:root {
        --gold: #f59e0b;
        --green: #16a34a;
        --red: #dc2626;
    }

    * {
        box-sizing: border-box;
    }

    body {
        font-family: 'Segoe UI', system-ui, sans-serif;
    }

    /* 1. Modern W3C Standard (Chrome, Firefox, Edge, Safari) */
    html {
        scrollbar-width: thin;
        /* Options: auto, thin, none */
        scrollbar-color: #4f46e5 #e0e7ff;
        /* color format: [thumb-color] [track-color] */
    }

    /* 2. WebKit Legacy Engine (Chrome, Safari, Edge) for granular styling */
    /* Defines the width/height of the scrollbar */
    html::-webkit-scrollbar {
        width: 10px;
        /* Width of vertical scrollbar */
        height: 10px;
        /* Height of horizontal scrollbar */
    }

    /* Styles the track (the background gutter) */
    html::-webkit-scrollbar-track {
        background: #e0e7ff;
        border-radius: 10px;
    }

    /* Styles the thumb (the draggable bar) */
    html::-webkit-scrollbar-thumb {
        background-color: #4f46e5;
        border-radius: 10px;
        /* Gives the thumb rounded edges */
        border: 2px solid #e0e7ff;
        /* Creates padding around the thumb */
    }

    /* Optional: Adds a hover effect to the thumb */
    html::-webkit-scrollbar-thumb:hover {
        background-color: #4338ca;
    }

    /*-------------------------*/

    .quiz {
        max-width: 750px;
        margin: 5rem auto;
        padding: 0;
        display: none;
    }

    .quiz-title {
        text-align: center;
        font-size: 2.6rem;
        font-weight: 900;
        color: #f59e0b;
        text-shadow: 0 0 12px rgba(245, 158, 11, 0.5);
        margin: 0.2rem 0 1rem;
        font-family: fantasy, system-ui;
        letter-spacing: 1px;
    }

    .quiz-header {
        display: flex;
        justify-content: space-between;
        align-items: center;
        background: white;
        padding: 1rem 1.5rem;
        border-radius: 1rem;
        box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
        margin-bottom: 1rem;
        flex-wrap: wrap;
        gap: 0.8rem;
    }

    .timer {
        font-weight: 700;
        font-size: 1.2rem;
        color: var(--red);
    }

    .score-box {
        font-weight: 700;
        font-size: 1.15rem;
        color: #374151;
        position: relative;
    }

    .streak-box {
        background: #fff7ed;
        border: 2px solid #fb923c;
        padding: 0.4rem 0.9rem;
        border-radius: 999px;
        font-weight: 700;
        color: #c2410c;
        display: flex;
        align-items: center;
        gap: 0.4rem;
    }

    .progress-container {
        height: 1rem;
        border-radius: 999px;
        overflow: hidden;
    }

    .progress-bar {
        height: 100%;
        background: linear-gradient(90deg, #f59e0b, #ef4444);
        width: 0%;
        transition: width 0.4s ease;
        border-radius: 999px;
    }

    .quiz-index {
        display: flex;
        gap: 1rem;
        flex-wrap: wrap;
        padding: 1rem;
        background: #f9f9f9;
        margin: 2rem 0;
        overflow: auto;
        max-height: 13rem;
        border-radius: 1rem;
        justify-content: center;
    }

    .index-btn {
        width: 3rem;
        height: 3rem;
        border: 2px solid #eee;
        border-radius: 50%;
        display: flex;
        align-items: center;
        justify-content: center;
        font-weight: 900;
        cursor: pointer;
        transition: all 0.2s;
    }

    .index-btn:hover {
        transform: scale(1.12);
    }

    .index-btn.active {
        border-color: #3b82f6;
        background: #dbeafe;
        transform: scale(1.1);
    }

    .index-btn.green {
        background: #dcfce7;
        border-color: #22c55e;
        color: #15803d;
    }

    .index-btn.red {
        background: #fee2e2;
        border-color: #ef4444;
        color: #b91c1c;
    }

    .question-box {
        display: none;
        background: white;
        animation: fadeIn 0.3s ease;
        padding: 2rem 0;
    }

    .question-box.active {
        display: block;
    }

    @keyframes fadeIn {
        from {
            opacity: 0;
            transform: translateY(12px);
        }

        to {
            opacity: 1;
            transform: translateY(0);
        }
    }

    .q-div {
        display: block;
        gap: 1rem;
        margin-bottom: 1.5rem;
    }

    .ql {
        display: flex;
        align-items: center;
        gap: 1rem;
    }

