body {
      margin: 0;
      min-height: 100vh;
      display: grid;
      place-items: center;
      background: linear-gradient(135deg, #dbe8ff, #eff5ff);
      font-family: Manrope, sans-serif;
    }
    form {
      width: min(430px, calc(100% - 24px));
      background: #fff;
      border-radius: 16px;
      border: 1px solid #d5e3fb;
      padding: 22px;
      box-shadow: 0 16px 36px rgba(22,61,126,.13);
    }
    h1 { margin: 0 0 14px; color: #1f4ea3; font-size: 22px; }
    input {
      width: 100%;
      padding: 10px 12px;
      margin-bottom: 10px;
      border: 1px solid #c8daf8;
      border-radius: 10px;
      font-size: 14px;
      box-sizing: border-box;
    }
    button {
      width: 100%;
      padding: 10px;
      border: 0;
      border-radius: 10px;
      color: #fff;
      font-weight: 700;
      background: linear-gradient(130deg, #1f4ea3, #3775de);
      cursor: pointer;
    }
    .error { color: #a02020; margin: 0 0 10px; font-size: 14px; }