* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body, html {
  height: 100%;
  background-color: #DDE6ED;
}

.container {
  display: flex;
  height: 100vh;
}

.sidebar {
  width: 220px;
  background-color: #27374D;
  color: white;
  padding: 20px;
}

.sidebar h2 {
  margin-bottom: 20px;
  font-size: 20px;
}

.sidebar ul {
  list-style: none;
}

.sidebar li {
  padding: 12px;
  cursor: pointer;
  border-radius: 6px;
  transition: background 0.3s ease;
}

.sidebar li:hover,
.sidebar li.active {
  background-color: #526D82;
}

.main {
  flex: 1;
  background-color: #DDE6ED;
  padding: 20px;
  overflow-y: auto;
}

.tool-section {
  display: flex;
  flex-direction: column;
  gap: 15px;
}

.tool-header,
.tool-footer {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.tool-body {
  display: flex;
  gap: 10px;
  flex-direction: row;
  height: auto;
}

textarea {
  flex: 1;
  padding: 12px;
  font-size: 14px;
  border: 1px solid #9DB2BF;
  resize: none;
  border-radius: 6px;
  background-color: white;
  transition: height 0.2s ease;
  overflow-y: hidden;
  min-height: 100px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

.btn {
  padding: 10px 18px;
  background-color: #526D82;
  border: none;
  color: white;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.3s, box-shadow 0.3s;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.btn:hover {
  background-color: #3f556b;
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.hidden {
  display: none;
}

/* Responsive */
@media (max-width: 768px) {
  .container {
    flex-direction: column;
  }

  .sidebar {
    width: 100%;
    display: flex;
    justify-content: center;
  }

  .tool-body {
    flex-direction: column;
  }
}

.welcome-banner {
  background-color: #27374D;
  color: #DDE6ED;
  padding: 15px 25px;
  text-align: center;
  font-size: 16px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
  border-bottom: 1px solid #526D82;
}

.welcome-banner strong {
  color: #9DB2BF;
}

.tool-footer {
  position: sticky;
  bottom: 0;
  background-color: #DDE6ED;
  padding: 12px;
  border-top: 1px solid #ccc;
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  z-index: 10;
}

.tool-body {
  padding-bottom: 80px;
}