/* === Sidebar Navigation (Enhanced) === */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: 260px;
  height: 100vh;
  background: linear-gradient(180deg, #0f172a, #1e293b);
  color: #fff;
  display: flex;
  flex-direction: column;
  padding: 2rem 1.25rem;
  box-shadow: 6px 0 20px rgba(0, 0, 0, 0.4);
  z-index: 1000;
  transform: translateX(0); /* visible by default on desktop */
  transition: transform 0.3s ease-in-out;
  border-right: 1px solid rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
}

/* === Brand Section === */
.brand {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  margin-bottom: 3rem;
}

.logo {
  background: linear-gradient(135deg, #3b82f6, #60a5fa);
  color: #fff;
  border-radius: 50%;
  padding: 0.7rem 1rem;
  font-size: 1.15rem;
  font-weight: bold;
  box-shadow: 0 3px 10px rgba(0, 0, 0, 0.3);
  transition: background 0.3s ease;
}

.logo:hover {
  background: linear-gradient(135deg, #2563eb, #3b82f6);
}

.full-name {
  font-size: 1.1rem;
  font-weight: 600;
  color: #f3f4f6;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* === Navigation Links === */
.nav-links {
  list-style: none;
  padding: 0;
  margin: 0;
  flex-grow: 1;
}

.nav-links li {
  margin-bottom: 0.5rem;
}

.tab-button {
  width: 100%;
  padding: 0.85rem 1rem;
  background: none;
  border: none;
  color: #d1d5db;
  font-size: 1rem;
  text-align: left;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s ease;
  font-weight: 500;
  position: relative;
}

.tab-button:hover,
.tab-button.active {
  background: linear-gradient(135deg, #2563eb, #3b82f6);
  color: #fff;
  box-shadow: 0 0 12px rgba(59, 130, 246, 0.4);
  transform: translateX(4px);
}

.tab-button:focus-visible {
  outline: 2px solid #60a5fa;
  outline-offset: 3px;
}

/* === Hamburger Button (Desktop default hidden) === */
.hamburger {
  display: none;
}

/* === Dark Mode Support === */
body.dark-mode .sidebar {
  background: linear-gradient(180deg, #0b1120, #1e293b);
}

body.dark-mode .tab-button {
  color: #cbd5e1;
}

body.dark-mode .tab-button:hover,
body.dark-mode .tab-button.active {
  background: linear-gradient(135deg, #2563eb, #60a5fa);
  color: #fff;
}


@media (max-width: 768px) {
  #sidebar {
    transform: translateX(-100%);
  }

  #sidebar.open {
    transform: translateX(0);
  }

  .hamburger {
    display: block;
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 1101;
    background: #2563eb;
    color: #fff;
    border: none;
    padding: 0.6rem 0.8rem;
    border-radius: 6px;
    font-size: 1.6rem;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
    cursor: pointer;
  }

  body::before {
    content: '';
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(2px);
    z-index: 999;
  }

  body.sidebar-open::before {
    display: block;
  }
}