:root {
  --bg: #ffffff;
  --text: #000000;
  --gutter: 20px;
}

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

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 40px 20px;
  width: 100%;
}

/* Site header */
header.site-header {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding: var(--gutter);
  position: relative;
}

header.site-header .logo {
  grid-column: 1;
  justify-self: start;
  font-size: 1.8rem;
  font-weight: bold;
  text-decoration: none;
  color: var(--text);
}

header.site-header h1 {
  grid-column: 2;
  justify-self: center;
  font-size: 2rem;
  font-weight: bold;
  text-align: center;
}

/* Hamburger menu */
nav.menu-nav {
  position: absolute;
  top: var(--gutter);
  right: var(--gutter);
  z-index: 1001;
}

.ham-menu {
  width: 30px;
  height: 22px;
  position: relative;
  cursor: pointer;
}
.ham-menu span {
  position: absolute;
  width: 100%;
  height: 4px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}
.ham-menu span:nth-child(1) { top: 0; }
.ham-menu span:nth-child(2) { top: 9px; }
.ham-menu span:nth-child(3) { bottom: 0; }

.ham-menu.active span:nth-child(1) {
  transform: translateY(9px) rotate(45deg);
}
.ham-menu.active span:nth-child(2) { opacity: 0; }
.ham-menu.active span:nth-child(3) {
  transform: translateY(-9px) rotate(-45deg);
}

/* Side panel */
.off-screen-menu {
  position: fixed;
  top: 0;
  right: -100%;
  width: 80%;
  max-width: 450px;
  height: 100%;
  background: var(--bg);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  font-size: 2rem;
  transition: right 0.3s ease;
  z-index: 1000;
}

.off-screen-menu.active {
  right: 0;
}

.off-screen-menu ul {
  list-style: none;
}

.off-screen-menu a {
  color: var(--text);
  text-decoration: none;
  display: block;
  margin: 10px 0;
}