:root {
            --space-bg: rgb(7, 9, 19);
            --space-card: rgb(15, 20, 38, 0.1);
            --space-border: rgba(255, 255, 255, 0.08);
            --mars-primary: #e05a36;
            --mars-amber: #f59e0b;
            --mars-glow: rgba(224, 90, 54, 0.25);
            --korolev-ice: #38bdf8;
            --korolev-glow: rgba(56, 189, 248, 0.22);
        }

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: 'Inter', sans-serif;
            background-color: var(--space-bg);
            color: #e2e8f0;
            background-image:
                radial-gradient(circle at 15% 15%, rgba(224, 90, 54, 0.08) 0%, transparent 40%),
                radial-gradient(circle at 85% 65%, rgba(56, 189, 248, 0.08) 0%, transparent 45%);
            overflow-x: hidden;
            padding-bottom: 5.5rem;
            /* Space for sticky bottom control bar */
            min-height: 100vh;
            display: flex;
            flex-direction: column;
        }

        h1,
        h2,
        h3,
        h4,
        .brand-font {
            font-family: 'Space Grotesk', sans-serif;
            letter-spacing: -0.02em;
        }

        /* Navbar & Stepper Styling */
        .navbar-space {
            background: rgba(7, 9, 19, 0.92);
            backdrop-filter: blur(14px);
            border-bottom: 1px solid var(--space-border);
            z-index: 1030;
        }

        .step-pill {
            background: rgba(255, 255, 255, 0.04);
            border: 1px solid var(--space-border);
            color: #94a3b8;
            font-size: 0.82rem;
            font-weight: 600;
            padding: 0.45rem 0.9rem;
            border-radius: 50px;
            transition: all 0.2s ease;
            cursor: pointer;
            white-space: nowrap;
        }

        .step-pill:hover {
            color: #ffffff;
            border-color: rgba(255, 255, 255, 0.25);
            background: rgba(255, 255, 255, 0.08);
        }

        .step-pill.active {
            background: linear-gradient(135deg, rgba(224, 90, 54, 0.25), rgba(245, 158, 11, 0.18));
            border-color: var(--mars-primary);
            color: #ffffff;
            box-shadow: 0 0 15px rgba(224, 90, 54, 0.25);
        }

        .step-pill.completed:not(.active) {
            border-color: rgba(16, 185, 129, 0.45);
            color: #6ee7b7;
        }

        /* Carousel Slide Stage */
        .tutorial-stage {
            flex: 1;
            display: flex;
            align-items: stretch;
        }

        #tutorialCarousel {
            width: 100%;
        }

        .carousel-item {
            padding: 2rem 0 2.5rem;
            transition: transform 0.55s cubic-bezier(0.25, 0.8, 0.25, 1);
        }

        /* Bottom Sticky Navigation Bar */
        .bottom-control-bar {
            position: fixed;
            bottom: 0;
            left: 0;
            right: 0;
            background: rgba(7, 9, 19, 0.94);
            backdrop-filter: blur(14px);
            border-top: 1px solid var(--space-border);
            padding: 0.85rem 0;
            z-index: 1030;
        }

        /* Module Badges & Cards */
        .module-badge {
            display: inline-flex;
            align-items: center;
            gap: 0.45rem;
            padding: 0.35rem 0.85rem;
            border-radius: 50px;
            font-size: 0.8rem;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 0.06em;
        }

        .badge-mars {
            background: rgba(224, 90, 54, 0.15);
            color: #ff8c6b;
            border: 1px solid rgba(224, 90, 54, 0.35);
        }

        .badge-ice {
            background: rgba(56, 189, 248, 0.15);
            color: #7dd3fc;
            border: 1px solid rgba(56, 189, 248, 0.35);
        }

        .space-card {
            background-color: rgba(171, 223, 234, 0.1);
            border: 1px solid var(--space-border);
            border-radius: 1rem;
            transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
        }

        .space-card:hover {
            transform: translateY(-4px);
            border-color: rgba(224, 90, 54, 0.4);
            box-shadow: 0 12px 30px rgba(0, 0, 0, 0.4);
        }

