:root {
  --bg: #060606;
  --bg-secondary: #0d0d0d;
  --panel: rgba(18, 18, 18, 0.94);
  --panel-strong: rgba(11, 11, 11, 0.97);
  --soft: rgba(255, 255, 255, 0.04);
  --soft-strong: rgba(255, 255, 255, 0.08);
  --text: #f6ede2;
  --text-strong: #fff7ee;
  --muted: #b9a591;
  --line: rgba(255, 122, 0, 0.2);
  --line-strong: rgba(255, 152, 41, 0.52);
  --accent: #ff7a00;
  --accent-bright: #ffb14a;
  --accent-soft: #ff9430;
  --accent-deep: #2a1200;
  --glow: rgba(255, 122, 0, 0.22);
  --glow-strong: rgba(255, 170, 73, 0.34);
  --shadow: 0 24px 80px rgba(0, 0, 0, 0.44);
  --code-block-padding: 18px;
  --code-toolbar-offset: 12px;
  --code-toolbar-size: 36px;
  --code-line-gap: 14px;
  --code-line-number-width: 3ch;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  font-family: "Space Grotesk", "Segoe UI", sans-serif;
  background:
    radial-gradient(circle at top right, rgba(255, 134, 28, 0.17), transparent 25rem),
    radial-gradient(circle at left 15%, rgba(255, 177, 74, 0.1), transparent 26rem),
    linear-gradient(180deg, #0c0c0c 0%, #060606 48%, #090909 100%);
  color: var(--text);
}

body::before,
body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
}

body::before {
  z-index: 0;
  opacity: 0.18;
  background-image:
    linear-gradient(rgba(255, 122, 0, 0.12) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 122, 0, 0.12) 1px, transparent 1px);
  background-size: 120px 120px;
  animation: grid-float 18s linear infinite;
}

body::after {
  z-index: 0;
  opacity: 0.11;
  background: repeating-linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.02) 0,
    rgba(255, 255, 255, 0.02) 2px,
    transparent 2px,
    transparent 8px
  );
}

::selection {
  background: rgba(255, 122, 0, 0.28);
  color: var(--text-strong);
}

a,
button {
  -webkit-tap-highlight-color: transparent;
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--accent-bright);
  outline-offset: 3px;
}

.layout {
  position: relative;
  z-index: 1;
  min-height: 100vh;
}

.sidebar,
.topbar,
.content,
.toc-box {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: var(--shadow), inset 0 1px 0 rgba(255, 255, 255, 0.04);
}

.sidebar::before,
.topbar::before,
.content::before,
.toc-box::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(135deg, rgba(255, 177, 74, 0.12), transparent 24%, transparent 72%, rgba(255, 122, 0, 0.1)),
    linear-gradient(180deg, rgba(255, 255, 255, 0.02), transparent 24%);
}

.sidebar {
  background:
    linear-gradient(180deg, rgba(30, 18, 10, 0.48), transparent 22%),
    linear-gradient(180deg, var(--panel) 0%, var(--panel-strong) 100%);
  padding: 24px 18px;
  position: fixed;
  left: 0;
  top: 0;
  z-index: 30;
  width: 320px;
  max-width: 86vw;
  height: 100vh;
  overflow-y: auto;
  border-right-color: var(--line-strong);
  transform: translateX(-100%);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.sidebar.open {
  box-shadow:
    20px 0 60px rgba(0, 0, 0, 0.58),
    0 0 0 1px rgba(255, 122, 0, 0.12),
    0 0 48px rgba(255, 122, 0, 0.12);
  transform: translateX(0);
}

.sidebar-head {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 22px;
}

.sidebar-head > div {
  min-width: 0;
}

.sidebar-head > div::before {
  display: block;
  margin-bottom: 10px;
  color: var(--accent-bright);
  font-family: "Orbitron", "Space Grotesk", sans-serif;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.28em;
  text-transform: uppercase;
}

.sidebar-head > div::before {
  content: "Module Grid";
}

.icon-btn,
.menu-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0.03)),
    linear-gradient(180deg, rgba(26, 26, 26, 0.96), rgba(16, 16, 16, 0.96));
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 14px;
  cursor: pointer;
  flex: 0 0 auto;
  font-size: 1.35rem;
  line-height: 1;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05), 0 10px 26px rgba(0, 0, 0, 0.28);
  transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.icon-btn:hover,
.menu-btn:hover {
  background:
    linear-gradient(180deg, rgba(255, 177, 74, 0.18), rgba(255, 122, 0, 0.1)),
    linear-gradient(180deg, #231108, #17110c);
  border-color: var(--line-strong);
  color: var(--text-strong);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05), 0 14px 28px rgba(0, 0, 0, 0.34), 0 0 24px rgba(255, 122, 0, 0.12);
  transform: translateY(-2px);
}

