/* =========================================================
   爱思助手 · 全站共享样式
   ========================================================= */

/* ---------- Design tokens ---------- */
:root {
  --bg: #0a0a0c;
  --bg-elevated: #111114;
  --panel: #141419;
  --panel-soft: #18181e;
  --ink: #ebe7de;
  --ink-strong: #fffaf0;
  --muted: #a49d90;
  --muted-2: #7e786d;
  --gold: #e3c56f;
  --gold-bright: #f5dc9c;
  --gold-deep: #b8934c;
  --line: rgba(227, 197, 111, 0.14);
  --line-strong: rgba(227, 197, 111, 0.32);
  --line-soft: rgba(255, 255, 255, 0.06);
  --gold-wash: rgba(227, 197, 111, 0.08);
  --shadow: 0 18px 40px rgba(0, 0, 0, 0.35);
  --radius-lg: 22px;
  --radius: 16px;
  --radius-sm: 10px;
  --max-width: 1180px;
  --gutter: clamp(18px, 4.5vw, 56px);
  --section-y: clamp(46px, 7vw, 86px);
  --font-sans: "Yuanti SC", "Hiragino Sans GB", "PingFang SC", "Microsoft YaHei", "Noto Sans SC", ui-rounded, sans-serif;
  --font-mono: "SFMono-Regular", "Consolas", "Menlo", monospace;
  --leading: 1.85;
}

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

html {
  color-scheme: dark;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background-color: var(--bg);
  background-image:
    radial-gradient(ellipse at 12% -10%, rgba(227, 197, 111, 0.11), transparent 46%),
    radial-gradient(ellipse at 90% 20%, rgba(227, 197, 111, 0.07), transparent 50%),
    radial-gradient(ellipse at 50% 100%, rgba(255, 255, 255, 0.03), transparent 60%);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: clamp(16px, 1.05vw, 17px);
  line-height: var(--leading);
  letter-spacing: 0.01em;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--gold-bright);
  text-decoration: none;
}

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

:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
}

::selection {
  background: rgba(227, 197, 111, 0.28);
  color: var(--ink-strong);
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 16px;
  z-index: 100;
  padding: 10px 14px;
  border-radius: 8px;
  background: var(--gold);
  color: #0a0a0c;
  font-weight: 600;
}

.skip-link:focus {
  top: 12px;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(10, 10, 12, 0.86);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}

.header-inner {
  max-width: var(--max-width);
  margin-inline: auto;
  padding: 16px var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink-strong);
}

.brand-mark {
  width: 48px;
  height: 48px;
  object-fit: contain;
  flex: none;
  border-radius: 10px;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.25;
}

.brand-name {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.brand-sub {
  font-size: 0.72rem;
  color: var(--muted);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: wrap;
}

.site-nav a {
  color: var(--muted);
  padding: 8px 14px;
  border-radius: 999px;
  font-size: 0.95rem;
  border: 1px solid transparent;
  transition: color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
}

.site-nav a:hover {
  color: var(--gold-bright);
  background: var(--gold-wash);
}

.site-nav a[aria-current="page"] {
  color: var(--gold-bright);
  background: var(--gold-wash);
  border-color: var(--line-strong);
}

/* ---------- Layout ---------- */
.wrap {
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  padding-block: var(--section-y);
}

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

.section-head {
  display: grid;
  gap: 12px;
  margin-bottom: clamp(28px, 4vw, 42px);
  max-width: 72ch;
}

.section-kicker {
  margin: 0;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--gold);
}

.section-lead {
  color: var(--muted);
  font-size: clamp(1rem, 1.3vw, 1.12rem);
  line-height: 1.9;
  max-width: 68ch;
}

/* ---------- Typography ---------- */
h1,
h2,
h3,
h4 {
  margin: 0;
  color: var(--ink-strong);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: 0.01em;
}

h1 {
  font-size: clamp(2.35rem, 5.8vw, 4.4rem);
  line-height: 1.18;
  text-wrap: balance;
}

h2 {
  font-size: clamp(1.7rem, 3.2vw, 2.6rem);
  line-height: 1.28;
  text-wrap: balance;
}

h3 {
  font-size: clamp(1.1rem, 1.8vw, 1.35rem);
}

p {
  margin: 0;
}

/* ---------- Hero ---------- */
.hero {
  padding-block: clamp(40px, 8vw, 96px) clamp(32px, 6vw, 72px);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: clamp(28px, 5vw, 64px);
  align-items: center;
}

.hero-copy {
  max-width: 640px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 18px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gold);
}