        .space-card-ice:hover {
            border-color: rgba(56, 189, 248, 0.45);
            box-shadow: 0 12px 30px rgba(56, 189, 248, 0.12);
        }

        /* Buttons */
        .btn-mars {
            background: linear-gradient(135deg, #e05a36 0%, #c2411d 100%);
            border: none;
            color: #fff;
            font-weight: 600;
            border-radius: 0.65rem;
            padding: 0.7rem 1.4rem;
            box-shadow: 0 4px 18px rgba(224, 90, 54, 0.35);
            transition: all 0.2s ease;
        }

        .btn-mars:hover {
            background: linear-gradient(135deg, #eb6946 0%, #d14822 100%);
            color: #fff;
            transform: translateY(-1px);
            box-shadow: 0 6px 22px rgba(224, 90, 54, 0.5);
        }

        .btn-ice {
            background: linear-gradient(135deg, #0284c7 0%, #0369a1 100%);
            border: none;
            color: #fff;
            font-weight: 600;
            border-radius: 0.65rem;
            box-shadow: 0 4px 15px rgba(56, 189, 248, 0.25);
        }

        .btn-ice:hover {
            background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
            color: #fff;
        }

        /* Mission Era Pills */
        .nav-pills-mars .nav-link {
            background-color: var(--space-card);
            border: 1px solid var(--space-border);
            color: #94a3b8 !important;
            border-radius: 0.75rem;
            padding: 0.75rem 1.25rem;
            margin: 0.25rem;
        }

        .nav-pills-mars .nav-link.active {
            background: linear-gradient(135deg, rgba(224, 90, 54, 0.22), rgba(245, 158, 11, 0.15));
            border-color: var(--mars-primary);
            color: #ffffff !important;
        }

        /* Korolev Crater SVG Animations */
        .wind-arrow {
            stroke-dasharray: 10 6;
            animation: windFlow 1.8s linear infinite;
        }

        @keyframes windFlow {
            from {
                stroke-dashoffset: 32;
            }

            to {
                stroke-dashoffset: 0;
            }
        }

        .cold-blanket-pulse {
            animation: blanketPulse 3s ease-in-out infinite;
        }

        @keyframes blanketPulse {

            0%,
            100% {
                opacity: 0.55;
            }

            50% {
                opacity: 0.85;
            }
        }

        /* Quiz Styling */
        .quiz-option {
            background-color: rgba(255, 255, 255, 0.03);
            border: 1px solid var(--space-border);
            border-radius: 0.75rem;
            padding: 0.85rem 1.1rem;
            cursor: pointer;
            transition: all 0.2s ease;
            text-align: left;
            width: 100%;
            color: #e2e8f0;
        }

        .quiz-option:hover:not(:disabled) {
            background-color: rgba(255, 255, 255, 0.08);
            border-color: rgba(255, 255, 255, 0.25);
        }

        .quiz-option.correct {
            background-color: rgba(16, 185, 129, 0.18) !important;
            border-color: #10b981 !important;
            color: #6ee7b7 !important;
        }

        .quiz-option.incorrect {
            background-color: rgba(239, 68, 68, 0.18) !important;
            border-color: #ef4444 !important;
            color: #fca5a5 !important;
        }

        .xxxxx {
            position: fixed;
            bottom: -10px;
            left: -30px;
            width: 300px;
            height: auto;
            z-index: 9999;
            pointer-events: none;
            transform: scaleX(-1);
        }
        .image-link {
    display: inline-block;
    position: relative;
}

.zoom-image {
    cursor: pointer;
    transition: all 0.8s ease-in-out;
    transform-origin: top left;
}

.zoom-image.zooming {
    position: fixed;
    z-index: 99999;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    object-fit: contain;
    border-radius: 0 !important;
}

@keyframes zoomFullscreen {
    from {
        width: 300px;
        height: auto;
        transform: translate(-50%, -50%) scale(0.3);
    }
    to {
        transform: translate(-50%, -50%) scale(2);
    }
}