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

body {
    background-color: #1a1a2e;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
    padding: 40px 20px;
}

.container {
    background-color: #16213e;
    border-radius: 16px;
    padding: 40px;
    width: 560px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.4);
    display: flex;
    flex-direction: column;
    gap: 24px;
}

h1 {
    color: #e94560;
    text-align: center;
    font-size: 26px;
}

.description {
    color: #a8a8b3;
    text-align: center;
    font-size: 14px;
}

.formule-principale {
    background-color: #0f3460;
    border-radius: 12px;
    padding: 20px;
    text-align: center;
    font-size: 32px;
    font-weight: bold;
    color: #e94560;
    letter-spacing: 4px;
}

.choix p {
    color: #a8a8b3;
    font-size: 14px;
    margin-bottom: 12px;
}

.boutons-choix {
    display: flex;
    gap: 12px;
}

.boutons-choix button {
    flex: 1;
    background-color: #0f3460;
    color: #ffffff;
    border: 2px solid #e94560;
    border-radius: 8px;
    padding: 14px;
    font-size: 15px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.boutons-choix button:hover,
.boutons-choix button.actif {
    background-color: #e94560;
}

.formulaire {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.input-group label {
    color: #a8a8b3;
    font-size: 14px;
}

.input-group input {
    background-color: #0f3460;
    color: #ffffff;
    border: 2px solid #e94560;
    border-radius: 8px;
    padding: 12px 16px;
    font-size: 16px;
    outline: none;
}

button {
    background-color: #e94560;
    color: white;
    border: none;
    border-radius: 8px;
    padding: 14px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.2s;
}

button:hover {
    background-color: #c73652;
}

.btn-reset {
    background-color: #444;
}

.btn-reset:hover {
    background-color: #666;
}

.resultat {
    background-color: #0f3460;
    border-radius: 12px;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    border-left: 4px solid #e94560;
}

.resultat-formule {
    color: #a8a8b3;
    font-size: 14px;
    font-style: italic;
}

.resultat-valeur {
    color: #ffffff;
    font-size: 28px;
    font-weight: bold;
}

.cache {
    display: none;
}

.erreur {
    color: #e74c3c;
    text-align: center;
    font-size: 14px;
    min-height: 20px;
}