@charset "utf-8";
/* ==========================================================================
   ao3阅读器 · 全站样式
   设计基调参考 AND CRECiA：蓝 #19b7e4 / 黄 #fdff8e / 米 #fcf8f2
   4px 间距体系、10px 卡片圆角、描边代替阴影、留白优先
   纯手写 CSS，无框架、无外链字体
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. 设计变量
   -------------------------------------------------------------------------- */
:root {
  /* 色板 */
  --c-primary: #19b7e4;
  --c-primary-dark: #159bcf;
  --c-primary-deep: #117ea0;
  --c-ink: #0b6f8d;          /* 浅底上的深蓝文字，用于保证可读性 */
  --c-primary-soft: #e8f8fd;
  --c-accent: #fdff8e;
  --c-accent-soft: #feffd9;
  --c-accent-line: #ecee7a;
  --c-surface: #fcf8f2;
  --c-bg: #ffffff;
  --c-text: #575757;
  --c-text-soft: #6f6f6f;
  --c-muted: #9a9a9a;
  --c-inverse: #ffffff;
  --c-border: #dcdcdc;
  --c-neutral: #c2c2c2;

  /* 圆角 */
  --r-sm: 3px;
  --r-md: 6px;
  --r-lg: 10px;
  --r-full: 9999px;

  /* 间距 */
  --sp-4: 4px;
  --sp-8: 8px;
  --sp-12: 12px;
  --sp-16: 16px;
  --sp-20: 20px;
  --sp-24: 24px;
  --sp-32: 32px;
  --sp-40: 40px;
  --sp-48: 48px;
  --sp-64: 64px;
  --sp-80: 80px;

  /* 排版 */
  --font: "LINE Seed JP", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    "Noto Sans SC", "Source Han Sans SC", sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
    "Liberation Mono", "Courier New", monospace;

  /* 布局与动效 */
  --w-xl: 1200px;
  --w-article: 880px;
  --dur: 0.2s;
  --ease: ease-out;
  --header-h: 68px;
}

/* --------------------------------------------------------------------------
   2. 基础重置
   -------------------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  background-color: var(--c-bg);
  color: var(--c-text);
  font-family: var(--font);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

main {
  display: block;
}

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

ul,
ol {
  padding: 0;
}

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

svg {
  display: block;
}

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

button {
  font: inherit;
  color: inherit;
}

code {
  font-family: var(--mono);
  font-size: 0.88em;
  line-height: 1.5;
  color: #4d4d4d;
  background-color: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--r-sm);
  padding: 1px 5px;
  overflow-wrap: break-word;
}

::selection {
  background-color: var(--c-accent);
  color: var(--c-text);
}

:focus-visible {
  outline: 2px solid var(--c-primary);
  outline-offset: 3px;
  border-radius: var(--r-sm);
}

/* 线路地址：禁止选中与复制 */
[data-nocopy],
[data-nocopy] * {
  -webkit-user-select: none;
  user-select: none;
  -webkit-touch-callout: none;
  cursor: default;
}

/* --------------------------------------------------------------------------
   3. 通用工具
   -------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--w-xl);
  margin: 0 auto;
  padding: 0 20px;
}

.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;
}

.skip-link {
  position: absolute;
  left: 16px;
  top: -80px;
  z-index: 1300;
  padding: 10px 16px;
  background-color: var(--c-bg);
  border: 1px solid var(--c-text);
  border-radius: var(--r-md);
  font-size: 14px;
  font-weight: 700;
  transition: top var(--dur) var(--ease);
}

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

.eyebrow {
  display: inline-block;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--c-ink);
}

.mark {
  position: relative;
  z-index: 0;
  padding: 0 2px;
}

.mark::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0.06em;
  z-index: -1;
  height: 0.34em;
  background-color: var(--c-accent);
  border-radius: 2px;
}

.note-box {
  margin: 24px 0 0;
  padding: 16px 20px;
  background-color: var(--c-surface);
  border: 1px solid var(--c-border);
  border-left: 3px solid var(--c-primary);
  border-radius: 0 var(--r-md) var(--r-md) 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--c-text);
}

.note-box strong {
  font-weight: 700;
}

/* --------------------------------------------------------------------------
   4. 按钮
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 11px 25px;
  border: 1px solid transparent;
  border-radius: var(--r-full);
  font-size: 16px;
  font-weight: 700;
  line-height: 1.2;
  text-align: center;
  cursor: pointer;
  transition: background-color var(--dur) var(--ease),
    border-color var(--dur) var(--ease), color var(--dur) var(--ease),
    opacity var(--dur) var(--ease);
}

