* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
    background: #F5F5F5;
    overflow: hidden;
    width: 100vw;
    height: 100vh;
    position: fixed;
}

/* Screen Management */
.screen {
    display: none;
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
}

.screen.active {
    display: flex;
    align-items: center;
    justify-content: center;
}

.container {
    width: 100%;
    padding: 40px;
    text-align: center;
}

/* Home Screen */
#homeScreen {
    background: #B8E6DD;
}

.title {
    font-size: 36px;
    font-weight: 300;
    color: #333;
    letter-spacing: 1px;
}

/* Scan Screen */
#scanScreen {
    background: #FFE5B4;
}

.countdown {
    font-size: 120px;
    font-weight: 200;
    color: #333;
    margin-bottom: 20px;
}

.scan-text {
    font-size: 24px;
    font-weight: 300;
    color: #666;
    letter-spacing: 0.5px;
}

/* Quiz Screen */
#quizScreen {
    background: #FFF;
}

.quiz-container {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.quiz-header {
    padding: 20px 30px;
    display: flex;
    justify-content: flex-end;
    background: #FFF;
    border-bottom: 1px solid #F0F0F0;
}

.timer {
    background: #FFE5B4;
    padding: 12px 28px;
    border-radius: 25px;
    font-size: 24px;
    font-weight: 300;
    color: #333;
}

.timer.warning {
    background: #FFB6C1;
    animation: pulse 0.5s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.6; }
}

.quiz-body {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 30px;
    gap: 30px;
    justify-content: center;
}

.question {
    font-size: 22px;
    font-weight: 400;
    color: #333;
    line-height: 1.5;
    padding: 30px;
    background: #FAFAFA;
    border-radius: 16px;
    border: 1px solid #E8E8E8;
}

.answers {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.answer-btn {
    padding: 24px 16px;
    font-size: 16px;
    font-weight: 400;
    color: #333;
    background: #FFF;
    border: 2px solid #E0E0E0;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.2s;
    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
}

.answer-btn:active {
    transform: scale(0.98);
}

.answer-btn.correct {
    background: #B8E6DD;
    border-color: #B8E6DD;
    color: #FFF;
}

.answer-btn.wrong {
    background: #FFB6C1;
    border-color: #FFB6C1;
    color: #FFF;
}

.answer-btn:disabled {
    opacity: 0.7;
}

/* Result Screen */
#resultScreen {
    background: #FFF;
}

.result-title {
    font-size: 48px;
    font-weight: 300;
    color: #333;
    margin-bottom: 16px;
    letter-spacing: 1px;
}

.result-message {
    font-size: 20px;
    font-weight: 300;
    color: #666;
    margin-bottom: 30px;
}

.result-detail {
    background: #FAFAFA;
    padding: 24px;
    border-radius: 16px;
    font-size: 16px;
    color: #333;
    line-height: 1.6;
    margin-bottom: 30px;
    border: 1px solid #E8E8E8;
}

.btn-home {
    background: #B8E6DD;
    color: #FFF;
    border: none;
    padding: 16px 60px;
    border-radius: 30px;
    font-size: 18px;
    font-weight: 400;
    cursor: pointer;
    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
    letter-spacing: 0.5px;
}

.btn-home:active {
    transform: scale(0.98);
}

/* Portrait Warning */
@media (orientation: portrait) {
    body::before {
        content: 'Please rotate your device';
        display: flex;
        align-items: center;
        justify-content: center;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: #FFF;
        color: #333;
        font-size: 20px;
        font-weight: 300;
        z-index: 9999;
        letter-spacing: 0.5px;
    }
}