/* Generel styling */
body {
    font-family: 'Inter', sans-serif;
    background-color: #f8fafc; /* Lighter background, Tailwind bg-slate-50 */
    color: #1e293b; /* Darker text, Tailwind text-slate-900 */
}

/* --- Hovedoverskrifter og Tekst --- */
.chapter-title {
    font-size: 2.5rem; /* text-4xl */
    font-weight: 800; /* font-extrabold */
    color: #1e293b; /* text-slate-900 */
    margin-top: 3rem; /* mt-12 */
    margin-bottom: 2rem; /* mb-8 */
    border-bottom: 3px solid #cbd5e1; /* border-slate-300 */
    padding-bottom: 0.75rem;
    text-align: center;
    letter-spacing: -0.025em; /* tracking-tight */
}

/* --- Flashcard Sektion --- */
.flashcard-section {
    display: block; /* Vises som standard */
}

.card {
    transform-style: preserve-3d;
    transition: transform 0.6s cubic-bezier(0.25, 0.8, 0.25, 1), box-shadow 0.3s ease-in-out; /* Smoother flip and shadow transition */
    box-shadow: 0 10px 20px -5px rgba(0, 0, 0, 0.15), 0 4px 6px -2px rgba(0, 0, 0, 0.08); /* Deeper shadow for elevation */
    border: 1px solid #e2e8f0; /* Subtle border */
    border-radius: 1.5rem; /* Consistent rounded corners */
}
.card:hover {
    box-shadow: 0 15px 30px -8px rgba(0, 0, 0, 0.2), 0 6px 12px -3px rgba(0, 0, 0, 0.1); /* Even deeper shadow on hover */
}
.card.is-flipped {
    transform: rotateY(180deg);
}
.card-face {
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    position: absolute;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2.5rem; /* More padding */
    text-align: center;
    border-radius: 1.5rem; /* Consistent rounded corners */
    /* Tilføjet for at håndtere overløb og lang tekst dynamisk */
    overflow-y: auto; /* Tillader scrolling hvis tekst er for lang */
    word-wrap: break-word; /* Bryder lange ord */
    hyphens: auto; /* Tillader orddeling */
}
.card-front-display {
    background-color: white;
    color: #1e293b; /* text-slate-900 */
    font-weight: 700; /* Bolder font */
    font-size: 2.5rem; /* Larger font */
    line-height: 1.2;
}
.card-back-display {
    background-color: #4f46e5; /* Tailwind indigo-600 for consistency */
    color: white;
    font-weight: 500;
    font-size: 2rem; /* Slightly smaller for back */
    line-height: 1.4;
    transform: rotateY(180deg);
}
.card-container-wrapper {
    transition: opacity 0.3s ease-in-out, transform 0.3s ease-in-out;
}
.card-container-wrapper.fade-out {
    opacity: 0;
    transform: scale(0.95);
}

/* --- Quiz Sektion --- */
.quiz-section {
    display: none; /* Skjult som standard */
}

.question-card {
    background-color: white;
    border-radius: 1.5rem; /* rounded-3xl */
    box-shadow: 0 8px 16px -4px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05); /* Deeper shadow */
    padding: 2.5rem; /* p-10 */
    margin-bottom: 2rem; /* mb-8 */
    border: 1px solid #e2e8f0; /* Subtle border */
}
.answer-option {
    display: flex;
    align-items: flex-start; /* Align text to start */
    padding: 1rem 1.25rem; /* py-4 px-5 */
    margin-bottom: 0.75rem; /* mb-3 */
    background-color: #f8fafc; /* bg-slate-50 */
    border-radius: 0.75rem; /* rounded-xl */
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s ease-out;
    border: 1px solid #e2e8f0; /* border-slate-200 */
}
.answer-option:hover:not(.correct-answer):not(.incorrect-answer) {
    background-color: #f1f5f9; /* bg-slate-100 */
    transform: translateY(-2px); /* Subtle lift on hover */
    box-shadow: 0 4px 8px -2px rgba(0, 0, 0, 0.08); /* Soft shadow on hover */
}
.answer-option input[type="radio"] {
    margin-top: 0.25rem; /* Align radio button with text */
    margin-right: 1rem; /* mr-4 */
    transform: scale(1.2); /* Slightly larger radio button */
    accent-color: #4f46e5; /* Custom color for checked radio */
}
.correct-answer {
    background-color: #dcfce7; /* bg-green-100 */
    border-color: #22c55e; /* border-green-500 */
    font-weight: 600;
}
.incorrect-answer {
    background-color: #fee2e2; /* bg-red-100 */
    border-color: #ef4444; /* border-red-500 */
    font-weight: 600;
}
.explanation {
    margin-top: 1rem;
    font-size: 0.95rem; /* Slightly larger text-sm */
    color: #475569; /* text-slate-700 */
    line-height: 1.5;
}