.sidebar-overlay,
.toc-overlay {
  position: fixed;
  inset: 0;
  display: none;
  background: rgba(0, 0, 0, 0.72);
  border: 0;
  cursor: pointer;
  backdrop-filter: blur(4px);
}

.sidebar-overlay {
  z-index: 25;
}

.toc-overlay {
  z-index: 22;
}

.sidebar-overlay.show,
.toc-overlay.show {
  display: block;
}

.reading-progress {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 24;
  height: 3px;
  background: rgba(255, 255, 255, 0.05);
  overflow: hidden;
  pointer-events: none;
}

.reading-progress-fill {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--accent), var(--accent-bright));
  box-shadow: 0 0 18px rgba(255, 122, 0, 0.4);
  transition: width 0.22s ease;
}

.reading-progress.error {
  background: rgba(255, 106, 61, 0.14);
}

.reading-progress.loading .reading-progress-fill {
  width: 32%;
  animation: reading-progress-loading 1.2s ease-in-out infinite;
}

.reading-progress.error .reading-progress-fill {
  background: linear-gradient(90deg, #ff6a3d, var(--accent-bright));
}

body.sidebar-open,
body.toc-open {
  overflow: hidden;
}

.brand {
  font-family: "Orbitron", "Space Grotesk", sans-serif;
  font-size: 1.16rem;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-strong);
  text-shadow: 0 0 18px rgba(255, 122, 0, 0.18);
}

.subtitle {
  color: var(--muted);
  margin-top: 8px;
  margin-bottom: 0;
  font-size: 0.86rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.module-list a {
  display: block;
  position: relative;
  color: var(--text);
  text-decoration: none;
  padding: 12px 14px 12px 18px;
  border-radius: 16px;
  margin-bottom: 10px;
  background: linear-gradient(90deg, rgba(255, 255, 255, 0.025), rgba(255, 255, 255, 0.015));
  border: 1px solid transparent;
  overflow-wrap: anywhere;
  transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.module-list a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  bottom: 12px;
  width: 3px;
  border-radius: 999px;
  background: transparent;
  transition: background 0.2s ease, box-shadow 0.2s ease;
}

.module-list a:hover,
.module-list a.touch-hover,
.module-list a.active {
  background: linear-gradient(90deg, rgba(255, 122, 0, 0.16), rgba(255, 255, 255, 0.02));
  border-color: var(--line-strong);
  color: var(--text-strong);
  box-shadow: 0 14px 28px rgba(0, 0, 0, 0.24), inset 0 0 0 1px rgba(255, 177, 74, 0.08);
  transform: translateX(4px);
}

.module-list a:hover::before,
.module-list a.touch-hover::before,
.module-list a.active::before {
  background: linear-gradient(180deg, var(--accent-bright), var(--accent));
  box-shadow: 0 0 18px var(--glow-strong);
}

.main {
  padding: 28px 24px 140px;
  min-width: 0;
  width: min(1180px, 100%);
  margin: 0 auto;
}

.topbar {
  display: flex;
  gap: 18px;
  align-items: center;
  justify-content: flex-start;
  margin-bottom: 24px;
  padding: 16px 18px;
  border-radius: 20px;
  background:
    linear-gradient(180deg, rgba(32, 16, 8, 0.5), transparent 34%),
    linear-gradient(180deg, rgba(24, 24, 24, 0.94), rgba(10, 10, 10, 0.96));
  animation: panel-boot 0.55s ease both;
}

.topbar h1 {
  margin: 0;
  font-family: "Orbitron", "Space Grotesk", sans-serif;
  font-size: clamp(1.35rem, 2vw + 0.72rem, 2.2rem);
  font-weight: 800;
  letter-spacing: 0.06em;
  line-height: 1.15;
  text-transform: uppercase;
  overflow-wrap: anywhere;
  color: var(--text-strong);
  text-shadow: 0 0 24px rgba(255, 122, 0, 0.12);
  flex: 1 1 auto;
}

