/* 灵感悬浮官网 · 全站样式
   视觉方向：工程档案。墨蓝版块承载首屏与页脚，纸色承载正文；
   等宽字体做编号与标注，细线做结构，不用卡片栅格与渐变色块。 */

:root {
  --ink: #0b1526;
  --ink-2: #101c31;
  --ink-3: #182845;
  --paper: #f5f3ee;
  --paper-2: #ece9e1;
  --paper-3: #e2ded3;
  --line: #d5d0c3;
  --line-strong: #b4ad9b;
  --text: #16202f;
  --muted: #5e687a;
  --blue: #1b4fb8;
  --accent: #e4572e;
  --accent-deep: #c8441d;
  --on-ink: #f5f3ee;
  --on-ink-muted: rgba(245, 243, 238, 0.64);
  --on-ink-faint: rgba(245, 243, 238, 0.4);
  --on-ink-line: rgba(245, 243, 238, 0.14);

  --container: 1920px;
  --gutter: clamp(20px, 5vw, 88px);
  --radius: 2px;
  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
  --header-height: 64px;

  --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei UI", "Microsoft YaHei", "Noto Sans CJK SC", "Source Han Sans SC",
    "Helvetica Neue", Arial, sans-serif;
  --font-serif: Georgia, "Iowan Old Style", "Palatino Linotype", "Book Antiqua",
    "Times New Roman", "Songti SC", serif;
  --font-mono: "SF Mono", SFMono-Regular, Menlo, Consolas, "Cascadia Mono",
    "Liberation Mono", "Courier New", "PingFang SC", "Microsoft YaHei", monospace;
}

/* ---------- 基础 ---------- */

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: calc(var(--header-height) + 24px);
}

html,
body {
  overflow-x: hidden;
  overflow-x: clip;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--blue);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

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

img,
svg {
  max-width: 100%;
  height: auto;
  display: block;
}

h1,
h2,
h3,
h4 {
  margin: 0 0 0.5em;
  color: var(--ink);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

h1 {
  font-size: clamp(2.2rem, 5vw, 3.6rem);
  line-height: 1.12;
}

h2 {
  font-size: clamp(1.7rem, 3.2vw, 2.5rem);
  line-height: 1.18;
}

h3 {
  font-size: 1.2rem;
}

h4 {
  font-size: 1rem;
}

p {
  margin: 0 0 1em;
}

ul,
ol {
  padding-left: 1.4em;
}

dl,
dd {
  margin: 0;
}

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.mono {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.04em;
}

/* 贯穿视口的细线：代替容器内的 border，让结构线冲出中间框 */
.index::before,
.index__row::after,
.case::before,
.channels::before,
.channels li::after,
.principles::before,
.principles::after {
  content: "";
  position: absolute;
  left: calc(var(--gutter) * -1);
  right: calc(var(--gutter) * -1);
  height: 1px;
  background: var(--line);
  pointer-events: none;
}

.index::before,
.case::before,
.channels::before,
.principles::before {
  top: 0;
}

.index__row::after,
.channels li::after,
.principles::after {
  bottom: 0;
}

/* 眉题：编号 + 中文 + 英文斜体 */
.eyebrow {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0 14px;
  margin: 0 0 20px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  color: var(--accent);
}

.eyebrow__num {
  color: var(--muted);
}

.eyebrow i {
  font: italic 400 1rem/1 var(--font-serif);
  letter-spacing: 0;
  color: var(--muted);
}

.on-ink .eyebrow__num,
.on-ink .eyebrow i {
  color: var(--on-ink-muted);
}

/* ---------- 版块 ---------- */

.section {
  padding: clamp(64px, 9vw, 112px) 0;
}

.section--tight {
  padding-top: clamp(48px, 6vw, 72px);
}

.section--alt {
  background: var(--paper-2);
}

.section--line {
  border-top: 1px solid var(--line);
}

.section__head {
  margin-bottom: clamp(36px, 5vw, 64px);
}

.section__head h2 {
  margin-bottom: 0;
}

.section__head--split {
  display: grid;
  gap: 20px 48px;
  align-items: end;
}

.section__lead {
  margin: 0;
  color: var(--muted);
  font-size: 1.05rem;
  max-width: 34em;
}

