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

body {
    font-family: 'Arial', sans-serif;
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
    overflow-x: hidden;
}

.container {
    background: white;
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    max-width: 900px;
    width: 100%;
    position: relative;
}

h1 {
    color: #333;
    text-align: center;
    margin-bottom: 25px;
    font-size: 32px;
}

.story-box {
    background: linear-gradient(135deg, #e3f2fd 0%, #bbdefb 100%);
    border-left: 5px solid #1976d2;
    padding: 25px;
    border-radius: 10px;
    margin-bottom: 30px;
}

.plant-header {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 15px;
}

.plant-icon {
    font-size: 50px;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.header-text strong {
    color: #0d47a1;
    font-size: 20px;
    display: block;
}

.header-text p {
    color: #666;
    font-size: 14px;
    margin-top: 3px;
}

.story-text {
    color: #333;
    line-height: 1.8;
    font-size: 16px;
    margin-bottom: 15px;
}

.story-text strong {
    color: #1565c0;
    font-size: 18px;
}

.question {
    color: #333;
    line-height: 1.8;
    font-size: 17px;
    font-weight: 500;
    text-align: center;
    margin-top: 15px;
    padding: 15px;
    background: rgba(255, 255, 255, 0.7);
    border-radius: 8px;
}

/* Plant Scene */
.plant-scene {
    background: linear-gradient(135deg, #f5f5f5 0%, #e0e0e0 100%);
    border-radius: 15px;
    padding: 50px;
    margin: 30px 0;
    display: flex;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.plant-scene::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 50%;
    background: linear-gradient(180deg, #e3f2fd 0%, transparent 100%);
    pointer-events: none;
}

.storage-tank {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0;
    position: relative;
    z-index: 1;
}

.tank-top {
    width: 120px;
    height: 40px;
    background: linear-gradient(135deg, #616161 0%, #424242 100%);
    border-radius: 60px 60px 0 0;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    box-shadow: 0 -3px 10px rgba(0, 0, 0, 0.3);
}

.tank-cap {
    width: 40px;
    height: 25px;
    background: linear-gradient(135deg, #757575 0%, #616161 100%);
    border-radius: 8px 8px 0 0;
    margin-top: -10px;
}

.tank-body {
    width: 200px;
    height: 280px;
    background: linear-gradient(135deg, #90caf9 0%, #64b5f6 100%);
    border: 5px solid #424242;
    border-top: none;
    border-bottom: none;
    position: relative;
    overflow: hidden;
    box-shadow: inset 0 5px 20px rgba(0, 0, 0, 0.2);
}

.water-level {
    position: absolute;
    bottom: 0;
    width: 100%;
    height: 90%;
    background: linear-gradient(180deg, #0288d1 0%, #0277bd 100%);
    animation: water-fill 3s ease-in-out infinite;
}

@keyframes water-fill {
    0%, 100% { height: 90%; }
    50% { height: 92%; }
}

.water-waves {
    position: absolute;
    top: -20px;
    width: 100%;
    height: 40px;
    overflow: hidden;
}

.wave {
    position: absolute;
    width: 200%;
    height: 100%;
    background: radial-gradient(ellipse at center, rgba(255, 255, 255, 0.3) 0%, transparent 70%);
    animation: wave-motion 4s linear infinite;
}

.wave:nth-child(2) {
    animation-delay: 1.3s;
    opacity: 0.7;
}

.wave:nth-child(3) {
    animation-delay: 2.6s;
    opacity: 0.5;
}

@keyframes wave-motion {
    0% { transform: translateX(-50%); }
    100% { transform: translateX(0); }
}

.tank-indicator {
    position: absolute;
    right: 10px;
    top: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
}

.indicator-line {
    width: 30px;
    height: 3px;
    background: #fff;
    box-shadow: 0 0 5px rgba(255, 255, 255, 0.8);
}

.indicator-text {
    color: #fff;
    font-size: 12px;
    font-weight: bold;
    text-shadow: 0 0 5px rgba(0, 0, 0, 0.5);
}

.tank-base {
    width: 220px;
    height: 50px;
    background: linear-gradient(135deg, #616161 0%, #424242 100%);
    border-radius: 0 0 20px 20px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.4);
}

.volume-display {
    margin-top: 20px;
    background: linear-gradient(135deg, #263238 0%, #37474f 100%);
    padding: 15px 30px;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

.display-label {
    color: #b0bec5;
    font-size: 12px;
    letter-spacing: 2px;
    margin-bottom: 5px;
}

.display-value {
    color: #00e676;
    font-size: 28px;
    font-weight: bold;
    font-family: 'Courier New', monospace;
    text-shadow: 0 0 10px #00e676;
}

/* Conversion Card */
.conversion-card {
    background: linear-gradient(135deg, #fff3e0 0%, #ffe0b2 100%);
    border-radius: 15px;
    padding: 25px;
    margin: 30px 0;
    border: 3px solid #ff9800;
    box-shadow: 0 5px 15px rgba(255, 152, 0, 0.3);
}

.card-header {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 20px;
}

.icon {
    font-size: 35px;
}

.title {
    font-size: 22px;
    font-weight: bold;
    color: #e65100;
}

.card-content {
    background: white;
    border-radius: 10px;
    padding: 20px;
}

.conversion-row {
    display: flex;
    justify-content: space-between;
    padding: 12px;
    border-bottom: 2px solid #e0e0e0;
}

.conversion-row:last-child {
    border-bottom: none;
}

.conversion-row.highlight {
    background: #fff9c4;
    border-radius: 8px;
    font-weight: bold;
    border: 2px solid #fbc02d;
}