.topbar-actions {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  margin-left: auto;
}

.topbar-action-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 10px 14px;
  border: 1px solid rgba(255, 122, 0, 0.18);
  border-radius: 14px;
  background:
    linear-gradient(180deg, rgba(255, 177, 74, 0.1), rgba(255, 122, 0, 0.04)),
    rgba(255, 255, 255, 0.02);
  color: var(--text);
  font: inherit;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  cursor: pointer;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04);
  transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.topbar-action-btn:hover {
  background:
    linear-gradient(180deg, rgba(255, 177, 74, 0.18), rgba(255, 122, 0, 0.1)),
    rgba(255, 255, 255, 0.03);
  border-color: var(--line-strong);
  color: var(--text-strong);
  transform: translateY(-2px);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04), 0 14px 28px rgba(0, 0, 0, 0.24);
}

.topbar-action-btn[data-state="active"] {
  border-color: rgba(255, 177, 74, 0.42);
  color: var(--accent-bright);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04), 0 0 0 1px rgba(255, 177, 74, 0.08), 0 0 24px rgba(255, 122, 0, 0.12);
}

.topbar-action-icon {
  font-size: 1rem;
  line-height: 1;
}

.topbar-action-text {
  white-space: nowrap;
}

.topbar-date {
  flex: 0 0 auto;
  padding: 10px 14px;
  border-radius: 14px;
  border: 1px solid rgba(255, 122, 0, 0.18);
  background:
    linear-gradient(180deg, rgba(255, 177, 74, 0.1), rgba(255, 122, 0, 0.04)),
    rgba(255, 255, 255, 0.02);
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04);
}

.content-layout {
  display: block;
}

.site-footer {
  margin-top: 24px;
  padding: 18px 22px;
  border: 1px solid var(--line);
  border-radius: 20px;
  background:
    linear-gradient(180deg, rgba(32, 16, 8, 0.34), transparent 34%),
    linear-gradient(180deg, rgba(24, 24, 24, 0.9), rgba(10, 10, 10, 0.94));
  box-shadow: var(--shadow), inset 0 1px 0 rgba(255, 255, 255, 0.04);
  text-align: center;
  animation: panel-boot 0.82s ease both;
}

.site-footer p {
  margin: 0;
  color: var(--muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.site-footer a {
  color: var(--accent-bright);
  font-weight: 700;
  text-decoration: none;
}

.site-footer a:hover {
  color: var(--text-strong);
  text-shadow: 0 0 18px rgba(255, 122, 0, 0.18);
}

.content,
.toc-box {
  background:
    linear-gradient(180deg, rgba(32, 17, 7, 0.34), transparent 18%),
    linear-gradient(180deg, rgba(21, 21, 21, 0.96), rgba(10, 10, 10, 0.98));
  border-radius: 28px;
  min-width: 0;
  backdrop-filter: blur(16px);
}

.content {
  padding: 30px;
  line-height: 1.8;
  animation: panel-boot 0.72s ease both;
}

.content h1,
.content h2,
.content h3 {
  position: relative;
  margin-top: 1.8em;
  font-family: "Orbitron", "Space Grotesk", sans-serif;
  color: var(--text-strong);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.content h1 {
  margin-bottom: 0.8rem;
  font-size: clamp(1.55rem, 1.2vw + 1.2rem, 2.35rem);
}

.content h1:first-child {
  margin-top: 0;
}

.content h2,
.content h3 {
  padding-left: 18px;
}

.content h2::before,
.content h3::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.3em;
  width: 8px;
  height: 1em;
  border-radius: 999px;
  background: linear-gradient(180deg, var(--accent-bright), var(--accent));
  box-shadow: 0 0 18px var(--glow);
}

.content p,
.content li {
  color: #f0e2d3;
}

.content strong {
  color: var(--accent-bright);
}

.content ul,
.content ol {
  padding-left: 1.3rem;
}

.content li + li {
  margin-top: 0.38rem;
}

.content code {
  background: #17110b;
  color: var(--accent-bright);
  padding: 3px 8px;
  border: 1px solid rgba(255, 122, 0, 0.26);
  border-radius: 8px;
  font-family: "JetBrains Mono", "Fira Code", "Cascadia Code", monospace;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04);
}

