/* ============================================================
   爱思助手 · i4Tools
   全站共享样式：设计变量、排版、页头页脚、通用组件、SVG 动效
   ============================================================ */

/* ---------- 设计变量 ---------- */
:root {
  --bg: #061224;
  --bg-deep: #04101e;
  --panel: #0b1c32;
  --panel-2: #102542;
  --ink: #eaf3ff;
  --muted: #a8bed9;
  --line: #23405c;
  --line-strong: #31536f;
  --accent: #63f5ff;
  --accent-2: #8fa8ff;
  --accent-3: #c6ff9a;
  --serif: "Cormorant Garamond", "Noto Serif SC", "Songti SC", Georgia, "Times New Roman", serif;
  --sans: "Inter", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --radius: 18px;
  --radius-sm: 12px;
  --shadow: 0 18px 50px rgba(0, 0, 0, .35);
  --shadow-neon: 0 0 0 1px rgba(99, 245, 255, .18), 0 10px 30px rgba(99, 245, 255, .12);
  --container: 1200px;
  --gutter: clamp(1rem, 4vw, 2.5rem);
}

/* ---------- 基础排版 ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
}

body {
  margin: 0;
  font-family: var(--sans);
  font-size: clamp(.98rem, 1vw, 1.12rem);
  line-height: 1.7;
  color: var(--ink);
  background:
    radial-gradient(1200px 600px at 12% -10%, rgba(80, 160, 255, .12), transparent 60%),
    radial-gradient(900px 500px at 92% 8%, rgba(99, 245, 255, .10), transparent 55%),
    var(--bg);
  overflow-x: clip;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection {
  background: var(--accent);
  color: #04101e;
}

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

h1,
h2,
h3,
h4 {
  font-family: var(--serif);
  font-weight: 650;
  line-height: 1.12;
  letter-spacing: -.01em;
  text-wrap: balance;
  margin: 0 0 .6em;
}

h1 {
  font-size: clamp(2.4rem, 4.8vw, 4.2rem);
}

h2 {
  font-size: clamp(1.8rem, 2.8vw, 2.8rem);
}

h3 {
  font-size: clamp(1.15rem, 1.2vw, 1.5rem);
}

h4 {
  font-size: clamp(1.05rem, 1.1vw, 1.25rem);
}

p {
  margin: 0 0 1rem;
}

a {
  color: var(--accent-2);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

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

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 6px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.container {
  width: min(100%, var(--container));
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* ---------- 页头 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(6, 18, 36, .88);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-block: .7rem;
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: .65rem;
  text-decoration: none;
  color: var(--ink);
}

.brand img {
  width: 40px;
  height: 40px;
  object-fit: contain;
  border-radius: 10px;
  box-shadow: var(--shadow-neon);
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.brand-name {
  font-family: var(--serif);
  font-size: 1.15rem;
  font-weight: 650;
  letter-spacing: .03em;
}

.brand-sub {
  font-size: .7rem;
  letter-spacing: .12em;
  color: var(--muted);
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: .3rem;
  align-items: center;
}

.nav a {
  display: inline-flex;
  align-items: center;
  padding: .5rem .85rem;
  border-radius: 999px;
  color: var(--muted);
  text-decoration: none;
  font-size: .92rem;
  border: 1px solid transparent;
  transition: color .2s ease, background-color .2s ease, border-color .2s ease, box-shadow .2s ease;
}

.nav a:hover {
  color: var(--ink);
  background: rgba(99, 245, 255, .08);
  border-color: rgba(99, 245, 255, .18);
}

