body {
    margin: 0;
    background-color: #0a0a0a;
    font-family: Arial, sans-serif;
    color: #d0e6ff;
}

/* HEADER */
header {
    background-color: #001a33;
    padding: 20px;
    text-align: center;
    border-bottom: 3px solid #0066cc;
}

header h1 {
    color: #66b3ff;
    margin: 0;
}

nav a {
    color: #cce6ff;
    margin: 0 15px;
    text-decoration: none;
    font-size: 18px;
}
header h1,
header nav {
    position: relative;  /* garante que fique acima do ::before */
    z-index: 1;          /* z-index maior que o pseudo-elemento */
}

.video_topo {
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 0;
  object-position: center 20%;
}

.video_topo video {
  width: 50%;
  height: 80%;
}

nav a:hover {
    color: #66b3ff;
}

/* BACKGROUND OPACIDADE BAIXA*/
header {
    position: relative;
    background-color: #001a33; /* fundo base */
    color: #66b3ff;
    padding: 40px 20px;
    text-align: center;
    overflow: hidden; /* garante que elementos não saiam do header */
    border-bottom: 3px solid #0066cc;
}
header::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 50%;
    height: 100%;
    background-image: url('img/pitagoras-bg-2.webp'); /* WebP funciona normalmente */
    background-size: cover;
    background-position: left center;
    opacity: 0.2;
    z-index: 0;
}


/* SESSÕES */
section {
    padding: 50px 20px;
    border-bottom: 2px solid #003366;
}

h2 {
    color: #66b3ff;
    margin-bottom: 15px;
}

/* CÍRCULO */
#circle-container {
    text-align: center;
    margin-bottom: 20px;
}

canvas {
    background-color: #000000;
    border: 2px solid #004d99;
    border-radius: 50%;
}

/* BOTÕES VER MAIS */
.btn-vermais,
#external-link {
    display: inline-block;
    margin-top: 20px;
    padding: 12px 22px;
    background-color: #004d99;
    color: white;
    border: none;
    text-decoration: none;
    font-size: 16px;
    border-radius: 6px;
    cursor: pointer;
}

.btn-vermais:hover,
#external-link:hover {
    background-color: #0066cc;
}
.gif_1{
    display:flex;
    justify-content: center;
    align-items: center;     
    
}