:root {
  /* Light Mode Colors */
  --bg-light: #f5f5f5;
  --panel-light: #fff;
  --text-light: #222;
  --accent-light: #007bff;
  --border-light: rgba(0,0,0,0.1);

  /* Dark Mode Colors */
  --bg-dark: #1a1a1a;
  --panel-dark: #2b2b2b;
  --text-dark: #e0e0e0;
  --accent-dark: #4f9aff;
  --border-dark: #444;

  --radius: 10px;
  --shadow: rgba(0,0,0,0.05);
}

/* Base Styles */
body {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  margin: 0;
  padding: 2rem;
  font-family: 'Segoe UI', Arial, sans-serif;
  background-color: var(--bg-light);
  color: var(--text-light);
  transition: background 0.3s, color 0.3s;
}

.wrapper {
  width: 100%;
  max-width: 900px;
  padding: 24px;
  border-radius: var(--radius);
  background-color: var(--panel-light);
  box-shadow: 0 6px 20px var(--shadow);
  display: flex;
  flex-direction: column;
  align-items: center;
  transition: background 0.3s, box-shadow 0.3s;
}

h1 {
  text-align: center;
  margin-bottom: 24px;
  color: var(--accent-light);
  transition: color 0.3s;
}

textarea {
  width: 100%;
  min-height: 120px;
  padding: 12px;
  font-size: 14px;
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
  background: var(--panel-light);
  color: var(--text-light);
  outline: none;
  resize: vertical;
  transition: background 0.3s, color 0.3s, border-color 0.3s;
}

textarea:focus {
  border-color: var(--accent-light);
  box-shadow: 0 0 10px rgba(0,123,255,0.4);
}

button, .copy-btn {
  padding: 10px 14px;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  background: var(--accent-light);
  color: #fff;
  font-weight: 700;
  margin-top: 12px;
  transition: 0.25s ease, transform 0.15s ease, background 0.25s;
}

button:hover, .copy-btn:hover {
  background: #339aff;
  transform: translateY(-2px);
}

.result-line {
  width: 100%;
  background: var(--panel-light);
  color: var(--text-light);
  font-weight: 600;
  padding: 10px 12px;
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 10px;
  font-family: monospace;
  transition: background 0.3s, color 0.3s, border-color 0.3s;
}

/* Dark Mode Active */
body.dark-mode {
  background-color: var(--bg-dark);
  color: var(--text-dark);
}

body.dark-mode .wrapper {
  background-color: var(--panel-dark);
  box-shadow: 0 6px 20px rgba(0,0,0,0.5);
}

body.dark-mode h1 {
  color: var(--accent-dark);
}

body.dark-mode textarea {
  background-color: var(--panel-dark);
  color: var(--text-dark);
  border-color: var(--border-dark);
}

body.dark-mode textarea:focus {
  border-color: var(--accent-dark);
  box-shadow: 0 0 10px rgba(79,154,255,0.4);
}

body.dark-mode button, body.dark-mode .copy-btn {
  background: var(--accent-dark);
}

body.dark-mode button:hover, body.dark-mode .copy-btn:hover {
  background: #1e70ff;
}

/* Responsive */
@media (max-width: 600px) {
  textarea {
    font-size: 13px;
  }
  button, .copy-btn {
    width: 100%;
  }
}