.hero h1 {
  max-width: 20ch;
  margin-bottom: 18px;
}

.hero-lead {
  max-width: 44em;
  margin-bottom: 26px;
  color: var(--muted);
  font-size: clamp(1rem, 1.3vw, 1.12rem);
  line-height: 1.9;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 26px;
}

.hero-facts {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.hero-facts li {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 7px 12px;
  font-size: 0.82rem;
  color: var(--muted);
  background: rgba(255, 255, 255, 0.02);
  line-height: 1.5;
}

.fact-label {
  color: var(--gold);
  font-weight: 600;
  margin-right: 6px;
}

/* ---------- Visual frames ---------- */
.hero-visual-wrap,
.timeline-visual-wrap,
.feature-visual-wrap {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: linear-gradient(145deg, rgba(227, 197, 111, 0.06), rgba(255, 255, 255, 0.02));
  padding: clamp(12px, 2vw, 22px);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.hero-visual-wrap {
  position: relative;
}

.hero-visual-wrap::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--line-strong), transparent);
  pointer-events: none;
}

.timeline-visual-wrap {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.feature-visual-wrap {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.hero-visual,
.timeline-visual,
.feature-visual {
  display: block;
  width: 100%;
  height: auto;
  margin-inline: auto;
}

.hero-visual {
  max-width: 720px;
}

.timeline-visual {
  max-width: 900px;
}

.feature-visual {
  max-width: 760px;
}

.visual-caption {
  margin-top: 10px;
  font-size: 0.78rem;
  color: var(--muted-2);
  line-height: 1.7;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  font-weight: 600;
  font-size: 0.95rem;
  line-height: 1.2;
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease, transform 0.2s ease;
}

.btn-primary {
  background: var(--gold);
  color: #111114;
  border-color: var(--gold);
}

.btn-primary:hover {
  background: var(--gold-bright);
  color: #0a0a0c;
  transform: translateY(-1px);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.02);
  color: var(--gold-bright);
  border-color: var(--line-strong);
}

.btn-secondary:hover {
  background: var(--gold-wash);
  border-color: var(--gold);
}

/* ---------- Cards & grids ---------- */
.card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(160deg, rgba(255, 255, 255, 0.035), rgba(255, 255, 255, 0.015));
  padding: clamp(18px, 2.4vw, 26px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.16);
  transition: border-color 0.2s ease;
}

.card:hover {
  border-color: var(--line-strong);
}

.two-col {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(16px, 2.5vw, 28px);
}

.three-col {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(16px, 2.5vw, 28px);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin-top: clamp(20px, 3vw, 32px);
}

.scenario-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(16px, 2.5vw, 28px);
}

.article-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(16px, 2.5vw, 28px);
}

.prose-card h3 {
  margin-bottom: 10px;
}

.prose-card p {
  color: var(--muted);
}

.prose-card p + p {
  margin-top: 0.8em;
}

/* ---------- Timeline ---------- */
.timeline-steps {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 14px;
  counter-reset: timeline;
}

.timeline-steps li {
  position: relative;
  padding: 16px 18px 16px 54px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.02);
  counter-increment: timeline;
}

.timeline-steps li::before {
  content: counter(timeline, decimal-leading-zero);
  position: absolute;
  left: 16px;
  top: 16px;
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  background: rgba(227, 197, 111, 0.06);
  color: var(--gold);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  box-sizing: border-box;
}

.step-title {
  display: block;
  margin-bottom: 4px;
  font-weight: 600;
  color: var(--ink-strong);
}

.timeline-steps p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.8;
}

/* ---------- Quick start ---------- */
.quickstart-steps {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.quickstart-steps li {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  background: rgba(255, 255, 255, 0.02);
  display: grid;
  gap: 8px;
}

.qs-no {
  font-family: var(--font-mono);
  color: var(--gold);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
}

.quickstart-steps h3 {
  font-size: 1rem;
}

.quickstart-steps p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.8;
}

/* ---------- Feature cards ---------- */
.feature-card {
  position: relative;
  padding-top: 20px;
}

.feature-index {
  display: inline-block;
  margin-bottom: 12px;
  padding-bottom: 4px;
  border-bottom: 1px solid var(--line-strong);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.feature-card h3 {
  margin-bottom: 8px;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.8;
}

/* ---------- Scenario cards ---------- */
.scenario-card h3 {
  margin-bottom: 10px;
}

.scenario-card .steps {
  margin: 0;
  padding-left: 1.2em;
  color: var(--muted);
}

