/* -------------------------------------------------
   GLOBAL RESET & BASE
   ------------------------------------------------- */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* -------------------------------------------------
   PAGE LAYOUT
   ------------------------------------------------- */
body {
    font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
    background: #f5f5f5;
    color: #333;
    line-height: 1.6;
    text-align: center;
    padding: 4rem 1rem;
}
h1 {
    font-size: 2.2rem;
    margin-bottom: 2rem;
    color: #933161;
}

/* -------------------------------------------------
   BUTTONS
   ------------------------------------------------- */
.btn-group {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1.2rem;
    margin-top: 2rem;
}
.btn {
    display: inline-block;
    padding: 0.9rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    color: #fff;
    background: linear-gradient(135deg, #933161, #c04a7f);
    border: none;
    border-radius: 0.5rem;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
    transition:
        transform 0.2s ease,
        box-shadow 0.2s ease,
        background 0.3s ease;
    cursor: pointer;
}
.btn:hover {
    background: linear-gradient(135deg, #c04a7f, #e0669b);
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.2);
}
.btn:active {
    transform: translateY(0);
    box-shadow: 0 3px 6px rgba(0, 0, 0, 0.15);
}
@media (max-width: 480px) {
    .btn {
        padding: 0.8rem 1.5rem;
        font-size: 0.9rem;
    }
}

/* -------------------------------------------------
   DEMO SECTIONS (hidden by default)
   ------------------------------------------------- */
.demo {
    display: none; /* tout est masqué au chargement */
    margin-top: 4rem;
}

/* -------------------------------------------------
   VIEWER‑4DV SPECIFIC STYLES
   ------------------------------------------------- */
.video-placeholder {
    margin: 2rem auto;
    max-width: 960px;
    width: 100%;
    aspect-ratio: 16/9; /* garde le bon ratio */
    background: #e0e0e0;
    position: relative;
}
viewer-4dv {
    width: 100%;
    height: 100%;
}