.nav a[aria-current="page"] {
  color: #04101e;
  background: var(--accent);
  border-color: var(--accent);
  font-weight: 700;
  box-shadow: 0 0 18px rgba(99, 245, 255, .28);
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .45rem;
  padding: .9rem 1.35rem;
  border-radius: 999px;
  border: 1px solid transparent;
  font-family: var(--sans);
  font-weight: 650;
  font-size: .95rem;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  transition: transform .25s ease, box-shadow .25s ease, background-color .25s ease, border-color .25s ease;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #04101e;
  box-shadow: var(--shadow-neon);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 0 1px rgba(99, 245, 255, .3), 0 16px 40px rgba(99, 245, 255, .2);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: rgba(255, 255, 255, .03);
  border-color: var(--line-strong);
  color: var(--ink);
}

.btn-secondary:hover {
  border-color: var(--accent);
  background: rgba(99, 245, 255, .06);
  color: var(--accent);
}

.btn-ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--muted);
}

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

.btn-small {
  padding: .5rem .85rem;
  font-size: .85rem;
}

/* ---------- 首屏 ---------- */
.hero {
  padding-block: clamp(2.2rem, 6vw, 5rem);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: center;
}

.hero-copy h1 {
  margin-bottom: .7rem;
}

.hero-copy .lead {
  color: var(--muted);
  font-size: clamp(1rem, 1.1vw, 1.15rem);
  max-width: 60ch;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .7rem;
  margin-top: 1.4rem;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem .8rem;
  margin-top: 1.2rem;
  color: var(--muted);
  font-size: .8rem;
}

.hero-meta span {
  display: inline-flex;
  align-items: center;
  gap: .3rem;
}

.hero-meta span::before {
  content: "";
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent);
}

.hero-visual {
  border: 1px solid var(--line);
  border-radius: 24px;
  background: linear-gradient(160deg, rgba(99, 245, 255, .06), rgba(255, 255, 255, .015));
  padding: clamp(.8rem, 2vw, 1.2rem);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.hero-svg {
  display: block;
  width: 100%;
  height: auto;
  max-width: 560px;
  margin-inline: auto;
}

.visual-caption {
  margin: .8rem 0 0;
  color: var(--muted);
  font-size: .8rem;
  text-align: center;
}

/* ---------- 区块与标题 ---------- */
.section {
  padding-block: clamp(2.5rem, 5vw, 4.5rem);
  border-top: 1px solid var(--line);
}

.section-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: clamp(1.2rem, 3vw, 2rem);
}

.section-head h2 {
  margin-bottom: 0;
}

.section-head p {
  max-width: 60ch;
  color: var(--muted);
  margin: 0;
}

.eyebrow {
  display: inline-block;
  font-family: var(--sans);
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .18em;
  color: var(--accent);
  margin-bottom: .4rem;
}

/* ---------- 品牌与产品介绍 ---------- */
.intro-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(0, .75fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: start;
}

.prose {
  max-width: 68ch;
}

.prose p:last-child {
  margin-bottom: 0;
}

.prose h2 {
  margin-top: 1.8rem;
}

.prose h3 {
  margin-top: 1.2rem;
}

.prose ul,
.prose ol {
  padding-left: 1.2rem;
}

.prose li {
  margin-bottom: .4rem;
}

.prose blockquote {
  border-left: 2px solid var(--accent);
  padding-left: 1rem;
  color: var(--muted);
  font-style: normal;
}

.intro-aside {
  border-left: 2px solid var(--accent);
  padding-left: 1rem;
}

.check-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: .55rem;
}

.check-list li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: .6rem;
  align-items: start;
  color: var(--muted);
  font-size: .95rem;
}

.check-list li::before {
  content: "✓";
  color: var(--accent);
  font-weight: 700;
}

.timeline {
  display: grid;
  gap: 0;
  margin-top: 1.5rem;
  border-left: 1px solid var(--line);
  padding-left: 1rem;
}

.timeline-item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1rem;
  padding-block: 1rem;
  border-bottom: 1px solid var(--line);
}

.timeline-item:last-child {
  border-bottom: 0;
}

.timeline-marker {
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  border: 1px solid var(--accent);
  display: grid;
  place-items: center;
  font-family: var(--serif);
  font-size: .85rem;
  color: var(--accent);
  background: rgba(99, 245, 255, .06);
}