.steps li {
  margin-bottom: 6px;
  font-size: 0.95rem;
  line-height: 1.8;
}

.steps li::marker {
  color: var(--gold);
}

.steps li:last-child {
  margin-bottom: 0;
}

/* ---------- Table ---------- */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.015);
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

table {
  width: 100%;
  min-width: 640px;
  border-collapse: collapse;
  font-size: 0.92rem;
  line-height: 1.6;
}

caption {
  caption-side: top;
  padding: 14px 18px;
  text-align: left;
  color: var(--gold);
  font-weight: 600;
  border-bottom: 1px solid var(--line);
}

thead th {
  padding: 12px 16px;
  border-bottom: 1px solid var(--line-strong);
  background: rgba(227, 197, 111, 0.06);
  color: var(--ink-strong);
  font-weight: 600;
  text-align: left;
  white-space: nowrap;
}

tbody td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  vertical-align: top;
}

tbody tr:last-child td {
  border-bottom: 0;
}

tbody tr:hover td {
  background: rgba(227, 197, 111, 0.04);
  color: var(--ink);
}

/* ---------- Check list ---------- */
.check-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 12px;
}

.check-list li {
  position: relative;
  padding-left: 26px;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.8;
}

.check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 8px;
  height: 8px;
  border: 1px solid var(--gold);
  border-radius: 50%;
  background: var(--gold-wash);
  box-sizing: border-box;
}

/* ---------- Meta list ---------- */
.meta-list {
  margin: 0;
  display: grid;
  gap: 10px;
}

.meta-row {
  display: grid;
  grid-template-columns: 8em 1fr;
  gap: 12px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
}

.meta-row:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.meta-list dt {
  color: var(--gold);
  font-weight: 600;
  font-size: 0.9rem;
  line-height: 1.6;
}

.meta-list dd {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.7;
  overflow-wrap: anywhere;
}

/* ---------- Code ---------- */
code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  color: var(--gold-bright);
  background: rgba(227, 197, 111, 0.06);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 2px 6px;
  overflow-wrap: anywhere;
}

/* ---------- Download panel ---------- */
.download-panel {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  gap: 18px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-lg);
  padding: clamp(18px, 3vw, 30px);
  background: radial-gradient(ellipse at 20% 0%, rgba(227, 197, 111, 0.1), transparent 55%), rgba(255, 255, 255, 0.015);
  margin-bottom: clamp(30px, 4vw, 48px);
  box-shadow: var(--shadow);
}

.download-copy h3 {
  margin-bottom: 10px;
}

.download-meta {
  list-style: none;
  padding: 0;
  margin: 0 0 18px;
  display: grid;
  gap: 8px;
}

.download-meta li {
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.7;
}

.download-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.download-file-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  background: rgba(0, 0, 0, 0.2);
  overflow: hidden;
}

.file-label {
  display: block;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gold);
}

.file-name {
  display: block;
  margin: 8px 0 12px;
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid var(--line-strong);
  background: rgba(227, 197, 111, 0.06);
  font-family: var(--font-mono);
  font-size: clamp(0.8rem, 1.2vw, 0.95rem);
  color: var(--gold-bright);
  overflow-wrap: anywhere;
  line-height: 1.5;
}

.download-file-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1.7;
  max-width: 40ch;
}

/* ---------- FAQ ---------- */
.faq-block {
  margin-top: clamp(28px, 4vw, 46px);
  max-width: 78ch;
}

.faq-block > h2 {
  margin-bottom: 16px;
}

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

.faq-item summary {
  list-style: none;
  cursor: pointer;
  padding: 16px 2px;
  font-weight: 600;
  color: var(--ink-strong);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  transition: color 0.2s ease;
}

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

.faq-item summary::after {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--gold);
}

.faq-item[open] summary::after {
  content: "−";
}

.faq-item[open] summary {
  color: var(--gold-bright);
}

.faq-item summary:hover {
  color: var(--gold-bright);
}

.faq-item p {
  margin: 0 0 18px;
  padding-left: 2px;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.8;
  max-width: 75ch;
}

/* ---------- Article cards ---------- */
.article-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.article-card:hover {
  transform: translateY(-2px);
}

.article-date {
  margin: 0;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--muted-2);
}

.article-card h3 {
  font-size: 1.08rem;
  line-height: 1.45;
}

.article-card p {
  color: var(--muted);
  font-size: 0.93rem;
  line-height: 1.8;
}

.card-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: auto;
  padding-top: 10px;
  border-top: 1px solid var(--line);
  font-weight: 600;
  color: var(--gold-bright);
  transition: color 0.2s ease;
}

