:root {
  --page: #ffffff;
  --page-soft: #f5f8fd;
  --surface: #ffffff;
  --surface-blue: #f1f6ff;
  --ink: #071838;
  --ink-2: #263653;
  --muted: #66748c;
  --line: #d9e2ef;
  --line-strong: #bdcce0;
  --blue: #0b61ff;
  --blue-dark: #084ed0;
  --cyan: #16bde2;
  --violet: #7357f6;
  --navy: #061c3c;
  --navy-2: #08294d;
  --success: #0e9f75;
  --radius-xs: 6px;
  --radius-sm: 9px;
  --radius: 13px;
  --shell: 1220px;
  --shadow-sm: 0 12px 34px rgba(17, 48, 96, 0.07);
  --shadow-md: 0 22px 60px rgba(17, 48, 96, 0.12);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  background: var(--page);
}

body {
  min-width: 320px;
  color: var(--ink);
  background: var(--page);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body.nav-open {
  overflow: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

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

button,
input,
textarea,
select {
  font: inherit;
}

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

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 3px solid rgba(11, 97, 255, 0.25);
  outline-offset: 3px;
}

::selection {
  color: #fff;
  background: var(--blue);
}

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 200;
  transform: translateY(-160%);
  padding: 9px 14px;
  border-radius: var(--radius-xs);
  color: #fff;
  background: var(--blue);
}

.skip-link:focus {
  transform: none;
}

.section-shell {
  width: min(var(--shell), calc(100% - 48px));
  margin-inline: auto;
}

/* Header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  border-bottom: 1px solid rgba(217, 226, 239, 0.85);
  background: rgba(255, 255, 255, 0.91);
  backdrop-filter: blur(18px) saturate(1.25);
  -webkit-backdrop-filter: blur(18px) saturate(1.25);
}

.site-nav {
  width: min(var(--shell), calc(100% - 48px));
  min-height: 76px;
  margin-inline: auto;
  display: flex;
  align-items: center;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  flex: 0 0 auto;
  color: var(--ink);
  font-size: 1.28rem;
  font-weight: 920;
  letter-spacing: -0.045em;
}

.brand-mark {
  width: 29px;
  height: 29px;
  display: inline-grid;
  place-items: center;
  border: 1px solid var(--blue);
  border-radius: var(--radius-xs);
  color: var(--blue);
  background: #fff;
  font-size: 0.68rem;
  font-weight: 950;
  letter-spacing: -0.04em;
}

.brand-logo {
  width: 44px;
  height: 44px;
  display: block;
  flex: 0 0 auto;
  object-fit: contain;
}

.nav-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 3px;
  margin-left: auto;
}

.nav-links a {
  position: relative;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  padding: 0 15px;
  color: var(--ink-2);
  font-size: 0.9rem;
  font-weight: 720;
  transition: color 0.2s ease;
}

.nav-links a::after {
  content: "";
  position: absolute;
  right: 14px;
  bottom: 5px;
  left: 14px;
  height: 2px;
  transform: scaleX(0);
  transform-origin: right;
  background: var(--blue);
  transition: transform 0.22s ease;
}

.nav-links .mobile-plan-link {
  display: none;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--blue);
}

.nav-links a:hover::after,
.nav-links a[aria-current="page"]::after {
  transform: scaleX(1);
  transform-origin: left;
}

.nav-action,
.primary-button,
.secondary-button {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid transparent;
  border-radius: var(--radius-xs);
  padding: 0 21px;
  font-weight: 820;
  line-height: 1.2;
  transition: transform 0.2s ease, box-shadow 0.2s ease, color 0.2s ease,
    background 0.2s ease, border-color 0.2s ease;
}

.nav-action,
.primary-button {
  color: #fff;
  background: var(--blue);
  box-shadow: 0 10px 24px rgba(11, 97, 255, 0.19);
}

.secondary-button {
  border-color: #84acf2;
  color: var(--blue);
  background: transparent;
}

.nav-action:hover,
.primary-button:hover,
.secondary-button:hover {
  transform: translateY(-2px);
}

.nav-action:hover,
.primary-button:hover {
  background: var(--blue-dark);
  box-shadow: 0 14px 30px rgba(11, 97, 255, 0.25);
}

.secondary-button:hover {
  border-color: var(--blue);
  background: var(--surface-blue);
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  margin-left: auto;
  border: 0;
  background: transparent;
  color: var(--ink);
}

.nav-toggle span {
  width: 22px;
  height: 2px;
  display: block;
  margin: 5px auto;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.site-nav.is-open .nav-toggle span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.site-nav.is-open .nav-toggle span:nth-child(2) {
  opacity: 0;
}

.site-nav.is-open .nav-toggle span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Homepage hero */

.hero {
  position: relative;
  overflow: hidden;
  padding: 68px 0 34px;
  background:
    linear-gradient(90deg, rgba(11, 97, 255, 0.025) 1px, transparent 1px),
    linear-gradient(rgba(11, 97, 255, 0.025) 1px, transparent 1px),
    linear-gradient(180deg, #fff 0%, #fafdff 100%);
  background-size: 72px 72px, 72px 72px, auto;
}

.hero::before,
.hero::after {
  content: "";
  position: absolute;
  z-index: 0;
  border: 1px solid rgba(11, 97, 255, 0.09);
  border-radius: 48% 52% 57% 43%;
  pointer-events: none;
}

