* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Tahoma, Verdana, sans-serif;
  background: #74c5ff;
  overflow: hidden;
}

.top-bar {
  position: relative;
  z-index: 10;
  height: 66px;
  margin: 20px;
  border-radius: 24px;
  background: linear-gradient(#ffffff, #d8efff);
  box-shadow: 0 5px 14px rgba(0, 0, 0, 0.25);
  display: flex;
  align-items: center;
  justify-content: center;
}

.top-bar h1 {
  margin: 0;
  color: #0757a8;
  font-size: 36px;
  font-weight: bold;
  text-shadow: 1px 1px 0 #ffffff;
}

.nav-icons {
  position: absolute;
  left: 24px;
  display: flex;
  gap: 18px;
}

.nav-icons button {
  border: 0;
  background: transparent;
  font-size: 24px;
  cursor: pointer;
  padding: 4px;
}

.sky {
  position: relative;
  height: calc(100vh - 86px);
  overflow: hidden;
  background: linear-gradient(#74c5ff 0%, #dff5ff 72%, #ffffff 100%);
}

.cloud-area {
  position: relative;
  z-index: 5;
  height: 55vh;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 220px;
  padding-top: 70px;
}

.cloud-link {
  position: relative;
  width: 390px;
  height: 180px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  background: #ffffff;
  border-radius: 90px;
  box-shadow: 0 18px 30px rgba(0, 80, 140, 0.22);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.cloud-link::before {
  content: "";
  position: absolute;
  width: 175px;
  height: 175px;
  left: 115px;
  top: -85px;
  background: #ffffff;
  border-radius: 50%;
  box-shadow:
    -72px 42px 0 6px #ffffff,
    74px 35px 0 10px #ffffff;
  z-index: -1;
}

.cloud-link span {
  color: #0757a8;
  font-size: 48px;
  font-weight: bold;
  transform: translateY(-26px);
}

.cloud-link:hover {
  transform: translateY(-6px) scale(1.03);
  box-shadow: 0 24px 36px rgba(0, 80, 140, 0.3);
}

.hills {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 42vh;
  z-index: 2;
}

.hill {
  position: absolute;
  border-radius: 50% 50% 0 0;
}

.hill-back {
  left: -5%;
  bottom: 80px;
  width: 110%;
  height: 260px;
  background: #7bd957;
}

.hill-front {
  left: -10%;
  bottom: -80px;
  width: 120%;
  height: 330px;
  background: linear-gradient(#5fbe3a, #3f9f2f);
}

.welcome-box {
  position: absolute;
  z-index: 4;
  left: 50%;
  bottom: 34px;
  transform: translateX(-50%);
  width: min(900px, calc(100% - 80px));
  padding: 24px 32px;
  border-radius: 30px;
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.22);
  text-align: center;
  color: #17405f;
}

.welcome-box h2 {
  margin: 0 0 8px;
  color: #0757a8;
  font-size: 28px;
  text-shadow: 1px 1px 0 white;
}

.welcome-box p {
  margin: 0;
  font-size: 18px;
}

@media (max-width: 900px) {
  .cloud-area {
    gap: 80px;
  }

  .cloud-link {
    width: 310px;
    height: 150px;
  }

  .cloud-link span {
    font-size: 38px;
  }
}

@media (max-width: 700px) {
  body {
    overflow: auto;
  }

  .sky {
    min-height: 900px;
  }

  .cloud-area {
    flex-direction: column;
    gap: 120px;
    height: auto;
    padding-top: 150px;
  }

  .top-bar h1 {
    font-size: 28px;
  }

  .nav-icons {
    left: 16px;
    gap: 12px;
  }
}