:root {
    --bg-color: #f4f7fe;
    --card-bg: #ffffff;
    --text-main: #2b3674;
    --text-muted: #a3aed1;
    --primary: #4318FF;
    --primary-hover: #3311db;
    --shadow: 0px 18px 40px rgba(112, 144, 176, 0.12);
    --radius: 20px;
    --transition: all 0.3s ease;
}

[data-theme="dark"] {
    --bg-color: #0b1437;
    --card-bg: #111c44;
    --text-main: #ffffff;
    --text-muted: #8f9bba;
    --primary: #7551FF;
    --primary-hover: #4318FF;
    --shadow: 0px 18px 40px rgba(0, 0, 0, 0.5);
}

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

body { 
    background-color: var(--bg-color); 
    color: var(--text-main); 
    transition: var(--transition); 
    min-height: 100vh; 
}

.hidden { 
    display: none !important; 
}

.login-overlay {
    position: fixed; 
    top: 0; 
    left: 0; 
    width: 100%; 
    height: 100%;
    background: var(--bg-color);
    display: flex; 
    justify-content: center; 
    align-items: center; 
    z-index: 1000;
}

.login-card {
    background: var(--card-bg); 
    padding: 40px; 
    border-radius: var(--radius);
    box-shadow: var(--shadow); 
    text-align: center; 
    max-width: 400px; 
    width: 90%;
}

.login-card h1 { 
    font-size: 2rem; 
    margin-bottom: 10px; 
}

.highlight { 
    color: var(--primary); 
}

.login-card p { 
    color: var(--text-muted); 
    margin-bottom: 30px; 
    font-size: 0.9rem; 
}

.input-group {
    display: flex; 
    align-items: center; 
    background: var(--bg-color);
    border-radius: 12px; 
    padding: 10px 15px; 
    margin-bottom: 20px; 
    border: 1px solid transparent;
}

.input-group:focus-within { 
    border-color: var(--primary); 
}

.input-group span { 
    color: var(--text-muted); 
    margin-right: 10px; 
}

.input-group input {
    border: none; 
    background: transparent; 
    outline: none; 
    width: 100%;
    color: var(--text-main); 
    font-size: 1rem;
}

.btn-primary {
    background: var(--primary); 
    color: white; 
    border: none; 
    width: 100%;
    padding: 15px; 
    border-radius: 12px; 
    font-size: 1rem; 
    font-weight: 600;
    cursor: pointer; 
    transition: var(--transition);
}

.btn-primary:hover { 
    background: var(--primary-hover); 
}

.app-container { 
    max-width: 900px; 
    margin: 0 auto; 
    padding: 20px; 
}

.main-header {
    display: flex; 
    justify-content: space-between; 
    align-items: center;
    margin-bottom: 30px; 
    padding: 10px 0;
}

.icon-btn {
    background: var(--card-bg); 
    border: none; 
    border-radius: 50%; 
    width: 45px; 
    height: 45px;
    display: flex; 
    justify-content: center; 
    align-items: center; 
    cursor: pointer;
    color: var(--text-main); 
    box-shadow: var(--shadow); 
    transition: var(--transition);
}

.icon-btn:hover { 
    transform: scale(1.05); 
}

.profile-section {
    background: var(--card-bg); 
    padding: 25px; 
    border-radius: var(--radius);
    box-shadow: var(--shadow); 
    margin-bottom: 30px;
}

.profile-info { 
    display: flex; 
    align-items: center; 
    gap: 20px; 
}

.avatar {
    width: 60px; 
    height: 60px; 
    background: var(--primary); 
    color: white;
    border-radius: 50%; 
    display: flex; 
    justify-content: center; 
    align-items: center; 
    font-size: 2rem;
}

.profile-info h2 { 
    font-size: 1.5rem; 
}

.subtitle { 
    color: var(--text-muted); 
    font-size: 0.9rem; 
}

.section-title { 
    margin-bottom: 20px; 
    font-size: 1.2rem; 
}

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

@media(min-width: 768px) { 
    .cards-grid { 
        grid-template-columns: 1fr 1fr; 
    } 
}

.course-card {
    background: var(--card-bg); 
    border-radius: var(--radius); 
    overflow: hidden;
    box-shadow: var(--shadow); 
    cursor: pointer; 
    transition: var(--transition);
    display: flex; 
    flex-direction: column;
}

.course-card:hover { 
    transform: translateY(-5px); 
}

.card-img { 
    width: 100%; 
    height: 180px; 
    object-fit: cover; 
}

.card-content { 
    padding: 20px; 
    display: flex; 
    flex-direction: column; 
    flex-grow: 1;
}

.card-content h3 { 
    font-size: 1.2rem; 
    margin-bottom: 8px; 
}

.card-content p { 
    color: var(--text-muted); 
    font-size: 0.85rem; 
    margin-bottom: 20px; 
    flex-grow: 1;
}

.progress-wrapper { 
    width: 100%; 
}

.progress-stats { 
    display: flex; 
    justify-content: space-between; 
    font-size: 0.8rem; 
    font-weight: 600; 
    margin-bottom: 5px;
}

.progress-bar { 
    width: 100%; 
    height: 8px; 
    background: var(--bg-color); 
    border-radius: 4px; 
    overflow: hidden; 
}

.progress-fill { 
    height: 100%; 
    background: var(--primary); 
    width: 0%; 
    border-radius: 4px; 
    transition: width 0.5s ease; 
}