.on-ink {
  background: var(--ink);
  color: var(--on-ink);
}

.on-ink h1,
.on-ink h2,
.on-ink h3 {
  color: var(--on-ink);
}

.on-ink a {
  color: var(--on-ink);
}

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

/* 墨蓝版块的工程网格底纹 */
.blueprint {
  position: relative;
  isolation: isolate;
}

.blueprint::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(var(--on-ink-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--on-ink-line) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 90% 90% at 70% 20%, #000 20%, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse 90% 90% at 70% 20%, #000 20%, transparent 80%);
  opacity: 0.55;
}

.blueprint::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: radial-gradient(600px 400px at 85% 0%, rgba(228, 87, 46, 0.14), transparent 70%);
}

/* ---------- 顶栏 ---------- */

.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(11, 21, 38, 0.92);
  backdrop-filter: saturate(160%) blur(12px);
  -webkit-backdrop-filter: saturate(160%) blur(12px);
  border-bottom: 1px solid var(--on-ink-line);
  color: var(--on-ink);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  height: var(--header-height);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--on-ink);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.brand:hover {
  color: var(--on-ink);
}

.brand__mark {
  width: 30px;
  height: 30px;
  flex: none;
}

.brand__name em {
  display: block;
  margin-top: -2px;
  font: italic 400 0.82rem/1 var(--font-serif);
  color: var(--on-ink-muted);
  letter-spacing: 0.02em;
}

.nav {
  display: none;
  align-items: center;
  gap: 32px;
}

.nav a {
  position: relative;
  padding: 6px 0;
  color: var(--on-ink-muted);
  font-size: 0.95rem;
  font-weight: 500;
}

.nav a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 100%;
  bottom: 0;
  height: 2px;
  background: var(--accent);
  transition: right 0.3s var(--ease);
}

.nav a:hover,
.nav a.is-active {
  color: var(--on-ink);
}

.nav a:hover::after,
.nav a.is-active::after {
  right: 0;
}

.header__aside {
  display: flex;
  align-items: center;
  gap: 12px;
}

.lang {
  padding: 5px 12px;
  border: 1px solid var(--on-ink-line);
  border-radius: var(--radius);
  color: var(--on-ink);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

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

.nav-toggle {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  width: 40px;
  height: 40px;
  padding: 9px;
  border: 1px solid var(--on-ink-line);
  border-radius: var(--radius);
  background: transparent;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  height: 1.5px;
  background: var(--on-ink);
  transition: transform 0.3s var(--ease), opacity 0.2s var(--ease);
}

.header.is-open .nav-toggle span:first-child {
  transform: translateY(3.75px) rotate(45deg);
}

.header.is-open .nav-toggle span:last-child {
  transform: translateY(-3.75px) rotate(-45deg);
}

.header.is-open .nav {
  display: flex;
  position: absolute;
  left: 0;
  right: 0;
  top: var(--header-height);
  flex-direction: column;
  align-items: stretch;
  gap: 0;
  padding: 8px var(--gutter) 24px;
  background: var(--ink);
  border-bottom: 1px solid var(--on-ink-line);
}

.header.is-open .nav a {
  padding: 14px 0;
  border-bottom: 1px solid var(--on-ink-line);
  font-size: 1.05rem;
}

.header.is-open .nav a::after {
  display: none;
}

/* ---------- 首屏 ---------- */

.hero {
  padding: clamp(64px, 10vw, 128px) 0 0;
  overflow: hidden;
}

.hero__grid {
  display: grid;
  gap: 48px;
  align-items: start;
}

.hero__kicker {
  margin: 0 0 28px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  color: var(--on-ink-muted);
}

