* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: #0a0a0a;
    background-image: 
        radial-gradient(circle at 20% 50%, rgba(255, 255, 255, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(255, 255, 255, 0.03) 0%, transparent 50%);
    min-height: 100vh;
    padding: 20px;
    color: #1a1a1a;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background: #ffffff;
    border-radius: 16px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4), 0 0 0 1px rgba(255, 255, 255, 0.1);
    overflow: hidden;
    border: 1px solid rgba(0, 0, 0, 0.1);
}

.form-header {
    background: #000000;
    color: #ffffff;
    padding: 50px 30px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.form-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        linear-gradient(45deg, transparent 30%, rgba(255, 255, 255, 0.05) 50%, transparent 70%);
    pointer-events: none;
}

.form-header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
    font-weight: 700;
    letter-spacing: -0.5px;
    position: relative;
    z-index: 1;
}

.subtitle {
    font-size: 1.1em;
    opacity: 0.85;
    position: relative;
    z-index: 1;
    font-weight: 300;
}

.form-container {
    padding: 40px 30px;
}

.form-section {
    margin-bottom: 40px;
    padding-bottom: 30px;
    border-bottom: 1px solid #e5e5e5;
}

.form-section:last-of-type {
    border-bottom: none;
}

.form-section h2 {
    color: #000000;
    font-size: 1.5em;
    margin-bottom: 25px;
    padding-bottom: 12px;
    border-bottom: 2px solid #000000;
    font-weight: 700;
    letter-spacing: -0.3px;
}

.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    margin-bottom: 10px;
    color: #1a1a1a;
    font-weight: 600;
    font-size: 0.9em;
    letter-spacing: 0.3px;
    text-transform: uppercase;
}

.form-group input[type="text"],
.form-group input[type="email"],
.form-group input[type="tel"],
.form-group input[type="number"],
.form-group input[type="date"],
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 14px 16px;
    border: 2px solid #000000;
    border-radius: 4px;
    font-size: 1em;
    font-family: inherit;
    transition: all 0.2s ease;
    background-color: #ffffff;
    color: #1a1a1a;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #000000;
    background-color: #ffffff;
    box-shadow: 0 0 0 4px rgba(0, 0, 0, 0.1);
    transform: translateY(-1px);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.form-group input[type="number"] {
    -moz-appearance: textfield;
}

.form-group input[type="number"]::-webkit-outer-spin-button,
.form-group input[type="number"]::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.form-actions {
    margin-top: 40px;
    text-align: center;
}

.btn-submit {
    background: #000000;
    color: #ffffff;
    border: 2px solid #000000;
    padding: 16px 50px;
    font-size: 1.1em;
    font-weight: 700;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    text-transform: uppercase;
    letter-spacing: 2px;
    position: relative;
    overflow: hidden;
}

.btn-submit::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn-submit:hover::before {
    width: 300px;
    height: 300px;
}

.btn-submit:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.4);
    background: #1a1a1a;
}

.btn-submit:active {
    transform: translateY(0);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.btn-submit:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

/* Responsive Design */
@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    .form-header {
        padding: 30px 20px;
    }

    .form-header h1 {
        font-size: 2em;
    }

    .form-container {
        padding: 30px 20px;
    }

    .form-section h2 {
        font-size: 1.3em;
    }

    .btn-submit {
        width: 100%;
        padding: 14px 30px;
    }
}

/* Animation pour les champs requis */
.form-group input:required:invalid:not(:placeholder-shown),
.form-group select:required:invalid,
.form-group textarea:required:invalid:not(:placeholder-shown) {
    border-color: #666666;
}

.form-group input:required:valid:not(:placeholder-shown),
.form-group select:required:valid,
.form-group textarea:required:valid:not(:placeholder-shown) {
    border-color: #000000;
}

/* Style pour les placeholders */
::placeholder {
    color: #999999;
    opacity: 0.7;
    font-weight: 400;
}

:-ms-input-placeholder {
    color: #999999;
    opacity: 0.7;
}

::-ms-input-placeholder {
    color: #999999;
    opacity: 0.7;
}