/* --- Knapper (Submit-btn general styling) --- */
/* Disse stilarter er nu mere robuste for at sikre, at knapperne altid ser korrekte ud */
.submit-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 600;
    padding: 0.85rem 2rem; /* Tilføjet padding for bedre udseende og klikområde */
    border-radius: 0.75rem; /* Afrundede hjørner */
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06); /* Shadow-md */
    transition: background-color 0.2s ease-in-out, transform 0.1s ease-out, box-shadow 0.2s ease-in-out;
    cursor: pointer;
    border: none; /* Fjern standard browser border */
    text-align: center; /* Sørg for tekst er centreret */
    white-space: nowrap; /* Undgå tekstombrydning på knapper */
}

.submit-btn:hover:not(:disabled) {
    transform: translateY(-2px); /* Subtilt løft ved hover */
    box-shadow: 0 6px 10px -2px rgba(0, 0, 0, 0.15), 0 3px 6px -1px rgba(0, 0, 0, 0.08);
}
.submit-btn:active:not(:disabled) {
    transform: translateY(0); /* "Tryk ned" effekt */
    box-shadow: 0 2px 4px -1px rgba(0, 0, 0, 0.08), 0 1px 2px -1px rgba(0, 0, 0, 0.04);
}
.submit-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none; /* Ingen løft når disabled */
    box-shadow: none; /* Ingen skygge når disabled */
}
.action-btn {
    background-color: #312e81;
}

/* --- Resultatbeskeder --- */
.result-message {
    margin-top: 1.5rem;
    font-size: 1.25rem; /* text-xl */
    font-weight: 700; /* font-bold */
    text-align: center;
}
.correct {
    color: #16a34a; /* text-green-600 */
}
.incorrect {
    color: #dc2626; /* text-red-600 */
}
.quiz-mode-container {
    display: none; /* Hidden by default, shown by JS */
}

/* --- Custom styles for select elements (overrides default browser styling) --- */
select {
    appearance: none; /* Fjerner standard pil */
    -webkit-appearance: none;
    -moz-appearance: none;
    /* Tilføjer en brugerdefineret SVG-pil */
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' fill='%236B7280'%3E%3Cpath fill-rule='evenodd' d='M5.293 7.293a1 1 0 011.414 0L10 10.586l3.293-3.293a1 1 0 111.414 1.414l-4 4a1 1 0 01-1.414 0l-4-4a1 1 0 010-1.414z' clip-rule='evenodd' /%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center; /* Placerer pilen til højre */
    padding-right: 2.5rem; /* Gør plads til den brugerdefinerede pil */
}
select:focus {
    border-color: #4f46e5; /* Tailwind indigo-600 fokusramme */
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.3); /* Blød skygge ved fokus */
}
select[multiple] {
    height: auto !important; /* Tillad multiselect at vokse */
    background-image: none; /* Fjern pil for multiselect */
    padding-right: 0.75rem;
}

/* --- Checkbox Styling (Custom form-checkbox like appearance for Tailwind forms) --- */
input[type="checkbox"].form-checkbox {
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    display: inline-block;
    height: 1.25rem; /* h-5 */
    width: 1.25rem; /* w-5 */
    border: 2px solid #94a3b8; /* border-slate-400 */
    border-radius: 0.25rem; /* rounded-md */
    background-color: #fff;
    cursor: pointer;
    transition: background-color 0.2s, border-color 0.2s;
    vertical-align: middle;
}

input[type="checkbox"].form-checkbox:checked {
    background-color: #4f46e5; /* Tailwind indigo-600 */
    border-color: #4f46e5; /* Tailwind indigo-600 */
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 16 16' fill='white' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M13.5 2.5 L6 10 L2.5 6.5 L1.5 7.5 L6 12 L14.5 3.5 Z'/%3E%3C/svg%3E");
    background-size: 80%;
    background-repeat: no-repeat;
    background-position: center;
}

input[type="checkbox"].form-checkbox:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.3); /* Blød skygge ved fokus, som select */
}

/* --- Mobile Responsiveness Adjustments --- */
@media (max-width: 640px) { /* Small screens (sm breakpoint in Tailwind) */
    .chapter-title {
        font-size: 2rem; /* text-3xl */
        margin-top: 2rem;
        margin-bottom: 1.5rem;
    }
    .card {
        height: auto; /* Tillad højde at tilpasse sig indhold */
        min-height: 20rem; /* Minimum højde for et pænt kort */
        max-height: 80vh; /* Maksimal højde for at undgå for store kort på små skærme */
    }
    .card-face {
        padding: 1.5rem; /* Lidt mindre padding på mobil */
    }
    .card-front-display {
        font-size: clamp(1rem, 5vw, 2rem); /* Dynamisk skriftstørrelse: min 1rem, ideal 5vw, max 2rem */
        line-height: 1.3;
    }
    .card-back-display {
        font-size: clamp(0.9rem, 4.5vw, 1.5rem); /* Dynamisk skriftstørrelse: min 0.9rem, ideal 4.5vw, max 1.5rem */
        line-height: 1.4;
    }
    .question-card {
        padding: 1.5rem; /* p-6 */
        border-radius: 1rem; /* rounded-xl */
    }
    .answer-option {
        padding: 0.75rem 1rem; /* py-3 px-4 */
    }
    .result-message {
        font-size: 1rem; /* text-base */
    }
}