:root {
    --primary-color: #059669; 
    --secondary-color: #fbbf24; 
    --bg-color: #f0fdf4;
    --text-dark: #374151; 
    --text-light: #6b7280; 
    --card-bg: #ffffff;
    --locked-bg: #e5e7eb; 
    --locked-text: #9ca3af; 
    --active-bg: #ecfdf5;
    --active-border: #10b981; 
    --completed-bg: #dcfce7; 
    --completed-text: #166534;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1); 
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --success-color: #16a34a; 
    --error-color: #dc2626; 
    --info-color: #3b82f6;
    --border-color: #e2e8f0; /* Added from kulaka dashboard for back-link */
}
body { 
    font-family: 'Noto Sans Sinhala', 'Poppins', sans-serif; 
    background-image: linear-gradient(135deg, #10b981 0%, #6ee7b7 100%); 
    color: var(--text-dark); 
    margin: 0; 
    padding: 24px; 
    visibility: hidden; 
}
body.loaded { 
    visibility: visible; 
}
.container { 
    max-width: 800px; 
    margin: 0 auto; 
}
.header { 
    background: var(--card-bg); 
    border-radius: 16px; 
    padding: 32px; 
    text-align: center; 
    box-shadow: var(--shadow-lg); 
    margin-bottom: 32px; 
    position: relative; 
}
.header h1 { 
    font-size: 2.25rem; 
    font-weight: 800; 
    color: var(--primary-color); 
}
.header p { 
    font-size: 1.125rem; 
    color: var(--text-light); 
}
.back-link { 
    position: absolute; 
    top: 20px; 
    left: 20px; 
    display: flex; 
    align-items: center; 
    text-decoration: none; 
    font-size: 14px; 
    font-weight: 600; 
    color: var(--primary-color); 
    padding: 6px 10px; 
    border-radius: 8px; 
    transition: all 0.3s; 
    border: 1px solid var(--border-color); 
    background-color: var(--card-bg); 
}
.back-link:hover { 
    background-color: var(--active-bg); 
}
.back-link svg { 
    width: 18px; 
    height: 18px; 
    margin-right: 6px; 
}
.progress-section { 
    background: var(--card-bg); 
    border-radius: 12px; 
    padding: 24px; 
    margin-bottom: 32px; 
    box-shadow: var(--shadow); 
}
.progress-label { 
    display: flex; 
    justify-content: space-between; 
    font-weight: 600; 
    margin-bottom: 12px; 
}
.progress-bar-container { 
    width: 100%; 
    height: 16px; 
    background-color: var(--locked-bg); 
    border-radius: 8px; 
    overflow: hidden; 
}
.progress-bar { 
    height: 100%; 
    width: 0%; 
    background: linear-gradient(90deg, #fcd34d, var(--secondary-color)); 
    border-radius: 8px; 
    transition: width 0.5s ease-in-out; 
}
.day-card { 
    background: var(--card-bg); 
    border-radius: 12px; 
    box-shadow: var(--shadow); 
    margin-bottom: 16px; 
    transition: all 0.3s ease; 
}
.day-header { 
    padding: 16px 24px; 
    font-size: 1.25rem; 
    font-weight: 700; 
    border-bottom: 1px solid #e5e7eb; 
    display: flex; 
    align-items: center; 
    justify-content: space-between; 
    cursor: pointer; 
}
.day-card.locked > .day-header { 
    background: var(--locked-bg); 
    color: var(--locked-text); 
    cursor: not-allowed; 
}
.day-card.active > .day-header { 
    background: var(--active-bg); 
    color: var(--primary-color); 
}
.day-card.completed > .day-header { 
    background: var(--completed-bg); 
    color: var(--completed-text); 
}
.day-content { 
    max-height: 0; 
    overflow: hidden; 
    transition: max-height 0.5s ease-in-out, padding 0.5s ease; 
}
.day-card.active .day-content { 
    max-height: 2000px; 
    padding: 24px; 
}
.notes-section { 
    padding-bottom: 24px; 
    border-bottom: 1px dashed #d1d5db; 
    margin-bottom: 24px; 
}
.question-container { 
    margin-bottom: 24px; 
}
.question-options-container { 
    display: flex; 
    flex-direction: column; 
    gap: 8px; 
    margin-top: 12px; 
}
.question-option { 
    display: flex; 
    align-items: center; 
    gap: 12px; 
    padding: 12px; 
    border: 2px solid #e5e7eb; 
    border-radius: 8px; 
    cursor: pointer; 
    transition: all 0.2s ease-in-out; 
}
.question-option:hover:not(.disabled) { 
    background-color: #f9fafb; 
    border-color: var(--primary-color); 
}
.question-option.correct { 
    border-color: var(--success-color); 
    background-color: #dcfce7; 
}
.question-option.incorrect { 
    border-color: var(--error-color); 
    background-color: #fee2e2; 
}
.question-option.disabled { 
    cursor: not-allowed; 
}
.explanation { 
    border-left: 4px solid var(--info-color); 
    padding: 12px 16px; 
    margin-top: 12px; 
    background-color: #eff6ff; 
    border-radius: 0 8px 8px 0; 
    color: #374151; 
    display: none; 
}
.explanation ol { 
    padding-left: 20px; 
    margin: 0; 
}
.explanation li { 
    margin-bottom: 8px; 
    line-height: 1.6; 
}
.explanation li:last-child { 
    margin-bottom: 0; 
}
.control-panel { 
    padding-top: 24px; 
    text-align: center; 
}
.btn { 
    padding: 12px 24px; 
    border-radius: 8px; 
    border: none; 
    font-weight: 600; 
    font-size: 1rem; 
    cursor: pointer; 
    transition: all 0.2s; 
}
.btn-check { 
    background-color: var(--primary-color); 
    color: white; 
}
.btn-check:hover { 
    background-color: #047857; 
}
.btn-next { 
    background-color: var(--secondary-color); 
    color: white; 
    display: none; 
    margin-left: 10px; 
}
.feedback-message { 
    margin-top: 16px; 
    font-size: 1.125rem; 
    font-weight: 600; 
}