.btn--primary {
  background-color: var(--c-primary);
  border-color: var(--c-primary);
  color: var(--c-inverse);
}

.btn--primary:hover {
  background-color: var(--c-primary-dark);
  border-color: var(--c-primary-dark);
}

.btn--primary:active {
  background-color: var(--c-primary-deep);
  border-color: var(--c-primary-deep);
}

.btn--accent {
  background-color: var(--c-accent);
  border-color: var(--c-text);
  color: var(--c-text);
}

.btn--accent:hover {
  background-color: #f2f47f;
  opacity: 0.9;
}

.btn--line {
  background-color: var(--c-bg);
  border-color: var(--c-border);
  color: var(--c-text);
}

.btn--line:hover {
  border-color: var(--c-muted);
  color: var(--c-ink);
}

.btn--block {
  width: 100%;
}

/* --------------------------------------------------------------------------
   5. 站头
   -------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(255, 255, 255, 0.95);
  border-bottom: 1px solid var(--c-border);
  -webkit-backdrop-filter: saturate(160%) blur(10px);
  backdrop-filter: saturate(160%) blur(10px);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: var(--header-h);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  color: var(--c-text);
  flex-shrink: 0;
}

.brand__mark {
  display: block;
  width: 40px;
  height: 40px;
  flex: 0 0 40px;
}

.brand__text {
  display: block;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.01em;
}

.nav-toggle {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0;
  background-color: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  cursor: pointer;
}

.nav-toggle__bar {
  display: block;
  width: 18px;
  height: 2px;
  background-color: var(--c-text);
  border-radius: 2px;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.nav {
  display: none;
  position: absolute;
  left: 0;
  right: 0;
  top: 100%;
  padding: 8px 20px 20px;
  background-color: var(--c-bg);
  border-bottom: 1px solid var(--c-border);
}

.nav.is-open {
  display: block;
}

.nav__list {
  display: flex;
  flex-direction: column;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav__link {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 8px 10px;
  border-radius: var(--r-sm);
  font-size: 16px;
  color: var(--c-text);
  transition: color var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.nav__link:hover {
  color: var(--c-ink);
  background-color: var(--c-primary-soft);
}

.nav__link[aria-current="page"] {
  color: var(--c-ink);
  font-weight: 700;
}

/* --------------------------------------------------------------------------
   6. 首屏
   -------------------------------------------------------------------------- */
.hero {
  position: relative;
  padding: 40px 0 48px;
  background-image: radial-gradient(
      circle at 92% -10%,
      rgba(25, 183, 228, 0.12),
      transparent 52%
    ),
    radial-gradient(circle at -6% 108%, rgba(253, 255, 142, 0.4), transparent 46%);
}

.hero__grid {
  display: grid;
  gap: 32px;
}

.display__line {
  display: block;
}

.display {
  margin-top: 16px;
  font-size: clamp(28px, 5vw, 42px);
  font-weight: 700;
  line-height: 1.24;
  letter-spacing: -0.01em;
  color: var(--c-text);
}

.hero__lead {
  max-width: 38em;
  margin-top: 20px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--c-text);
}

.hero__lead strong {
  font-weight: 700;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
  font-size: 14px;
  color: var(--c-muted);
}

.hero__meta li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.hero__meta li::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--c-primary);
}

/* 结构速览面板 */
.panel {
  padding: 24px;
  background-color: rgba(252, 248, 242, 0.9);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
}

.panel__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--c-border);
}

.panel__title {
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
}

.panel__note {
  font-size: 10px;
  letter-spacing: 0.08em;
  color: var(--c-muted);
  white-space: nowrap;
}

.stat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
}

.stat {
  padding: 20px 0;
}

.stat:nth-child(odd) {
  padding-right: 16px;
  border-right: 1px solid var(--c-border);
}

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

.stat:nth-child(-n + 2) {
  border-bottom: 1px solid var(--c-border);
}

.stat__num {
  display: block;
  font-size: 24px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--c-ink);
  font-variant-numeric: tabular-nums;
}

.stat__num span {
  margin-left: 2px;
  font-size: 14px;
  color: var(--c-muted);
}

.stat__label {
  display: block;
  margin-top: 6px;
  font-size: 14px;
  font-weight: 700;
  color: var(--c-text);
}

.stat__sub {
  display: block;
  margin-top: 2px;
  font-size: 10px;
  line-height: 1.6;
  color: var(--c-muted);
}