.timeline-body h3 {
  margin-bottom: .3rem;
  font-size: 1.05rem;
}

.timeline-body p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: .95rem;
}

/* ---------- 功能卡片 ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(.8rem, 2vw, 1.2rem);
}

.feature-card {
  position: relative;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(160deg, rgba(255, 255, 255, .035), rgba(255, 255, 255, .012));
  padding: clamp(1rem, 2vw, 1.4rem);
  overflow: hidden;
  transition: border-color .3s ease, transform .3s ease, background .3s ease;
}

.feature-card:hover {
  border-color: var(--accent);
  transform: translateY(-3px);
  background: linear-gradient(160deg, rgba(99, 245, 255, .08), rgba(255, 255, 255, .015));
}

.feature-num {
  display: inline-block;
  font-family: var(--serif);
  font-size: 1.6rem;
  color: var(--accent);
  line-height: 1;
  margin-bottom: .6rem;
}

.feature-card h3 {
  margin-bottom: .45rem;
}

.feature-card p {
  color: var(--muted);
  font-size: .95rem;
  margin-bottom: 0;
}

/* ---------- 使用场景 ---------- */
.scenario-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(.9rem, 2vw, 1.3rem);
}

.scenario-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  padding: clamp(1rem, 2vw, 1.4rem);
}

.scenario-card h3 {
  margin-bottom: .4rem;
}

.scenario-card > p {
  color: var(--muted);
  font-size: .95rem;
}

.steps {
  list-style: none;
  counter-reset: step;
  padding: 0;
  margin: .8rem 0 0;
  display: grid;
  gap: .55rem;
}

.steps li {
  counter-increment: step;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: .6rem;
  align-items: start;
  color: var(--muted);
  font-size: .92rem;
}

.steps li::before {
  content: counter(step);
  width: 1.5rem;
  height: 1.5rem;
  border-radius: 50%;
  border: 1px solid var(--line-strong);
  display: grid;
  place-items: center;
  font-family: var(--serif);
  font-size: .75rem;
  color: var(--accent);
}

/* ---------- 快速上手 ---------- */
.quick-start-grid {
  display: grid;
  grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: center;
}

.svg-frame {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  padding: clamp(.8rem, 2vw, 1.2rem);
  overflow: hidden;
}

.svg-frame svg {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
}

.timeline-svg {
  max-width: 920px;
  margin-inline: auto;
}

.security-svg {
  max-width: 320px;
  margin-inline: auto;
}

.quick-steps {
  list-style: none;
  counter-reset: quick;
  padding: 0;
  margin: 0;
  display: grid;
  gap: .7rem;
}

.quick-steps li {
  counter-increment: quick;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: .7rem;
  align-items: start;
  padding: .8rem 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, .025);
}

.quick-steps li::before {
  content: counter(quick);
  width: 1.8rem;
  height: 1.8rem;
  border-radius: 50%;
  background: var(--accent);
  color: #04101e;
  display: grid;
  place-items: center;
  font-family: var(--serif);
  font-weight: 700;
  font-size: .9rem;
}

.quick-steps strong {
  display: block;
  color: var(--ink);
  font-size: .95rem;
}

.quick-steps span {
  color: var(--muted);
  font-size: .9rem;
}

/* ---------- 表格 ---------- */
.table-wrap {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.compare-table {
  width: 100%;
  min-width: 680px;
  border-collapse: collapse;
  font-size: .92rem;
}

.compare-table th,
.compare-table td {
  padding: .8rem 1rem;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.compare-table thead th {
  font-family: var(--serif);
  font-size: .95rem;
  color: var(--accent);
  background: rgba(99, 245, 255, .05);
  letter-spacing: .02em;
}

