:root {
    --bg-color: #f0f2f5;
    --primary: #46178f; /* Kahoot purple-ish */
    --secondary: #25076b;
    --text-dark: #333;
    --text-light: #fff;
    
    /* Option colors */
    --opt-red: #e21b3c;
    --opt-blue: #1368ce;
    --opt-yellow: #d89e00;
    --opt-green: #26890c;
    
    --opt-red-hover: #c41230;
    --opt-blue-hover: #0f54a8;
    --opt-yellow-hover: #b88600;
    --opt-green-hover: #1e700a;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Nunito', sans-serif;
}

body {
    background: linear-gradient(135deg, #46178f, #25076b, #1368ce, #e21b3c);
    background-size: 400% 400%;
    animation: gradientBG 15s ease infinite;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    position: relative;
}

@keyframes gradientBG {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.background-shapes {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: 0;
    margin: 0;
    padding: 0;
}

.background-shapes li {
    position: absolute;
    display: block;
    list-style: none;
    width: 20px;
    height: 20px;
    background: rgba(255, 255, 255, 0.15);
    animation: float 25s linear infinite;
    bottom: -150px;
}

.background-shapes li:nth-child(1) { left: 25%; width: 80px; height: 80px; animation-delay: 0s; }
.background-shapes li:nth-child(2) { left: 10%; width: 20px; height: 20px; animation-delay: 2s; animation-duration: 12s; }
.background-shapes li:nth-child(3) { left: 70%; width: 20px; height: 20px; animation-delay: 4s; }
.background-shapes li:nth-child(4) { left: 40%; width: 60px; height: 60px; animation-delay: 0s; animation-duration: 18s; }
.background-shapes li:nth-child(5) { left: 65%; width: 20px; height: 20px; animation-delay: 0s; }
.background-shapes li:nth-child(6) { left: 75%; width: 110px; height: 110px; animation-delay: 3s; }
.background-shapes li:nth-child(7) { left: 35%; width: 150px; height: 150px; animation-delay: 7s; }
.background-shapes li:nth-child(8) { left: 50%; width: 25px; height: 25px; animation-delay: 15s; animation-duration: 45s; }
.background-shapes li:nth-child(9) { left: 20%; width: 15px; height: 15px; animation-delay: 2s; animation-duration: 35s; }
.background-shapes li:nth-child(10) { left: 85%; width: 150px; height: 150px; animation-delay: 0s; animation-duration: 11s; }

@keyframes float {
    0% { transform: translateY(0) rotate(0deg); opacity: 1; border-radius: 0; }
    100% { transform: translateY(-1000px) rotate(720deg); opacity: 0; border-radius: 50%; }
}

.lang-selector {
    position: absolute;
    top: 20px;
    right: 20px;
    display: flex;
    gap: 0.5rem;
    z-index: 100;
}

.lang-btn {
    background-color: #e0e0e0;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-weight: 700;
    color: #666;
    cursor: pointer;
    transition: all 0.2s ease;
}

.lang-btn.active {
    background-color: var(--primary);
    color: white;
}

#app-container {
    width: 100%;
    max-width: 800px;
    height: 95vh;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    box-shadow: 0 15px 35px rgba(0,0,0,0.2);
    position: relative;
    overflow: hidden;
    z-index: 10;
}

.screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.4s ease-in-out, transform 0.4s ease;
    transform: scale(0.95);
}

.screen.active {
    opacity: 1;
    pointer-events: auto;
    transform: scale(1);
}

/* Typography & Buttons */
h1, h2, h3 { color: var(--text-dark); text-align: center; }

.logo {
    font-size: 4rem;
    font-weight: 900;
    color: var(--primary);
    margin-bottom: 1rem;
    text-shadow: 2px 2px 0px rgba(0,0,0,0.1);
}
.logo span { color: var(--opt-red); }

.subtitle {
    font-size: 1.5rem;
    color: #666;
    margin-bottom: 3rem;
    text-align: center;
}

.btn {
    border: none;
    padding: 1rem 2.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    outline: none;
}

.primary-btn {
    background-color: var(--primary);
    color: white;
    border-bottom: 5px solid var(--secondary);
}
.primary-btn:active {
    transform: translateY(5px);
    border-bottom-width: 0px;
    margin-top: 5px;
}

