:root {
  --bg: #0e1117;
  --bg-elevated: #161b22;
  --bg-code: #1f2630;
  --text: #e6edf3;
  --text-muted: #8b949e;
  --accent: #2f81f7;
  --accent-hover: #58a6ff;
  --accent-alt: #a371f7;
  --border: #30363d;
  --radius: 8px;
  --transition: 0.25s ease;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  background-color: var(--bg);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans",
    Helvetica, Arial, sans-serif;
  line-height: 1.6;
  color: var(--text);
  margin: 0;
}

p {
  color: var(--text);
  margin-left: 5% !important;
  margin-right: 5% !important;
  margin-bottom: 1em;
}

p.discription {
  color: var(--text-muted);
  font-style: italic;
}

p.copyright {
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
  bottom: 0;
  padding: 1.5em 0;
}

h1,
h2,
h3 {
  color: var(--text);
  line-height: 1.25;
  margin-top: 1.5em;
  margin-bottom: 0.6em;
}

.name {
  text-align: center;
}

h1.name {
  font-size: 2.4rem !important;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-top: 0.5em;
  background: linear-gradient(
    135deg,
    var(--accent) 0%,
    var(--accent-alt) 35%,
    #58a6ff 50%,
    var(--accent-alt) 65%,
    var(--accent) 100%
  );
  background-size: 300% 300%;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: h1-shimmer 12s ease-in-out infinite;
}

@keyframes h1-shimmer {
  0%   { background-position: 0% 50%; }
  50%  { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

h2.name {
  font-size: 1.8rem;
  font-weight: 600;
}

a {
  text-decoration: none;
  color: var(--accent);
  transition: color var(--transition);
}

a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

.top {
  color: var(--text);
  background-color: rgba(22, 27, 34, 0.85);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 0.5em 1.2em;
  margin: 0.6em 1.2%;
  top: 0.6em;
  position: sticky;
  z-index: 100;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.4);
  flex-shrink: 0;
}

.top-bar {
  display: flex;
  align-items: center;
  gap: 0.5em;
}

.next-ico {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  color: var(--text);
  text-decoration: none;
  transition: color var(--transition);
  line-height: 1;
  white-space: nowrap;
}

.next-ico:hover {
  color: var(--accent);
  text-decoration: none;
}

.ico {
  display: inline-block;
  height: 1.9em;
  width: 1.9em;
  flex-shrink: 0;
}

.menu-toggle {
  display: none;
  margin-left: auto;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  font-size: 1.2rem;
  line-height: 1;
  padding: 0.35em 0.65em;
  cursor: pointer;
  transition: background var(--transition), border-color var(--transition);
}

.menu-toggle:hover {
  background: var(--bg-elevated);
  border-color: var(--accent);
}

.tab1,
.tab2 {
  margin-left: 0;
  color: var(--text);
  transition: color var(--transition), background var(--transition);
  padding: 0.35em 0.75em;
  border-radius: 6px;
  white-space: nowrap;
}

.tab1:hover,
.tab2:hover {
  color: var(--accent-hover);
  background: var(--bg-elevated);
  text-decoration: none;
}

.active {
  text-decoration: none !important;
  font-weight: 600;
  color: var(--accent) !important;
  background: rgba(47, 129, 247, 0.14);
}

@media (min-width: 769px) {
  .top {
    display: flex;
    align-items: center;
    gap: 1em;
  }

  .top-bar {
    flex-shrink: 0;
  }

  .nav-tabs {
    position: relative;
    display: flex;
    align-items: stretch;
    gap: 0;
    margin-left: 2em;
    width: auto;
  }

  .nav-tabs::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    height: 2px;
    width: 1px;
    background: var(--accent);
    box-shadow: 0 0 10px rgba(47, 129, 247, 0.55);
    border-radius: 2px 2px 0 0;
    pointer-events: none;
    transform-origin: left center;
    transform: translateX(var(--nav-x, 0px)) scaleX(var(--nav-w, 0));
    opacity: 0;
  }

  .nav-tabs.is-ready::after {
    opacity: 1;
    transition:
      transform 0.4s cubic-bezier(.22, .61, .36, 1),
      background 0.25s ease,
      box-shadow 0.25s ease,
      opacity 0.25s ease;
  }

  .nav-tabs.no-anim::after {
    opacity: 1;
    transition: none !important;
  }

  .nav-tabs.line-muted::after {
    background: var(--text-muted);
    box-shadow: 0 0 10px rgba(139, 148, 158, 0.45);
  }

  .menu-toggle {
    display: none !important;
  }

  .tab1,
  .tab2 {
    position: relative;
    margin-left: 0;
    padding: 0.55em 0.9em;
    background: transparent;
    border-radius: 0;
    color: var(--text);
    transition: color var(--transition);
    white-space: nowrap;
  }

  .tab1:hover,
  .tab2:hover {
    color: var(--accent-hover);
    background: transparent;
    text-decoration: none;
  }

