body {
  font-family: Arial, sans-serif;
  background: #f5f7fa;
  margin: 0;
  padding: 20px;
}

.container {
  max-width: 720px;
  margin: auto;
  background: #ffffff;
  padding: 30px;
  border-radius: 12px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.08);
}

h1 {
  margin-top: 0;
  font-size: 28px;
  color: #111;
}

p {
  color: #555;
}

.mode-buttons {
  display: flex;
  gap: 12px;
  margin: 20px 0;
}

.mode-btn {
  flex: 1;
  padding: 14px;
  font-size: 16px;
  border-radius: 8px;
  border: 1px solid #dcdfe4;
  background: #f3f6f9;
  color: #111;
  cursor: pointer;
  transition: all 0.2s ease;
}

.mode-btn.active {
  background: #1a73e8;
  color: #ffffff;
  border-color: #1a73e8;
  font-weight: bold;
}

.inputs {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 20px;
}

input,
select,
button.calculate {
  padding: 12px;
  font-size: 16px;
  border-radius: 8px;
  border: 1px solid #dcdfe4;
}

button.calculate {
  display: flex;
  flex-direction: column;
  background: #1a73e8;
  width: 100%;
  color: #ffffff;
  border: none;
  cursor: pointer;
  margin-top: 30px;
}

button.calculate:hover {
  background: #155ec2;
}

.result {
  margin-top: 20px;
  font-size: 22px;
  font-weight: bold;
  color: #111;
}

footer {
  margin-top: 40px;
  text-align: center;
  font-size: 14px;
}

footer a {
  color: #1a73e8;
  text-decoration: none;
  margin: 0 6px;
}

/* =========================
   Google AdSense Containers
   ========================= */
.adsense {
  margin: 25px 0;
  min-height: 90px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.ad-top,
.ad-middle,
.ad-bottom {
  width: 100%;
}