/* =========================================================
   新普京 · 版本档案库 / assets/site.css
   共享层：reset、变量、排版、头部、页脚、通用组件
   ========================================================= */

/* ---------- 1. 变量 ---------- */
:root {
  --ink-1000: #050A12;
  --ink-950: #0A1424;
  --ink-800: #12213A;
  --ink-700: #1B2D4A;
  --silver-200: #C8D2E0;
  --silver-500: #8593AA;
  --amber: #FF8A2A;
  --cyan: #36E6D6;
  --violet: #8B7CFF;
  --paper: #F2F5FA;
  --accent: var(--amber);

  --font-display: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", "JetBrains Mono", SFMono-Regular, Consolas, "Courier New", monospace;

  --wrap: 1240px;
  --gutter: clamp(1rem, 3vw, 2.5rem);
  --ease: cubic-bezier(.2, .7, .3, 1);
  --r: 2px;
}

/* ---------- 2. reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body,
h1, h2, h3, h4, h5,
p, figure, blockquote, dl, dd,
ul, ol, form { margin: 0; }

ul[class],
ol[class] { list-style: none; padding: 0; }

img, svg, picture, video { max-width: 100%; }

[hidden] { display: none !important; }

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
}

a { color: inherit; }

::selection {
  background: var(--accent);
  color: var(--ink-1000);
}

/* ---------- 3. 基础排版 ---------- */
body {
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--silver-200);
  background-color: var(--ink-950);
  background-image:
    radial-gradient(1100px 620px at 84% -12%, rgba(54, 230, 214, .09), transparent 62%),
    radial-gradient(900px 520px at 6% 2%, rgba(255, 138, 42, .07), transparent 60%),
    repeating-linear-gradient(0deg, rgba(200, 210, 224, .032) 0 1px, transparent 1px 88px),
    repeating-linear-gradient(90deg, rgba(200, 210, 224, .032) 0 1px, transparent 1px 88px);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5 {
  font-family: var(--font-display);
  font-weight: 800;
  color: #FFFFFF;
  line-height: 1.12;
  letter-spacing: -0.02em;
  text-wrap: balance;
}

h1 {
  font-size: clamp(2.8rem, 6vw, 5.6rem);
  line-height: 0.98;
  letter-spacing: -0.04em;
}

h2 {
  font-size: clamp(1.8rem, 3.2vw, 3rem);
  line-height: 1.05;
}

h3 {
  font-size: clamp(1.15rem, 1.6vw, 1.7rem);
  line-height: 1.2;
  letter-spacing: -0.01em;
}

p + p { margin-top: 0.9em; }

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.04em;
}

.index-num {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--silver-500);
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
}

.kicker::before {
  content: "";
  width: 22px;
  height: 2px;
  background: currentColor;
}

/* ---------- 4. 焦点与动效原则 ---------- */
:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

/* ---------- 5. 容器与网格 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.wrap--narrow { max-width: 860px; }
.wrap--wide { max-width: 1440px; }

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(1rem, 2.2vw, 1.75rem);
}

.span-3 { grid-column: span 3; }
.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-6 { grid-column: span 6; }
.span-7 { grid-column: span 7; }
.span-8 { grid-column: span 8; }
.span-9 { grid-column: span 9; }
.span-10 { grid-column: span 10; }
.span-12 { grid-column: span 12; }

.rule {
  height: 1px;
  border: 0;
  background: var(--ink-700);
  margin-block: clamp(1.5rem, 4vw, 2.75rem);
}

@media (max-width: 1024px) {
  .span-3, .span-4, .span-5 { grid-column: span 6; }
  .span-7, .span-8, .span-9, .span-10 { grid-column: span 12; }
}

@media (max-width: 720px) {
  .grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .grid > [class*="span-"] { grid-column: 1 / -1; }
}

