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

body{
  font-family:"Segoe UI", Tahoma, sans-serif;
  min-height:100vh;
  background:linear-gradient(180deg,#d9ecff,#ffffff);
  color:#0b1d3b;
  transition:.4s;
}

body.dark{
  background:#0b1d3b;
  color:#e6f0ff;
}

header{
  position:fixed;
  top:0;
  width:100%;
  padding:15px 10%;
  background:#3399ff;
  color:#fff;
  text-align:center;
  z-index:100;
}

header span{color:#e6f0ff;}

nav{margin-top:10px;}
nav a{margin:0 10px;cursor:pointer;font-weight:600;}

.controls{
  margin-top:10px;
  display:flex;
  justify-content:center;
  gap:15px;
}

.controls select,
.controls button{
  padding:8px 14px;
  border-radius:8px;
  border:none;
  cursor:pointer;
}

main{
  padding:190px 10% 40px;
}

section{
  display:none;
  max-width:1000px;
  margin:auto;
  text-align:center;
}

section.active{display:block;}

h2{
  color:#3399ff;
  margin-bottom:20px;
  font-size:2.3rem;
}

p{line-height:1.7;font-size:1.1rem;}

.services{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(220px,1fr));
  gap:25px;
}

.card{
  background:#fff;
  padding:25px;
  border-radius:15px;
  box-shadow:0 10px 25px rgba(51,153,255,.25);
  cursor:pointer;
  transition:.3s;
}

.card:hover{transform:translateY(-6px);}

.emoji{font-size:3rem;}

.definition{
  display:none;
  margin-top:10px;
  font-size:.95rem;
  text-align:left;
}

body.dark .card{
  background:#122a52;
  color:#e6f0ff;
}

.contact-buttons a{
  background:#25D366;
  color:#fff;
  padding:12px 22px;
  border-radius:10px;
  text-decoration:none;
  font-weight:600;
}

footer{
  text-align:center;
  padding:20px;
  background:#3399ff;
  color:#fff;
}

/* Modal */
.modal{
  display:none;
  position:fixed;
  inset:0;
  background:rgba(0,0,0,.6);
  justify-content:center;
  align-items:center;
}

.modal-content{
  background:#fff;
  padding:25px;
  border-radius:15px;
  width:90%;
  max-width:400px;
}

.modal-content input{
  width:100%;
  padding:10px;
  margin-bottom:10px;
  border-radius:8px;
  border:1px solid #ccc;
}

.modal-content button{
  width:100%;
  padding:12px;
  background:#25D366;
  color:#fff;
  border:none;
  border-radius:8px;
  cursor:pointer;
}