.panel__foot {
  padding-top: 12px;
  border-top: 1px solid var(--c-border);
  font-size: 10px;
  line-height: 1.8;
  color: var(--c-muted);
}

/* --------------------------------------------------------------------------
   7. 区块与标题
   -------------------------------------------------------------------------- */
.section {
  padding: 56px 0;
}

.section--surface {
  background-color: var(--c-surface);
  border-top: 1px solid var(--c-border);
  border-bottom: 1px solid var(--c-border);
}

.section__head {
  max-width: 46em;
  margin-bottom: 32px;
}

.section__eyebrow {
  display: block;
  margin-bottom: 10px;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--c-ink);
}

.section__title {
  font-size: clamp(21px, 3vw, 24px);
  font-weight: 700;
  line-height: 1.35;
  color: var(--c-text);
}

.section__desc {
  margin-top: 12px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--c-text);
}

.section__desc strong {
  font-weight: 700;
}

/* --------------------------------------------------------------------------
   8. 卡片通用
   -------------------------------------------------------------------------- */
.card {
  background-color: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
  transition: border-color var(--dur) var(--ease);
}

.card:hover {
  border-color: var(--c-muted);
}

.tag {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  border: 1px solid transparent;
  border-radius: var(--r-full);
  font-size: 14px;
  font-weight: 700;
  line-height: 1.4;
  white-space: nowrap;
}

.tag--brand {
  background-color: var(--c-primary-soft);
  border-color: #cdeef8;
  color: var(--c-ink);
}

.tag--short {
  background-color: var(--c-accent);
  border-color: var(--c-accent-line);
  color: var(--c-text);
}

.tag--multi {
  background-color: var(--c-bg);
  border-color: var(--c-border);
  color: var(--c-text);
}

/* 线路卡片与确认页右上角：只保留文字，去掉底色与描边 */
.line-card .tag,
.go-card .tag {
  padding: 0;
  border: 0;
  border-radius: 0;
  background-color: transparent;
  font-weight: 400;
  color: var(--c-text-soft);
}

/* --------------------------------------------------------------------------
   9. 三步走
   -------------------------------------------------------------------------- */
.step-grid {
  display: grid;
  gap: 20px;
}

.step {
  padding: 24px;
  background-color: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
}

.step__num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: var(--c-accent);
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 700;
  color: var(--c-text);
}

.step__title {
  margin: 16px 0 8px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.5;
}

.step__text {
  font-size: 14px;
  line-height: 1.85;
  color: var(--c-text);
}

.step__text + .step__text {
  margin-top: 8px;
}

/* --------------------------------------------------------------------------
   10. 线路总表
   -------------------------------------------------------------------------- */
.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin: 0 0 24px;
  padding: 0;
  list-style: none;
  font-size: 14px;
  color: var(--c-text-soft);
}

.legend li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.line-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.line-card {
  display: flex;
  flex-direction: column;
  padding: 20px;
}

.line-card__top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.line-card__no {
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.08em;
  color: var(--c-muted);
}

.line-card__no b {
  color: var(--c-text);
  font-weight: 700;
}

.line-card__domain {
  margin-bottom: 6px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: 0.01em;
  color: var(--c-text);
  word-break: break-all;
}

.line-card__url {
  margin-bottom: 12px;
  padding: 8px 10px;
  background-color: var(--c-surface);
  border: 1px dashed var(--c-border);
  border-radius: var(--r-sm);
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.6;
  color: #7d7d7d;
  word-break: break-all;
}

.line-card__note {
  margin-bottom: 16px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--c-text);
}

.line-card__cta {
  display: inline-flex;
  align-self: flex-start;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  margin-top: auto;
  padding: 8px 18px;
  border: 1px solid var(--c-primary);
  border-radius: var(--r-full);
  background-color: var(--c-bg);
  font-size: 14px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--c-ink);
  transition: background-color var(--dur) var(--ease),
    border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.line-card__cta:hover {
  background-color: var(--c-primary-soft);
  border-color: var(--c-primary-dark);
  color: var(--c-primary-deep);
}

.line-card__cta:active {
  background-color: #d8f2fb;
}

.line-card__cta svg {
  width: 16px;
  height: 16px;
  flex: 0 0 16px;
  transition: transform var(--dur) var(--ease);
}

.line-card__cta:hover svg {
  transform: translateX(2px);
}

/* --------------------------------------------------------------------------
   11. 域名结构
   -------------------------------------------------------------------------- */
.type-grid {
  display: grid;
  gap: 20px;
}

.type-card {
  display: flex;
  flex-direction: column;
  padding: 24px;
  background-color: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
}

