* {
  margin: 0;
  padding: 0;
}

body {
  background-color: #f1f2f3;
}

.container {
  width: 100%;
  max-width: 1560px;
  min-width: 1240px;
  box-sizing: border-box;
  margin: 20px auto;
  color: #333;
}

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

header {
  text-align: center;
  margin-bottom: 20px;
}

h1 {
  font-size: 2.2rem;
  color: #2c3e50;
  margin-bottom: 5px;
}

.subtitle {
  font-size: 1rem;
  color: #7f8c8d;
  max-width: 95%;
  margin: 0 auto;
}

.main-content {
  display: flex;
  gap: 20px;
}

.input-section, .output-section {
  flex: 1;
  background: #fff;
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.03);
}

.section-title {
  font-size: 1.2rem;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
  color: #2c3e50;
}

.input-group {
  margin-bottom: 25px;
}

label {
  display: block;
  margin-bottom: 10px;
  font-weight: 500;
  font-size: 1.1rem;
  color: #34495e;
}

input[type="text"],
textarea {
  width: 100%;
  padding: 14px;
  border: 2px solid #e0e6ed;
  border-radius: 10px;
  font-size: 1.1rem;
  transition: border-color 0.3s;
}

input[type="text"]:focus,
textarea:focus {
  border-color: #3498db;
  outline: none;
  box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

.checkbox-group {
  display: flex;
  align-items: center;
  margin: 25px 0;
}

.checkbox-group label{
  margin-bottom: 0;
}

input[type="checkbox"] {
  width: 20px;
  height: 20px;
  margin-right: 12px;
  accent-color: #3498db;
}

.button-group {
  display: flex;
  gap: 15px;
  margin-top: 15px;
}

button {
  flex: 1;
  padding: 16px;
  border: none;
  border-radius: 10px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.btn-primary {
  background: linear-gradient(135deg, #3498db, #2c80d0);
  color: white;
}

.btn-secondary {
  background: linear-gradient(135deg, #2ecc71, #27ae60);
  color: white;
}

.btn-warning {
  background: linear-gradient(135deg, #e74c3c, #c0392b);
  color: white;
}

.btn-neutral {
  background: linear-gradient(135deg, #95a5a6, #7f8c8d);
  color: white;
}

button:hover {
  transform: translateY(-3px);
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

button:active {
  transform: translateY(0);
}

.sup-phone {
  vertical-align: super;
  font-size: 0.7em;
}

.sub-phone {
  vertical-align: sub;
  font-size: 0.7em;
}

.tel-symbol {
  margin-right: 3px;
}

.result-textarea {
  width: 100%;
  height: 310px;
  resize: none;
  font-size: 1.1rem;
}

.instructions {
  background: #fff;
  border-radius: 12px;
  padding: 20px;
  margin-top: 25px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.03);
}

.instructions h2 {
  font-size: 1.8rem;
  margin-bottom: 20px;
  color: #2c3e50;
  text-align: center;
}

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

.instruction-item {
  background: white;
  border-radius: 10px;
  padding: 20px;
  box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
  border: 1px solid #eee;
}

.instruction-item h3 {
  font-size: 1.3rem;
  margin-bottom: 12px;
  color: #3498db;
  display: flex;
  align-items: center;
  gap: 10px;
}

.instruction-item p {
  line-height: 1.7;
  color: #34495e;
}

footer {
  text-align: center;
  color: #7f8c8d;
  margin-top: 25px;
  font-size: 1rem;
}