  .tab1.active,
  .tab2.active {
    color: var(--accent) !important;
    background: transparent;
    text-decoration: none !important;
    font-weight: 600;
  }

  .nav-tabs.line-muted .active:not(:hover) {
    color: var(--text) !important;
    font-weight: 400;
  }
}

code {
  color: var(--text);
  background-color: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.15em 0.45em;
  font-family: "Roboto Mono", "SF Mono", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.9em;
  word-break: break-word;
}

pre {
  background-color: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1em;
  overflow-x: auto;
}

pre code {
  background: transparent;
  border: none;
  padding: 0;
}

hr {
  position: relative;
  border: none;
  height: 2px;
  margin: 2.5em auto;
  width: 80%;
  border-radius: 2px;
  overflow: hidden;
  background: linear-gradient(
    90deg,
    transparent 0%,
    var(--border) 15%,
    var(--border) 50%,
    var(--border) 85%,
    transparent 100%
  );
  box-shadow: 0 0 8px rgba(47, 129, 247, 0.25);
}

@media (hover: hover) and (pointer: fine) {
  hr {
    background:
      radial-gradient(
        circle 90px at var(--mx, 50%) 50%,
        var(--accent),
        rgba(47, 129, 247, 0.25) 45%,
        transparent 100%
      ),
      linear-gradient(
        90deg,
        transparent 0%,
        var(--border) 15%,
        var(--border) 85%,
        transparent 100%
      );
    box-shadow: 0 0 10px rgba(47, 129, 247, 0.35);
  }
}

.log-in {
  color: #ffffff;
  background: linear-gradient(135deg, var(--accent), var(--accent-alt));
  border: none;
  border-radius: var(--radius);
  float: right;
  margin-right: 1%;
  padding: 0.4em 1em;
  font-weight: 600;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition),
    filter var(--transition);
}

.log-in:hover {
  filter: brightness(1.15);
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(47, 129, 247, 0.4);
}

.log-in:active {
  transform: translateY(0);
}

.warn {
  position: relative;
  margin: 1.5em 5%;
  padding: 0;
  border: 1px solid rgba(255, 128, 0, 0.4);
  border-left: 4px solid #ff8000;
  border-radius: var(--radius);
  background: rgba(255, 128, 0, 0.06);
  overflow: hidden;
}

.warn2 {
  display: block;
  color: #ffffff;
  background: #ff8000;
  border: none;
  margin: 0;
  padding: 0.45em 1em;
  font-weight: 600;
  font-size: 0.9rem;
  letter-spacing: 0.03em;
}

.warn2::before {
  content: "⚠ Внимание!";
}

.warn p {
  margin: 0.75em 1em !important;
  color: var(--text);
}

.warn strong {
  color: #ffb366;
}

.warn a {
  color: var(--accent-hover);
}

@media (hover: hover) and (pointer: fine) {
  .warn::after {
    content: "";
    position: absolute;
    inset: 0;
    pointer-events: none;
    border-radius: var(--radius);
    background: radial-gradient(
      320px circle at var(--mx, 50%) var(--my, 50%),
      rgba(255, 128, 0, 0.22),
      rgba(255, 128, 0, 0.06) 40%,
      transparent 65%
    );
    transition: opacity 0.25s ease;
  }

  .warn:hover::after {
    background: radial-gradient(
      320px circle at var(--mx, 50%) var(--my, 50%),
      rgba(255, 128, 0, 0.32),
      rgba(255, 128, 0, 0.1) 40%,
      transparent 65%
    );
  }
}

ul,
ol {
  margin: 1em 5% 1.5em;
  padding-left: 1.8em;
  color: var(--text);
}

li {
  margin-bottom: 0.5em;
  line-height: 1.6;
}

li::marker {
  color: var(--accent);
}

li a {
  color: var(--accent);
  transition: color var(--transition);
}

li a:hover {
  color: var(--accent-hover);
}

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

::-webkit-scrollbar-track {
  background: var(--bg);
}

::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 6px;
}

::-webkit-scrollbar-thumb:hover {
  background: #4a5560;
}

::selection {
  background-color: var(--accent);
  color: #ffffff;
}

html,
body {
  overflow: hidden;
  height: 100vh;
  height: 100svh;
}

body {
  display: flex;
  flex-direction: column;
}

.top {
  flex-shrink: 0;
}

h1.name {
  flex-shrink: 0;
  margin: 0.4em 0 0.2em;
}

.stage {
  flex: 1 1 auto;
  min-height: 0;
  position: relative;
  overflow: hidden;
}

.page-section {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  padding: 1em 0 2em;
  overflow-y: auto;
  overflow-x: hidden;
  overscroll-behavior: contain;

  opacity: 0;
  transform: translateY(24px) scale(0.985);
  pointer-events: none;
  transition:
    opacity 0.6s cubic-bezier(.22, .61, .36, 1),
    transform 0.6s cubic-bezier(.22, .61, .36, 1);
}

