/* Root is Focus */
:root {
  --primary: red;
  --transition: 0.3s ease;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

.header {
  background: #fff;
  border-bottom: 1px solid #ddd;
  position: relative;
}

/* ===== Hamburger Button ===== */
.hamburger {
  display: flex;
  flex-direction: column;
  gap: 6px;
  width: 44px;
  height: 44px;
  padding: 10px;       /* center lines of burger*/
  background: none;
  border: 2px solid white;
  border-radius: 4px;
  cursor: pointer;
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 1001;
}
.hamburger:focus-visible {
  outline: 3px solid var(--primary);
  outline-offset: 2px;
}

.hamburger__line {
  width: 20px;
  height: 3px;
  background: white;
  transition: all var(--transition);
  border-radius: 2px;
}

/* Hamburger animation → X */
.hamburger[aria-expanded="true"] .hamburger__line:nth-child(1) {
  transform: rotate(45deg) translateY(11px);
  margin-left: 7px;
}
.hamburger[aria-expanded="true"] .hamburger__line:nth-child(2) {
  opacity: 0;
}
.hamburger[aria-expanded="true"] .hamburger__line:nth-child(3) {
  transform: rotate(-45deg) translateY(-11px);
  margin-left: 7px; 
}

/* ===== Off-Screen Navigation ===== */
.nav-menu {
  position: fixed;
  display: none;
  top: 0;
  left: 0;
  width: 280px;
  height: 100vh;
  background: #fff;
  box-shadow: 2px 0 10px rgba(0, 0, 0, 0.2);
  transform: translateX(-100%);
  transition: transform var(--transition);
  z-index: 1000;
  overflow-y: auto;
  padding-top: 80px;
}

.nav-menu[aria-hidden="false"] {
  transform: translateX(0);
}

.nav-menu__list {
  list-style: none;
}

.nav-menu__link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 16px 20px;
  background: none;
  border: none;
  border-bottom: 1px solid #eee;
  font-size: 16px;
  color: #333;
  text-decoration: none;
  cursor: pointer;
  font-family: inherit;
  transition: background var(--transition);
}

.nav-menu__link:hover,
.nav-menu__link:focus-visible {
  background: #f5f5f5;
  outline: none;
}

.nav-menu__link:focus-visible {
  outline: 3px solid var(--primary);
  outline-offset: -3px;
}

/* ===== Dropdown Menu ===== */
.nav-menu__dropdown {
  list-style: none;
  background: #f9f9f9;
  border-left: 4px solid var(--primary);
}

.nav-menu__dropdown .nav-menu__link {
  padding-left: 40px;
  font-size: 14px;
  color: #555;
}

.nav-menu__icon {
  font-size: 12px;
  transition: transform var(--transition);
}

.nav-menu__dropdown-btn[aria-expanded="true"] .nav-menu__icon {
  transform: rotate(180deg);
}

/* ===== Backdrop ===== */
.nav-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 999;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition);
}

.nav-backdrop.active {
  opacity: 1;
  pointer-events: auto;
}

/* ===== Desktop: Inline Navigation ===== */
@media (min-width: 768px) {
  .hamburger {
    display: none;
  }

  .nav-menu {
    position: static;
    width: 100%;
    height: auto;
    background: transparent;
    box-shadow: none;
    transform: none;
    padding-top: 0;
  }

  .nav-menu[aria-hidden="true"] {
    display: block;
  }

  .nav-menu__list {
    display: flex;
  }

  .nav-menu__link {
    padding: 12px 20px;
    border-bottom: none;
    border-right: 1px solid #ddd;
  }

  .nav-menu__dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    background: #fff;
    border: 1px solid #ddd;
    border-left: 4px solid var(--primary);
    display: none;
    min-width: 150px;
  }

  .nav-menu__dropdown-btn[aria-expanded="true"] + .nav-menu__dropdown {
    display: block;
  }

  .nav-backdrop {
    display: none;
  }
}

main {
	background-color: green;
	width: 100%;
	overflow: hidden;
    padding: 40px;
}