* {
  margin: 0;
  padding: 0;
}

body {
  background: #f1f2f3;
}

.container {
  box-sizing: border-box;
  width: 100%;
  max-width: 1640px;
  min-width: 1240px;
  margin: 25px auto;
  color: #333;
}

.container  *{
  box-sizing: border-box;
}

header {
  margin-bottom: 25px;
  text-align: center;
}

header h1 {
  font-size: 2.1rem;
  margin-bottom: 5px;
}


header p {
  font-size: 1rem;
  opacity: 0.9;
  max-width: 90%;
  margin: 0 auto;
  line-height: 1.6;
}

.content {
  background: #fff;
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 25px;
}

.mode-select {
  display: flex;
  align-items: center;
  margin-bottom: 20px;
}

.mode-select label {
  font-weight: 600;
  margin-right: 15px;
  font-size: 1.1rem;
}

#mode {
  padding: 8px 15px;
  border-radius: 6px;
  border: 1px solid #ddd;
  font-size: 1rem;
  min-width: 200px;
  background: white;
  cursor: pointer;
}

.input-area {
  margin-bottom: 20px;
}

.input-area textarea {
  width: 100%;
  height: 120px;
  padding: 15px;
  border: 1px solid #ddd;
  border-radius: 8px;
  font-size: 1.1rem;
  resize: vertical;
  transition: border-color 0.3s;
}

.input-area textarea:focus {
  outline: none;
  border-color: #3498db;
  box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

.input-hint {
  color: #666;
  font-size: 0.95rem;
  margin-top: 8px;
  padding-left: 5px;
}

.buttons {
  display: flex;
  gap: 20px;
  margin-bottom: 20px;
}

.buttons button {
  padding: 14px 50px;
  font-size: 1.1rem;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s;
  font-weight: 600;
}

#calculate {
  background: #2ecc71;
  color: white;
}

#calculate:hover {
  background: #27ae60;
}

#clear {
  background: #e74c3c;
  color: white;
}

#clear:hover {
  background: #c0392b;
}

.results-title {
  font-size: 1.3rem;
  margin-bottom: 20px;
  color: #2c3e50;
  display: flex;
  align-items: center;
}

.result-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.result-item {
  background: #f8f9fa;
  border-radius: 8px;
  padding: 20px;
  border-left: 4px solid #3498db;
}

.result-label {
  font-weight: 600;
  margin-bottom: 10px;
  color: #2c3e50;
  display: flex;
  align-items: center;
}

.result-value {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.value-text {
  font-size: 1.3rem;
  font-family: monospace;
  word-break: break-all;
}

.copy-btn {
  background: #3498db;
  color: white;
  border: none;
  border-radius: 6px;
  padding: 8px 15px;
  cursor: pointer;
  font-size: 1rem;
  transition: background 0.3s;
  display: flex;
  align-items: center;
  gap: 5px;
}

.copy-btn:hover {
  background: #2980b9;
}

.footer {
  background: #fff;
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 25px;
}

.footer-title {
  font-size: 1.3rem;
  margin-bottom: 20px;
}

.knowledge-list {
  width: 100%;
  margin: 0 auto;
}

.knowledge-item {
  margin-bottom: 20px;
  padding-left: 30px;
  position: relative;
  font-size: 1.1rem;
}

.knowledge-item::before {
  content: "🔹";
  position: absolute;
  left: 0;
  top: 0;
  color: #3498db;
}

footer {
  text-align: center;
  opacity: 0.8;
}