.content pre {
  position: relative;
  background:
    linear-gradient(180deg, rgba(255, 122, 0, 0.06), transparent 20%),
    linear-gradient(180deg, #0c0c0c, #090909);
  color: #ffd4a6;
  padding: 18px;
  border-radius: 20px;
  overflow-x: auto;
  border: 1px solid rgba(255, 122, 0, 0.22);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.03), 0 20px 40px rgba(0, 0, 0, 0.4), 0 0 38px rgba(255, 122, 0, 0.08);
}

.content pre code {
  background: transparent;
  color: inherit;
  display: block;
  border: 0;
  padding: 0;
  font-family: "JetBrains Mono", "Fira Code", "Cascadia Code", monospace;
  font-size: 0.95rem;
  line-height: 1.7;
  white-space: pre;
}

.content pre.code-block {
  padding:
    var(--code-block-padding)
    calc(var(--code-block-padding) + var(--code-toolbar-size) + var(--code-toolbar-offset))
    var(--code-block-padding)
    var(--code-block-padding);
}

.code-block-shell {
  position: relative;
}

.copy-code-btn {
  position: absolute;
  top: var(--code-toolbar-offset);
  right: var(--code-toolbar-offset);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: var(--code-toolbar-size);
  height: var(--code-toolbar-size);
  padding: 0;
  background:
    linear-gradient(180deg, rgba(255, 177, 74, 0.14), rgba(255, 122, 0, 0.08)),
    linear-gradient(180deg, #17120d, #0f0d0a);
  color: var(--accent-bright);
  border: 1px solid rgba(255, 122, 0, 0.28);
  border-radius: 12px;
  cursor: pointer;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04), 0 10px 24px rgba(0, 0, 0, 0.2);
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.copy-code-btn:hover {
  background:
    linear-gradient(180deg, rgba(255, 177, 74, 0.2), rgba(255, 122, 0, 0.14)),
    linear-gradient(180deg, #24160d, #15100b);
  border-color: var(--line-strong);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05), 0 14px 28px rgba(0, 0, 0, 0.28), 0 0 22px rgba(255, 122, 0, 0.12);
  transform: translateY(-1px);
}

.copy-code-btn:active {
  transform: translateY(1px) scale(0.98);
}

.copy-code-btn svg {
  width: 17px;
  height: 17px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.copy-code-btn[data-copy-state="copied"] {
  background: linear-gradient(180deg, var(--accent-bright), var(--accent));
  border-color: var(--accent-bright);
  color: #120a04;
}

.copy-code-btn[data-copy-state="error"] {
  background: #2a1111;
  border-color: #7f1d1d;
  color: #fca5a5;
}

.content pre.code-block code {
  padding: 0;
  display: inline-block;
  min-width: 100%;
}

.content pre.code-block .code-line {
  display: grid;
  grid-template-columns: var(--code-line-number-width) minmax(0, 1fr);
  gap: var(--code-line-gap);
  align-items: start;
  width: max-content;
  min-width: 100%;
}

.content pre.code-block .code-line-number {
  min-width: 0;
  padding-right: 12px;
  border-right: 1px solid rgba(255, 122, 0, 0.18);
  color: rgba(255, 177, 74, 0.66);
  text-align: right;
  user-select: none;
  font-variant-numeric: tabular-nums;
}

.content pre.code-block .code-line-text {
  display: block;
  white-space: pre;
}

.content pre.code-block .code-line-text span {
  background: transparent !important;
}

.content a {
  color: var(--accent-bright);
  text-decoration-color: rgba(255, 177, 74, 0.38);
  text-underline-offset: 0.18em;
}

.content a[href^="http"] {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0.2rem 0.35rem 0.2rem 0;
  padding: 0.72rem 1rem;
  border: 1px solid rgba(255, 152, 41, 0.3);
  border-radius: 999px;
  background:
    linear-gradient(180deg, rgba(255, 177, 74, 0.18), rgba(255, 122, 0, 0.08)),
    linear-gradient(180deg, #1b140f, #110e0b);
  color: var(--text-strong);
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 700;
  line-height: 1.4;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04), 0 12px 24px rgba(0, 0, 0, 0.2);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.content a[href^="http"]::after {
  content: "↗";
  font-size: 0.95em;
  line-height: 1;
}