.subhead {
  margin: 40px 0 16px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--c-text);
}

.type-card__count {
  font-size: 42px;
  font-weight: 700;
  line-height: 1;
  color: var(--c-ink);
  font-variant-numeric: tabular-nums;
}

.type-card__count span {
  margin-left: 4px;
  font-size: 14px;
  color: var(--c-muted);
}

.type-card__title {
  margin: 12px 0 8px;
  font-size: 18px;
  font-weight: 700;
}

.type-card__text {
  font-size: 14px;
  line-height: 1.85;
  color: var(--c-text);
}

.type-card__list {
  margin: 16px 0 0;
  padding: 12px 0 0;
  border-top: 1px solid var(--c-border);
  list-style: none;
  font-family: var(--mono);
  font-size: 14px;
  line-height: 2;
  color: var(--c-text-soft);
  word-break: break-all;
}

.type-card__list li::before {
  content: "· ";
  color: var(--c-neutral);
}

/* 对照表 */
.table-wrap {
  margin-top: 8px;
  background-color: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
  overflow: hidden;
}

.cmp {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

.cmp th {
  padding: 14px 20px;
  background-color: var(--c-surface);
  border-bottom: 1px solid var(--c-border);
  font-size: 14px;
  font-weight: 700;
  text-align: left;
  color: var(--c-text);
}

.cmp td {
  padding: 16px 20px;
  border-bottom: 1px solid var(--c-border);
  line-height: 1.75;
  vertical-align: top;
}

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

.cmp td strong {
  font-weight: 700;
  color: var(--c-text);
}

/* --------------------------------------------------------------------------
   12. 设计说明 / 判断要点 / 提醒
   -------------------------------------------------------------------------- */
.why-grid,
.check-grid,
.notice-grid,
.readmore {
  display: grid;
  gap: 20px;
}

.why-item {
  padding: 24px;
  background-color: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
}

.why-item h3 {
  margin-bottom: 8px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.5;
}

.why-item p {
  font-size: 14px;
  line-height: 1.85;
  color: var(--c-text);
}

.why-item p + p {
  margin-top: 8px;
}

.check-item {
  display: flex;
  gap: 16px;
  padding: 20px;
  background-color: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
}

.check-item__num {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: var(--c-primary-soft);
  border: 1px solid #cdeef8;
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 700;
  color: var(--c-ink);
}

.check-item h3 {
  margin-bottom: 4px;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.6;
}

.check-item p {
  font-size: 14px;
  line-height: 1.8;
  color: var(--c-text);
}

.notice {
  display: flex;
  gap: 16px;
  padding: 24px;
  background-color: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
}

.notice__icon {
  flex: 0 0 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: var(--c-accent);
  color: var(--c-text);
}

.notice__icon svg {
  width: 20px;
  height: 20px;
}

.notice h3 {
  margin-bottom: 6px;
  font-size: 18px;
  font-weight: 700;
}

.notice p {
  font-size: 14px;
  line-height: 1.85;
  color: var(--c-text);
}

/* --------------------------------------------------------------------------
   13. 问答
   -------------------------------------------------------------------------- */
.faq {
  display: grid;
  gap: 12px;
  max-width: var(--w-article);
}

.faq details {
  padding: 0 20px;
  background-color: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
  transition: border-color var(--dur) var(--ease);
}

.faq details[open] {
  border-color: var(--c-muted);
}

.faq summary {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 0;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.6;
  cursor: pointer;
  list-style: none;
}

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

.faq summary::after {
  content: "+";
  flex: 0 0 auto;
  font-size: 24px;
  font-weight: 400;
  line-height: 1;
  color: var(--c-ink);
}

.faq details[open] summary::after {
  content: "\2212";
}

.faq__body {
  padding: 16px 0 20px;
  border-top: 1px dashed var(--c-border);
  font-size: 14px;
  line-height: 1.9;
  color: var(--c-text);
}

.faq__body p + p {
  margin-top: 10px;
}

.faq__body ul {
  margin: 10px 0 0;
  padding-left: 20px;
}

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

.faq__body a {
  color: var(--c-ink);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.faq-more {
  margin-top: 24px;
  font-size: 14px;
  color: var(--c-text-soft);
}

.faq-more a {
  font-weight: 700;
  color: var(--c-ink);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* --------------------------------------------------------------------------
   14. 维护记录
   -------------------------------------------------------------------------- */
.timeline {
  max-width: var(--w-article);
  margin: 0;
  padding: 0 0 0 20px;
  border-left: 1px solid var(--c-border);
  list-style: none;
}

