:root {
  --accent:#333;
  --panel:#fff;
  --glass: rgba(0,0,0,0.04);
  --width-panel:320px;
  --ease: cubic-bezier(.2,.9,.3,1);
}

*{
  box-sizing: border-box
}

/* Header area */


/* Hamburger button */
.hamburger-wrap {
  position: relative;
  display: flex;
  align-items: center;
  gap: 12px
}

.hamburger {
  position: relative;
  width: 56px;
  height: 56px;
  border-radius: 14px;
  background: transparent;   /* 背景を消す */
  border: none;              /* 枠線を消す */
  display: inline-grid;
  place-items: center;
  padding: 0;
  cursor: pointer;
  outline: none;
  transition: all 250ms var(--ease);
  -webkit-tap-highlight-color: transparent;
}

.hamburger:focus {
  box-shadow: none;          /* フォーカス時の影も消す */
  transform: translateY(-2px);
}

/* bars (3 lines) */
.bars {
  position: relative;
  width: 28px;
  height: 20px
}

.bars span {
  display: block;
  position: absolute;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent);
  border-radius: 6px;
  transform-origin: center;
  transition: transform 380ms var(--ease), opacity 240ms var(--ease), top 380ms var(--ease);
}

.bars span.mid {
  top: 50%;
  transform: translateY(-50%);
}

.bars span.top {
  top: 0;
}

.bars span.bot {
  bottom: 0;
}

/* circular stroke surrounding the icon (SVG) */
.ring {
  position: absolute;
  inset: 6px;
  pointer-events: none
}

.ring svg {
  display: block;
  width: 48px;
  height: 48px;
}

.ring circle {
  fill: none;
  stroke: #ccc;
  stroke-width: 2;
}

.ring .stroke {
  stroke: var(--accent);
  stroke-width: 2.6;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-dasharray: 126;
  stroke-dashoffset: 126;
  transition: stroke-dashoffset 420ms var(--ease), transform 420ms var(--ease);
  transform-origin: center;
}

/* open state: morph bars to X */
.hamburger.open .bars span.top {
  top: 50%;
  transform: translateY(-50%) rotate(45deg);
}

.hamburger.open .bars span.bot {
  bottom: auto;
  top: 50%;
  transform: translateY(-50%) rotate(-45deg);
}

.hamburger.open .bars span.mid {
  opacity: 0;
  transform: translateY(-50%) scaleX(0.4);
}

.hamburger.open .ring .stroke {
  stroke-dashoffset: 0;
  transform: scale(1.06);
}

.hamburger.open {
  transform: translateY(-2px) scale(1.02);
}

/* sliding panel (from left) */
.overlay {
  position: fixed;
  left: 0;
  top: 0;
  height: 100vh;
  width: var(--width-panel);
  transform: translateX(-110%);
  background: #f1f2eb;
  z-index: 60;
  padding: 28px 20px;
  transition: transform 480ms var(--ease);
  border-right: 1px solid #ddd;
  color: #222;
}

.overlay.open {
  transform: translateX(0);
}

/* dimmed backdrop */
.backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  opacity: 0;
  pointer-events: none;
  transition: opacity 360ms var(--ease);
  z-index: 50;
}

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

/* menu content */
.menu-list {
  margin-top: 18px;
  padding: 8px 12px;
}

.menu-list a {
  display: block;
  padding: 12px 14px;
  border-radius: 10px;
  text-decoration: none;
  color: inherit;
  font-weight: 600;
  margin-bottom: 8px;
  transition: background 220ms var(--ease), transform 200ms var(--ease);
}

.menu-list a:hover {
  background: #f0f0f0;
  transform: translateX(6px);
}

.brand-dot {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent);
}

/* small responsiveness */
@media (max-width:560px)
{
  :root {
    --width-panel: 64vw;
  }

}