.page-section.is-active {
  opacity: 1;
  transform: none;
  pointer-events: auto;
  z-index: 1;
}

.page-section > * {
  flex-shrink: 0;
  opacity: 0;
  transform: translateY(14px);
  transition:
    opacity 0.5s cubic-bezier(.22, .61, .36, 1),
    transform 0.5s cubic-bezier(.22, .61, .36, 1);
}

.page-section.is-active > * {
  opacity: 1;
  transform: none;
}

.page-section.is-active > *:nth-child(1) { transition-delay: 0.10s; }
.page-section.is-active > *:nth-child(2) { transition-delay: 0.17s; }
.page-section.is-active > *:nth-child(3) { transition-delay: 0.24s; }
.page-section.is-active > *:nth-child(4) { transition-delay: 0.31s; }
.page-section.is-active > *:nth-child(5) { transition-delay: 0.38s; }
.page-section.is-active > *:nth-child(6) { transition-delay: 0.45s; }
.page-section.is-active > *:nth-child(7) { transition-delay: 0.52s; }
.page-section.is-active > *:nth-child(8) { transition-delay: 0.59s; }

.copyright-bar {
  flex-shrink: 0;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--bg);
  padding: 0.35em 1em;
  margin: 0.4em 1.2% 0.6em;
  text-align: center;
}

.copyright-bar .copyright {
  margin: 0 !important;
  padding: 0 !important;
  font-size: 0.8rem;
  line-height: 1.4;
}

@media (max-width: 768px) {
  body {
    font-size: 15px;
  }

  body.centered-page h1.name {
    margin-bottom: 0.4em;
  }
  body.centered-page .page-section {
    padding: 0.3em 0;
  }

  p {
    margin-left: 4% !important;
    margin-right: 4% !important;
  }

  h1.name {
    font-size: 1.5rem !important;
    margin: 0.4em 0;
  }

  h2.name {
    font-size: 1.35rem;
  }

  h2,
  h3 {
    font-size: 1.15rem;
  }

  .top {
  padding: 0.6em 4%;
  margin: 0.5em 3%;
  border-radius: 12px;
  top: 0.5em;
  }

  .menu-toggle {
    display: block;
  }

  .nav-tabs {
    display: none;
    flex-direction: column;
    margin-top: 0.6em;
    padding-top: 0.4em;
    border-top: 1px solid var(--border);
  }

  .nav-tabs.open {
    display: flex;
    animation: menu-slide 0.2s ease-out;
  }

  @keyframes menu-slide {
    from { opacity: 0; transform: translateY(-6px); }
    to   { opacity: 1; transform: translateY(0); }
  }

  .tab1,
  .tab2 {
    margin-left: 0;
    margin-right: 0;
    display: block;
    padding: 0.55em 0.2em;
    font-size: 1rem;
  }

  .ico {
    height: 1.7em;
    width: 1.7em;
  }

  .page-section {
  padding: 0.6em 0 1.5em;
  }

  hr {
    margin: 1.8em auto;
    width: 90%;
    height: 2px;
    background: linear-gradient(
      90deg,
      transparent 0%,
      var(--accent) 25%,
      var(--accent-alt) 50%,
      var(--accent) 75%,
      transparent 100%
    );
    background-size: 200% 100%;
    animation: hr-shimmer 8s ease-in-out infinite;
  }

  @keyframes hr-shimmer {
    0%, 100% { background-position: 100% 50%; }
    50%      { background-position: 0% 50%; }
  }

  .warn {
    margin: 1.2em 4%;
    border-left-width: 3px;
  }

  .warn::after {
    content: "";
    position: absolute;
    inset: 0;
    pointer-events: none;
    background: linear-gradient(
      120deg,
      transparent 35%,
      rgba(255, 128, 0, 0.1) 50%,
      transparent 65%
    );
    background-size: 200% 100%;
    animation: warn-shimmer 4s ease-in-out infinite;
  }

  @keyframes warn-shimmer {
    0%, 100% { background-position: 100% 50%; }
    50%      { background-position: 0% 50%; }
  }

  .warn p {
    margin: 0.6em 0.8em !important;
  }

  .warn2 {
    font-size: 0.85rem;
    padding: 0.4em 0.8em;
  }

  ul,
  ol {
    margin: 1em 4% 1.2em;
    padding-left: 1.5em;
  }

  code {
    font-size: 0.85em;
    word-break: break-all;
  }

  .copyright-bar .copyright {
    font-size: 0.75rem;
  }
}

@media (max-width: 400px) {
  h1.name { font-size: 1.35rem !important; }
  h2.name { font-size: 1.2rem; }
}

@media (prefers-reduced-motion: reduce) {
  hr,
  .warn::after,
  .nav-tabs.open {
    animation: none !important;
  }

  .page-section,
  .page-section > * {
    transition: none !important;
  }
}