.content a[href^="http"]:hover {
  transform: translateY(-2px);
  border-color: var(--line-strong);
  background:
    linear-gradient(180deg, rgba(255, 177, 74, 0.26), rgba(255, 122, 0, 0.12)),
    linear-gradient(180deg, #24160d, #15100b);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05), 0 16px 30px rgba(0, 0, 0, 0.26), 0 0 22px rgba(255, 122, 0, 0.1);
}

.content .katex {
  font-size: 1.02em;
}

.content .katex-display {
  margin: 1.1rem 0;
  overflow-x: auto;
  overflow-y: hidden;
  padding: 0.2rem 0;
}

.content .katex-display > .katex {
  display: inline-block;
  min-width: max-content;
}

.content blockquote {
  margin: 20px 0;
  padding: 14px 16px 14px 18px;
  border-left: 4px solid var(--accent);
  border-radius: 0 16px 16px 0;
  background: rgba(255, 122, 0, 0.06);
  color: var(--muted);
}

.toc-head {
  display: flex;
  gap: 12px;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
  flex: 0 0 auto;
}

.toc-box h2 {
  margin-top: 0;
  margin-bottom: 0;
  font-family: "Orbitron", "Space Grotesk", sans-serif;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.toc-close-btn,
.toc-toggle-btn {
  display: inline-flex;
}

.toc-toggle-btn,
.scroll-top-btn {
  position: fixed;
  right: 24px;
  z-index: 18;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  padding: 0;
  border: 1px solid rgba(255, 152, 41, 0.38);
  border-radius: 18px;
  box-shadow: 0 16px 38px rgba(0, 0, 0, 0.42), 0 0 26px rgba(255, 122, 0, 0.08);
  cursor: pointer;
  font-weight: 700;
  line-height: 1;
  transition: background 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.toc-toggle-btn {
  bottom: 24px;
  background:
    linear-gradient(180deg, rgba(255, 177, 74, 0.25), rgba(255, 122, 0, 0.12)),
    linear-gradient(180deg, #241409, #120f0c);
  color: var(--accent-bright);
}

.toc-toggle-btn:hover {
  background:
    linear-gradient(180deg, rgba(255, 177, 74, 0.34), rgba(255, 122, 0, 0.16)),
    linear-gradient(180deg, #30190a, #16100c);
  border-color: var(--line-strong);
  box-shadow: 0 18px 46px rgba(0, 0, 0, 0.46), 0 0 34px rgba(255, 122, 0, 0.16);
  transform: translateY(-2px);
}

.list-icon {
  display: grid;
  gap: 4px;
  width: 21px;
}

.list-icon span {
  position: relative;
  display: block;
  height: 2px;
  margin-left: 6px;
  background: currentColor;
  border-radius: 999px;
}

.list-icon span::before {
  content: "";
  position: absolute;
  left: -6px;
  top: 50%;
  width: 3px;
  height: 3px;
  background: currentColor;
  border-radius: 50%;
  transform: translateY(-50%);
}

.toc-box {
  position: fixed;
  left: 50%;
  top: 50%;
  z-index: 28;
  width: min(440px, calc(100vw - 32px));
  max-height: min(80dvh, 560px);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  padding: 22px;
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, -48%) scale(0.96);
  transition: opacity 0.2s ease, transform 0.25s ease, box-shadow 0.25s ease;
}

.toc-box.open {
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.58), 0 0 40px rgba(255, 122, 0, 0.12);
  opacity: 1;
  pointer-events: auto;
  transform: translate(-50%, -50%) scale(1);
}

.toc-close-btn {
  width: 40px;
  height: 40px;
  font-size: 1.15rem;
}

.scroll-top-btn {
  bottom: 92px;
  z-index: 17;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0.03)),
    linear-gradient(180deg, #1a1a1a, #101010);
  color: var(--text);
  font-size: 1.35rem;
  opacity: 0;
  pointer-events: none;
  transform: translateY(10px);
}

.scroll-top-btn.show {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.scroll-top-btn:hover {
  background:
    linear-gradient(180deg, rgba(255, 177, 74, 0.18), rgba(255, 122, 0, 0.1)),
    linear-gradient(180deg, #241409, #17110c);
  border-color: var(--line-strong);
  color: var(--text-strong);
  box-shadow: 0 16px 38px rgba(0, 0, 0, 0.44), 0 0 28px rgba(255, 122, 0, 0.12);
  transform: translateY(-2px);
}

#toc {
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
  touch-action: pan-y;
  padding-right: 4px;
}