.hero::before {
  width: 520px;
  height: 260px;
  top: 80px;
  right: -170px;
  transform: rotate(-14deg);
  box-shadow:
    0 0 0 34px rgba(11, 97, 255, 0.025),
    0 0 0 68px rgba(11, 97, 255, 0.018);
}

.hero::after {
  width: 330px;
  height: 170px;
  right: 28%;
  bottom: -126px;
  transform: rotate(18deg);
}

.hero .section-shell {
  position: relative;
  z-index: 1;
}

.hero-grid {
  min-height: 560px;
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(500px, 0.92fr);
  align-items: center;
  gap: clamp(42px, 5vw, 76px);
}

.hero-copy {
  max-width: 710px;
}

.hero h1,
.article-title {
  color: var(--ink);
  font-weight: 930;
  letter-spacing: -0.048em;
  text-wrap: balance;
}

.hero h1 {
  max-width: 760px;
  font-size: clamp(2.9rem, 3.5vw, 3.45rem);
  line-height: 1.08;
  text-wrap: wrap;
}

.hero-text {
  max-width: 650px;
  margin-top: 27px;
  color: var(--ink-2);
  font-size: clamp(1.05rem, 1.5vw, 1.22rem);
  line-height: 1.82;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 32px;
}

.hero .primary-button,
.hero .secondary-button {
  min-width: 178px;
}

.compat-panel {
  position: relative;
  min-height: 520px;
  isolation: isolate;
}

.compat-panel::before {
  content: "";
  position: absolute;
  inset: 28px -20px 18px;
  z-index: -2;
  background:
    radial-gradient(circle at 50% 12%, rgba(115, 87, 246, 0.08), transparent 23%),
    radial-gradient(circle at 15% 52%, rgba(22, 189, 226, 0.08), transparent 22%),
    radial-gradient(circle at 87% 58%, rgba(11, 97, 255, 0.08), transparent 25%);
}

.compat-panel::after {
  content: "";
  position: absolute;
  inset: 16px 6px 22px;
  z-index: -1;
  opacity: 0.42;
  background:
    repeating-radial-gradient(
      ellipse at 84% 32%,
      transparent 0 26px,
      rgba(11, 97, 255, 0.09) 27px 28px,
      transparent 29px 46px
    );
  mask-image: linear-gradient(90deg, transparent, #000 30%, #000 100%);
}

.panel-label {
  position: absolute;
  top: 10px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 820;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.signal-map {
  position: absolute;
  inset: 0;
  z-index: -1;
}

.signal-map svg {
  width: 100%;
  height: 100%;
}

.route {
  fill: none;
  stroke-linecap: round;
  stroke-width: 1.6;
}

.route-main {
  stroke: var(--blue);
}

.route-alt {
  stroke: var(--cyan);
  stroke-dasharray: 5 8;
}

.route-faint {
  stroke: rgba(115, 87, 246, 0.34);
  stroke-dasharray: 2 8;
}

.client-list {
  position: absolute;
  inset: 0;
}

.client-row {
  position: absolute;
  width: 205px;
  min-height: 76px;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: center;
  gap: 11px;
  padding: 10px 12px;
  border: 1px solid rgba(189, 204, 224, 0.9);
  border-radius: 38px;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 14px 36px rgba(16, 48, 98, 0.09);
  backdrop-filter: blur(8px);
  transition: transform 0.22s ease, border-color 0.22s ease, box-shadow 0.22s ease;
}

.client-row:hover {
  border-color: #8cb3f2;
  box-shadow: 0 18px 42px rgba(16, 48, 98, 0.14);
}

.client-row:nth-child(1) {
  top: 48px;
  left: 50%;
  transform: translateX(-50%);
}

.client-row:nth-child(1):hover {
  transform: translateX(-50%) translateY(-3px);
}

.client-row:nth-child(2) {
  top: 205px;
  right: -4px;
}

.client-row:nth-child(3) {
  top: 202px;
  left: -4px;
}

.client-row:nth-child(4) {
  bottom: 36px;
  left: 10%;
}

.client-row:nth-child(5) {
  right: 7%;
  bottom: 28px;
}

.client-icon {
  width: 47px;
  height: 47px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 auto;
  border: 1px solid rgba(162, 183, 214, 0.78);
  border-radius: 14px;
  color: var(--blue);
  background: #fff;
  font-size: 0.72rem;
  font-weight: 920;
  box-shadow: 0 0 0 6px rgba(11, 97, 255, 0.045);
  overflow: hidden;
}

.client-icon img {
  display: block;
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
}

.client-icon.app-logo {
  padding: 0;
  border-color: rgba(162, 183, 214, 0.62);
}

.client-icon.app-logo img {
  width: 100%;
  height: 100%;
}

.client-icon.platform-logo {
  padding: 9px;
}

.client-icon.platform-pair {
  gap: 4px;
  padding: 8px 6px;
}

.client-icon.platform-pair img {
  width: 17px;
  height: 17px;
}

.client-row strong,
.client-card h3 {
  display: block;
  color: var(--ink);
  font-weight: 850;
}