.hero__kicker::before {
  content: "";
  display: inline-block;
  width: 28px;
  height: 1px;
  margin-right: 14px;
  vertical-align: middle;
  background: var(--accent);
}

.hero__title {
  margin: 0 0 28px;
  font-size: clamp(2.5rem, 6.4vw, 4.6rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
}

.hero__title span {
  color: var(--accent);
}

.hero__lead {
  max-width: 30em;
  margin: 0 0 36px;
  font-size: 1.08rem;
  line-height: 1.8;
  color: var(--on-ink-muted);
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

/* 规格表 */
.spec {
  position: relative;
  padding: 28px 28px 20px;
  border: 1px solid var(--on-ink-line);
  background: rgba(16, 28, 49, 0.6);
  backdrop-filter: blur(6px);
}

.spec::before,
.spec::after {
  content: "";
  position: absolute;
  width: 14px;
  height: 14px;
  border-color: var(--accent);
  border-style: solid;
}

.spec::before {
  top: -1px;
  left: -1px;
  border-width: 1px 0 0 1px;
}

.spec::after {
  right: -1px;
  bottom: -1px;
  border-width: 0 1px 1px 0;
}

.spec__head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--on-ink-line);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.12em;
  color: var(--on-ink-muted);
}

.spec__dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  margin-right: 10px;
  border-radius: 50%;
  background: var(--accent);
  vertical-align: middle;
  animation: pulse 2.4s ease-in-out infinite;
}

.spec__list > div {
  display: grid;
  grid-template-columns: 5.5em 1fr;
  gap: 14px;
  padding: 13px 0;
  border-bottom: 1px solid var(--on-ink-line);
}

.spec__list > div:last-child {
  border-bottom: 0;
}

.spec__list dt {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.08em;
  color: var(--on-ink-muted);
  padding-top: 3px;
}

.spec__list dd {
  color: var(--on-ink);
  font-weight: 500;
}

/* 首屏下方事实条 */
.facts {
  margin-top: clamp(56px, 8vw, 96px);
  border-top: 1px solid var(--on-ink-line);
}

.facts__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
}

.fact {
  padding: 24px 0;
  border-bottom: 1px solid var(--on-ink-line);
}

.fact:nth-child(odd) {
  padding-right: 20px;
  border-right: 1px solid var(--on-ink-line);
}

.fact:nth-child(even) {
  padding-left: 20px;
}

.fact strong {
  display: block;
  font: 500 clamp(2rem, 4vw, 2.8rem)/1 var(--font-mono);
  letter-spacing: -0.03em;
  color: var(--on-ink);
}

.fact strong sup {
  font-size: 0.5em;
  color: var(--accent);
  vertical-align: top;
  top: 0.1em;
  position: relative;
}

.fact span {
  display: block;
  margin-top: 8px;
  font-size: 0.9rem;
  color: var(--on-ink-muted);
}

/* ---------- 按钮 ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 13px 22px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  line-height: 1;
  transition: background 0.2s var(--ease), color 0.2s var(--ease),
    border-color 0.2s var(--ease), transform 0.2s var(--ease);
}

.btn::after {
  content: "→";
  font-family: var(--font-mono);
  transition: transform 0.2s var(--ease);
}

.btn:hover::after {
  transform: translateX(4px);
}

.btn--primary {
  background: var(--ink);
  color: var(--on-ink);
}

.btn--primary:hover {
  background: var(--accent);
  color: var(--on-ink);
}

.btn--light,
.on-ink .btn--light {
  background: var(--on-ink);
  color: var(--ink);
}

.btn--light:hover,
.on-ink .btn--light:hover {
  background: var(--accent);
  color: var(--on-ink);
}

.btn--outline {
  border-color: var(--on-ink-line);
  color: var(--on-ink);
}

.btn--outline:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.btn--outline-dark {
  border-color: var(--line-strong);
  color: var(--ink);
}