    .ql b {
        background: linear-gradient(135deg, #fbbf24, #f59e0b);
        color: #000;
        width: 42px;
        height: 42px;
        border-radius: 12px;
        display: flex;
        align-items: center;
        justify-content: center;
        font-weight: 800;
        font-size: 1.2rem;
        flex-shrink: 0;
    }

    .q-main {
        font-size: 1.25rem;
        line-height: 1.5;
        font-weight: 500;
        margin: 1rem 0;
        overflow: auto;
        padding-bottom: 1rem;
    }

    .q-status {
        display: block;
        font-weight: 700;
    }

    .options {
        list-style: none;
        padding: 0;
        margin: 0;
        display: flex;
        flex-direction: column;
        gap: 0.7rem;
    }

    .options li {
        padding: 1rem 1.2rem;
        background: #fff;
        border: 2px solid #fcd34d;
        border-radius: 1rem;
        cursor: pointer;
        font-size: 1.15rem;
        display: flex;
        align-items: center;
        gap: 1rem;
        transition: all 0.2s ease;
        position: relative;
        user-select: none;
        overflow: auto;
    }

    .options li:hover:not(.disabled) {
        background: #fffbeb;
        transform: translateX(6px);
        border-color: #f59e0b;
    }

    .options li.green {
        background: #dcfce7 !important;
        border-color: #22c55e !important;
        color: #14532d;
        animation: bounceIn 0.45s ease;
    }

    .options li.red {
        background: #fee2e2 !important;
        border-color: #ef4444 !important;
        color: #7f1d1d;
        animation: shake 0.5s ease;
    }

    .options li.disabled {
        cursor: default;
        opacity: 0.95;
    }

    .options li::before {
        content: "";
        width: 28px;
        height: 28px;
        border-radius: 50%;
        border: 2.5px solid #fbbf24;
        background: white;
        flex-shrink: 0;
        display: flex;
        align-items: center;
        justify-content: center;
        font-weight: 800;
        font-size: 1rem;
    }

    .options li.green::before {
        content: "✓";
        background: #16a34a;
        color: white;
        border-color: #16a34a;
    }

    .options li.red::before {
        content: "✕";
        background: #dc2626;
        color: white;
        border-color: #dc2626;
    }

    @keyframes bounceIn {
        0% {
            transform: scale(0.9);
        }

        50% {
            transform: scale(1.05);
        }

        100% {
            transform: scale(1);
        }
    }

    @keyframes shake {

        0%,
        100% {
            transform: translateX(0);
        }

        20% {
            transform: translateX(-8px);
        }

        40% {
            transform: translateX(8px);
        }

        60% {
            transform: translateX(-6px);
        }

        80% {
            transform: translateX(6px);
        }
    }

    .quiz-explanation {
        margin-top: 1.2rem;
        padding: 1rem 1.2rem;
        background: #f0fdf4;
        border-left: 5px solid #22c55e;
        border-radius: 0 0.8rem 0.8rem 0;
        display: none;
        font-size: 1.05rem;
        line-height: 1.5;
    }

    .quiz-controls {
        display: flex;
        gap: 0.8rem;
        margin-top: 1.5rem;
        flex-wrap: wrap;
    }

    .quiz-controls button {
        flex: 1;
        min-width: 120px;
        padding: 0.9rem;
        border: none;
        border-radius: 0.9rem;
        font-weight: 600;
        font-size: 1rem;
        cursor: pointer;
        transition: all 0.2s;
    }

    .quiz-controls button:hover:not(:disabled) {
        transform: translateY(-2px);
    }

    .quiz-controls button:active:not(:disabled) {
        transform: translateY(0);
    }

    #prev-btn,
    #next-btn {
        background: #f3f4f6;
        color: #374151;
    }

    #prev-btn:hover:not(:disabled),
    #next-btn:hover:not(:disabled) {
        background: #e5e7eb;
    }

    #prev-btn:disabled,
    #next-btn:disabled {
        opacity: 0.45;
        cursor: not-allowed;
    }

    #submit-btn {
        background: linear-gradient(135deg, #16a34a, #15803d);
        color: white;
        flex: 2;
    }

    #submit-btn:hover {
        box-shadow: 0 6px 15px rgba(22, 163, 74, 0.35);
    }

    #reset-btn {
        display: none;
        background: #fee2e2;
        color: #b91c1c;
        cursor: pointer;
    }

    .quiz-message {
        display: none;
        margin-top: 1rem;
        padding: 0.9rem 1.2rem;
        background: #fef2f2;
        color: #b91c1c;
        border-radius: 0.8rem;
        font-weight: 600;
        text-align: center;
    }