.client-row strong {
  overflow: hidden;
  font-size: 0.84rem;
  line-height: 1.3;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.client-row small,
.client-card p {
  display: block;
  color: var(--muted);
}

.client-row small {
  margin-top: 2px;
  font-size: 0.72rem;
  line-height: 1.35;
}

.support-label {
  display: none;
}

.trust-strip {
  margin-top: 8px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-block: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.74);
}

.trust-item {
  min-height: 94px;
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  align-items: center;
  gap: 14px;
  padding: 16px 24px;
}

.trust-item + .trust-item {
  border-left: 1px solid var(--line);
}

.mini-icon {
  width: 42px;
  height: 42px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid #9ebdf0;
  border-radius: 50%;
  color: var(--blue);
  background: #fff;
  font-size: 0.74rem;
  font-weight: 900;
}

.trust-item strong {
  display: block;
  color: var(--ink);
  font-size: 0.93rem;
}

.trust-item span span {
  display: block;
  margin-top: 1px;
  color: var(--muted);
  font-size: 0.78rem;
  line-height: 1.5;
}

/* Homepage sections */

.home-section {
  position: relative;
  padding: 108px 0;
}

.home-section.soft {
  border-block: 1px solid #e7edf5;
  background: var(--page-soft);
}

.section-heading {
  max-width: 800px;
  margin: 0 0 46px;
  text-align: left;
}

.section-heading::before {
  display: block;
  margin-bottom: 18px;
  color: rgba(11, 97, 255, 0.24);
  font-size: 0.93rem;
  font-weight: 900;
  letter-spacing: 0.18em;
}

.client-section .section-heading::before {
  content: "01 / CLIENTS";
}

.trust-section .section-heading::before {
  content: "03 / TRUST";
}

.steps-section .section-heading::before {
  content: "04 / START";
}

.guides-section .section-heading::before {
  content: "05 / GUIDES";
}

.faq-section .section-heading::before {
  content: "06 / FAQ";
}

.section-heading.align-left {
  margin-inline: 0;
}

.section-heading h2,
.content-band h2,
.article-main h2,
.lower-section h2 {
  color: var(--ink);
  font-weight: 900;
  letter-spacing: -0.035em;
  text-wrap: balance;
}

.section-heading h2,
.content-band h2 {
  font-size: clamp(2.25rem, 4vw, 3.7rem);
  line-height: 1.14;
}

.section-heading p {
  max-width: 670px;
  margin-top: 14px;
  color: var(--muted);
  font-size: 1rem;
}

/* Editorial client index */

.client-grid {
  counter-reset: client-row;
  border-top: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
}

.client-card {
  position: relative;
  min-height: 132px;
  display: grid;
  grid-template-columns: 175px minmax(210px, 0.8fr) minmax(280px, 1.35fr) auto;
  align-items: center;
  gap: 26px;
  padding: 24px 12px 24px 92px;
  background: transparent;
  counter-increment: client-row;
  transition: background 0.2s ease;
}

.client-card + .client-card {
  border-top: 1px solid var(--line);
}

.client-card::before {
  content: "0" counter(client-row);
  position: absolute;
  left: 12px;
  color: var(--blue);
  font-size: 1.5rem;
  font-weight: 880;
  letter-spacing: -0.04em;
}

.client-card::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 61px;
  width: 8px;
  height: 8px;
  transform: translateY(-50%);
  border: 2px solid #9ebdf0;
  border-radius: 50%;
  background: #fff;
}

.client-card:hover {
  background: #f8fbff;
}

.client-card-top {
  display: flex;
  align-items: center;
  gap: 12px;
}

.client-card-top .client-icon {
  width: 44px;
  height: 44px;
  box-shadow: none;
}

.client-tag {
  color: var(--muted);
  font-size: 0.73rem;
  font-weight: 760;
}

.client-card h3 {
  font-size: 1.08rem;
  line-height: 1.4;
}

.client-card p {
  font-size: 0.9rem;
  line-height: 1.65;
}

.text-link {
  color: var(--blue);
  font-size: 0.86rem;
  font-weight: 820;
  white-space: nowrap;
}

.text-link::after {
  content: "→";
  margin-left: 8px;
  transition: margin-left 0.2s ease;
}

.text-link:hover::after {
  margin-left: 12px;
}

/* Dark terminology band */

.concept-section,
.home-section.soft.concept-section {
  overflow: hidden;
  border: 0;
  color: #fff;
  background:
    radial-gradient(circle at 74% 35%, rgba(22, 189, 226, 0.12), transparent 30rem),
    linear-gradient(135deg, var(--navy) 0%, var(--navy-2) 100%);
}

.concept-section::before,
.concept-section::after {
  content: "";
  position: absolute;
  border: 1px dashed rgba(22, 189, 226, 0.38);
  border-radius: 50%;
  pointer-events: none;
}

.concept-section::before {
  width: 640px;
  height: 250px;
  right: -190px;
  bottom: -90px;
  transform: rotate(10deg);
}

.concept-section::after {
  width: 420px;
  height: 170px;
  right: 14%;
  bottom: -120px;
  border-color: rgba(115, 87, 246, 0.45);
}

.content-band {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 0.78fr) minmax(0, 1.22fr);
  gap: clamp(50px, 8vw, 110px);
  align-items: start;
}