.card-link::after {
  content: "→";
  color: var(--gold);
}

.card-link:hover {
  color: var(--gold);
}

/* ---------- Related reading ---------- */
.related-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.related-link {
  display: block;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.015);
  color: var(--ink);
  transition: border-color 0.2s ease, background-color 0.2s ease;
}

.related-link:hover {
  border-color: var(--line-strong);
  background: var(--gold-wash);
}

.related-title {
  display: block;
  margin-bottom: 3px;
  font-weight: 600;
  color: var(--gold-bright);
}

.related-desc {
  display: block;
  color: var(--muted);
  font-size: 0.88rem;
  line-height: 1.7;
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--line);
  background: rgba(14, 14, 18, 0.9);
  padding-block: clamp(30px, 5vw, 56px) 18px;
}

.footer-inner {
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--gutter);
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(0, 0.8fr) minmax(0, 1fr);
  gap: clamp(20px, 4vw, 48px);
  align-items: start;
}

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

.footer-brand p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.8;
  max-width: 34em;
}

.footer-nav h2,
.footer-download h2 {
  margin-bottom: 10px;
  font-size: 0.95rem;
  letter-spacing: 0.04em;
  color: var(--gold);
}

.footer-nav ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 8px;
}

.footer-nav a {
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.6;
  transition: color 0.2s ease;
}

.footer-nav a:hover {
  color: var(--gold-bright);
}

.footer-nav a[aria-current="page"] {
  color: var(--gold-bright);
  font-weight: 600;
}

.footer-download p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.7;
  max-width: 32em;
}

.footer-file {
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  line-height: 1.5;
  color: var(--gold-bright);
  overflow-wrap: anywhere;
}

.footer-download-link {
  display: inline-flex;
  margin-top: 10px;
  padding-bottom: 2px;
  border-bottom: 1px solid var(--line-strong);
  font-weight: 600;
  color: var(--gold-bright);
  transition: color 0.2s ease;
}

.footer-download-link:hover {
  color: var(--gold);
}

.footer-bottom {
  max-width: var(--max-width);
  margin-inline: auto;
  padding: 18px var(--gutter) 0;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  color: var(--muted-2);
  font-size: 0.8rem;
}

.footer-bottom p {
  margin: 0;
  line-height: 1.6;
  max-width: 60ch;
}

/* ---------- Shared page patterns ---------- */
.page-hero {
  padding-block: clamp(38px, 6vw, 76px);
  border-bottom: 1px solid var(--line);
}

.page-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  gap: clamp(24px, 4vw, 50px);
  align-items: center;
}

.page-hero .eyebrow {
  margin-bottom: 14px;
}

.download-hero {
  padding-block: clamp(38px, 6vw, 76px);
  border-bottom: 1px solid var(--line);
}

.download-hero .hero-lead {
  max-width: 60ch;
}

.article-hero {
  padding-block: clamp(38px, 6vw, 76px);
  border-bottom: 1px solid var(--line);
}

.article-hero .hero-lead {
  max-width: 62ch;
}

.download-card {
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-lg);
  padding: clamp(18px, 3vw, 28px);
  background: linear-gradient(145deg, rgba(227, 197, 111, 0.08), rgba(255, 255, 255, 0.02));
  box-shadow: var(--shadow);
}

.download-steps {
  display: grid;
  gap: 12px;
  list-style: none;
  padding: 0;
  margin: 0;
}

.download-steps li {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
  background: rgba(255, 255, 255, 0.02);
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.8;
}

.info-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.longform {
  max-width: 78ch;
}

.longform h2 {
  margin-top: clamp(28px, 4vw, 44px);
}

.longform h3 {
  margin-top: 24px;
}

.longform p,
.longform li {
  color: var(--muted);
}

.longform ul,
.longform ol {
  padding-left: 1.3em;
}

.longform blockquote {
  margin: 24px 0;
  border-left: 2px solid var(--gold);
  padding: 4px 0 4px 18px;
  color: var(--ink);
  font-size: 1rem;
  line-height: 1.8;
}

.callout {
  margin: 18px 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  background: var(--gold-wash);
  color: var(--ink);
  font-size: 0.95rem;
  line-height: 1.8;
}

.toc {
  margin-bottom: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  background: rgba(255, 255, 255, 0.015);
}

.toc ol {
  margin: 0;
  padding-left: 1.2em;
}

.toc a {
  color: var(--muted);
}

.toc a:hover {
  color: var(--gold-bright);
}

.toc li {
  margin-bottom: 6px;
}

.note {
  margin: 18px 0;
  border-left: 2px solid var(--gold);
  padding-left: 16px;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.8;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 5px 10px;
  font-size: 0.78rem;
  color: var(--muted);
  background: rgba(255, 255, 255, 0.02);
  line-height: 1.5;
}