.btn--outline-dark:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ---------- 编号索引（产品线 / 业务方向） ---------- */

.index {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
}

.index__row {
  position: relative;
  display: grid;
  gap: 12px 32px;
  padding: 32px 0 32px 20px;
  transition: background 0.3s var(--ease);
}

.index__row::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: -1px;
  width: 2px;
  background: var(--accent);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 0.35s var(--ease);
}

.index__row:hover::before {
  transform: scaleY(1);
}

.index__num {
  font: 500 0.85rem/1.4 var(--font-mono);
  letter-spacing: 0.08em;
  color: var(--accent);
}

.index__body h3 {
  margin-bottom: 10px;
  font-size: 1.35rem;
}

.index__body p {
  margin: 0;
  max-width: 36em;
  color: var(--muted);
}

.index__tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  align-content: start;
}

.index__tags li {
  padding: 4px 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.04em;
  color: var(--muted);
  background: var(--paper);
}

.index__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--ink);
  white-space: nowrap;
}

.index__link small {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 400;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.index__link::after {
  content: "→";
  font-family: var(--font-mono);
  transition: transform 0.2s var(--ease);
}

.index__link:hover::after {
  transform: translateX(4px);
}

/* ---------- 案例档案 ---------- */

.dossier {
  display: grid;
  gap: 1px;
  margin-inline: calc(var(--gutter) * -1);
  background: var(--line);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.dossier > article {
  display: flex;
  flex-direction: column;
  padding: 32px var(--gutter);
  background: var(--paper);
  transition: background 0.3s var(--ease);
}

.dossier p {
  max-width: 40em;
}

.dossier > article:hover {
  background: #fbfaf7;
}

.dossier__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  margin-bottom: 20px;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.dossier__meta b {
  font-weight: 500;
  color: var(--accent);
}

.dossier h3 {
  font-size: 1.45rem;
  margin-bottom: 14px;
}

.dossier__main h3 {
  font-size: clamp(1.7rem, 2.6vw, 2.2rem);
}

.dossier p {
  color: var(--muted);
  margin-bottom: 20px;
}

.dossier .kv {
  margin: auto 0 24px;
}

.dossier__link {
  margin-top: auto;
  align-self: flex-start;
  font-weight: 600;
  color: var(--ink);
}

.dossier__link::after {
  content: " →";
  font-family: var(--font-mono);
}

/* 键值表 */
.kv > div {
  display: grid;
  grid-template-columns: max-content minmax(0, 1fr);
  gap: 8px 20px;
  padding: 10px 0;
  border-top: 1px solid var(--line);
}

.kv > div:last-child {
  border-bottom: 1px solid var(--line);
}

.kv dt {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.08em;
  color: var(--muted);
  padding-top: 4px;
  white-space: nowrap;
}

.kv dd {
  color: var(--text);
  font-size: 0.95rem;
}

.kv--ink > div {
  border-color: var(--on-ink-line);
}

.kv--ink dt {
  color: var(--on-ink-muted);
}

.kv--ink dd {
  color: var(--on-ink);
}

/* ---------- 原则 ---------- */

.principles {
  position: relative;
  display: grid;
  gap: 1px;
  background: var(--line);
}

.principle {
  padding: 32px 28px 32px 0;
  background: var(--paper);
}

.principle__num {
  display: block;
  margin-bottom: 20px;
  font: italic 400 1.6rem/1 var(--font-serif);
  color: var(--accent);
}

.principle strong {
  display: block;
  margin-bottom: 10px;
  font-size: 1.25rem;
  color: var(--ink);
  letter-spacing: -0.01em;
}

.principle p {
  margin: 0;
  font-size: 0.95rem;
  color: var(--muted);
}

/* ---------- 步骤 ---------- */

.steps {
  list-style: none;
  counter-reset: step;
  margin: 0;
  padding: 0;
  border-bottom: 1px solid var(--line);
}