.content-intro {
  position: sticky;
  top: 116px;
}

.content-intro::before {
  content: "02 / CONCEPTS";
  display: block;
  margin-bottom: 18px;
  color: rgba(255, 255, 255, 0.42);
  font-size: 0.93rem;
  font-weight: 900;
  letter-spacing: 0.18em;
}

.concept-section .content-intro h2 {
  color: #fff;
}

.content-intro p {
  margin-top: 20px;
  color: rgba(224, 235, 250, 0.72);
}

.concept-section .text-link {
  display: inline-block;
  margin-top: 26px;
  color: #72dbf1;
}

.definition-list {
  border-block: 1px solid rgba(210, 227, 250, 0.24);
}

.definition-item {
  display: grid;
  grid-template-columns: minmax(150px, 0.34fr) minmax(0, 1fr);
  gap: 30px;
  padding: 27px 0;
}

.definition-item + .definition-item {
  border-top: 1px solid rgba(210, 227, 250, 0.18);
}

.definition-item dt {
  position: relative;
  padding-left: 18px;
  color: #fff;
  font-weight: 900;
}

.definition-item dt::before {
  content: "";
  position: absolute;
  top: 0.67em;
  left: 0;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 5px rgba(22, 189, 226, 0.12);
}

.definition-item:nth-child(even) dt::before {
  background: var(--violet);
  box-shadow: 0 0 0 5px rgba(115, 87, 246, 0.13);
}

.definition-item dd {
  color: rgba(224, 235, 250, 0.72);
}

/* Trust section */

.trust-section {
  overflow: hidden;
}

.trust-section::before {
  content: "";
  position: absolute;
  top: 24%;
  left: -120px;
  width: 52%;
  height: 320px;
  border: 1px solid rgba(11, 97, 255, 0.11);
  border-radius: 50%;
  transform: rotate(-12deg);
  box-shadow:
    0 0 0 34px rgba(11, 97, 255, 0.018),
    0 0 0 68px rgba(11, 97, 255, 0.012);
  pointer-events: none;
}

.trust-section .section-shell {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(420px, 0.78fr);
  column-gap: clamp(70px, 10vw, 150px);
}

.trust-section .section-heading {
  align-self: start;
}

.trust-section .section-heading h2 {
  max-width: 590px;
}

.trust-section .section-heading h2::after {
  content: "专注事实、清晰来源与可验证的配置说明。";
  display: block;
  max-width: 560px;
  margin-top: 30px;
  color: var(--ink);
  font-family: Georgia, "Times New Roman", "Songti SC", serif;
  font-size: clamp(1.45rem, 2.4vw, 2.15rem);
  font-weight: 500;
  line-height: 1.48;
  letter-spacing: -0.02em;
}

.principle-grid {
  grid-column: 2;
  grid-row: 1 / span 2;
  display: grid;
  align-content: start;
  border-top: 1px solid var(--line-strong);
}

.principle-grid article {
  position: relative;
  padding: 23px 4px 23px 62px;
  border-bottom: 1px solid var(--line);
  background: transparent;
}

.principle-grid article::before {
  content: "";
  position: absolute;
  top: 28px;
  left: 9px;
  width: 30px;
  height: 30px;
  border: 1px solid #9ebdf0;
  border-radius: 50%;
  background:
    radial-gradient(circle, var(--blue) 0 3px, transparent 4px),
    #fff;
}

.principle-grid strong {
  display: block;
  color: var(--ink);
  font-size: 1.02rem;
}

.principle-grid p {
  margin-top: 6px;
  color: var(--muted);
  font-size: 0.9rem;
}

.trust-actions {
  align-self: end;
  margin-top: 8px;
}

/* Steps */

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

.steps-grid {
  position: relative;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
}

.steps-grid::before {
  content: "";
  position: absolute;
  top: 26px;
  right: 16%;
  left: 16%;
  height: 1px;
  background: var(--line-strong);
}

.step-card {
  position: relative;
  padding: 0 clamp(18px, 3vw, 42px);
  text-align: center;
  background: transparent;
}

.step-number {
  position: relative;
  z-index: 1;
  width: 54px;
  height: 54px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid #9ebdf0;
  border-radius: 50%;
  color: var(--blue);
  background: #fff;
  font-size: 0.9rem;
  font-weight: 900;
  box-shadow: 0 0 0 8px #fbfdff;
}

.step-card:nth-child(2) .step-number {
  color: #fff;
  border-color: var(--blue);
  background: var(--blue);
}

.step-card h3 {
  margin-top: 22px;
  color: var(--ink);
  font-size: 1.05rem;
}

.step-card p {
  max-width: 310px;
  margin: 9px auto 0;
  color: var(--muted);
  font-size: 0.88rem;
}

/* Guides and FAQ */

.guide-list,
.issue-list,
.related-list {
  counter-reset: editorial-link;
  border-top: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
}

.guide-link,
.issue-link,
.related-link {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 20px;
  padding: 22px 22px 22px 74px;
  counter-increment: editorial-link;
  transition: padding-left 0.2s ease, background 0.2s ease;
}

.guide-link::before,
.issue-link::before,
.related-link::before {
  content: "0" counter(editorial-link);
  position: absolute;
  left: 18px;
  color: rgba(11, 97, 255, 0.48);
  font-size: 0.82rem;
  font-weight: 900;
  letter-spacing: 0.08em;
}