.compare-table tbody tr:hover {
  background: rgba(99, 245, 255, .04);
}

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

.compare-table td:first-child {
  font-weight: 650;
  color: var(--ink);
}

/* ---------- 安全与隐私 ---------- */
.security-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: center;
}

.security-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  padding: clamp(1rem, 2vw, 1.4rem);
}

.security-card h3 {
  margin-bottom: .5rem;
}

.security-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: .6rem;
}

.security-list li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: .6rem;
  color: var(--muted);
  font-size: .95rem;
}

.security-list li::before {
  content: "";
  width: .55rem;
  height: .55rem;
  border-radius: 2px;
  background: var(--accent);
  transform: rotate(45deg);
  margin-top: .45rem;
}

/* ---------- 版本与平台 ---------- */
.version-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: start;
}

.facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .7rem;
  margin: 0;
}

.fact {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, .025);
  padding: .8rem 1rem;
}

.fact dt {
  font-family: var(--serif);
  font-size: .85rem;
  color: var(--accent);
  margin-bottom: .2rem;
}

.fact dd {
  margin: 0;
  color: var(--ink);
  font-size: .92rem;
}

/* ---------- 下载面板 ---------- */
.download-panel {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(0, .7fr);
  gap: clamp(1rem, 3vw, 1.8rem);
  align-items: center;
  border: 1px solid var(--line-strong);
  border-radius: 24px;
  background: radial-gradient(700px 300px at 10% 0%, rgba(99, 245, 255, .1), transparent 65%), var(--panel-2);
  padding: clamp(1.2rem, 3vw, 2rem);
  box-shadow: var(--shadow);
}

.download-panel h3 {
  margin-top: .7rem;
}

.download-panel p {
  color: var(--muted);
}

.download-panel .download-badge {
  display: inline-flex;
  border: 1px solid var(--accent);
  border-radius: 999px;
  background: rgba(99, 245, 255, .08);
  color: var(--accent);
  padding: .3rem .7rem;
  font-size: .75rem;
  font-weight: 650;
  letter-spacing: .12em;
  margin-bottom: .6rem;
}

.download-panel .download-meta {
  display: grid;
  gap: .4rem;
  margin-top: .8rem;
  color: var(--muted);
  font-size: .9rem;
}

.download-panel .download-meta span {
  display: block;
}

.download-panel .download-meta strong {
  color: var(--ink);
}

.download-panel .download-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .7rem;
  margin-top: 1rem;
}

.download-panel .download-aside {
  border-left: 1px solid var(--line);
  padding-left: 1.2rem;
}

.download-panel .download-aside h3 {
  margin-bottom: .5rem;
}

.download-panel .download-aside .steps {
  margin-top: .6rem;
}

.download-panel .download-aside .steps li {
  font-size: .9rem;
}

/* ---------- 下载页通用卡片 ---------- */
.download-card {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(0, .7fr);
  gap: clamp(1rem, 3vw, 1.8rem);
  align-items: center;
  border: 1px solid var(--line-strong);
  border-radius: 24px;
  background: radial-gradient(700px 300px at 10% 0%, rgba(99, 245, 255, .1), transparent 65%), var(--panel-2);
  padding: clamp(1.2rem, 3vw, 2rem);
  box-shadow: var(--shadow);
}

.download-card h3 {
  margin-top: .7rem;
}

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

.download-card .download-badge {
  display: inline-flex;
  border: 1px solid var(--accent);
  border-radius: 999px;
  background: rgba(99, 245, 255, .08);
  color: var(--accent);
  padding: .3rem .7rem;
  font-size: .75rem;
  font-weight: 650;
  letter-spacing: .12em;
  margin-bottom: .6rem;
}

.download-card .download-meta {
  display: grid;
  gap: .4rem;
  margin-top: .8rem;
  color: var(--muted);
  font-size: .9rem;
}

.download-card .download-meta span {
  display: block;
}

.download-card .download-meta strong {
  color: var(--ink);
}

.download-card .download-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .7rem;
  margin-top: 1rem;
}