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  padding: 0.78rem 1.3rem;
  border: 1px solid var(--ink-700);
  border-radius: var(--r);
  background: var(--ink-800);
  color: var(--silver-200);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-decoration: none;
  cursor: pointer;
  transition:
    background-color 160ms var(--ease),
    border-color 160ms var(--ease),
    color 160ms var(--ease);
}

.btn:hover {
  border-color: var(--accent);
  background: var(--ink-700);
  color: #FFFFFF;
}

.btn--primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--ink-1000);
  font-weight: 700;
}

.btn--primary:hover {
  background: #FFFFFF;
  border-color: #FFFFFF;
  color: var(--ink-1000);
}

.btn--ghost {
  background: transparent;
  border-color: var(--ink-700);
}

/* ---------- 7. 面包屑 ---------- */
.breadcrumb {
  padding-block: 1.4rem 0;
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0 0.6rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.08em;
  color: var(--silver-500);
}

.breadcrumb li {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.breadcrumb li:not(:first-child)::before {
  content: "/";
  color: var(--ink-700);
}

.breadcrumb a {
  color: var(--silver-200);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 150ms var(--ease), border-color 150ms var(--ease);
}

.breadcrumb a:hover {
  color: #FFFFFF;
  border-bottom-color: var(--accent);
}

/* ---------- 8. 纸面正文层 ---------- */
.prose {
  background: var(--paper);
  color: #101B2C;
  padding: clamp(1.4rem, 4vw, 3.25rem);
  border: 1px solid rgba(27, 45, 74, 0.12);
  border-radius: var(--r);
  box-shadow: 0 28px 64px -34px rgba(0, 0, 0, 0.85);
}

.prose > * + * { margin-top: 1.05em; }

.prose h2,
.prose h3,
.prose h4 {
  color: #071021;
  margin-top: 1.9em;
  margin-bottom: 0.55em;
}

.prose h2 { font-size: clamp(1.5rem, 2.6vw, 2.1rem); }
.prose h3 { font-size: clamp(1.15rem, 1.8vw, 1.4rem); }

.prose p { max-width: 68ch; }

.prose ul,
.prose ol { padding-left: 1.35em; }

.prose li + li { margin-top: 0.4em; }

.prose a {
  color: #0A6D63;
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 150ms var(--ease);
}

.prose a:hover { color: #084B45; }

.prose strong { color: #071021; }

.prose blockquote {
  border-left: 3px solid var(--accent);
  padding-left: 1rem;
  color: #31405A;
}

.prose code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: rgba(27, 45, 74, 0.08);
  padding: 0.1em 0.35em;
  border-radius: var(--r);
}

.prose hr {
  border: 0;
  height: 1px;
  background: rgba(27, 45, 74, 0.16);
  margin-block: 2em;
}

/* ---------- 9. 表格 ---------- */
.table-wrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border: 1px solid rgba(27, 45, 74, 0.14);
  border-radius: var(--r);
}

.table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  line-height: 1.6;
}

.table th,
.table td {
  padding: 0.72rem 0.9rem;
  text-align: left;
  border-bottom: 1px solid rgba(27, 45, 74, 0.14);
  vertical-align: top;
}

.table thead th {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #31405A;
  background: rgba(27, 45, 74, 0.05);
  white-space: nowrap;
}

.table tbody tr:hover,
.table tbody tr:focus-within {
  background: rgba(54, 230, 214, 0.12);
}

.table tbody td:first-child {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.05em;
  white-space: nowrap;
}

/* ---------- 10. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.26rem 0.6rem;
  border: 1px solid var(--ink-700);
  border-radius: var(--r);
  background: rgba(18, 33, 58, 0.65);
  color: var(--silver-200);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  line-height: 1.4;
}

.tag--cyan {
  border-color: rgba(54, 230, 214, 0.5);
  background: rgba(54, 230, 214, 0.08);
  color: var(--cyan);
}

.tag--amber {
  border-color: rgba(255, 138, 42, 0.5);
  background: rgba(255, 138, 42, 0.08);
  color: var(--amber);
}

.tag--violet {
  border-color: rgba(139, 124, 255, 0.5);
  background: rgba(139, 124, 255, 0.1);
  color: var(--violet);
}

