:root {
    --core-blue: #0a0e1a;
    --neon-blue: #00d2ff;
    --neon-purple: #9d50bb;
    --neon-green: #39ff14;
    --neon-red: #ff3131;
    --text-main: #e0e0e0;
    --glass-bg: rgba(13, 22, 43, 0.85);
    --border-color: rgba(0, 210, 255, 0.3);
}

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

body {
    font-family: 'Exo 2', 'Zen Maru Gothic', sans-serif;
    color: var(--text-main);
    background-color: var(--core-blue);
    min-height: 100vh;
    overflow-x: hidden;
    display: flex;
    flex-direction: column;
}

/* 宇宙背景 */
.space-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: radial-gradient(circle at center, #1b2735 0%, #090a0f 100%);
    overflow: hidden;
}

.stars {
    position: absolute;
    width: 100%;
    height: 100%;
    background-image:
        radial-gradient(1px 1px at 20px 30px, #fff, rgba(0, 0, 0, 0)),
        radial-gradient(1.5px 1.5px at 100px 150px, #fff, rgba(0, 0, 0, 0)),
        radial-gradient(1px 1px at 200px 100px, #fff, rgba(0, 0, 0, 0));
    background-size: 250px 250px;
    opacity: 0.5;
    animation: starsMove 100s linear infinite;
}

@keyframes starsMove {
    from {
        transform: translateY(0);
    }

    to {
        transform: translateY(-500px);
    }
}

.grid {
    position: absolute;
    width: 200%;
    height: 200%;
    top: -50%;
    left: -50%;
    background-image:
        linear-gradient(rgba(0, 210, 255, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 210, 255, 0.05) 1px, transparent 1px);
    background-size: 50px 50px;
    transform: perspective(500px) rotateX(60deg);
    animation: gridMove 20s linear infinite;
}

@keyframes gridMove {
    from {
        transform: perspective(500px) rotateX(60deg) translateY(0);
    }

    to {
        transform: perspective(500px) rotateX(60deg) translateY(50px);
    }
}

.formula-bg {
    position: absolute;
    font-family: serif;
    font-size: 2rem;
    color: var(--neon-blue);
    opacity: 0.1;
    font-style: italic;
}

.container {
    max-width: 750px;
    margin: 60px auto;
    padding: 0 20px;
    width: 100%;
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
}

.screen {
    display: none;
    width: 100%;
    background: var(--glass-bg);
    padding: 35px 30px;
    border-radius: 20px;
    border: 1px solid var(--border-color);
    box-shadow: 0 0 40px rgba(0, 210, 255, 0.15), inset 0 0 10px rgba(0, 210, 255, 0.1);
    backdrop-filter: blur(10px);
    text-align: center;
    position: relative;
}

.screen.active {
    display: block;
    animation: screenEnter 0.5s ease-out;
}

@keyframes screenEnter {
    from {
        transform: scale(0.95);
        opacity: 0;
    }

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

.hero-icon {
    font-size: 4rem;
    margin-bottom: 15px;
    filter: drop-shadow(0 0 15px var(--neon-blue));
    animation: rocketFloat 3s ease-in-out infinite;
}

@keyframes rocketFloat {

    0%,
    100% {
        transform: translateY(0) rotate(0deg);
    }

    50% {
        transform: translateY(-15px) rotate(5deg);
    }
}

h1 {
    font-size: 1.9rem;
    color: var(--neon-blue);
    letter-spacing: 4px;
    text-shadow: 0 0 10px rgba(0, 210, 255, 0.5);
    margin-bottom: 5px;
}

.subtitle {
    font-size: 1.2rem;
    color: var(--neon-purple);
    font-weight: bold;
    letter-spacing: 8px;
    margin-bottom: 30px;
}

.description-box {
    background: rgba(0, 0, 0, 0.3);
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 40px;
    border-left: 4px solid var(--neon-purple);
}

.btn {
    font-family: 'Exo 2', sans-serif;
    padding: 15px 40px;
    font-size: 1.2rem;
    font-weight: bold;
    border: 2px solid var(--neon-blue);
    background: transparent;
    color: var(--neon-blue);
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.3s;
    letter-spacing: 2px;
}

