body {
  background: #bfe5e8;
  font-family: "Poppins", "Arial", sans-serif;
}

.splitter-app {
  max-width: 700px;
  margin: 40px auto;
  text-align: center;
}

h1 {
  font-size: 2em;
  color: #235e5d;
  letter-spacing: 0.2em;
}

.splitter-card {
  display: flex;
  background: #fff;
  border-radius: 20px;
  box-shadow: 0 8px 30px rgba(32, 61, 74, 0.08);
  overflow: hidden;
  margin-top: 20px;
}

.left-panel,
.right-panel {
  flex: 1;
  padding: 30px;
}

.left-panel {
  background: #fff;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.tip-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
}

.tip-btn {
  background: #235e5d;
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 12px 24px;
  font-size: 1em;
  cursor: pointer;
  transition: background 0.2s;
}

.tip-btn.active,
.tip-btn:hover {
  background: #70cfcf;
  color: #235e5d;
}

#tip-custom {
  width: 90px;
  padding: 10px;
  border: 1px solid #70cfcf;
  border-radius: 8px;
  font-size: 1em;
  outline: none;
}

input[type="number"] {
  height: 40px;
  border-radius: 8px;
  padding: 0 10px;
  border: 1px solid #70cfcf;
  font-size: 1em;
}

.right-panel {
  background: #235e5d;
  color: #bfe5e8;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  align-items: center;
  border-top-right-radius: 20px;
  border-bottom-right-radius: 20px;
}

.tip-output {
  margin: 40px 0;
}

.tip-output div {
  margin-bottom: 24px;
  font-size: 1.1em;
}

#tipAmount,
#totalAmount {
  display: block;
  font-size: 2em;
  color: #70cfcf;
  font-weight: bold;
}

#reset {
  background: #70cfcf;
  color: #235e5d;
  border: none;
  border-radius: 10px;
  font-size: 1.2em;
  padding: 14px 60px;
  cursor: pointer;
  margin-bottom: 24px;
  margin-top: 24px;
}

#reset:disabled {
  opacity: 0.5;
}

@media (max-width: 800px) {
  .splitter-card {
    flex-direction: column;
  }
  .right-panel,
  .left-panel {
    border-radius: 0 0 20px 20px;
    padding: 25px;
  }
}

@media (max-width: 480px) {
  .splitter-app {
    max-width: 98vw;
    margin: 12px;
  }
  h1 {
    font-size: 1.1em;
  }
  .splitter-card {
    border-radius: 12px;
  }
  .left-panel,
  .right-panel {
    padding: 15px;
  }
  #reset {
    padding: 12px 20px;
    font-size: 1em;
  }
}

.footer-about {
  margin-top: 32px;
  background: #235e5d;
  color: #bfe5e8;
  text-align: center;
  padding: 24px 12px;
  border-radius: 20px;
  font-size: 1.1em;
  letter-spacing: 0.05em;
  width: 98vw;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
  box-shadow: 0 4px 18px rgba(32, 61, 74, 0.07);
}

.footer-about strong {
  color: #70cfcf;
  font-size: 1.2em;
}