.guide-link + .guide-link,
.issue-link + .issue-link,
.related-link + .related-link {
  border-top: 1px solid var(--line);
}

.guide-link:hover,
.issue-link:hover,
.related-link:hover {
  padding-left: 80px;
  background: #fff;
}

.guide-link strong,
.issue-link strong,
.related-link strong {
  display: block;
  color: var(--ink);
}

.guide-link span span,
.issue-link span span,
.related-link span span {
  display: block;
  margin-top: 3px;
  color: var(--muted);
  font-size: 0.86rem;
}

.arrow {
  color: var(--blue);
  font-size: 1.18rem;
  font-weight: 900;
}

.faq-section {
  background:
    linear-gradient(90deg, transparent 0 66%, rgba(11, 97, 255, 0.026) 66% 100%),
    #fff;
}

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

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

.faq-item summary {
  position: relative;
  display: block;
  cursor: pointer;
  padding: 21px 58px 21px 4px;
  color: var(--ink);
  font-weight: 830;
  list-style: none;
}

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

.faq-item summary::after {
  content: "+";
  position: absolute;
  top: 50%;
  right: 8px;
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  transform: translateY(-50%);
  border: 1px solid var(--line);
  border-radius: 50%;
  color: var(--blue);
  font-size: 1.15rem;
  font-weight: 500;
}

.faq-item[open] summary::after {
  content: "−";
  color: #fff;
  border-color: var(--blue);
  background: var(--blue);
}

.faq-answer {
  max-width: 900px;
  padding: 0 58px 24px 4px;
  color: var(--muted);
}

/* Article cover */

.article-hero {
  position: relative;
  min-height: 430px;
  overflow: hidden;
  padding-top: 54px;
  padding-bottom: 50px;
}

.article-hero::before {
  content: "";
  position: absolute;
  z-index: -1;
  top: -12%;
  right: -12%;
  width: 62%;
  height: 125%;
  opacity: 0.9;
  background:
    radial-gradient(circle at 55% 44%, rgba(22, 189, 226, 0.11), transparent 4px),
    repeating-radial-gradient(
      ellipse at 70% 48%,
      transparent 0 28px,
      rgba(11, 97, 255, 0.08) 29px 30px,
      transparent 31px 46px
    );
  mask-image: linear-gradient(90deg, transparent 0, #000 38%, #000 100%);
}

.article-hero::after {
  content: "";
  position: absolute;
  z-index: -1;
  right: 3%;
  bottom: 23%;
  width: 47%;
  height: 2px;
  transform: rotate(-13deg);
  background: linear-gradient(90deg, transparent, var(--blue) 18% 76%, var(--cyan));
  box-shadow:
    90px 64px 0 -0.4px rgba(11, 97, 255, 0.55),
    -35px -68px 0 -0.4px rgba(115, 87, 246, 0.42);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  color: var(--muted);
  font-size: 0.82rem;
}

.breadcrumb a:hover {
  color: var(--blue);
}

.breadcrumb span:not(:last-child)::after,
.breadcrumb a::after {
  content: "/";
  margin-left: 8px;
  color: #9ba9be;
}

.article-title {
  max-width: 940px;
  margin-top: 34px;
  font-size: clamp(3rem, 5.4vw, 5.1rem);
  line-height: 1.08;
}

.article-lead {
  max-width: 820px;
  margin-top: 23px;
  color: var(--ink-2);
  font-size: 1.08rem;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 9px 22px;
  margin-top: 22px;
  color: var(--muted);
  font-size: 0.8rem;
}

.article-meta span {
  position: relative;
}

.article-meta span + span::before {
  content: "";
  position: absolute;
  top: 50%;
  left: -12px;
  width: 3px;
  height: 3px;
  transform: translateY(-50%);
  border-radius: 50%;
  background: var(--line-strong);
}

.article-meta a {
  color: var(--blue);
  font-weight: 800;
}

/* Article body */

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: clamp(44px, 7vw, 92px);
  align-items: start;
  padding: 44px 0 104px;
}

.article-main {
  min-width: 0;
}

.article-aside {
  position: sticky;
  top: 104px;
  display: grid;
  gap: 22px;
}

.toc,
.aside-card {
  padding: 22px 0 22px 24px;
  border-left: 1px solid var(--line-strong);
  background: transparent;
}

.toc h2,
.aside-card h2 {
  color: var(--ink);
  font-size: 0.94rem;
  font-weight: 900;
}

.toc ol {
  margin-top: 13px;
  list-style: none;
}

.toc li + li {
  margin-top: 2px;
}

.toc a {
  position: relative;
  display: block;
  padding: 6px 0;
  color: var(--muted);
  font-size: 0.82rem;
  transition: color 0.2s ease, padding-left 0.2s ease;
}

.toc a:hover {
  padding-left: 8px;
  color: var(--blue);
}

.aside-links {
  margin-top: 12px;
  list-style: none;
}

.aside-links a {
  display: block;
  padding: 10px 0;
  border-top: 1px solid var(--line);
  color: var(--ink-2);
  font-size: 0.84rem;
  font-weight: 740;
}