.steps li {
  position: relative;
  padding: 20px 0 20px 64px;
  border-top: 1px solid var(--line);
}

.steps li::before {
  counter-increment: step;
  content: counter(step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 23px;
  font: 500 0.8rem/1 var(--font-mono);
  letter-spacing: 0.08em;
  color: var(--accent);
}

.steps strong {
  display: block;
  margin-bottom: 4px;
  color: var(--ink);
}

.steps p {
  margin: 0;
  color: var(--muted);
}

/* ---------- CTA 横幅 ---------- */

.band {
  padding: clamp(72px, 10vw, 120px) 0;
}

.band__inner {
  display: grid;
  gap: 32px 72px;
  align-items: center;
}

.band h2 {
  margin: 0;
  font-size: clamp(2rem, 4.8vw, 3.6rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.band p {
  margin: 0 0 28px;
  color: var(--on-ink-muted);
  max-width: 30em;
}

.band__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px 28px;
}

.band__mail {
  font-family: var(--font-mono);
  font-size: 1rem;
  letter-spacing: 0.04em;
  color: var(--on-ink);
  border-bottom: 1px solid var(--on-ink-line);
  padding-bottom: 2px;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

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

/* ---------- 页脚 ---------- */

.footer {
  position: relative;
  overflow: hidden;
  padding: clamp(56px, 7vw, 80px) 0 32px;
  background: var(--ink-2);
  border-top: 1px solid var(--on-ink-line);
  color: var(--on-ink-muted);
  font-size: 0.92rem;
}

.footer__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 40px;
  margin-bottom: clamp(48px, 7vw, 88px);
}

.footer__brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 18px;
  color: var(--on-ink);
  font-weight: 700;
}

.footer__brand svg {
  width: 28px;
  height: 28px;
}

.footer__brand em {
  font: italic 400 0.95rem/1 var(--font-serif);
  color: var(--on-ink-muted);
  margin-left: 2px;
}

.footer__desc {
  max-width: 28em;
  margin: 0;
}

.footer h4 {
  margin-bottom: 16px;
  font: 500 0.72rem/1 var(--font-mono);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--on-ink-muted);
}

.footer ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer li {
  margin-bottom: 10px;
}

.footer a {
  color: var(--on-ink);
}

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

.footer__bottom {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 24px;
  margin-top: 8px;
  padding: 20px 0 6px;
  border-top: 1px solid var(--on-ink-line);
  background: var(--ink-2);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.04em;
}

.footer__word {
  position: absolute;
  right: -0.04em;
  bottom: -0.42em;
  z-index: 0;
  font: italic 700 clamp(4rem, 11vw, 8.5rem)/1 var(--font-serif);
  letter-spacing: -0.04em;
  color: rgba(245, 243, 238, 0.05);
  pointer-events: none;
  user-select: none;
}

/* ---------- 内页标题区 ---------- */

.page-head {
  padding: clamp(56px, 8vw, 96px) 0 clamp(40px, 6vw, 64px);
}

.page-head__grid {
  display: grid;
  gap: 28px;
  align-items: end;
}

.page-head h1 {
  margin: 0 0 20px;
}

.page-head__lead {
  max-width: 34em;
  margin: 0;
  font-size: 1.05rem;
  color: var(--on-ink-muted);
}

.page-head__meta {
  justify-self: start;
}

/* ---------- 正文（协议类） ---------- */

.prose {
  max-width: 760px;
}

.prose .meta {
  margin-bottom: 40px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.prose h2 {
  margin-top: 2.4em;
  padding-top: 1.1em;
  border-top: 1px solid var(--line);
  font-size: 1.35rem;
}

.prose h2:first-of-type {
  margin-top: 0;
}

.prose h3 {
  margin-top: 1.6em;
  font-size: 1.05rem;
}

.prose li {
  margin-bottom: 0.45em;
}

.prose strong {
  color: var(--ink);
}

/* ---------- 解决方案页：案例 ---------- */

.case {
  position: relative;
  display: grid;
  gap: 36px 56px;
  padding: clamp(56px, 7vw, 96px) 0;
}

