Inline Form

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Leftover Elements</title>

  <link rel="stylesheet" href="./styles.css">
</head>
<body>
  <div class="wrapper">
    <form class="form">
      <input class="destiny" type="text" placeholder="Where do you want to go?">

      <label for="from"><span>From</span></label>
      <input type="date" name="from">

      <label for="to"><span>To</span></label>
      <input type="date" name="to">

      <select class="guest-select" name="guest-select">
        <option value="1">1 Guest</option>
        <option value="2">2 Guest</option>
        <option value="3">3 Guest</option>
        <option value="4">4 Guest</option>
        <option value="5">5 Guest</option>
      </select>

      <input class="submit-button" type="submit" value="Search">
    </form>
  </div>
</body>
</html>

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

body {
  height: 100vh;
  display: flex;
  background: #5D6627;
}

.wrapper {
  width: 90%;
  height: 100%;
  margin: auto;
  display: flex;
  justify-content: center;
  align-items: center;
}

.form {
  width: 90%;
  height: 100px;
  padding: 20px;
  display: flex;
  background: rgba(0,0,0,.3);
}

.form > * {
  flex: 1;
  border-right: 1px solid rgba(0,0,0,.1);
  background: #fff;
}

.form > *:last-child {
  border-right: 0;
}

.destiny {
  flex: 2.5;
  padding: 0 10px;
  font-size: 16px;
  border-radius: 5px 0 0 5px;
}

.form label {
  flex: 0.5;
  display: flex;
  justify-content: center;
  align-items: center;
}

input {
  border: none;
}

input[type="date"] {
  padding: 0 5px;
}

.guest-select {
  padding: 0 5px;
  border: none;
  -webkit-appearance: none;
  -webkit-border-radius: 0px;
}

.submit-button {
  background: #88C0FF;
  border-radius: 0 5px 5px 0;
}