/* ---------- 11. 图片容器基础规则 ---------- */
.figure {
  margin: 0;
  position: relative;
}

.figure__frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  border: 1px solid var(--ink-700);
  border-radius: var(--r);
  background:
    linear-gradient(150deg, var(--ink-800) 0%, var(--ink-950) 58%, var(--ink-1000) 100%);
}

.figure__frame > img,
.figure__frame > picture,
.figure__frame > picture > img,
.figure__frame > svg {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.figure__frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(
    0deg,
    rgba(200, 210, 224, 0.055) 0 1px,
    transparent 1px 4px
  );
  opacity: 0.7;
}

.figure__cap {
  margin-top: 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--silver-500);
}

.figure--wide .figure__frame { aspect-ratio: 21 / 9; }
.figure--tall .figure__frame { aspect-ratio: 4 / 5; }
.figure--square .figure__frame { aspect-ratio: 1 / 1; }

@media (max-width: 720px) {
  .figure--wide .figure__frame { aspect-ratio: 16 / 9; }
  .figure--tall .figure__frame { aspect-ratio: 3 / 4; }
}

/* ---------- 12. 头部 ---------- */
.skip-link {
  position: absolute;
  left: 1rem;
  top: -120px;
  z-index: 200;
  padding: 0.7rem 1.15rem;
  background: var(--accent);
  color: var(--ink-1000);
  font-weight: 700;
  font-size: 0.9rem;
  text-decoration: none;
  border-radius: var(--r);
  transition: top 160ms var(--ease);
}

.skip-link:focus {
  top: 0.7rem;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 20, 36, 0.92);
  border-bottom: 0;
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  backdrop-filter: blur(14px) saturate(140%);
}

.site-header::before {
  content: "";
  display: block;
  height: 3px;
  background: linear-gradient(
    90deg,
    var(--amber) 0%,
    var(--cyan) 48%,
    var(--violet) 100%
  );
}

/* 状态条 */
.topline {
  background: var(--ink-1000);
  border-bottom: 1px solid rgba(27, 45, 74, 0.7);
  color: var(--silver-500);
  font-size: 0.74rem;
}

.topline__inner {
  max-width: var(--wrap);
  margin-inline: auto;
  padding: 0.42rem var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.6rem 1.25rem;
  flex-wrap: wrap;
  font-family: var(--font-mono);
  letter-spacing: 0.08em;
}

.topline__status {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
  color: var(--silver-200);
}

.topline__quiet { color: var(--silver-500); }

.topline__sep {
  color: var(--ink-700);
  margin-inline: 0.1rem;
}

.topline__meta {
  color: var(--silver-500);
  white-space: nowrap;
}

.dot {
  width: 7px;
  height: 7px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 0 rgba(54, 230, 214, 0.5);
  animation: dot-pulse 2.4s ease-out 1 both;
}

@keyframes dot-pulse {
  0% { box-shadow: 0 0 0 0 rgba(54, 230, 214, 0.5); }
  70% { box-shadow: 0 0 0 7px rgba(54, 230, 214, 0); }
  100% { box-shadow: 0 0 0 0 rgba(54, 230, 214, 0); }
}

/* 刊头 */
.masthead {
  max-width: var(--wrap);
  margin-inline: auto;
  padding: clamp(0.7rem, 1.6vw, 1.05rem) var(--gutter);
}

.masthead__inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: clamp(1rem, 3vw, 2.25rem);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: #FFFFFF;
}

.brand__mark {
  position: relative;
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  background: var(--ink-800);
  border: 1px solid var(--ink-700);
  color: var(--accent);
  font-family: var(--font-display);
  font-size: 1.02rem;
  font-weight: 800;
  line-height: 1;
  transition: border-color 160ms var(--ease), color 160ms var(--ease);
}

.brand__mark::after {
  content: "";
  position: absolute;
  top: -1px;
  right: -1px;
  width: 9px;
  height: 9px;
  background: var(--accent);
}