.quiz-list-grid { 
    display: grid; 
    gap: 16px; 
    margin-top: 20px;
}

.quiz-item {
    background: var(--card-bg); 
    padding: 20px 25px; 
    border-radius: 16px;
    display: flex; 
    justify-content: space-between; 
    align-items: center;
    box-shadow: var(--shadow); 
    cursor: pointer; 
    transition: var(--transition);
    border-left: 6px solid var(--primary);
    position: relative;
    overflow: hidden;
}

.quiz-item:hover:not(.locked) { 
    transform: translateY(-3px); 
    box-shadow: 0px 20px 40px rgba(67, 24, 255, 0.2);
}

.quiz-item.locked {
    opacity: 0.6; 
    cursor: not-allowed; 
    border-left-color: var(--text-muted);
    background: #e9ecef;
}

[data-theme="dark"] .quiz-item.locked {
    background: #1a2035;
}

.quiz-item-title { 
    font-weight: 600; 
    font-size: 1.1rem; 
    color: var(--text-main);
}

.quiz-status-icon { 
    color: var(--primary); 
    font-size: 1.8rem;
}

.locked .quiz-status-icon { 
    color: var(--text-muted); 
}

.quiz-top-bar { 
    margin-bottom: 25px; 
    background: var(--card-bg);
    padding: 15px 20px;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.quiz-top-bar span { 
    font-size: 1rem; 
    font-weight: 700; 
    color: var(--primary); 
    display: block; 
    margin-bottom: 10px;
}

.mini-bar { 
    height: 8px; 
    border-radius: 4px; 
}

.quiz-content-area {
    background: var(--card-bg); 
    padding: 25px; 
    border-radius: 16px;
    box-shadow: var(--shadow); 
    margin-bottom: 25px;
    text-align: center;
}

#quizImage { 
    max-width: 100%; 
    max-height: 350px; 
    object-fit: contain; 
    border-radius: 12px; 
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

#quizText { 
    font-size: 1.1rem; 
    line-height: 1.7; 
    text-align: justify; 
    color: var(--text-main);
}

.question-area {
    background: var(--card-bg);
    padding: 25px;
    border-radius: 16px;
    box-shadow: var(--shadow);
}

.question-area h3 { 
    font-size: 1.25rem; 
    margin-bottom: 25px; 
    color: var(--text-main);
    line-height: 1.4;
}

.options-grid { 
    display: flex !important; 
    flex-direction: column !important; 
    gap: 15px !important; 
    width: 100% !important;
}

.option-btn {
    display: block !important;
    width: 100% !important;
    background-color: var(--bg-color) !important; 
    border: 2px solid #cbd5e1 !important;
    color: var(--text-main) !important;
    padding: 18px 25px !important; 
    border-radius: 12px !important; 
    font-size: 1.1rem !important; 
    text-align: left !important; 
    cursor: pointer !important; 
    transition: all 0.3s ease !important; 
    font-weight: 500 !important;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05) !important;
}

.option-btn:hover:not(.disabled) { 
    border-color: var(--primary) !important; 
    background-color: #f8fafc !important;
    transform: scale(1.02) !important;
}

.option-btn.correct { 
    background-color: #ecfdf5 !important;
    color: #047857 !important;
    border-color: #10b981 !important;
    font-weight: 700 !important;
    box-shadow: 0 0 15px rgba(16, 185, 129, 0.4) !important;
}

.option-btn.wrong { 
    background-color: #fef2f2 !important;
    color: #b91c1c !important;
    border-color: #ef4444 !important;
    box-shadow: 0 0 15px rgba(239, 68, 68, 0.4) !important;
}

.option-btn.disabled { 
    pointer-events: none !important; 
    opacity: 0.7 !important;
}

.result-screen { 
    text-align: center; 
    padding: 50px 20px; 
    background: var(--card-bg); 
    border-radius: 16px; 
    box-shadow: var(--shadow); 
}

.result-emoji { 
    font-size: 6rem; 
    margin-bottom: 15px; 
    animation: bounce 1.5s ease infinite; 
}

.result-screen h2 { 
    font-size: 2.2rem; 
    margin-bottom: 15px; 
    color: var(--primary); 
}

.result-screen p { 
    color: var(--text-muted); 
    margin-bottom: 25px; 
    font-size: 1.1rem; 
}

.score-display { 
    font-size: 1.8rem; 
    font-weight: 800; 
    margin-bottom: 40px; 
    background: var(--primary); 
    color: white;
    display: inline-block; 
    padding: 15px 30px; 
    border-radius: 30px;
    box-shadow: 0 10px 20px rgba(67, 24, 255, 0.3);
}

@keyframes bounce { 
    0%, 100% { transform: translateY(0); } 
    50% { transform: translateY(-15px); } 
}

.profile-upload-container { 
    text-align: center; 
    margin-bottom: 20px; 
}

.upload-label {
    width: 80px; 
    height: 80px; 
    border-radius: 50%;
    background: var(--bg-color); 
    border: 2px dashed var(--primary);
    display: inline-flex; 
    justify-content: center; 
    align-items: center;
    cursor: pointer; 
    color: var(--primary); 
    overflow: hidden;
    transition: var(--transition); 
    margin: 0 auto;
}

.upload-label:hover { 
    background: rgba(67, 24, 255, 0.1); 
    transform: scale(1.05); 
}

.upload-label img { 
    width: 100%; 
    height: 100%; 
    object-fit: cover; 
}

#appAvatar img { 
    width: 100%; 
    height: 100%; 
    object-fit: cover; 
    border-radius: 50%; 
}