@import url("https://fonts.googleapis.com/css2?family=Space+Grotesk&family=Syne:wght@400;731&display=swap");

:root {
  --bg: #112; /* 0012b2 */
  --main: #fef; /* 36ffa4 */
  --a-bg-grad: #23d;
  --main-outlilne-width: 1.6px;
  --main-outline: solid var(--main-outlilne-width) var(--main);
  --window-frame: 36px;
  font-size: 16px;
  box-sizing: border-box;
}

::selection {
  color: #fff;
  background: #00f;
}

html {
  image-rendering: optimizeQuality;
  background: url(./oc_vert_1834_20251011023829.PNG) center/cover fixed;
  font-family: "Space Grotesk", sans-serif;
  color: var(--main);
  transition: color 0.5s;
}

body {
  margin: 0;
}

hr {
  border-color: var(--main);
}

header {
  position: fixed;
  top: calc(var(--window-frame) * 1.25 - var(--main-outlilne-width));
  left: calc(var(--window-frame) * 1 - var(--main-outlilne-width));
  height: calc(100% - (var(--window-frame) * 2.25));
  width: calc(100% - (var(--window-frame) * 2));
  outline: calc(var(--window-frame) * 4) solid var(--bg);
  border-radius: 3rem;
  pointer-events: none;
}

header > * {
  display: inline-block;
  position: absolute;
  top: calc(var(--window-frame) * -1 + var(--main-outlilne-width));
}

header > h1 {
  left: calc(var(--window-frame) * -0.8 + var(--main-outlilne-width));
  margin: 0;
}

/* chackbox */
/* https://qiita.com/McbeEringi/items/dcbf35c9aa02aeefaad0 */
#magic-box {
  pointer-events: all;
  right: calc(var(--window-frame) * -0.8 + var(--main-outlilne-width));
  font-size: 1.4rem;
}
input[type="checkbox"].toggly {
  --toggly-height: 1.4rem;
  border-radius: 100%;
  appearance: none;
  margin: 0;
  width: calc(var(--toggly-height) * 1.8);
  height: var(--toggly-height);
  vertical-align: calc(var(--toggly-height) * -0.1);
  outline: var(--main-outline);
  background: var(--bg);
}
input[type="checkbox"].toggly::before {
  border-radius: 100%;
  content: "";
  display: block;
  position: relative;
  top: 0.21em;
  left: 0.21em;
  width: calc(var(--toggly-height) - 0.42em);
  height: calc(var(--toggly-height) - 0.42em);
  background: var(--main);
  transition: 0.1s;
}
input[type="checkbox"]:checked.toggly {
  background: #5d8;
}
input[type="checkbox"]:checked.toggly::before {
  outline-color: #5d8;
  transform: translateX(calc(var(--toggly-height) * (1.8 / 2 - 0.1))); /* a half of width - outline-offset */
}
input[type="checkbox"]:hover.toggly::before {
  transform: translateX(calc(var(--toggly-height) * 0.1));
}
input[type="checkbox"]:checked:hover.toggly::before {
  transform: translateX(calc(var(--toggly-height) * (1.8 / 2 - 0.1 - 0.1)));
}

#a {
  height: 120svh;
  background: linear-gradient(var(--a-bg-grad), transparent);
}

#a1 {
  padding-top: 36svh;
  text-align: center;
}

#b {
  display: flex;
  flex-wrap: wrap;
  flex-shrink: 0;
  justify-content: space-around;
  padding: calc(var(--window-frame) + 1rem);
  padding-top: calc(var(--window-frame) * 1.25 + 1rem);
}

.b1 {
  margin-bottom: 2em;
  width: min(24em, 80%);
  padding: 1rem;
  background: var(--bg);
  box-shadow: 0 0.4em 0.4em #0094;
}

.b1-face {
  width: 100%;
  aspect-ratio: 1/1;
  background: center/cover no-repeat;
}

.b1 > h4 {
  display: inline;
  margin: 0.1rem;
  vertical-align: text-top;
  padding: 0 0.1rem;
  font-family: "Syne", "Space Grotesk", sans-serif;
  font-weight: bold;
  font-size: 0.75rem;
  outline: var(--main-outline);
  border-radius: 0.4em;
}

.b1 > h3 {
  display: inline-block;
  margin: 0.4rem 0;
  font-family: "Syne", "Space Grotesk", sans-serif;
  font-weight: bold;
  font-size: 2rem;
  line-height: 1;
}

.b1 > a {
  display: inline-block;
  margin: 0.4em 0;
  padding: 0 0.4em;
  font-weight: bold;
  color: var(--bg);
  background: var(--main);
  outline: var(--main) 4px double;
  border-radius: 1em;
}
.b1 > a:hover {
  color: var(--main);
  background: var(--bg);
}