.brand:hover .brand__mark { border-color: var(--accent); }

.brand__text {
  display: flex;
  flex-direction: column;
  gap: 0.18rem;
  line-height: 1.05;
}

.brand__name {
  font-family: var(--font-display);
  font-size: 1.18rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: #FFFFFF;
}

.brand__sub {
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--silver-500);
}

.masthead__tagline {
  justify-self: end;
  text-align: right;
  padding-right: 1rem;
  border-right: 1px solid var(--ink-700);
  font-size: 0.82rem;
  line-height: 1.5;
  color: var(--silver-500);
  max-width: 26ch;
}

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.6rem;
  padding: 0.55rem 0 0.55rem 0.9rem;
  border-left: 1px solid var(--ink-700);
  color: var(--silver-200);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  cursor: pointer;
  transition: color 150ms var(--ease);
}

.nav-toggle:hover { color: var(--accent); }

.nav-toggle__bars {
  display: grid;
  gap: 5px;
  width: 18px;
}

.nav-toggle__bars span {
  display: block;
  height: 2px;
  background: currentColor;
  transition: transform 180ms var(--ease), opacity 180ms var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:first-child {
  transform: translateY(3.5px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:last-child {
  transform: translateY(-3.5px) rotate(-45deg);
}

.nav-toggle__label { line-height: 1; }

/* 栏目带 */
.site-nav {
  border-top: 1px solid var(--ink-700);
  background: rgba(5, 10, 18, 0.28);
}

.site-nav__list {
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0 clamp(0.5rem, 2.2vw, 1.9rem);
}

.site-nav a {
  position: relative;
  display: inline-block;
  padding: 0.82rem 0.15rem 0.95rem;
  font-size: 0.92rem;
  letter-spacing: 0.1em;
  color: var(--silver-200);
  text-decoration: none;
  transition: color 150ms var(--ease);
}

.site-nav a::after {
  content: "";
  position: absolute;
  left: 0.15rem;
  right: 0.15rem;
  bottom: 0.6rem;
  height: 2px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 180ms var(--ease);
}

.site-nav a:hover { color: #FFFFFF; }
.site-nav a:hover::after { transform: scaleX(1); }

.site-nav a[aria-current="page"] { color: var(--accent); }
.site-nav a[aria-current="page"]::after { transform: scaleX(1); }

/* 阅读进度 */
.progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--ink-800);
  pointer-events: none;
}

.progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--amber), var(--cyan));
  transition: width 80ms linear;
}

@media (max-width: 900px) {
  .masthead__inner { grid-template-columns: 1fr auto; }
  .masthead__tagline { display: none; }
  .nav-toggle { display: inline-flex; }

  .site-nav {
    max-height: 0;
    overflow: hidden;
    border-top-color: transparent;
    transition: max-height 240ms var(--ease), border-color 240ms var(--ease);
  }

  .site-nav[data-open="true"] {
    max-height: 72vh;
    overflow-y: auto;
    border-top-color: var(--ink-700);
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding-block: 0.35rem 0.9rem;
  }

  .site-nav a {
    padding: 0.82rem 0.8rem;
    border-bottom: 1px solid rgba(27, 45, 74, 0.75);
  }

  .site-nav a::after { display: none; }

  .site-nav a[aria-current="page"] {
    color: var(--accent);
    box-shadow: inset 2px 0 0 var(--accent);
  }
}

@media (max-width: 600px) {
  .topline__meta { display: none; }
  .topline__inner { justify-content: flex-start; }
}

/* ---------- 13. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(3rem, 8vw, 6rem);
  background: var(--ink-1000);
  border-top: 1px solid var(--ink-700);
  color: var(--silver-500);
}

.footer__band {
  height: 4px;
  background: linear-gradient(
    90deg,
    var(--violet) 0%,
    var(--cyan) 26%,
    var(--amber) 62%,
    var(--ink-700) 100%
  );
}