.download-card .download-aside {
  border-left: 1px solid var(--line);
  padding-left: 1.2rem;
}

.download-card .download-aside h3 {
  margin-bottom: .5rem;
}

.download-card .download-aside .steps {
  margin-top: .6rem;
}

.download-card .download-aside .steps li {
  font-size: .9rem;
}

/* ---------- FAQ ---------- */
.faq-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .8rem;
}

.faq-item {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--panel);
}

.faq-item summary {
  list-style: none;
  cursor: pointer;
  padding: .9rem 1rem;
  display: flex;
  justify-content: space-between;
  gap: .8rem;
  align-items: center;
  font-weight: 650;
  font-size: .95rem;
  color: var(--ink);
}

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

.faq-item summary::after {
  content: "+";
  font-family: var(--serif);
  font-size: 1.2rem;
  color: var(--accent);
  line-height: 1;
}

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

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

.faq-body {
  padding: .9rem 1rem 1rem;
  color: var(--muted);
  font-size: .92rem;
}

.faq-body p:last-child {
  margin-bottom: 0;
}

/* ---------- 最新文章 ---------- */
.article-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(.8rem, 2vw, 1.2rem);
}

.article-card {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  padding: clamp(1rem, 2vw, 1.3rem);
  transition: border-color .3s ease, transform .3s ease;
}

.article-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.article-meta {
  display: flex;
  justify-content: space-between;
  gap: .8rem;
  color: var(--muted);
  font-size: .78rem;
  margin-bottom: .6rem;
}

.article-card h3 {
  margin-bottom: .5rem;
}

.article-card p {
  color: var(--muted);
  font-size: .93rem;
  margin-bottom: 1rem;
}

.article-card .btn-small {
  margin-top: auto;
  align-self: flex-start;
}

/* ---------- 相关阅读 ---------- */
.link-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .6rem;
}

.link-item {
  display: block;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, .02);
  padding: .85rem 1rem;
  text-decoration: none;
  color: var(--ink);
  transition: border-color .2s ease, background-color .2s ease;
}

.link-item strong {
  display: block;
  font-family: var(--serif);
  font-size: 1rem;
  color: var(--ink);
  margin-bottom: .2rem;
}

.link-item span {
  display: block;
  color: var(--muted);
  font-size: .85rem;
}

.link-item:hover {
  border-color: var(--accent);
  background: rgba(99, 245, 255, .05);
}

.link-item:hover strong {
  color: var(--accent);
}

/* ---------- 专题页通用 ---------- */
.page-hero {
  padding-block: clamp(2.2rem, 5vw, 4rem);
  border-bottom: 1px solid var(--line);
}

.page-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: center;
}

.page-hero .lead {
  color: var(--muted);
  max-width: 60ch;
}

.badge-row {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
  margin-top: 1rem;
}

.badge {
  display: inline-flex;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: rgba(255, 255, 255, .03);
  color: var(--accent);
  padding: .3rem .7rem;
  font-size: .75rem;
  font-weight: 650;
  letter-spacing: .12em;
}

.article-body {
  max-width: 78ch;
  margin-inline: auto;
}

.article-body h2 {
  margin-top: 1.8rem;
}

.article-body h3 {
  margin-top: 1.2rem;
}

.article-body ul,
.article-body ol {
  padding-left: 1.2rem;
}

.article-body li {
  margin-bottom: .4rem;
}

.article-body blockquote {
  border-left: 2px solid var(--accent);
  padding-left: 1rem;
  color: var(--muted);
  font-style: normal;
}

.callout {
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
  background: var(--panel);
  padding: 1rem;
}

.callout p:last-child {
  margin-bottom: 0;
}

/* ---------- 页脚 ---------- */
.site-footer {
  background: var(--bg-deep);
  border-top: 1px solid var(--line);
  padding-block: clamp(2rem, 4vw, 3.5rem);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: clamp(1.5rem, 4vw, 3rem);
}

