            color: #bfdbfe;
            font-size: 1.05rem;
            max-width: 760px;
            margin: 0 auto;
            line-height: 1.6;
            position: relative;
            z-index: 1;
        }

        .stepper-container {
            padding: 3rem 2.5rem 1rem;
            background: #f8fafc;
            border-bottom: 1px solid var(--nvl);
            position: relative;
        }

        .stepper-track-wrap {
            position: relative;
            max-width: 850px;
            margin: 0 auto;
            --progress-width: 0%; /* Dynamic variable updated by JS */
        }

        /* The background gray line */
        .stepper-track-wrap::before {
            content: '';
            position: absolute;
            top: 20px; /* Center of the 40px nodes */
            left: 20px;
            right: 20px;
            height: 4px;
            background: #e2e8f0;
            border-radius: 2px;
            z-index: 1;
        }

        /* The colored progress line */
        .stepper-track-wrap::after {
            content: '';
            position: absolute;
            top: 20px;
            left: 20px;
            width: calc(100% - 40px);
            height: 4px;
            background: linear-gradient(to right, var(--nva) var(--progress-width), transparent var(--progress-width));
            border-radius: 2px;
            z-index: 2;
            transition: background 0.5s ease;
        }

        .stepper-nodes {
            display: flex;
            justify-content: space-between;
            position: relative;
            z-index: 3;
        }

        .stepper-node {
            display: flex;
            flex-direction: column;
            align-items: center;
            cursor: pointer;
            width: 14.28%; /* 100 / 7 */
            position: relative;
            group: node;
        }

        /* The Circle */
        .node-circle {
            width: 44px;
            height: 44px;
            border-radius: 50%;
            background: #fff;
            border: 3px solid #cbd5e1;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 700;
            color: #64748b;
            transition: all 0.3s ease;
            box-shadow: 0 2px 5px rgba(0,0,0,0.05);
            margin-bottom: 12px;
        }

        .stepper-node:hover .node-circle {
            border-color: #94a3b8;
            transform: scale(1.05);
        }

        .stepper-node.is-completed .node-circle {
            background: var(--nva);
            border-color: var(--nva);
            color: #fff;
        }

        .stepper-node.is-active .node-circle {
            background: #fff;
            border-color: var(--nva);
            color: var(--nva);
            box-shadow: 0 0 0 4px rgba(6, 48, 70, 0.2);
            transform: scale(1.1);
        }

        /* Optional pulse animation for active node */
        @keyframes activePulse {
            0% { box-shadow: 0 0 0 0 rgba(6, 48, 70, 0.4); }
            70% { box-shadow: 0 0 0 10px rgba(6, 48, 70, 0); }
            100% { box-shadow: 0 0 0 0 rgba(6, 48, 70, 0); }
        }
        
        .stepper-node.is-active .node-circle {
            animation: activePulse 2s infinite;
        }

        /* The Label */
        .node-label {
            font-size: 0.8rem;
            font-weight: 600;
            color: var(--nvm);
            text-align: center;
            line-height: 1.3;
            transition: all 0.3s ease;
            padding: 0 4px;
        }

        .stepper-node.is-active .node-label,
        .stepper-node.is-completed .node-label {
            color: var(--nvd);
        }

        .timeline-body {
            padding: 3rem 2.5rem;
            background: #fff;
            min-height: 380px;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .phase-content {
            display: none;
            width: 100%;
            max-width: 760px;
            margin: 0 auto;
        }

        .phase-content.is-active {
            display: block;
            animation: fadeInRight 0.4s ease forwards;
        }

        @keyframes fadeInRight {
            from { opacity: 0; transform: translateX(20px); }
            to { opacity: 1; transform: translateX(0); }
        }

        .content-card {
            background: #fff;
            border: 1px solid #eef2f7;
            border-radius: 16px;
            box-shadow: 0 10px 30px -10px rgba(0,0,0,0.08);
            padding: 2.5rem;
            position: relative;
            border-left: 6px solid var(--nva);
        }

        .phase-meta {
            display: flex;
            align-items: center;
            gap: 12px;
            margin-bottom: 1rem;
        }

        .phase-number {
            font-size: 0.85rem;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 0.05em;
            color: var(--nva);
            background: #eff6ff;
            padding: 4px 10px;
            border-radius: 6px;
        }

        .phase-weeks {
            font-size: 0.9rem;
            font-weight: 600;
            color: var(--nvm);
            display: flex;
            align-items: center;
            gap: 6px;
        }

        .content-card h3 {
            font-size: 1.8rem;
            color: var(--nvd);
            margin-bottom: 1.25rem;
        }

        .content-card p {
            font-size: 1.05rem;
            line-height: 1.6;
            color: #475569;
            margin: 0;
        }

        .content-card strong {
            color: var(--nvd);
        }

        @media(max-width: 768px) {
            .stepper-container {
                padding: 2rem 1rem 1rem;
                overflow-x: auto;
                -webkit-overflow-scrolling: touch;
                scroll-snap-type: x mandatory;
            }
            .stepper-track-wrap {
                min-width: 600px; /* Force scroll on small screens */
                padding-bottom: 10px;
            }
            .timeline-header { padding: 2rem 1.5rem; }
            .timeline-header h2 { font-size: 1.6rem; }
            .timeline-body { padding: 2rem 1.5rem; min-height: auto; }
            .content-card { padding: 1.5rem; }
            .content-card h3 { font-size: 1.4rem; }
            .stepper-node { scroll-snap-align: center; }
        }