html, body, main, header, footer {
  padding: 0px;
  margin: 0px;
}

#app {
  max-width: 720px;
  margin: 0 auto;
  padding: 24px 16px;
}

#app-title {
  text-align: center;
  font-size: 24px;
  font-weight: 700;
  color: #1a1a2e;
  margin-bottom: 28px;
}

#calculator {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.input-group label {
  font-size: 15px;
  font-weight: 600;
  color: #333;
}

.input-wrapper {
  display: flex;
  align-items: center;
  border: 2px solid #e0e0e0;
  border-radius: 10px;
  overflow: hidden;
  transition: border-color 0.2s ease;
  background: #fff;
}

.input-wrapper:focus-within {
  border-color: #4a6cf7;
}

.input-field {
  flex: 1;
  border: none;
  outline: none;
  font-size: 18px;
  padding: 14px 16px;
  min-width: 0;
  background: transparent;
  color: #1a1a2e;
}

.input-field::placeholder {
  color: #bbb;
}

.input-unit {
  padding: 14px 16px;
  font-size: 15px;
  color: #666;
  background: #f7f8fc;
  font-weight: 500;
  white-space: nowrap;
  border-left: 1px solid #e0e0e0;
}

.error-message {
  background: #fff0f0;
  color: #d32f2f;
  padding: 12px 16px;
  border-radius: 8px;
  font-size: 14px;
  border: 1px solid #ffcdd2;
}

.error-message.hidden {
  display: none;
}

#results {
  display: flex;
  gap: 16px;
  margin-top: 8px;
}

.result-card {
  flex: 1;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 14px;
  padding: 22px 18px;
  text-align: center;
  color: #fff;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

.result-card:nth-child(2) {
  background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  box-shadow: 0 4px 15px rgba(245, 87, 108, 0.3);
}

.result-card h3 {
  font-size: 14px;
  font-weight: 500;
  margin: 0 0 10px 0;
  opacity: 0.9;
}

.result-value {
  font-size: 32px;
  font-weight: 700;
  margin: 0 0 6px 0;
  line-height: 1.2;
}

.result-unit {
  font-size: 14px;
  opacity: 0.85;
  font-weight: 500;
}

#__fork {
  text-align: center;
  padding: 24px 0;
}

#__fork button {
  background: #4a6cf7;
  color: #fff;
  border: none;
  padding: 12px 32px;
  border-radius: 8px;
  font-size: 16px;
  cursor: pointer;
  transition: background 0.2s ease;
}

#__fork button:hover {
  background: #3b5de7;
}

#features {
  max-width: 720px;
  margin: 0 auto;
  padding: 8px 16px 24px;
}

#features h2 {
  font-size: 20px;
  color: #1a1a2e;
  margin-bottom: 12px;
}

#features p {
  font-size: 15px;
  line-height: 1.8;
  color: #555;
}

#scenarios {
  max-width: 720px;
  margin: 0 auto;
  padding: 8px 16px 24px;
}

#scenarios h2 {
  font-size: 20px;
  color: #1a1a2e;
  margin-bottom: 12px;
}

#scenarios ul {
  padding-left: 20px;
}

#scenarios li {
  font-size: 15px;
  line-height: 2;
  color: #555;
}

#FAQ {
  max-width: 720px;
  margin: 0 auto;
  padding: 8px 16px 40px;
}

#FAQ h2 {
  font-size: 20px;
  color: #1a1a2e;
  margin-bottom: 12px;
}

#FAQ dt {
  font-size: 16px;
  font-weight: 600;
  color: #333;
  margin-top: 16px;
}

#FAQ dd {
  font-size: 15px;
  line-height: 1.8;
  color: #555;
  margin-left: 0;
  margin-top: 6px;
}

footer {
  text-align: center;
  padding: 20px 16px;
  font-size: 13px;
  color: #999;
}

footer a {
  color: #4a6cf7;
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}

@media (max-width: 600px) {
  #app-title {
    font-size: 20px;
  }

  #results {
    flex-direction: column;
  }

  .result-value {
    font-size: 26px;
  }

  .input-field {
    font-size: 16px;
    padding: 12px 14px;
  }
}