.case:first-of-type::before {
  display: none;
}

.case__body p,
.case__body .steps p {
  max-width: 44em;
}

.case__side {
  align-self: start;
}

.case__num {
  display: block;
  margin-bottom: 18px;
  font: 500 clamp(2.4rem, 4vw, 3.4rem)/1 var(--font-mono);
  letter-spacing: -0.03em;
  color: var(--paper-3);
  -webkit-text-stroke: 1px var(--line-strong);
}

.case__side .eyebrow {
  margin-bottom: 24px;
}

.case__status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 20px;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.case__status::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
}

.case__status--dev::before {
  background: transparent;
  border: 1px solid var(--accent);
}

.case__body h2 {
  margin-bottom: 18px;
}

.case__lead {
  font-size: 1.1rem;
  color: var(--text);
  margin-bottom: 32px;
}

.case__sub {
  margin: 40px 0 16px;
  font: 500 0.74rem/1 var(--font-mono);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.caps {
  list-style: none;
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.caps li {
  padding: 14px 16px;
  background: var(--paper);
  font-size: 0.92rem;
}

.caps li b {
  display: block;
  margin-bottom: 2px;
  font-weight: 600;
  color: var(--ink);
}

.caps li span {
  color: var(--muted);
  font-size: 0.86rem;
}

/* ---------- 联系渠道 ---------- */

.channels {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
}

.channels li {
  position: relative;
  display: grid;
  gap: 8px 32px;
  padding: 28px 0;
}

.channels p {
  max-width: 40em;
}

.channels h3 {
  margin: 0;
  font-size: 1.15rem;
}

.channels p {
  margin: 0;
  color: var(--muted);
}

.channels .mail {
  justify-self: start;
  font-family: var(--font-mono);
  font-size: 1rem;
  letter-spacing: 0.02em;
  color: var(--ink);
  border-bottom: 1px solid var(--line-strong);
  padding-bottom: 2px;
  white-space: nowrap;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.channels .mail:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.channels .note {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.06em;
  color: var(--muted);
}

/* ---------- FAQ ---------- */

.faq {
  border-top: 1px solid var(--line);
}

.faq details {
  border-bottom: 1px solid var(--line);
}

.faq summary {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  padding: 20px 0;
  cursor: pointer;
  list-style: none;
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--ink);
}

.faq summary::-webkit-details-marker {
  display: none;
}

.faq summary::after {
  content: "+";
  flex: none;
  font: 400 1.4rem/1 var(--font-mono);
  color: var(--accent);
  transition: transform 0.3s var(--ease);
}

.faq details[open] summary::after {
  transform: rotate(45deg);
}

.faq details p {
  margin: 0 0 22px;
  max-width: 44em;
  color: var(--muted);
}

/* ---------- 两栏 ---------- */

.two-col {
  display: grid;
  gap: 40px 72px;
}

.two-col > aside {
  align-self: start;
}

.two-col p {
  max-width: 40em;
}

.lead-statement {
  font-size: clamp(1.3rem, 2.2vw, 1.7rem);
  line-height: 1.55;
  color: var(--ink);
  letter-spacing: -0.01em;
  max-width: 28em;
  margin: 0 0 1.2em;
}

/* ---------- 404 ---------- */

.notfound {
  padding: clamp(96px, 16vw, 200px) 0;
  text-align: left;
}

.notfound h1 {
  font: 500 clamp(5rem, 16vw, 11rem)/1 var(--font-mono);
  letter-spacing: -0.05em;
  color: var(--paper-3);
  -webkit-text-stroke: 1px var(--line-strong);
  margin-bottom: 24px;
}

