* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: Arial, sans-serif; background: #f7f7f7; color: #333; }

header {
    background: #2d3748; color: white;
    padding: 32px 24px; text-align: center;
}
header h1 { font-size: 2rem; margin-bottom: 8px; }
header p { color: #a0aec0; }

main { max-width: 760px; margin: 40px auto; padding: 0 16px; }

.formulaire { background: white; padding: 32px; border-radius: 12px;
              box-shadow: 0 2px 8px rgba(0,0,0,.08); }
label { display: block; margin: 16px 0 4px; font-weight: bold; font-size: 14px; }
input[type=text], input[type=email], input[type=number], input[type=file] {
    width: 100%; padding: 10px; border: 1px solid #cbd5e0; border-radius: 6px;
    font-size: 15px; margin-top: 4px;
}
.reglages label { font-weight: normal; font-size: 13px; color: #555; }
.parametres { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 16px; }

.onglets { display: flex; gap: 8px; margin-bottom: 20px; }
.onglet {
    flex: 1; padding: 10px; border: 2px solid #e2e8f0; background: white;
    border-radius: 6px; cursor: pointer; font-size: 14px;
}
.onglet.actif { border-color: #e53e3e; background: #fff5f5; color: #e53e3e; font-weight: bold; }

.btn-apercu {
    width: 100%; margin-top: 24px; padding: 14px;
    background: #4a5568; color: white; border: none;
    border-radius: 8px; font-size: 16px; cursor: pointer;
}
.btn-apercu:hover { background: #2d3748; }

.bandeau-rouge {
    background: #e53e3e; color: white; padding: 12px 16px;
    border-radius: 8px; font-weight: bold; text-align: center;
    margin: 24px 0 16px;
}

#section-apercu { margin-top: 32px; background: white;
                  padding: 24px; border-radius: 12px;
                  box-shadow: 0 2px 8px rgba(0,0,0,.08); }

#img-apercu { width: 100%; border: 1px solid #e2e8f0; border-radius: 6px; margin-top: 8px; }
.info-apercu { color: #718096; font-size: 13px; margin: 12px 0 20px; text-align: center; }

.champ-email { margin-bottom: 16px; }
.btn-payer {
    width: 100%; padding: 16px; background: #e53e3e; color: white;
    border: none; border-radius: 8px; font-size: 18px;
    font-weight: bold; cursor: pointer;
}
.btn-payer:hover { background: #c53030; }

.alerte.annule {
    background: #fff3cd; border: 1px solid #ffc107;
    padding: 12px; border-radius: 6px; text-align: center;
    margin-bottom: 16px; color: #856404;
}

footer { text-align: center; padding: 40px 16px; color: #718096; font-size: 13px; }
footer a { color: #e53e3e; }

@media (max-width: 500px) {
    .parametres { grid-template-columns: 1fr; }
    header h1 { font-size: 1.5rem; }
}