:root {
  --bg: #f2f6fa;
  --surface: #ffffff;
  --surface-soft: color-mix(in srgb, #ffffff 78%, transparent);
  --ink: #13202f;
  --ink-medium: #455a72;
  --ink-soft: #5f7590;
  --primary: #2f6ea8;
  --primary-light: #e6eff8;
  --border: #cfd9e4;
  --shadow-lg: 0 20px 44px rgba(16, 31, 45, 0.13);
  --panel-slide: 0;
  --panel-tail-space: 52vh;
}

body[data-theme="dark"] {
  --bg: #151515;
  --surface: #232323;
  --surface-soft: color-mix(in srgb, #232323 86%, transparent);
  --ink: #ece8e1;
  --ink-medium: #c8c1b7;
  --ink-soft: #a69f94;
  --primary: #c9a66b;
  --primary-light: #3a3022;
  --border: #3a3530;
  --shadow-lg: 0 24px 56px rgba(0, 0, 0, 0.42);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Inter", "Noto Sans JP", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.7;
  min-height: 100vh;
  padding-bottom: calc(var(--panel-tail-space) + 1.5rem);
  position: relative;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(circle at 10% 14%, color-mix(in srgb, var(--primary) 14%, transparent) 0%, transparent 34%),
    radial-gradient(circle at 86% 9%, color-mix(in srgb, var(--ink) 9%, transparent) 0%, transparent 42%),
    linear-gradient(160deg, color-mix(in srgb, var(--primary-light) 44%, transparent) 0%, transparent 38%);
}

.ambient-bg-wrap {
  position: fixed;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
  z-index: 1;
}

.ambient-bg-host {
  position: relative;
  width: 100%;
  height: 100%;
}

.ambient-bg-host::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: url("../assets/base_img.png");
  background-size: cover;
  background-position: center;
  opacity: 0.05;
  filter: saturate(0.9) brightness(0.92) blur(0.22px);
}

.ambient-bg-host.is-live::before {
  opacity: 0;
}

.ambient-bg-canvas {
  position: relative;
  z-index: 1;
  width: 100% !important;
  height: 100% !important;
  display: block;
  opacity: 0.13;
  filter: saturate(0.9) brightness(0.92) blur(0.22px);
}

.theme-toggle {
  position: fixed;
  top: 0.75rem;
  right: 0.85rem;
  z-index: 9;
  border: 1px solid color-mix(in srgb, var(--border) 86%, transparent);
  background: color-mix(in srgb, var(--surface-soft) 90%, transparent);
  color: var(--ink);
  border-radius: 999px;
  padding: 0.38rem 0.84rem;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.66rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: transform 180ms ease, border-color 180ms ease, background-color 180ms ease;
  backdrop-filter: blur(8px);
}

.theme-toggle:hover {
  transform: translateY(-1px);
  border-color: color-mix(in srgb, var(--primary) 48%, var(--border));
  background: color-mix(in srgb, var(--primary-light) 48%, var(--surface-soft));
}

main {
  position: relative;
  z-index: 2;
  width: min(980px, 94vw);
  margin: clamp(3.6rem, 6vh, 4.7rem) auto 1.3rem;
  padding: clamp(1.1rem, 2vw, 1.5rem) clamp(1rem, 2.5vw, 1.4rem) 1.2rem;
  background: color-mix(in srgb, var(--surface-soft) 48%, transparent);
  border: 1px solid color-mix(in srgb, var(--border) 86%, transparent);
  border-radius: 16px;
  box-shadow: var(--shadow-lg);
  backdrop-filter: blur(8px);
  animation: panel-in 320ms ease;
  transform: translateY(calc(var(--panel-slide) * -48px)) scale(calc(1 - (var(--panel-slide) * 0.05)));
  opacity: calc(1 - (var(--panel-slide) * 1.14));
  transition: opacity 220ms ease, transform 220ms ease;
}

@keyframes panel-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.page-kicker {
  margin: 0 0 0.15rem;
  color: var(--ink-soft);
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1 {
  margin: 0 0 0.15rem;
  font-size: clamp(1.2rem, 2vw, 1.45rem);
  font-family: "Lora", "Noto Serif JP", serif;
  letter-spacing: -0.01em;
}

.page-subtitle {
  margin: 0 0 0.9rem;
  color: var(--ink-medium);
  font-size: 0.82rem;
}

.slide-hint {
  margin: -0.45rem 0 0.85rem;
  color: var(--ink-soft);
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.68rem;
}

ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.52rem;
}

.status-text {
  margin: 0.2rem 0 0.9rem;
  color: var(--ink-medium);
  font-size: 0.78rem;
  font-family: "IBM Plex Mono", monospace;
}

.sections {
  display: grid;
  gap: 0.95rem;
}

.sections section {
  background: color-mix(in srgb, var(--surface) 30%, transparent);
  border: 1px solid color-mix(in srgb, var(--border) 78%, transparent);
  border-radius: 12px;
  padding: 0.72rem 0.72rem 0.8rem;
  backdrop-filter: blur(4px);
}

.section-title {
  margin: 0 0 0.52rem;
  font-size: 0.8rem;
  color: var(--ink-soft);
  font-family: "IBM Plex Mono", monospace;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

a.file-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.45rem;
  width: 100%;
  padding: 0.5rem 0.72rem;
  border: 1px solid color-mix(in srgb, var(--primary) 40%, var(--border));
  border-radius: 8px;
  text-decoration: none;
  color: var(--primary);
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.74rem;
  background: color-mix(in srgb, var(--surface) 22%, transparent);
  transition: transform 170ms ease, border-color 170ms ease, background-color 170ms ease;
}

a.file-link::after {
  content: "↗";
  opacity: 0.85;
}

a.file-link:hover {
  transform: translateY(-1px);
  border-color: color-mix(in srgb, var(--primary) 65%, var(--border));
  background: linear-gradient(140deg, color-mix(in srgb, var(--primary-light) 44%, transparent) 0%, color-mix(in srgb, var(--surface) 70%, transparent) 100%);
}

.footer-link {
  display: inline-block;
  margin-top: 0.95rem;
  color: var(--primary);
  text-decoration: none;
  font-size: 0.82rem;
}

.footer-link:hover {
  text-decoration: underline;
}

body.panel-hidden main {
  pointer-events: none;
}

.panel-restore {
  position: fixed;
  right: 0.9rem;
  bottom: 0.95rem;
  z-index: 10;
  border: 1px solid color-mix(in srgb, var(--primary) 58%, var(--border));
  background: color-mix(in srgb, var(--surface-soft) 84%, transparent);
  color: var(--ink);
  border-radius: 999px;
  padding: 0.45rem 0.85rem;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.68rem;
  letter-spacing: 0.03em;
  cursor: pointer;
  backdrop-filter: blur(8px);
  transform: translateY(12px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 180ms ease, transform 180ms ease;
}

body.panel-hidden .panel-restore {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

@media (max-width: 640px) {
  .theme-toggle {
    top: 0.6rem;
    right: 0.6rem;
  }

  main {
    width: min(960px, 95vw);
    margin-top: 3.2rem;
    padding: 0.95rem 0.84rem 1rem;
    border-radius: 12px;
  }
}