.notice,
.answer-box {
  border-left: 4px solid var(--blue);
}

.notice {
  padding: 17px 20px;
  color: var(--ink-2);
  background: #f3f7fd;
}

.answer-box {
  margin-top: 22px;
  padding: 23px 25px;
  background: linear-gradient(100deg, #edf5ff, #f8fbff);
}

.answer-box h2 {
  margin: 0;
  padding: 0;
  color: var(--blue);
  font-size: 1.14rem;
}

.answer-box ul {
  margin: 12px 0 0 20px;
  color: var(--ink-2);
}

.answer-box p {
  margin-top: 10px;
}

.article-main h2 {
  position: relative;
  margin-top: 58px;
  padding-top: 12px;
  font-size: clamp(1.65rem, 2.8vw, 2.25rem);
  line-height: 1.25;
  scroll-margin-top: 100px;
}

.article-main h2::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 34px;
  height: 3px;
  background: var(--blue);
}

.answer-box h2::before,
.lower-section h2::before,
.toc h2::before,
.aside-card h2::before {
  display: none;
}

.article-main section[id] {
  scroll-margin-top: 100px;
}

.article-main h3 {
  margin-top: 30px;
  color: var(--ink);
  font-size: 1.16rem;
}

.article-main p {
  max-width: 790px;
  margin-top: 15px;
  color: var(--ink-2);
}

.article-main ul,
.article-main ol:not(.steps) {
  max-width: 790px;
  margin: 15px 0 0 24px;
  color: var(--ink-2);
}

.article-main li + li {
  margin-top: 7px;
}

.article-main a:not(.primary-button):not(.secondary-button):not(.guide-link):not(.issue-link):not(.related-link) {
  color: var(--blue);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.steps {
  position: relative;
  max-width: 790px;
  margin-top: 24px;
  list-style: none;
  counter-reset: article-step;
}

.steps li {
  position: relative;
  min-height: 66px;
  padding: 2px 0 22px 56px;
  counter-increment: article-step;
}

.steps li::before {
  content: counter(article-step);
  position: absolute;
  top: 0;
  left: 0;
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border: 1px solid #8fb2ee;
  border-radius: 50%;
  color: var(--blue);
  background: #fff;
  font-size: 0.82rem;
  font-weight: 900;
}

.steps li::after {
  content: "";
  position: absolute;
  top: 40px;
  bottom: -1px;
  left: 16px;
  width: 1px;
  background: var(--line);
}

.steps li:last-child::after {
  display: none;
}

.device-frame {
  min-height: 250px;
  margin-top: 26px;
  display: grid;
  place-items: center;
  border-block: 1px solid var(--line);
  background:
    linear-gradient(rgba(11, 97, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(11, 97, 255, 0.035) 1px, transparent 1px),
    #fafdff;
  background-size: 34px 34px;
}

.phone-outline {
  width: 126px;
  height: 210px;
  display: grid;
  place-items: center;
  border: 3px solid #9bb4d5;
  border-bottom: 0;
  border-radius: 28px 28px 0 0;
  color: var(--muted);
  font-size: 0.76rem;
}

.table-wrap {
  margin-top: 22px;
  overflow-x: auto;
  border-block: 1px solid var(--line-strong);
  background: #fff;
}

.compare-table {
  width: 100%;
  min-width: 720px;
  border-collapse: collapse;
}

.compare-table th,
.compare-table td {
  padding: 16px 17px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.compare-table th {
  color: var(--blue);
  background: #f5f8fd;
  font-size: 0.86rem;
  font-weight: 850;
}

.compare-table td {
  color: var(--ink-2);
  font-size: 0.88rem;
}

.compare-table th:first-child,
.compare-table td:first-child {
  width: 150px;
  color: var(--ink);
  font-weight: 850;
}

.compare-table tr:last-child td {
  border-bottom: 0;
}

.compare-table th:last-child,
.compare-table td:last-child {
  border-right: 0;
}

.check-list {
  margin-top: 18px;
  list-style: none;
}

.check-list li {
  position: relative;
  padding-left: 26px;
}

.check-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--success);
  font-weight: 900;
}

.principle-grid,
.source-list {
  margin-top: 20px;
}

.article-main .principle-grid {
  grid-column: auto;
  grid-row: auto;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--line-strong);
}

.article-main .principle-grid article:nth-child(odd) {
  border-right: 1px solid var(--line);
}

.article-main .principle-grid article {
  padding-right: 24px;
}

.source-list {
  border-top: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
  background: #fff;
}

.article-main .source-list {
  margin: 20px 0 0;
  padding: 0;
}

.source-list li {
  margin: 0 !important;
  padding: 16px 4px;
  list-style: none;
}

.source-list li + li {
  border-top: 1px solid var(--line);
}

.source-list a {
  font-weight: 800;
}

.source-list small {
  display: block;
  margin-top: 3px;
  color: var(--muted);
}

.lower-section {
  margin-top: 58px;
}

.lower-section h2 {
  margin: 0 0 19px;
  padding: 0;
}

.cta-band {
  margin-top: 58px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  padding: 28px 0;
  border-block: 1px solid var(--line-strong);
}

.cta-band h2 {
  margin: 0;
  padding: 0;
  font-size: 1.45rem;
}

.cta-band p {
  margin-top: 6px;
  color: var(--muted);
}

/* Footer */

.site-footer {
  color: #fff;
  background:
    radial-gradient(circle at 80% 10%, rgba(22, 189, 226, 0.1), transparent 24rem),
    var(--navy);
}

