body {
  margin: 0;
  padding: 20px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #f5f7fa;
  color: #222;
  box-sizing: border-box;
}

.main {
  margin: 0 auto;
  max-width: 600px;
  min-height: 550px;
  background: #ffffff;
  border-radius: 16px;
  padding: 24px;
  box-sizing: border-box;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

h1 {
  text-align: center;
  font-size: 20px;
  margin: 0 0 24px;
  font-weight: 600;
}

.info {
  margin-top: 20px;
  padding: 18px;
  background: #f8f9fb;
  border-radius: 12px;
}

.info h2 {
  margin: 0 0 14px;
  font-size: 18px;
  font-weight: 600;
}

.info p {
  margin: 8px 0;
  font-size: 15px;
}

label {
  display: block;
  margin-bottom: 6px;
  font-size: 15px;
  font-weight: 600;
}

input[type="file"],
input[type="number"],
select {
  width: 100%;
  box-sizing: border-box;
  padding: 12px 14px;
  font-size: 17px;
  border: 1px solid #d5dbe1;
  border-radius: 10px;
  background: #ffffff;
  outline: none;
}

input[type="number"] {
  width: 180px;
}

#resizeDimensions {
  margin-top: 18px;
  font-size: 20px;
  font-weight: 600;
}

#estimatedSize {
  color: #666;
}

#resizeButton {
  width: 100%;
  margin-top: 20px;
  padding: 12px;
  font-size: 17px;
  font-weight: 600;
  border: none;
  border-radius: 10px;
  background: #333;
  color: #fff;
  cursor: pointer;
}

#resizeButton:active {
  transform: scale(0.85);
}