@font-face {
  font-family: "ZenzaiItacha";
  src: url("../fonts/ZenzaiItacha-vElZ.ttf") format("truetype");
  font-weight: normal;
  font-style: normal;
}
:root {
  --bg-paper: #ffffff;
  --bg-cream: #fbfbf8;
  --ink: #0b1220;
  --accent: #e23b3b;
  --muted: #58606a;
  --white: #ffffff;
  --radius: 12px;
  --paper-grain: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="6" height="6"><circle cx="1.5" cy="1.5" r="0.5" fill="%23f3f3f1"/></svg>');
}

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

html,
body {
  height: 100%;
  width: 100%;
  overflow: hidden;
}

body {
  font-family:
    "Inter",
    system-ui,
    -apple-system,
    "Segoe UI",
    Roboto,
    "Noto Sans JP",
    sans-serif;
  background: linear-gradient(180deg, var(--bg-paper) 0%, var(--bg-cream) 100%);
  color: var(--ink);
  line-height: 1.5;
  position: relative;
  user-select: none;
}

html,
body,
* {
  cursor: none !important;
}

.cursor,
.cursor-dot {
  position: fixed;
  pointer-events: none;
  z-index: 9999;
  transform: translate(-50%, -50%);
  will-change: transform, width, height, opacity;
}

.cursor {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: #ffffff;
  mix-blend-mode: difference;
  transition:
    width 160ms cubic-bezier(0.2, 0.9, 0.2, 1),
    height 160ms cubic-bezier(0.2, 0.9, 0.2, 1),
    transform 220ms cubic-bezier(0.2, 0.9, 0.2, 1);
}

.cursor-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #ffffff;
  mix-blend-mode: difference;
}

.cursor.hover {
  width: 30px;
  height: 30px;
}

.theme-toggle {
  position: relative;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: none;
  background: rgba(0, 0, 0, 0.06);
  font-size: 18px;
  cursor: pointer;
}

body.invert {
  background: #000;
}

body.invert::before {
  display: none;
}

body.invert .app {
  filter: invert(1) hue-rotate(180deg);
}

body.invert .cursor,
body.invert .cursor-dot {
  mix-blend-mode: difference;
  background: #ffffff;
}

body.invert .cursor.hover {
  mix-blend-mode: normal;
  background: #ffffff;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image:
    radial-gradient(circle at 8% 12%, rgba(0, 0, 0, 0.015), transparent 6%),
    radial-gradient(circle at 88% 88%, rgba(0, 0, 0, 0.01), transparent 6%),
    var(--paper-grain);
  background-repeat: repeat;
  opacity: 0.9;
  mix-blend-mode: multiply;
  pointer-events: none;
  z-index: 0;
}

.viewport {
  height: calc(100vh - 120px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
body.invert nav a:hover ~ .cursor,
body.invert .cursor.hover {
  mix-blend-mode: exclusion;
}
nav {
  height: 60px;
  display: flex;
  align-items: center;
  gap: 24px;
  justify-content: space-between;
  padding: 0 36px;
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.9),
    rgba(250, 250, 248, 0.85)
  );
  border-bottom: 1px solid rgba(3, 7, 16, 0.05);
  backdrop-filter: blur(4px);
}

nav ul {
  display: flex;
  gap: 22px;
  list-style: none;
}

nav a {
  color: var(--muted);
  text-decoration: none;
  font-weight: 600;
}
nav .logo {
  font-family: "ZenzaiItacha", sans-serif;
  font-size: 30px;
  font-weight: 700;
  margin: 0;
  line-height: 1;
  letter-spacing: 0.4px;
}

.hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 0 20px;
}

.hero h1 {
  font-size: clamp(2.2rem, 4vw, 3.2rem);
  font-weight: 800;
  margin-bottom: 10px;
  padding: 8px 14px;
}

.hero p {
  color: var(--muted);
}

.hero h1 span {
  color: var(--accent);
  font-family: "Noto Sans JP", sans-serif;
  padding: 6px 12px;
  border-radius: 10px;
  background-color: rgba(226, 59, 59, 0.12);
  background-image: radial-gradient(
    circle at 1px 1px,
    rgba(226, 59, 59, 0.35) 0.8px,
    transparent 0
  );
  background-size: 6px 6px;
}

.corner-art {
  position: fixed;
  bottom: 0;
  right: -60px;
  width: 450px;
  max-width: 40vw;
  pointer-events: none;
  user-select: none;
  z-index: 5;
}

footer {
  height: 60px;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
}

@media (max-width: 720px) {
  .cursor,
  .cursor-dot {
    display: none;
  }
  body {
    cursor: default;
  }
}