#toc .toc-link {
  display: block;
  color: var(--muted);
  text-decoration: none;
  margin-bottom: 8px;
  padding: 11px 12px 11px 16px;
  border: 1px solid transparent;
  border-radius: 14px;
  font-size: 0.95rem;
  background: rgba(255, 255, 255, 0.02);
  transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

#toc .toc-link:hover,
#toc .toc-link.touch-hover,
#toc .toc-link:focus-visible,
#toc .toc-link:active {
  background: linear-gradient(90deg, rgba(255, 122, 0, 0.14), rgba(255, 255, 255, 0.02));
  border-color: var(--line-strong);
  color: var(--accent-bright);
  box-shadow: 0 10px 22px rgba(0, 0, 0, 0.2);
  transform: translateX(2px);
}

#toc .toc-h2 {
  padding-left: 16px;
  font-size: 0.95rem;
}

#toc .toc-h3 {
  margin-left: 14px;
  padding-left: 24px;
  font-size: 0.9rem;
  position: relative;
}

#toc .toc-h3::before {
  content: "";
  position: absolute;
  left: 12px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  border-radius: 999px;
  background: linear-gradient(180deg, rgba(255, 122, 0, 0.28), rgba(255, 255, 255, 0.05));
}

.icon-btn:active,
.menu-btn:active,
.topbar-action-btn:active,
.toc-toggle-btn:active,
.scroll-top-btn:active,
.module-list a:active {
  transform: translateY(1px) scale(0.98);
}

.icon-btn:active,
.menu-btn:active,
.scroll-top-btn:active {
  background:
    linear-gradient(180deg, rgba(255, 177, 74, 0.18), rgba(255, 122, 0, 0.08)),
    linear-gradient(180deg, #23150b, #15100b);
  border-color: var(--line-strong);
  color: var(--text-strong);
}

.toc-toggle-btn:active {
  background:
    linear-gradient(180deg, rgba(255, 177, 74, 0.42), rgba(255, 122, 0, 0.18)),
    linear-gradient(180deg, #341a08, #170f0a);
}

.module-list a:active,
#toc .toc-link:active {
  border-color: var(--line-strong);
  color: var(--accent-bright);
}

::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: rgba(255, 255, 255, 0.03);
}

::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, rgba(255, 177, 74, 0.5), rgba(255, 122, 0, 0.5));
  border-radius: 999px;
  border: 2px solid transparent;
  background-clip: padding-box;
}

@keyframes reading-progress-loading {
  0% {
    transform: translateX(-48%);
  }

  50% {
    transform: translateX(86%);
  }

  100% {
    transform: translateX(-48%);
  }
}

@keyframes panel-boot {
  from {
    opacity: 0;
    transform: translateY(18px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes grid-float {
  from {
    transform: translate3d(0, 0, 0);
  }

  50% {
    transform: translate3d(-18px, -12px, 0);
  }

  to {
    transform: translate3d(0, 0, 0);
  }
}

@media (max-width: 720px) {
  .topbar {
    flex-wrap: wrap;
    align-items: flex-start;
    padding: 16px;
  }

  .topbar-actions {
    width: 100%;
    flex-wrap: wrap;
    margin-left: 0;
  }

  .topbar-action-btn,
  .topbar-date {
    flex: 1 1 100%;
    width: 100%;
  }

  .topbar h1 {
    letter-spacing: 0.05em;
  }

  .sidebar-head > div::before,
  .subtitle {
    letter-spacing: 0.14em;
  }
}

@media (max-width: 560px) {
  .main {
    padding: 16px 16px 132px;
  }

  .sidebar {
    padding: 20px 16px;
  }

  .content,
  .toc-box {
    border-radius: 22px;
  }

  .content {
    padding: 20px;
    padding-bottom: 112px;
  }

  .site-footer {
    padding: 16px 18px;
  }

  .site-footer p {
    font-size: 0.82rem;
    line-height: 1.7;
  }

  .toc-box {
    width: min(420px, calc(100vw - 20px));
    max-height: min(84dvh, calc(100vh - 20px));
    padding: 18px;
  }

  .toc-toggle-btn,
  .scroll-top-btn {
    right: 16px;
    width: 48px;
    height: 48px;
    border-radius: 16px;
  }

  .toc-toggle-btn {
    bottom: 16px;
  }

  .scroll-top-btn {
    bottom: 76px;
  }
}