.secondary-btn {
    background-color: #e0e0e0;
    color: #333;
    border-bottom: 5px solid #bdbdbd;
}
.secondary-btn:active {
    transform: translateY(5px);
    border-bottom-width: 0px;
    margin-top: 5px;
}

.btn.small {
    padding: 0.8rem 2rem;
    font-size: 1.2rem;
    margin-top: 2rem;
}

.pulse {
    animation: pulse-animation 2s infinite;
}

@keyframes pulse-animation {
    0% { transform: scale(1); box-shadow: 0 0 0 0 rgba(70, 23, 143, 0.7); }
    70% { transform: scale(1.05); box-shadow: 0 0 0 10px rgba(70, 23, 143, 0); }
    100% { transform: scale(1); box-shadow: 0 0 0 0 rgba(70, 23, 143, 0); }
}

/* Podium Screen */
.podium-place {
    transition: transform 0.3s;
}
.podium-place:hover {
    transform: translateY(-10px);
}
.podium-place span {
    text-shadow: 1px 1px 2px rgba(255,255,255,0.8);
}

/* Class Screen */
#class-screen h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
}

.class-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    width: 100%;
    max-width: 600px;
}

.class-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem 1rem;
    border: none;
    border-radius: 15px;
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
    background-color: var(--primary);
    cursor: pointer;
    transition: transform 0.2s, filter 0.2s;
    box-shadow: 0 6px 0 var(--secondary);
}

.class-btn:hover { filter: brightness(1.2); transform: translateY(-5px); }
.class-btn:active { transform: translateY(6px); box-shadow: 0 0 0 rgba(0,0,0,0); }


/* Subject Screen */
#subject-screen h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
}

.subject-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    width: 100%;
    max-width: 600px;
}

.subject-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 2rem 1rem;
    border: none;
    border-radius: 15px;
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
    cursor: pointer;
    transition: transform 0.2s, filter 0.2s;
    box-shadow: 0 6px 0 rgba(0,0,0,0.2);
}

.subject-btn:hover { filter: brightness(1.1); transform: translateY(-5px); }
.subject-btn:active { transform: translateY(6px); box-shadow: 0 0 0 rgba(0,0,0,0); }

.subject-btn .icon { font-size: 3rem; margin-bottom: 0.5rem; }

.math { background-color: var(--opt-red); }
.indo { background-color: var(--opt-blue); }
.english { background-color: var(--opt-yellow); color: #333; }
.general { background-color: var(--opt-green); }

/* Quiz Screen */
#quiz-screen {
    justify-content: flex-start;
    padding: 1.5rem;
}

.quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    margin-bottom: 1rem;
    font-weight: 700;
    font-size: 1.2rem;
}

.score-display { background: var(--primary); color: white; padding: 0.5rem 1rem; border-radius: 10px; }
.question-tracker { background: #e0e0e0; padding: 0.5rem 1rem; border-radius: 10px; }

.timer {
    position: relative;
    width: 60px;
    height: 60px;
}

.timer-circle {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    background-color: var(--primary);
    color: white;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.8rem;
    font-weight: 900;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
    transition: background-color 0.3s;
}

.timer-circle.warning { background-color: var(--opt-red); animation: shake 0.5s infinite; }

@keyframes shake {
    0% { transform: translate(1px, 1px) rotate(0deg); }
    10% { transform: translate(-1px, -2px) rotate(-1deg); }
    20% { transform: translate(-3px, 0px) rotate(1deg); }
    30% { transform: translate(3px, 2px) rotate(0deg); }
    40% { transform: translate(1px, -1px) rotate(1deg); }
    50% { transform: translate(-1px, 2px) rotate(-1deg); }
    60% { transform: translate(-3px, 1px) rotate(0deg); }
    70% { transform: translate(3px, 1px) rotate(-1deg); }
    80% { transform: translate(-1px, -1px) rotate(1deg); }
    90% { transform: translate(1px, 2px) rotate(0deg); }
    100% { transform: translate(1px, -2px) rotate(-1deg); }
}

.question-container {
    width: 100%;
    flex-grow: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background: white;
    border-radius: 15px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    padding: 2rem;
    margin-bottom: 2rem;
    text-align: center;
}