.footer__inner {
  max-width: var(--wrap);
  margin-inline: auto;
  padding: clamp(2.25rem, 5vw, 3.75rem) var(--gutter) clamp(1.75rem, 4vw, 2.75rem);
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr) minmax(0, 1.15fr);
  gap: clamp(2rem, 4vw, 3.5rem);
}

.footer__lockup {
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 2.4vw, 1.85rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.2;
  color: #FFFFFF;
}

.footer__desc {
  margin-top: 0.85rem;
  max-width: 34ch;
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--silver-500);
}

.footer__brand .btn { margin-top: 1.4rem; }

.footer__label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--silver-500);
  padding-bottom: 0.7rem;
  margin-bottom: 0.85rem;
  border-bottom: 1px solid var(--ink-700);
}

.footer__nav ul {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0 0.85rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.footer__nav a {
  display: block;
  padding: 0.42rem 0;
  font-size: 0.9rem;
  color: var(--silver-200);
  text-decoration: none;
  border-bottom: 1px solid rgba(27, 45, 74, 0.55);
  transition: color 150ms var(--ease), border-color 150ms var(--ease), padding-left 150ms var(--ease);
}

.footer__nav a:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
  padding-left: 0.35rem;
}

.contact-list {
  display: grid;
  gap: 0.7rem;
  margin: 0;
}

.contact-list__row {
  display: grid;
  grid-template-columns: 3.4rem minmax(0, 1fr);
  gap: 0.75rem;
  align-items: start;
  padding-bottom: 0.65rem;
  border-bottom: 1px solid rgba(27, 45, 74, 0.6);
}

.contact-list dt {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  color: var(--silver-500);
  padding-top: 0.18rem;
}

.contact-list dd {
  margin: 0;
  font-size: 0.88rem;
  line-height: 1.65;
  color: var(--silver-200);
  overflow-wrap: anywhere;
}

.contact-note {
  margin-top: 1rem;
  padding-left: 0.8rem;
  border-left: 2px solid var(--ink-700);
  font-size: 0.78rem;
  line-height: 1.7;
  color: var(--silver-500);
}

.footer__base {
  border-top: 1px solid var(--ink-700);
  background: rgba(18, 33, 58, 0.35);
}

.footer__base-inner {
  max-width: var(--wrap);
  margin-inline: auto;
  padding: 1.05rem var(--gutter) 1.45rem;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.65rem 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--silver-500);
}

.chip-copy {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.28rem 0.6rem;
  border: 1px solid var(--ink-700);
  border-radius: var(--r);
  background: rgba(18, 33, 58, 0.8);
  color: var(--silver-200);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  cursor: pointer;
  transition: border-color 150ms var(--ease), color 150ms var(--ease), background-color 150ms var(--ease);
}

.chip-copy:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

.chip-copy[data-copied="true"] {
  border-color: var(--cyan);
  background: rgba(54, 230, 214, 0.12);
  color: var(--cyan);
}

.to-top {
  position: fixed;
  right: clamp(0.9rem, 2.5vw, 1.8rem);
  bottom: clamp(0.9rem, 2.5vw, 1.8rem);
  z-index: 90;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid var(--ink-700);
  border-radius: var(--r);
  background: rgba(10, 20, 36, 0.92);
  color: var(--silver-200);
  font-family: var(--font-mono);
  font-size: 1rem;
  line-height: 1;
  cursor: pointer;
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  transition: border-color 150ms var(--ease), color 150ms var(--ease), background-color 150ms var(--ease);
}

.to-top:hover {
  border-color: var(--accent);
  background: var(--ink-800);
  color: var(--accent);
}

@media (max-width: 1024px) {
  .footer__inner { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .footer__brand { grid-column: 1 / -1; }
}

@media (max-width: 720px) {
  .footer__inner { grid-template-columns: minmax(0, 1fr); }
  .footer__brand .btn { width: 100%; }
  .footer__base-inner { font-size: 0.68rem; }
  .chip-copy { font-size: 0.66rem; }
}