.footer-inner {
  min-height: 194px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(380px, auto);
  align-items: center;
  gap: 54px;
}

.site-footer .brand {
  color: #fff;
}

.site-footer .brand-mark {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.5);
  background: transparent;
}

.footer-copy p {
  max-width: 620px;
  margin-top: 12px;
  color: rgba(225, 235, 249, 0.65);
  font-size: 0.84rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 9px 22px;
}

.footer-links a {
  color: rgba(238, 245, 255, 0.78);
  font-size: 0.84rem;
  font-weight: 700;
}

.footer-links a:hover {
  color: #fff;
}

.legal-note {
  padding: 17px 0 25px;
  border-top: 1px solid rgba(220, 234, 252, 0.14);
  color: rgba(225, 235, 249, 0.48);
  font-size: 0.76rem;
}

/* Responsive */

@media (max-width: 1080px) {
  .hero-grid {
    grid-template-columns: minmax(0, 1fr) minmax(430px, 0.86fr);
    gap: 32px;
  }

  .client-row {
    width: 188px;
  }

  .client-card {
    grid-template-columns: 155px minmax(190px, 0.8fr) minmax(220px, 1.2fr);
  }

  .client-card .text-link {
    grid-column: 2 / -1;
    justify-self: start;
    margin-top: -14px;
  }

  .trust-section .section-shell {
    grid-template-columns: minmax(0, 0.9fr) minmax(380px, 0.8fr);
    column-gap: 60px;
  }
}

@media (max-width: 900px) {
  .nav-links a {
    padding-inline: 10px;
    font-size: 0.84rem;
  }

  .hero-grid,
  .content-band,
  .article-layout {
    grid-template-columns: 1fr;
  }

  .hero-grid {
    min-height: auto;
  }

  .hero-copy {
    max-width: 780px;
  }

  .compat-panel {
    width: min(620px, 100%);
    margin: 8px auto 0;
  }

  .content-intro,
  .article-aside {
    position: static;
  }

  .article-aside {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .trust-section .section-shell {
    grid-template-columns: 1fr;
  }

  .principle-grid {
    grid-column: auto;
    grid-row: auto;
    margin-top: 14px;
  }

  .trust-actions {
    margin-top: 34px;
  }

  .footer-inner {
    grid-template-columns: 1fr;
    align-content: center;
    padding-block: 42px;
  }

  .footer-links {
    justify-content: flex-start;
  }
}

@media (max-width: 820px) {
  .site-nav {
    position: relative;
    width: min(100% - 32px, 760px);
    min-height: 66px;
  }

  .nav-toggle {
    display: block;
  }

  .nav-action {
    display: none;
  }

  .nav-links {
    position: absolute;
    top: calc(100% + 1px);
    right: -16px;
    left: -16px;
    display: none;
    align-items: stretch;
    padding: 10px 16px 16px;
    border-bottom: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-md);
  }

  .site-nav.is-open .nav-links {
    display: grid;
  }

  .nav-links a {
    min-height: 48px;
    padding-inline: 4px;
    border-bottom: 1px solid var(--line);
    font-size: 0.93rem;
  }

  .site-nav .nav-links .mobile-plan-link {
    display: inline-flex;
    justify-content: center;
    margin-top: 8px;
    padding-inline: 16px;
    border: 1px solid transparent;
    border-radius: var(--radius-xs);
    color: #fff;
    background: var(--blue);
    box-shadow: 0 10px 24px rgba(11, 97, 255, 0.16);
  }

  .site-nav .nav-links .mobile-plan-link:hover {
    color: #fff;
    background: var(--blue-dark);
  }

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

  .client-card {
    grid-template-columns: 140px minmax(180px, 0.8fr) minmax(0, 1.2fr);
    padding-left: 78px;
  }

  .client-card::before {
    left: 5px;
  }

  .client-card::after {
    left: 50px;
  }

  .steps-grid {
    grid-template-columns: 1fr;
    gap: 34px;
  }

  .steps-grid::before {
    top: 26px;
    bottom: 26px;
    left: 27px;
    width: 1px;
    height: auto;
  }

  .step-card {
    display: grid;
    grid-template-columns: 54px minmax(0, 1fr);
    column-gap: 20px;
    padding: 0;
    text-align: left;
  }

  .step-number {
    grid-row: 1 / span 2;
    box-shadow: 0 0 0 8px #fbfdff;
  }

  .step-card h3,
  .step-card p {
    margin-inline: 0;
  }

  .step-card h3 {
    margin-top: 0;
  }

  .step-card p {
    margin-top: 5px;
  }
}

@media (max-width: 680px) {
  body {
    font-size: 15.5px;
  }

  .section-shell {
    width: min(100% - 32px, var(--shell));
  }

  .site-nav {
    width: calc(100% - 32px);
  }

  .brand {
    font-size: 1.14rem;
  }

  .brand-mark {
    width: 27px;
    height: 27px;
  }

  .brand-logo {
    width: 38px;
    height: 38px;
  }

  .hero {
    padding: 42px 0 24px;
    background-size: 48px 48px, 48px 48px, auto;
  }

