:root {
  --nav-width: 300px;
  --color-primary: #172e59;
  --color-accent: #626be5;
  --color-danger: #ed3242;
  --color-border: #e7e9f0;
  --color-white: #fff;
  --hamburger-size: 60px;
  --transition-speed: 0.4s;
  --z-index-menu: 100;
  /* ヘッダーは最前面に */
}

html {
  scrollbar-gutter: stable;
}

/* 古いブラウザ用フォールバック */
@supports not (scrollbar-gutter: stable) {
  html {
    overflow-y: scroll;
  }
}

a {
  font-family: sans-serif;
  text-decoration: none;
  color: inherit;
}

/* ==========================================================================
   Hamburger Button
   ========================================================================== */
.hamburger {
  display: block;
  position: fixed;
  top: 10px;
  right: 10px;
  width: var(--hamburger-size);
  height: var(--hamburger-size);
  z-index: calc(var(--z-index-menu) + 10);
  border: none;
  border-radius: 2px;
  background-color: var(--color-white);
  cursor: pointer;
}

/* ----------------------------------------------------
   1. 上下の線を担当するエリア (回転させない)
   ---------------------------------------------------- */
.hamburger__line {
  display: block;
  position: absolute;
  top: 23px;
  left: 50%;
  transform: translateX(-50%);
  width: 24px;
  height: 2px;
  background-color: transparent;
  transition: var(--transition-speed);
}

/* 上の線 */
.hamburger__line::before {
  content: "";
  display: block;
  position: absolute;
  top: -7px;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: var(--color-primary);
  transition: inherit;
}

/* 下の線 */
.hamburger__line::after {
  content: "";
  display: block;
  position: absolute;
  top: 7px;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: var(--color-primary);
  transition: inherit;
}

/* ----------------------------------------------------
   2. 真ん中の線 & ×印を担当するエリア (回転する)
   ---------------------------------------------------- */
.hamburger__cross {
  display: block;
  position: absolute;
  top: 23px;
  left: 50%;
  transform: translateX(-50%);
  width: 24px;
  height: 2px;
  background-color: var(--color-primary);
  transition: var(--transition-speed);
}

.hamburger__cross::before {
  content: "";
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: var(--color-primary);
  transition: inherit;
  transform: rotate(0deg);
  opacity: 0;
}

/* ----------------------------------------------------
   3. Active State (クリック時の動き)
   ---------------------------------------------------- */

.hamburger.-active .hamburger__line::before {
  top: -14px;
  opacity: 0;
}

.hamburger.-active .hamburger__line::after {
  top: 14px;
  opacity: 0;
}

.hamburger.-active .hamburger__cross {
  transform: translateX(-50%) rotate(135deg);
}

.hamburger.-active .hamburger__cross::before {
  opacity: 1;
  transform: rotate(90deg);
}


.hamburger__text {
  position: absolute;
  bottom: 8px;
  left: 50%;
  transform: translateX(-50%);
  width: 100%;
}

.hamburger__text::before {
  content: "MENU";
  display: block;
  text-align: center;
  color: var(--color-primary);
  font-size: 10px;
  font-weight: 900;
}

.hamburger.-active .hamburger__text::before {
  content: "BACK";
}

/* ==========================================================================
   Navigation Area
   ========================================================================== */

.header__nav-area {
  position: fixed;
  top: 0;
  right: -100%;
  z-index: var(--z-index-menu);
  height: 100vh;
  width: var(--nav-width);
  visibility: hidden;
  padding-top: var(--hamburger-size);
  background-color: var(--color-white);
  transition: var(--transition-speed);
  box-shadow: -2px 0 10px rgba(0, 0, 0, 0.1);
}

.header__nav-area.-active {
  right: 0;
  visibility: visible;
}

.global-navigation {
  display: flex;
  padding: 40px 25px 120px;
  height: 100%;
  min-height: 100vh;
  flex-direction: column;
  padding-bottom: 2rem;
  overflow-y: auto;
  box-sizing: border-box;
}

.global-navigation__list>li {
  padding-bottom: 0;
}

.global-navigation__list>li+li {
  margin-top: 0;
}

.global-navigation__link {
  /* --- レイアウトとサイズ --- */
  display: flex;
  align-items: center;
  justify-content: space-between;

  width: 100%;
  box-sizing: border-box;
  padding: 18px 10px;

  color: var(--color-accent);
  font-weight: 900;
  font-size: 0.875rem;
  background-color: transparent;

  border: none;
  border-bottom: 3px solid var(--color-border);
  /* border-radius: 4px; */

  appearance: none;
  -webkit-appearance: none;
  cursor: pointer;
  text-align: left;
  font-family: inherit;

  transition: transform 0.3s ease, background-color 0.3s ease, color 0.3s ease;
}

.global-navigation__link:hover {
  background-color: rgba(23, 46, 89, 0.05);
}

.global-navigation__footer {
  margin-top: auto;
  text-align: center;
  padding: 40px 0;
  color: #333;
}

.nav-footer-logo img {
  max-width: 100px;
  height: auto;
  margin-bottom: 10px;
}

.nav-footer-text {
  font-size: 0.875rem;
  font-weight: bold;
  opacity: 0.8;
  margin: 0;
}

/* ==========================================================================
   Accordion
   ========================================================================== */
.global-navigation__link.-accordion {
  position: relative;
  padding-right: 40px;
}

/* Plus/Minus Icon */
.global-navigation__link.-accordion::before,
.global-navigation__link.-accordion::after {
  content: "";
  display: block;
  position: absolute;
  top: 50%;
  background-color: var(--color-danger);
  transform: translateY(-50%);
  transition: transform var(--transition-speed);
}

/* Horizontal Line */
.global-navigation__link.-accordion::before {
  right: 15px;
  width: 16px;
  height: 4px;
}

/* Vertical Line */
.global-navigation__link.-accordion::after {
  right: 21px;
  width: 4px;
  height: 16px;
}

.global-navigation__link.-active::after {
  transform: translateY(-50%) rotate(-270deg);
}

.accordion {
  height: 0;
  overflow: hidden;
  visibility: hidden;
  transition: var(--transition-speed);
  opacity: 0;
}

.accordion.-active {
  height: auto;
  padding-top: 2x;
  visibility: visible;
  opacity: 1;
}

.accordion__list li {
  font-size: 0.75rem;
}

.accordion__list li+li {
  margin-top: 1px;
  margin-bottom: 1px;
}

.accordion__link {
  color: var(--color-primary);
  display: block;
  padding: 13px 10px;
  transition: transform 0.3s ease, background-color 0.3s ease, color 0.3s ease;
  border-radius: 2px;
}

.accordion__link:hover {
  background-color: rgba(23, 46, 89, 0.05);
  transform: translateX(2px);
}