.notfound h2 {
  margin-bottom: 12px;
}

.notfound p {
  color: var(--muted);
  margin-bottom: 32px;
}

/* ---------- 动效 ---------- */

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(18px);
  }

  to {
    opacity: 1;
    transform: none;
  }
}

@keyframes pulse {
  0%,
  100% {
    box-shadow: 0 0 0 0 rgba(228, 87, 46, 0.5);
  }

  60% {
    box-shadow: 0 0 0 7px rgba(228, 87, 46, 0);
  }
}

.hero [data-rise],
.page-head [data-rise] {
  animation: rise 0.8s var(--ease) both;
  animation-delay: calc(var(--i, 0) * 110ms);
}

.js .reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

.js .reveal.is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .spec__list > div {
    grid-template-columns: 7.5em 1fr;
    gap: 16px;
  }

  .channels li {
    grid-template-columns: 180px 1fr;
  }

  .channels .mail {
    grid-column: 2;
  }

  .channels .note {
    grid-column: 2;
  }

  .caps {
    grid-template-columns: repeat(2, 1fr);
  }

  .facts__grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .fact {
    border-bottom: 0;
    padding: 28px 20px 32px;
    border-right: 1px solid var(--on-ink-line);
  }

  .fact:first-child {
    padding-left: 0;
  }

  .fact:last-child {
    border-right: 0;
  }

  .principles {
    grid-template-columns: repeat(2, 1fr);
  }

  .principle {
    padding: 32px 28px;
  }

  .principle:nth-child(odd) {
    padding-left: 0;
  }
}

@media (min-width: 900px) {
  .nav {
    display: flex;
  }

  .nav-toggle {
    display: none;
  }

  .hero__grid {
    grid-template-columns: minmax(0, 1fr) minmax(320px, 520px);
    gap: clamp(48px, 6vw, 120px);
    align-items: center;
  }

  .hero__title {
    font-size: clamp(2.5rem, 5.6vw, 6rem);
  }

  .spec {
    margin-top: 12px;
  }

  .section__head--split {
    grid-template-columns: minmax(0, 1.15fr) minmax(260px, 34em);
    justify-content: space-between;
  }

  .index__row {
    grid-template-columns: 72px minmax(0, 1.15fr) minmax(0, 1fr) minmax(220px, 0.6fr);
    align-items: start;
    padding: 40px 0 40px 24px;
  }

  .index__link {
    justify-self: end;
    justify-content: flex-end;
    max-width: 16em;
    text-align: right;
    white-space: normal;
  }

  .dossier {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    grid-template-rows: auto auto;
  }

  .dossier__main {
    grid-row: 1 / span 2;
    padding: 48px 48px 48px var(--gutter);
  }

  .dossier > article:not(.dossier__main) {
    padding: 40px var(--gutter) 40px 40px;
  }

  .principles {
    grid-template-columns: repeat(4, 1fr);
  }

  .principle {
    padding: 36px 28px 40px;
  }

  .principle:first-child {
    padding-left: 0;
  }

  .band__inner {
    grid-template-columns: minmax(0, 1fr) minmax(280px, 34em);
  }

  .footer__grid {
    grid-template-columns: 1.6fr 1fr 1fr 1fr;
  }

  .page-head__grid {
    grid-template-columns: minmax(0, 1fr) auto;
  }

  .page-head__meta {
    justify-self: end;
    min-width: 220px;
  }

  .case {
    grid-template-columns: minmax(280px, 380px) minmax(0, 1fr);
  }

  .case__side {
    position: sticky;
    top: calc(var(--header-height) + 32px);
  }

  .two-col {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  }

  .channels li {
    grid-template-columns: 200px minmax(0, 1fr) auto;
    align-items: start;
  }

  .channels .mail {
    grid-column: 3;
    grid-row: 1;
  }

  .channels .note {
    grid-column: 3;
    grid-row: 2;
    justify-self: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .js .reveal {
    opacity: 1;
    transform: none;
  }
}