#question-text {
    font-size: 2.2rem;
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    width: 100%;
    height: 40%;
}

.option-btn {
    border: none;
    border-radius: 10px;
    color: white;
    font-size: 1.5rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    padding: 1rem;
    cursor: pointer;
    transition: filter 0.2s, transform 0.1s;
    box-shadow: 0 6px 0 rgba(0,0,0,0.2);
    position: relative;
    overflow: hidden;
    text-align: left;
}

.option-btn:hover { filter: brightness(1.1); }
.option-btn:active { transform: translateY(6px); box-shadow: none; }

.option-btn.disabled { pointer-events: none; filter: grayscale(50%); }

.option-btn .shape {
    font-size: 2rem;
    margin-right: 1rem;
    opacity: 0.8;
}

.opt-red { background-color: var(--opt-red); }
.opt-blue { background-color: var(--opt-blue); }
.opt-yellow { background-color: var(--opt-yellow); color: #333; }
.opt-green { background-color: var(--opt-green); }

/* Animations for correctness */
.option-btn.correct {
    animation: correct-ans 0.5s forwards;
    z-index: 10;
}

.option-btn.wrong {
    animation: wrong-ans 0.5s forwards;
    opacity: 0.5;
}

@keyframes correct-ans {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); filter: brightness(1.3); }
    100% { transform: scale(1); background-color: #00e676; color: white; box-shadow: 0 0 20px #00e676; z-index: 100; }
}

@keyframes wrong-ans {
    0% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    50% { transform: translateX(5px); }
    75% { transform: translateX(-5px); }
    100% { transform: translateX(0); background-color: #e21b3c; color: white;}
}


/* Result Screen */
#result-screen h2 {
    font-size: 3rem;
    margin-bottom: 2rem;
    color: var(--primary);
}

.final-score-box {
    background: white;
    padding: 3rem 4rem;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    text-align: center;
    margin-bottom: 2rem;
    transform: scale(0.8);
    animation: popIn 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
    animation-delay: 0.2s;
}

@keyframes popIn {
    to { transform: scale(1); }
}

.final-score-box p {
    font-size: 1.5rem;
    color: #666;
    font-weight: 700;
}

#final-score {
    font-size: 5rem;
    color: var(--opt-red);
    margin-top: 1rem;
}

#feedback-message {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 3rem;
}

.result-actions {
    display: flex;
    gap: 1rem;
}

/* Modern Mobile Responsiveness */
@media (max-width: 768px) {
    /* Make the app feel like a native mobile app */
    #app-container {
        height: 100vh;
        width: 100vw;
        border-radius: 0;
        box-shadow: none;
    }

    .screen {
        padding: 1.5rem 1rem;
    }

    .logo { 
        font-size: 2.5rem; 
        margin-bottom: 1.5rem;
    }

    h2 {
        font-size: 1.8rem;
    }

    /* Stack grids beautifully */
    .class-grid, .subject-grid { 
        grid-template-columns: 1fr; 
        gap: 1rem;
        width: 100%;
        max-width: 400px;
    }

    .mode-grid {
        flex-direction: column;
        gap: 1rem !important;
        width: 100%;
        max-width: 400px;
    }
    
    .mode-grid .btn {
        width: 100%;
    }

    /* Adjust quiz screen layout */
    .question-container {
        padding: 1.5rem 1rem;
        margin-bottom: 1rem;
        min-height: 120px;
        flex-grow: 0;
    }

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

    .options-grid { 
        grid-template-columns: 1fr; 
        gap: 0.8rem;
        height: auto;
        flex-grow: 1;
        overflow-y: auto;
        padding-bottom: 1rem;
    }

    .option-btn {
        font-size: 1.2rem;
        padding: 1.2rem 1rem;
    }

    .option-btn .shape {
        font-size: 1.5rem;
    }

    /* Resize podium elements */
    .podium-container {
        flex-direction: column;
        align-items: center;
        gap: 1rem;
    }
    
    .final-score-box {
        padding: 2rem;
        width: 100%;
        max-width: 350px;
    }
    
    #final-score {
        font-size: 3.5rem;
    }
}