:root {
  --bg: #f9f9f9;
  --text: #222;
  --subtext: #666;
  --card: #fff;
  --border: #ddd;
  --link: #007acc;
  --shadow: rgba(0, 0, 0, 0.05);

  --dark-bg: #121212;
  --dark-text: #e0e0e0;
  --dark-subtext: #999;
  --dark-card: #1e1e1e;
  --dark-border: #333;
  --dark-link: #4fc3f7;
  --dark-shadow: rgba(255, 255, 255, 0.05);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  scroll-behavior: smooth;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--bg);
  color: var(--text);
  transition: all 0.3s ease;
}

body.dark-mode {
  background-color: var(--dark-bg);
  color: var(--dark-text);
}

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

/* Sidebar */
.sidebar {
  width: 250px;
  background-color: #222;
  color: #fff;
  padding: 20px;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
}

.sidebar h2 {
  font-size: 1.3rem;
  margin-bottom: 20px;
}

.sidebar ul {
  list-style: none;
  padding-left: 0;
}

.sidebar ul li {
  margin-bottom: 15px;
}

.sidebar ul li a {
  color: #61dafb;
  text-decoration: none;
}

.sidebar ul li a:hover {
  text-decoration: underline;
}

/* Main Content */
.main-content {
  flex: 1;
  padding: 40px;
  max-width: 900px;
}

.page-header .title-and-toggle {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 10px;
}

.page-header h1 {
  margin: 0;
  font-size: 2rem;
}

.page-header p {
  color: var(--subtext);
  margin-top: 5px;
  margin-bottom: 30px;
}

body.dark-mode .page-header p {
  color: var(--dark-subtext);
}

.gist-block {
  background-color: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  box-shadow: 0 4px 12px var(--shadow);
  padding: 20px;
  margin-bottom: 40px;
  transition: all 0.3s ease;
}

body.dark-mode .gist-block {
  background-color: var(--dark-card);
  border-color: var(--dark-border);
  box-shadow: 0 4px 12px var(--dark-shadow);
}

.gist-block h2 {
  margin-bottom: 15px;
  color: var(--link);
}

body.dark-mode .gist-block h2 {
  color: var(--dark-link);
}

/* Toggle Button */
#theme-toggle {
  background-color: #007acc;
  color: white;
  border: none;
  padding: 8px 14px;
  font-size: 0.9rem;
  border-radius: 5px;
  cursor: pointer;
  transition: background-color 0.2s ease;
}

#theme-toggle:hover {
  background-color: #005f99;
}

body.dark-mode #theme-toggle {
  background-color: #4fc3f7;
  color: #121212;
}

body.dark-mode #theme-toggle:hover {
  background-color: #29b6f6;
}

/* Footer */
footer {
  text-align: center;
  margin-top: 50px;
  color: var(--subtext);
  font-size: 0.9rem;
}

body.dark-mode footer {
  color: var(--dark-subtext);
}

footer a {
  color: var(--link);
  text-decoration: none;
}

body.dark-mode footer a {
  color: var(--dark-link);
}

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

  .sidebar {
    width: 100%;
    height: auto;
    position: relative;
  }

  .main-content {
    padding: 20px;
  }

  .page-header .title-and-toggle {
    flex-direction: column;
    align-items: flex-start;
  }
}

.fade-transition {
  transition: background-color 0.4s ease, color 0.4s ease;
}

/* Search Input in Sidebar */
#search-gist {
  width: 100%;
  padding: 8px 10px;
  margin-bottom: 15px;
  font-size: 0.95rem;
  border: none;
  border-radius: 5px;
  outline: none;
  background-color: #fff;
  color: #000;
}

.sidebar input::placeholder {
  color: #777;
}

body.dark-mode #search-gist {
  background-color: #2a2a2a;
  color: #fff;
}

body.dark-mode .sidebar input::placeholder {
  color: #aaa;
}