body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    margin: 0;
    padding: 0;
    background-color: #FAF7F0;
    color: #2C1810;
    transition: background-color 0.3s, color 0.3s;
}

header {
    background-color: #2C1810;
    color: #F5ECD7;
    padding: 1rem;
    text-align: center;
    position: relative;
}

nav button {
    margin: 0.5rem;
    padding: 0.5rem 1rem;
    background: #F5ECD7;
    color: #2C1810;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-weight: 500;
}

nav button:hover {
    background: #C8A06E;
}

main {
    padding: 1rem;
    max-width: 900px;
    margin: 0 auto;
}

.section {
    display: none;
}

.section.active {
    display: block;
}

.card {
    background: #FFFDF6;
    padding: 1rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(44, 24, 16, 0.12);
    margin: 1rem 0;
    border-left: 4px solid #C8A06E;
}

button {
    background: #6B3A2A;
    color: #F5ECD7;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    cursor: pointer;
    margin: 0.5rem;
    font-weight: 500;
}

button:hover {
    background: #4A2512;
}

label {
    display: block;
    margin: 1rem 0;
}

.option-label {
    display: block;
    margin: 0.5rem 0;
    padding: 0.75rem;
    border: 1px solid #C8A06E;
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.15s;
}

.option-label:hover {
    background: #F5ECD7;
}

.option-label.option-correct {
    border-color: #4A7856;
    background: #EAF4ED;
    color: #2E5E3E;
    font-weight: 500;
}

.option-label.option-incorrect {
    border-color: #8B3A3A;
    background: #F9ECEC;
    color: #6B2222;
}

.feedback {
    margin: 1rem 0 0.5rem;
    padding: 0.75rem 1rem;
    border-radius: 6px;
    font-weight: 500;
    min-height: 1rem;
}

.feedback-right {
    background: #EAF4ED;
    color: #2E5E3E;
    border: 1px solid #4A7856;
}

.feedback-wrong {
    background: #F9ECEC;
    color: #6B2222;
    border: 1px solid #8B3A3A;
}

#status {
    position: absolute;
    top: 15px;
    right: 15px;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.85rem;
    color: #F5ECD7;
}

.online { background: #4A7856; }
.offline { background: #8B3A3A; }

.dark-mode {
    background-color: #160C07;
    color: #F5ECD7;
}

.dark-mode header {
    background-color: #0F0704;
}

.dark-mode .card, .dark-mode label {
    background: #2C1810;
    color: #F5ECD7;
}

.dark-mode .option-label {
    border-color: #8D6A4E;
    color: #F5ECD7;
}

.dark-mode .option-label:hover {
    background: #3D2318;
}

.dark-mode .option-label.option-correct {
    border-color: #4A7856;
    background: #1B3A2B;
    color: #A5D6A7;
}

.dark-mode .option-label.option-incorrect {
    border-color: #8B3A3A;
    background: #3A1B1B;
    color: #FFAB91;
}

.dark-mode .feedback-right {
    background: #1B3A2B;
    color: #A5D6A7;
    border-color: #4A7856;
}

.dark-mode .feedback-wrong {
    background: #3A1B1B;
    color: #FFAB91;
    border-color: #8B3A3A;
}