.footer-brand p {
  color: var(--muted);
  font-size: .92rem;
  max-width: 45ch;
  margin-top: .8rem;
}

.footer-title {
  font-family: var(--serif);
  font-size: 1.1rem;
  color: var(--ink);
  margin: 0 0 .7rem;
  letter-spacing: .02em;
}

.footer-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .4rem;
}

.footer-nav a {
  color: var(--muted);
  text-decoration: none;
}

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

.footer-nav a[aria-current="page"] {
  color: var(--accent);
  font-weight: 700;
}

.footer-meta p {
  color: var(--muted);
  font-size: .9rem;
  margin-bottom: .3rem;
}

.footer-download {
  display: inline-flex;
  margin-top: .6rem;
  padding: .45rem .8rem;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  color: var(--ink);
  text-decoration: none;
  font-size: .85rem;
}

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

.footer-bottom {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  border-top: 1px solid var(--line);
  margin-top: clamp(1.5rem, 4vw, 2.5rem);
  padding-top: 1rem;
  color: var(--muted);
  font-size: .8rem;
}

.footer-bottom p {
  margin: 0;
}

/* ---------- SVG 动效 ---------- */
.rot-a,
.rot-b,
.rot-c,
.drift {
  transform-box: fill-box;
  transform-origin: center;
}

.rot-a {
  animation: rotate-ccw 18s ease-in-out infinite;
  animation-delay: -3s;
}

.rot-b {
  animation: rotate-cw 16s ease-in-out infinite;
}

.rot-c {
  animation: rotate-cw 12s ease-in-out infinite;
  animation-delay: -4s;
}

.drift {
  animation: drift 10s ease-in-out infinite;
}

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

.pulse-soft {
  animation: pulse-soft 8s ease-in-out infinite;
}

@keyframes rotate-cw {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes rotate-ccw {
  from { transform: rotate(0deg); }
  to { transform: rotate(-360deg); }
}

@keyframes drift {
  0%, 100% { transform: translate(0, 0); }
  50% { transform: translate(6px, -4px); }
}

@keyframes draw-line {
  0% { stroke-dashoffset: 1; }
  100% { stroke-dashoffset: 0; }
}

@keyframes pulse-soft {
  0%, 100% { opacity: 1; }
  50% { opacity: .55; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 980px) {
  .hero-grid,
  .intro-grid,
  .quick-start-grid,
  .security-grid,
  .version-grid,
  .download-panel,
  .download-card,
  .page-hero-grid {
    grid-template-columns: 1fr;
  }

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

  .scenario-grid {
    grid-template-columns: 1fr;
  }

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

  .intro-aside {
    border-left: 0;
    border-top: 1px solid var(--line);
    padding-left: 0;
    padding-top: 1rem;
  }

  .download-panel .download-aside,
  .download-card .download-aside {
    border-left: 0;
    padding-left: 0;
    border-top: 1px solid var(--line);
    padding-top: 1rem;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }

  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 680px) {
  .feature-grid,
  .faq-grid,
  .link-list,
  .facts {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 1.2rem;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: .4rem;
  }

  .header-inner {
    gap: .6rem;
  }

  .nav a {
    padding: .45rem .7rem;
    font-size: .85rem;
  }

  .section-head {
    align-items: flex-start;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .download-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .download-actions .btn {
    width: 100%;
  }

  .hero-meta {
    font-size: .78rem;
  }
}

@media (max-width: 520px) {
  .brand-sub {
    display: none;
  }
}

/* ---------- 减少动态效果 ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
    scroll-behavior: auto !important;
  }

  .rot-a,
  .rot-b,
  .rot-c,
  .drift,
  .draw,
  .pulse-soft {
    animation: none !important;
  }

  .draw {
    stroke-dashoffset: 0;
  }
}