/* --- VISUAL IDENTITY INSPIRED BY VALVE & STEAMOS --- */
:root {
    --bg-main: #171a21;       /* Noir d'ambiance Steam */
    --bg-card: #1b2838;       /* Bleu sombre de structure */
    --border-steam: #2a475e;  /* Bleu de délimitation */
    --text-blue: #66c0f4;     /* Bleu d'action rétroéclairé */
    --text-light: #dcdedf;    /* Gris clair Motiva */
    --text-muted: #8f98a0;    /* Gris de description */
}

body {
    margin: 0;
    padding: 0;
    font-family: 'Motiva Sans', 'Segoe UI', Tahoma, Arial, sans-serif;
    background-color: var(--bg-main);
    color: var(--text-light);
    line-height: 1.6;
}

/* --- EN-TÊTE / NAVBAR --- */
header {
    background-color: var(--bg-card);
    border-bottom: 1px solid var(--border-steam);
    padding: 15px 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    color: var(--text-blue);
    text-decoration: none;
    letter-spacing: 0.5px;
}

.logo span { color: white; }

.lang-control {
    background-color: var(--bg-main);
    color: var(--text-blue);
    border: 1px solid var(--border-steam);
    padding: 6px 12px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 13px;
    font-weight: bold;
    outline: none;
}

/* --- VUE PRINCIPALE (HERO) --- */
.hero {
    padding: 90px 5% 70px 5%;
    text-align: center;
    background: radial-gradient(circle at top, #1b2838 0%, #171a21 80%);
}

.hero h1 {
    font-size: 44px;
    color: white;
    margin-bottom: 20px;
    font-weight: 800;
}

.hero p {
    font-size: 18px;
    color: var(--text-muted);
    max-width: 720px;
    margin: 0 auto 45px auto;
}

/* --- ACTIONS PRINCIPALES (1-CLICK BOUTON) --- */
.btn-container {
    display: flex;
    justify-content: center;
    margin-bottom: 50px;
}

.btn-steam {
    display: inline-block;
    background-color: var(--text-blue);
    color: #171a21;
    font-size: 16px;
    font-weight: bold;
    padding: 14px 36px;
    border-radius: 4px;
    border: 1px solid var(--text-blue);
    text-decoration: none;
    transition: all 0.2s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.4);
    cursor: pointer;
}

.btn-steam:hover {
    background-color: white;
    border-color: white;
    box-shadow: 0 0 20px rgba(102, 192, 244, 0.6);
    transform: translateY(-1px);
}

/* --- ZONE GRILLE (FEATURES) --- */
.features {
    padding: 40px 5%;
    max-width: 1100px;
    margin: 0 auto;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
}

.card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-steam);
    padding: 25px;
    border-radius: 4px;
    transition: border-color 0.2s;
}

.card:hover {
    border-color: var(--text-blue);
}

.card h3 { color: white; margin-top: 0; font-size: 18px; }
.card p { color: var(--text-muted); font-size: 13.5px; margin-bottom: 0; }

/* --- PIED DE PAGE --- */
footer {
    background-color: #11151d;
    border-top: 1px solid var(--border-steam);
    padding: 35px 5%;
    text-align: center;
    font-size: 12px;
    color: var(--text-muted);
    margin-top: 80px;
}