.side-nav {
  position: fixed;
  top: 0;
  left: calc(var(--menu-width) * -1);
  width: var(--menu-width);
  height: 100vh;
  background: var(--menu-bg);
  z-index: 2500;
  transition: transform var(--transition-speed);
  padding-top: 80px;
}

body.menu-open .side-nav {
  transform: translateX(var(--menu-width));
}

.nav-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.nav-item a {
  display: block;
  padding: 15px 40px;
  color: #fff;
  text-decoration: none;
  font-size: 0.95rem;
  letter-spacing: 0.2em;
  transition: 0.3s;
  opacity: 0;
  transform: translateX(-20px);
}

body.menu-open .nav-item a {
  opacity: 1;
  transform: translateX(0);
  transition-delay: 0.2s;
}

.nav-item a:hover {
  background: rgba(255, 255, 255, 0.05);
  transform: translateX(35px);
  padding-left: 50px;
}

.menu-btn {
  position: fixed;
  top: 25px;
  left: 25px;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 3000;
  cursor: pointer;
  border-radius: 50%;
  transition: 0.3s;
}

.hamburger {
  width: 18px;
  height: 12px;
  position: relative;
}

.hamburger span {
  display: block;
  position: absolute;
  width: 100%;
  height: 2px;
  background: #fff;
  transition: 0.3s;
}

.hamburger span:nth-child(1) { top: 0; }
.hamburger span:nth-child(2) { top: 5px; }
.hamburger span:nth-child(3) { top: 10px; }

.menu-btn.open span:nth-child(1) { transform: translateY(5px) rotate(45deg); }
.menu-btn.open span:nth-child(2) { opacity: 0; }
.menu-btn.open span:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

.overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: none;
  z-index: 2000;
}

body.menu-open .overlay {
  display: block;
}