.btn:hover {
    background: var(--neon-blue);
    color: var(--core-blue);
    box-shadow: 0 0 20px var(--neon-blue);
}

.btn.large {
    font-size: 1.3rem;
    padding: 15px 40px;
}

.back-link {
    display: block;
    margin-top: 25px;
    color: var(--neon-purple);
    text-decoration: none;
    font-size: 0.9rem;
    transition: 0.3s;
}

.back-link:hover {
    color: var(--neon-blue);
    text-shadow: 0 0 5px var(--neon-blue);
}

/* クイズ画面 */
.quiz-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 15px;
    font-weight: bold;
    font-family: 'Exo 2', sans-serif;
}

.mission-info {
    color: var(--neon-purple);
}

.score-info {
    color: var(--neon-blue);
}

.progress-container {
    width: 100%;
    height: 4px;
    background: rgba(255, 255, 255, 0.1);
    margin-bottom: 25px;
    border-radius: 2px;
}

.progress-bar {
    height: 100%;
    width: 0;
    background: linear-gradient(90deg, var(--neon-blue), var(--neon-purple));
    box-shadow: 0 0 10px var(--neon-blue);
    transition: width 0.3s ease;
}

.question-container {
    margin-bottom: 30px;
}

#question-text {
    font-size: 1.4rem;
    line-height: 1.6;
    color: white;
}

.choices-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.choice-btn {
    padding: 15px;
    font-size: 1.1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: white;
    border-radius: 10px;
    cursor: pointer;
    transition: 0.2s;
    font-family: 'Zen Maru Gothic', sans-serif;
}

.choice-btn:hover {
    background: rgba(0, 210, 255, 0.1);
    border-color: var(--neon-blue);
}

.choice-btn.correct {
    background: var(--neon-green) !important;
    color: var(--core-blue) !important;
    border-color: var(--neon-green) !important;
    font-weight: bold;
}

.choice-btn.incorrect {
    background: var(--neon-red) !important;
    color: white !important;
    border-color: var(--neon-red) !important;
    font-weight: bold;
}

/* フィードバックパネル */
.feedback-panel {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
}

.feedback-content {
    width: 90%;
    max-width: 500px;
    background: var(--glass-bg);
    padding: 40px;
    border-radius: 20px;
    border: 2px solid var(--neon-blue);
    box-shadow: 0 0 50px rgba(0, 210, 255, 0.3);
}

.feedback-icon {
    font-size: 4rem;
    margin-bottom: 20px;
}

.explanation-box {
    text-align: left;
    background: rgba(0, 0, 0, 0.4);
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 30px;
    max-height: 250px;
    overflow-y: auto;
}

.explanation-box h4 {
    color: var(--neon-purple);
    margin-bottom: 10px;
}

.explanation-box p {
    font-size: 1.1rem;
    line-height: 1.8;
}

.btn.next {
    width: 100%;
}

.hidden {
    display: none !important;
}

/* 結果画面 */
.result-rank-box {
    margin: 30px 0;
}

#rank-badge {
    font-size: 4rem;
    font-weight: bold;
    color: var(--neon-blue);
    text-shadow: 0 0 20px var(--neon-blue);
    font-family: 'Exo 2', sans-serif;
}

.final-score {
    font-size: 2.5rem;
    color: white;
    margin-bottom: 20px;
}

#result-message {
    font-size: 1.3rem;
    color: var(--neon-purple);
    margin-bottom: 40px;
}

.result-actions {
    display: flex;
    gap: 20px;
    justify-content: center;
}

.btn.portal {
    border-color: var(--neon-purple);
    color: var(--neon-purple);
}

.btn.portal:hover {
    background: var(--neon-purple);
    color: white;
}

footer {
    text-align: center;
    padding: 20px;
    font-size: 0.8rem;
    color: #444;
}

@media (max-width: 600px) {
    .screen {
        padding: 30px 20px;
    }

    h1 {
        font-size: 2rem;
    }

    .choices-container {
        grid-template-columns: 1fr;
    }

    #question-text {
        font-size: 1.4rem;
    }
}