* {
  margin: 0;
  padding: 0;
}

body {
  background-color: #f1f2f3;

}

.container {
  box-sizing: border-box;
  max-width: 1560px;
  min-width: 1240px;
  margin: 20px auto;
  background: white;
  border-radius: 12px;
  color: #333;
  box-shadow: 0 5px 25px rgba(0, 0, 0, 0.08);
  overflow: hidden;
}

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

header {
  width: 100%;
  box-sizing: border-box;
  color: #333;
  padding-top: 30px;
  padding-bottom: 10px;
  text-align: center;
}

h1 {
  font-size: 2.2rem;
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 15px;
}

.subtitle {
  font-size: 1.1rem;
  opacity: 0.9;
  max-width: 90%;
  color: #8a8a8a;
  margin: 0 auto;
}

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

.control-panel {
  flex: 1;
  background: #f9fafb;
  border-radius: 10px;
  padding: 15px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.io-panel {
  flex: 1.5;
  display: flex;
  flex-direction: column;
  gap: 25px;
}

.panel-title {
  font-size: 1.4rem;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid #eaecef;
  color: #2c3e50;
  display: flex;
  align-items: center;
  gap: 10px;
}

.panel-title span {
  font-size: 1.6rem;
}

.form-group {
  margin-bottom: 22px;
}

.container label {
  display: block;
  margin-bottom: 8px;
  font-weight: 600;
  color: #2d3748;
  font-size: 1.05rem;
}

.container select,
.container input {
  width: 100%;
  padding: 12px 15px;
  border: 1px solid #d1d5db;
  border-radius: 8px;
  font-size: 1rem;
  background: white;
  transition: all 0.2s;
}

.container select:focus,
.container input:focus {
  outline: none;
  border-color: #6a11cb;
  box-shadow: 0 0 0 3px rgba(106, 17, 203, 0.2);
}

.form-row {
  display: flex;
  gap: 20px;
  margin-bottom: 22px;
}

.form-row .form-group {
  flex: 1;
  margin-bottom: 0;
}

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

.btn {
  flex: 1;
  padding: 14px 16px;
  border: none;
  border-radius: 8px;
  font-size: 1.05rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.btn-encrypt {
  background: linear-gradient(to right, #3498db, #2c80b9);
  color: white;
}

.btn-decrypt {
  background: linear-gradient(to right, #2ecc71, #27ae60);
  color: white;
}

.btn-copy {
  background: linear-gradient(to right, #9b59b6, #8e44ad);
  color: white;
}

.btn-clear {
  background: linear-gradient(to right, #e74c3c, #c0392b);
  color: white;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

textarea {
  width: 100%;
  min-height: 200px;
  padding: 18px;
  border: 1px solid #d1d5db;
  border-radius: 10px;
  font-size: 1.05rem;
  line-height: 1.6;
  resize: vertical;
  transition: all 0.2s;
}

textarea:focus {
  outline: none;
  border-color: #6a11cb;
  box-shadow: 0 0 0 3px rgba(106, 17, 203, 0.2);
}

.info-section {
  background: #edf2f7;
  border-radius: 10px;
  padding: 25px;
  margin-top: 25px;
}

.info-section h3 {
  font-size: 1.4rem;
  margin-bottom: 15px;
  color: #2c3e50;
  display: flex;
  align-items: center;
  gap: 10px;
}

.info-section h3 span {
  font-size: 1.5rem;
}

.info-content {
  background: white;
  border-radius: 8px;
  padding: 20px;
  font-size: 1.05rem;
  line-height: 1.7;
}

.info-content p {
  margin-bottom: 15px;
}

.info-content ul {
  padding-left: 25px;
  margin-bottom: 15px;
}

.info-content li {
  margin-bottom: 8px;
}

.warning {
  background: #fff8e1;
  border-left: 4px solid #ffc107;
  padding: 15px;
  border-radius: 0 4px 4px 0;
  margin: 20px 0;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
  margin: 20px 0;
}

.feature-card {
  background: #f8f9fa;
  border-radius: 8px;
  padding: 15px;
  text-align: center;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
  transition: transform 0.3s;
}

.feature-card:hover {
  transform: translateY(-5px);
}

.feature-icon {
  font-size: 2.5rem;
  margin-bottom: 10px;
  color: #6a11cb;
}

.feature-title {
  font-weight: 600;
  margin-bottom: 5px;
  color: #2c3e50;
}

.footer {
  text-align: center;
  padding: 25px;
  color: #718096;
  font-size: 1rem;
  border-top: 1px solid #eaecef;
}