* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

/* Le fond global de l'écran reste sombre */
body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #0f172a;
    padding: 15px;
}

/* L'image de billets est uniquement à l'intérieur de la carte */
.chat-card {
    background: linear-gradient(rgba(255, 255, 255, 0.88), rgba(255, 255, 255, 0.88)), 
                url('../images/billets-mix.jpg') no-repeat center center/cover;
    width: 100%;
    max-width: 380px;
    border-radius: 20px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
    border: 2px solid #334155;
    overflow: hidden;
    text-align: center;
    padding: 20px 15px 30px 15px;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 15px;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    margin-bottom: 25px;
}

.logo-img {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid #10b981;
    background-color: white;
}

.header-title {
    font-size: 1.2rem;
    font-weight: bold;
    color: #111827;
}

.card-body {
    display: flex;
    flex-direction: column;
    gap: 20px;
    align-items: center;
}

.welcome-box {
    background-color: rgba(255, 255, 255, 0.9);
    border: 1px solid #d1d5db;
    border-radius: 12px;
    padding: 18px;
    width: 100%;
    font-size: 1.05rem;
    font-weight: 600;
    color: #1f2937;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.instruction-text {
    font-size: 0.9rem;
    color: #374151;
    line-height: 1.4;
    font-weight: 500;
}

.start-btn {
    background-color: #10B981;
    color: white;
    border: none;
    width: 65px;
    height: 65px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.4);
    transition: transform 0.2s, background-color 0.2s;
    margin-top: 10px;
}

.start-btn:hover {
    transform: scale(1.08);
    background-color: #059669;
}

.start-btn svg {
    width: 30px;
    height: 30px;
    fill: white;
}