  .hero h1 {
    font-size: clamp(2.55rem, 11.9vw, 3.55rem);
    line-height: 1.1;
    letter-spacing: -0.045em;
    overflow-wrap: anywhere;
  }

  .hero-text {
    margin-top: 20px;
    font-size: 1rem;
    line-height: 1.72;
  }

  .hero-actions {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
    margin-top: 25px;
  }

  .hero .primary-button,
  .hero .secondary-button {
    min-width: 0;
    padding-inline: 12px;
    font-size: 0.89rem;
  }

  .compat-panel {
    min-height: 470px;
    margin-top: 6px;
  }

  .panel-label {
    top: 18px;
  }

  .client-row {
    width: 164px;
    min-height: 64px;
    padding: 8px 9px;
    border-radius: 33px;
  }

  .client-row:nth-child(1) {
    top: 48px;
  }

  .client-row:nth-child(2) {
    top: 188px;
    right: 0;
  }

  .client-row:nth-child(3) {
    top: 188px;
    left: 0;
  }

  .client-row:nth-child(4) {
    bottom: 36px;
    left: 0;
  }

  .client-row:nth-child(5) {
    right: 0;
    bottom: 28px;
  }

  .client-icon {
    width: 39px;
    height: 39px;
    font-size: 0.64rem;
    box-shadow: 0 0 0 4px rgba(11, 97, 255, 0.04);
  }

  .client-row strong {
    font-size: 0.75rem;
  }

  .client-row small {
    font-size: 0.64rem;
  }

  .trust-strip {
    display: block;
  }

  .trust-item {
    min-height: 76px;
    padding: 12px 6px;
  }

  .trust-item + .trust-item {
    border-top: 1px solid var(--line);
    border-left: 0;
  }

  .mini-icon {
    width: 38px;
    height: 38px;
  }

  .home-section {
    padding: 76px 0;
  }

  .section-heading {
    margin-bottom: 31px;
  }

  .section-heading::before,
  .content-intro::before {
    margin-bottom: 13px;
    font-size: 0.78rem;
  }

  .section-heading h2,
  .content-band h2 {
    font-size: 2.2rem;
  }

  .client-card {
    min-height: 0;
    grid-template-columns: minmax(0, 1fr);
    gap: 9px;
    padding: 24px 8px 24px 62px;
  }

  .client-card::before {
    top: 24px;
    left: 4px;
    font-size: 1.2rem;
  }

  .client-card::after {
    top: 55px;
    left: 14px;
  }

  .client-card-top {
    grid-row: auto;
  }

  .client-card .text-link {
    grid-column: auto;
    margin-top: 4px;
  }

  .client-card h3 {
    font-size: 1rem;
  }

  .content-band {
    gap: 42px;
  }

  .definition-item {
    grid-template-columns: 1fr;
    gap: 8px;
    padding: 22px 0;
  }

  .trust-section .section-heading h2::after {
    margin-top: 22px;
    font-size: 1.38rem;
  }

  .principle-grid article {
    padding: 20px 0 20px 52px;
  }

  .principle-grid article::before {
    left: 3px;
  }

  .trust-actions {
    display: grid;
  }

  .guide-link,
  .issue-link,
  .related-link {
    padding: 19px 40px 19px 52px;
  }

  .guide-link::before,
  .issue-link::before,
  .related-link::before {
    left: 7px;
  }

  .guide-link:hover,
  .issue-link:hover,
  .related-link:hover {
    padding-left: 56px;
  }

  .faq-section {
    background: #fff;
  }

  .faq-item summary {
    padding: 19px 48px 19px 2px;
  }

  .faq-answer {
    padding: 0 48px 22px 2px;
  }

  .article-hero {
    min-height: auto;
    padding-top: 34px;
    padding-bottom: 36px;
  }

  .article-hero::before {
    top: 35%;
    right: -45%;
    width: 120%;
    height: 75%;
    opacity: 0.5;
  }

  .article-title {
    margin-top: 25px;
    font-size: clamp(1.95rem, 7.9vw, 2.6rem);
    line-height: 1.16;
    letter-spacing: -0.04em;
    overflow-wrap: anywhere;
  }

  .article-lead {
    font-size: 1rem;
  }

  .article-meta span + span::before {
    display: none;
  }

  .article-layout {
    gap: 42px;
    padding-top: 26px;
    padding-bottom: 76px;
  }

  .article-aside {
    grid-template-columns: 1fr;
  }

  .toc {
    display: none;
  }

  .notice,
  .answer-box {
    padding: 16px 17px;
  }

  .article-main h2 {
    margin-top: 46px;
  }

  .article-main .principle-grid {
    grid-template-columns: 1fr;
  }

  .article-main .principle-grid article:nth-child(odd) {
    border-right: 0;
  }

  .device-frame {
    min-height: 230px;
  }

  .cta-band {
    display: grid;
    padding: 24px 0;
  }

  .cta-band .primary-button {
    width: 100%;
  }

  .footer-inner {
    min-height: 0;
    padding-block: 40px;
  }

  .footer-links {
    gap: 10px 18px;
  }
}

@media (max-width: 380px) {
  .hero-actions {
    grid-template-columns: 1fr;
  }

  .client-row {
    width: 150px;
  }

  .client-row strong {
    font-size: 0.7rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}