.article-meta {
  font-size: 0.8rem;
  color: var(--muted-2);
  line-height: 1.6;
}

.download-note {
  margin-top: 12px;
  font-size: 0.85rem;
  color: var(--muted);
  line-height: 1.7;
}

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

/* ---------- SVG ---------- */
.svg-frame {
  fill: rgba(227, 197, 111, 0.03);
  stroke: var(--line);
  stroke-width: 1;
  stroke-linejoin: round;
}

.svg-device {
  fill: rgba(227, 197, 111, 0.04);
  stroke: var(--line-strong);
  stroke-width: 1.2;
  stroke-linejoin: round;
}

.svg-line {
  fill: none;
  stroke: var(--gold-deep);
  stroke-width: 1.3;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.svg-node {
  fill: none;
  stroke: var(--gold);
  stroke-width: 1.4;
  stroke-linecap: round;
}

.svg-star {
  fill: var(--gold-bright);
  stroke: none;
}

.svg-tile {
  fill: rgba(227, 197, 111, 0.035);
  stroke: var(--line-strong);
  stroke-width: 1;
  stroke-linejoin: round;
}

.svg-tile-icon {
  fill: none;
  stroke: var(--gold);
  stroke-width: 1.2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* ---------- SVG motion ---------- */
@keyframes star-twinkle {
  0%,
  100% {
    opacity: 0.55;
  }
  50% {
    opacity: 1;
  }
}

@keyframes line-draw {
  from {
    stroke-dashoffset: 1;
  }
  to {
    stroke-dashoffset: 0;
  }
}

@keyframes node-pulse {
  0%,
  100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.12);
  }
}

.twinkle-a {
  animation: star-twinkle 7s ease-in-out infinite;
}

.twinkle-b {
  animation: star-twinkle 9.5s ease-in-out infinite;
  animation-delay: -2.5s;
}

.twinkle-c {
  animation: star-twinkle 12s ease-in-out infinite;
  animation-delay: -5s;
}

.draw-line {
  stroke-dasharray: 1;
  stroke-dashoffset: 0;
  animation: line-draw 9s ease-in-out infinite alternate;
}

.draw-line--slow {
  animation-duration: 12s;
}

.draw-line--fast {
  animation-duration: 6s;
}

.draw-line--d1 {
  animation-delay: -2s;
}

.draw-line--d2 {
  animation-delay: -4s;
}

.draw-line--d3 {
  animation-delay: -6s;
}

.node-pulse {
  transform-box: fill-box;
  transform-origin: center;
  animation: node-pulse 6s ease-in-out infinite;
}

.node-pulse--slow {
  animation-duration: 10s;
}

/* ---------- Responsive ---------- */
@media (max-width: 980px) {
  .hero-grid,
  .two-col,
  .download-panel,
  .footer-inner,
  .page-hero-grid,
  .info-grid {
    grid-template-columns: 1fr;
  }

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

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

@media (max-width: 720px) {
  .feature-grid,
  .scenario-grid,
  .article-grid,
  .related-list,
  .quickstart-steps,
  .info-grid {
    grid-template-columns: 1fr;
  }

  .hero h1,
  .hero-copy,
  .hero-lead,
  .section-head,
  .section-lead,
  .hero-visual,
  .timeline-visual,
  .feature-visual {
    max-width: none;
  }

  .hero-actions .btn,
  .download-actions .btn {
    flex: 1 1 220px;
  }

  .meta-row {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 620px) {
  .header-inner {
    padding-block: 12px;
    gap: 10px;
  }

  .brand-mark {
    width: 40px;
    height: 40px;
  }

  .brand-name {
    font-size: 1rem;
  }

  .brand-sub {
    font-size: 0.66rem;
  }

  .site-nav {
    width: 100%;
    justify-content: space-between;
  }

  .site-nav a {
    padding: 8px 10px;
    flex: 1 1 auto;
    text-align: center;
  }
}

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

  .twinkle-a,
  .twinkle-b,
  .twinkle-c,
  .draw-line,
  .draw-line--slow,
  .draw-line--fast,
  .draw-line--d1,
  .draw-line--d2,
  .draw-line--d3,
  .node-pulse,
  .node-pulse--slow {
    animation: none;
  }

  .card,
  .article-card,
  .btn,
  .related-link,
  .site-nav a,
  .footer-nav a,
  .faq-item summary {
    transition: none;
  }
}