    /* Modal */
    .modal {
        display: none;
        position: fixed;
        inset: 0;
        background: rgba(0, 0, 0, 0.55);
        align-items: center;
        justify-content: center;
        z-index: 9999;
        padding: 1rem;
    }

    .modal.open {
        display: flex;
    }

    .modal-content {
        background: white;
        border-radius: 1.5rem;
        padding: 2rem;
        max-width: 440px;
        width: 100%;
        text-align: center;
        box-shadow: 0 25px 50px rgba(0, 0, 0, 0.2);
        animation: popIn 0.35s ease;
    }

    @keyframes popIn {
        from {
            transform: scale(0.85);
            opacity: 0;
        }

        to {
            transform: scale(1);
            opacity: 1;
        }
    }

    #modal-title {
        font-size: 1.8rem;
        margin: 0 0 1rem;
    }

    .results-summary {
        text-align: left;
        margin: 1.2rem 0;
        max-height: 280px;
        overflow-y: auto;
    }

    .rt {
        width: 100%;
        border-collapse: collapse;
    }

    .rt td {
        padding: 0.7rem 0.5rem;
        border-bottom: 1px solid #f3f4f6;
    }

    .rt caption b {
        display: inline-block;
        width: 110px;
        height: 110px;
        line-height: 110px;
        border-radius: 50%;
        background: linear-gradient(135deg, #fbbf24, #f59e0b);
        font-size: 1.6rem;
        margin-bottom: 1rem;
        box-shadow: 0 8px 20px rgba(245, 158, 11, 0.4);
    }

    .modal-actions {
        display: flex;
        gap: 0.8rem;
        margin-top: 1.5rem;
    }

    .modal-actions button {
        flex: 1;
        padding: 0.9rem;
        border: none;
        border-radius: 0.9rem;
        font-weight: 600;
        cursor: pointer;
        transition: all 0.2s;
    }

    .modal-actions button:hover {
        transform: translateY(-2px);
    }

    .btn-primary {
        background: #2563eb;
        color: white;
    }

    .btn-secondary {
        background: #f3f4f6;
        color: #374151;
    }

    /* Score pop */
    .score-pop {
        position: absolute;
        font-weight: 800;
        font-size: 1.4rem;
        pointer-events: none;
        animation: scoreFly 1s ease forwards;
        z-index: 10;
    }

    .score-pop.plus {
        color: #16a34a;
    }

    .score-pop.minus {
        color: #dc2626;
    }

    @keyframes scoreFly {
        0% {
            opacity: 1;
            transform: translateY(0) scale(1);
        }

        100% {
            opacity: 0;
            transform: translateY(-50px) scale(1.3);
        }
    }

    #confetti-canvas {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        pointer-events: none;
        z-index: 9998;
    }

    .keyboard-hint {
        text-align: center;
        font-size: 0.85rem;
        color: #9ca3af;
        margin-top: 1rem;
    }

    /* ====================== LOADER ====================== */
    #quiz-loader {
        position: fixed;
        inset: 0;
        background: rgba(15, 23, 42, 0.92);
        display: none;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        z-index: 10000;
        backdrop-filter: blur(8px);
    }

    #quiz-loader.show {
        display: flex;
    }

    .loader-spinner {
        width: 90px;
        height: 90px;
        border-radius: 50%;
        border: 6px solid transparent;
        border-top-color: #f59e0b;
        border-right-color: #ec4899;
        border-bottom-color: #8b5cf6;
        border-left-color: #06b6d4;
        animation: spin 1s linear infinite, colorShift 3s ease infinite;
        margin-bottom: 2rem;
    }

    @keyframes spin {
        to {
            transform: rotate(360deg);
        }
    }

    @keyframes colorShift {
        0% {
            filter: hue-rotate(0deg);
        }

        100% {
            filter: hue-rotate(360deg);
        }
    }

    .countdown-number {
        font-size: 5.5rem;
        font-weight: 900;
        color: white;
        text-shadow: 0 0 30px rgba(255, 255, 255, 0.4);
        animation: popNumber 0.6s ease;
        min-height: 90px;
        display: flex;
        align-items: center;
        justify-content: center;
    }

    @keyframes popNumber {
        0% {
            transform: scale(0.4);
            opacity: 0;
        }

        60% {
            transform: scale(1.15);
        }

        100% {
            transform: scale(1);
            opacity: 1;
        }
    }

    .loader-text {
        margin-top: 1.2rem;
        font-size: 1.1rem;
        color: #94a3b8;
        letter-spacing: 2px;
        text-transform: uppercase;
    }