.label {
    color: #555;
    font-size: 18px;
}

.conversion-row.highlight .label {
    color: #f57f17;
}

.value {
    color: #1976d2;
    font-size: 20px;
    font-weight: bold;
    font-family: 'Courier New', monospace;
}

.conversion-row.highlight .value {
    color: #e65100;
    font-size: 22px;
}

/* Choices Section */
.choices-section {
    margin: 40px 0;
}

.choices-section h3 {
    color: #333;
    text-align: center;
    margin-bottom: 25px;
    font-size: 20px;
}

.choices-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.choice-card {
    background: linear-gradient(135deg, #f5f7fa 0%, #e8edf2 100%);
    border: 3px solid #bdbdbd;
    border-radius: 15px;
    padding: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    min-height: 100px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.choice-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(79, 172, 254, 0.3);
    border-color: #4facfe;
}

.choice-label {
    position: absolute;
    top: 10px;
    left: 15px;
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    color: white;
    width: 35px;
    height: 35px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 18px;
}

.choice-content {
    text-align: center;
    margin-top: 15px;
}

.choice-text {
    color: #333;
    font-size: 26px;
    font-weight: bold;
    font-family: 'Courier New', monospace;
}

.choice-card.correct {
    background: linear-gradient(135deg, #4caf50 0%, #45a049 100%);
    border-color: #2e7d32;
    animation: correct-pulse 0.6s ease;
}

.choice-card.correct .choice-text,
.choice-card.correct .choice-label {
    color: white;
}

.choice-card.incorrect {
    animation: shake 0.5s ease;
}

@keyframes correct-pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

.choice-card.disabled {
    pointer-events: none;
    opacity: 0.6;
}

/* Feedback */
.feedback {
    text-align: center;
    font-size: 20px;
    font-weight: bold;
    min-height: 30px;
    margin: 20px 0;
}

.feedback.success {
    color: #4caf50;
}

.feedback.error {
    color: #f44336;
}

/* Reset Button */
.reset-btn {
    display: block;
    margin: 20px auto;
    background: #4caf50;
    color: white;
    border: none;
    padding: 15px 40px;
    border-radius: 10px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
}

.reset-btn:hover {
    background: #388e3c;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(76, 175, 80, 0.4);
}

.reset-btn:active {
    transform: translateY(0);
}

/* Info Box */
.info-box {
    background: #e8f5e9;
    border-left: 5px solid #4caf50;
    padding: 20px;
    border-radius: 10px;
    margin-top: 30px;
}

.info-box h3 {
    color: #2e7d32;
    margin-bottom: 10px;
    font-size: 18px;
}

.info-box p {
    color: #555;
    line-height: 1.8;
    margin-bottom: 10px;
}

/* Clapping Animation */
.clapping-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 9999;
    display: none;
}

.clapping-animation.active {
    display: block;
}

.clap-emoji {
    position: absolute;
    font-size: 70px;
    animation: clapping 2s ease-out forwards;
    opacity: 0;
}

.clap-emoji:nth-child(1) {
    left: 10%;
    top: 20%;
    animation-delay: 0s;
}

.clap-emoji:nth-child(2) {
    left: 25%;
    top: 35%;
    animation-delay: 0.15s;
}

.clap-emoji:nth-child(3) {
    left: 45%;
    top: 15%;
    animation-delay: 0.3s;
}

.clap-emoji:nth-child(4) {
    left: 60%;
    top: 40%;
    animation-delay: 0.45s;
}

.clap-emoji:nth-child(5) {
    left: 80%;
    top: 25%;
    animation-delay: 0.6s;
}

.clap-emoji:nth-child(6) {
    left: 20%;
    top: 60%;
    animation-delay: 0.75s;
}

.clap-emoji:nth-child(7) {
    left: 40%;
    top: 70%;
    animation-delay: 0.9s;
}

.clap-emoji:nth-child(8) {
    left: 65%;
    top: 65%;
    animation-delay: 1.05s;
}

.clap-emoji:nth-child(9) {
    left: 85%;
    top: 55%;
    animation-delay: 1.2s;
}

.clap-emoji:nth-child(10) {
    left: 50%;
    top: 50%;
    animation-delay: 1.35s;
}

@keyframes clapping {
    0% {
        opacity: 0;
        transform: scale(0.3) rotate(0deg);
    }
    15% {
        opacity: 1;
        transform: scale(1.2) rotate(15deg);
    }
    30% {
        transform: scale(0.9) rotate(-10deg);
    }
    45% {
        transform: scale(1.1) rotate(10deg);
    }
    60% {
        transform: scale(1) rotate(-5deg);
    }
    100% {
        opacity: 0;
        transform: scale(0.5) rotate(20deg);
    }
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 25px;
    }

    h1 {
        font-size: 26px;
    }

    .choices-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    .plant-scene {
        padding: 30px;
    }

    .tank-body {
        width: 180px;
        height: 250px;
    }

    .tank-base {
        width: 200px;
    }

    .choice-text {
        font-size: 22px;
    }
}

@media (max-width: 480px) {
    .story-box {
        padding: 15px;
    }

    .story-text,
    .question {
        font-size: 14px;
    }

    .plant-scene {
        padding: 20px;
    }

    .tank-body {
        width: 150px;
        height: 220px;
    }

    .tank-top {
        width: 100px;
    }

    .tank-base {
        width: 170px;
    }

    .display-value {
        font-size: 22px;
    }

    .choice-text {
        font-size: 20px;
    }
}