* {
    box-sizing: border-box;
}

body {
    margin: 0;

    min-height: 100vh;

    padding: 20px;

    font-family: Arial, sans-serif;

    background: #111827;

    color: #111827;
}

.app {
    width: 100%;

    max-width: 480px;

    margin: auto;
}

.card {
    background: white;

    padding: 25px;

    border-radius: 20px;

    box-shadow:
        0 10px 30px
        rgba(0, 0, 0, 0.25);

    text-align: center;
}

.logo {
    font-size: 70px;

    margin-bottom: 10px;
}

h1 {
    margin: 5px 0 10px;
}

h2 {
    line-height: 1.4;
}

p {
    color: #64748b;
}

input {
    width: 100%;

    padding: 15px;

    margin-top: 12px;

    border: 1px solid #cbd5e1;

    border-radius: 10px;

    font-size: 16px;
}

button {
    width: 100%;

    padding: 15px;

    margin-top: 12px;

    border: none;

    border-radius: 10px;

    background: #2563eb;

    color: white;

    font-size: 16px;

    font-weight: bold;

    cursor: pointer;
}

button:disabled {
    opacity: 0.6;

    cursor: not-allowed;
}

.secondary {
    background: #475569;
}

.danger {
    background: #dc2626;
}

.hidden {
    display: none;
}

a {
    color: #2563eb;

    font-weight: bold;

    text-decoration: none;
}

#loginMessage,
#registerMessage {
    margin-top: 15px;

    font-weight: bold;
}

.stats {
    display: flex;

    gap: 12px;

    margin: 20px 0;
}

.stats > div {
    flex: 1;

    padding: 15px;

    background: #f1f5f9;

    border-radius: 12px;

    font-size: 25px;
}

.stats strong {
    display: block;

    font-size: 24px;

    margin-top: 5px;
}

.stats small {
    display: block;

    color: #64748b;

    font-size: 13px;

    margin-top: 5px;
}

.quizTop {
    display: flex;

    justify-content: space-between;

    padding: 12px;

    background: #f1f5f9;

    border-radius: 10px;

    font-weight: bold;
}

.answer {
    background: #334155;

    text-align: left;
}

.answer.correct {
    background: #16a34a;
}

.answer.wrong {
    background: #dc2626;
}

.bigScore {
    font-size: 45px;

    font-weight: bold;

    margin: 25px 0;
}

.rank {
    display: flex;

    justify-content: space-between;

    align-items: center;

    padding: 15px;

    margin-top: 10px;

    background: #f1f5f9;

    border-radius: 10px;
}