.timeline li {
  position: relative;
  padding: 0 0 24px 20px;
}

.timeline li:last-child {
  padding-bottom: 0;
}

.timeline li::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background-color: var(--c-accent);
  border: 1px solid var(--c-border);
}

.timeline time {
  display: block;
  margin-bottom: 4px;
  font-family: var(--mono);
  font-size: 14px;
  color: var(--c-muted);
}

.timeline p {
  font-size: 14px;
  line-height: 1.8;
  color: var(--c-text);
}

/* --------------------------------------------------------------------------
   15. 继续阅读
   -------------------------------------------------------------------------- */
.readmore a {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 24px;
  background-color: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
  transition: border-color var(--dur) var(--ease);
}

.readmore a:hover {
  border-color: var(--c-muted);
}

.readmore strong {
  font-size: 18px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--c-text);
}

.readmore span {
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-text-soft);
}

/* --------------------------------------------------------------------------
   16. 内页通用
   -------------------------------------------------------------------------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 20px;
  padding: 0;
  list-style: none;
  font-size: 14px;
  color: var(--c-muted);
}

.breadcrumb li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb li + li::before {
  content: "/";
  color: var(--c-neutral);
}

.breadcrumb a {
  color: var(--c-text);
}

.breadcrumb a:hover {
  color: var(--c-ink);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-hero {
  padding: 32px 0 32px;
  background-image: radial-gradient(
    circle at 96% 0%,
    rgba(25, 183, 228, 0.1),
    transparent 48%
  );
  border-bottom: 1px solid var(--c-border);
}

.page-hero__title {
  max-width: 24em;
  font-size: clamp(24px, 3.8vw, 36px);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--c-text);
}

.page-hero__lead {
  max-width: 44em;
  margin-top: 16px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--c-text);
}

.page-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin-top: 20px;
  font-size: 10px;
  letter-spacing: 0.04em;
  color: var(--c-muted);
}

.article {
  max-width: var(--w-article);
  padding: 40px 0 56px;
}

.toc {
  margin: 0 0 32px;
  padding: 20px;
  background-color: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
}

.toc__title {
  margin-bottom: 12px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--c-text);
}

.toc ol {
  margin: 0;
  padding-left: 20px;
  font-size: 14px;
  line-height: 1.9;
}

@media (min-width: 768px) {
  .toc--cols ol {
    columns: 2;
    column-gap: 32px;
  }

  .toc--cols li {
    break-inside: avoid;
  }
}

.toc a {
  color: var(--c-text);
  text-decoration: underline;
  text-decoration-color: var(--c-neutral);
  text-underline-offset: 3px;
  transition: color var(--dur) var(--ease);
}

.toc a:hover {
  color: var(--c-ink);
  text-decoration-color: currentColor;
}

.prose h2 {
  margin: 40px 0 12px;
  font-size: 24px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--c-text);
}

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

.prose h3 {
  margin: 28px 0 8px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--c-text);
}

.prose p,
.prose li {
  font-size: 16px;
  line-height: 1.95;
  color: var(--c-text);
}

.prose p {
  margin-bottom: 16px;
}

.prose ul,
.prose ol {
  margin: 0 0 16px;
  padding-left: 24px;
}

.prose li {
  margin-bottom: 8px;
}

.prose a {
  color: var(--c-text);
  text-decoration: underline;
  text-decoration-color: var(--c-neutral);
  text-underline-offset: 3px;
  transition: color var(--dur) var(--ease);
}

.prose a:hover {
  color: var(--c-ink);
  text-decoration-color: currentColor;
}

.prose strong {
  font-weight: 700;
}

.prose .note-box {
  margin: 24px 0;
}

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

.flow {
  margin: 0 0 24px;
  padding: 0;
  list-style: none;
  counter-reset: flow;
}

.flow li {
  position: relative;
  padding: 0 0 20px 44px;
  counter-increment: flow;
}

.flow li::before {
  content: counter(flow, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background-color: var(--c-accent);
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 700;
  color: var(--c-text);
}

.flow li::after {
  content: "";
  position: absolute;
  left: 13px;
  top: 34px;
  bottom: 6px;
  width: 1px;
  background-color: var(--c-border);
}

.flow li:last-child {
  padding-bottom: 0;
}

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

.flow strong {
  display: block;
  margin-bottom: 4px;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.6;
}

.flow p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--c-text);
}

.checklist {
  margin: 0 0 16px;
  padding: 0;
  list-style: none;
}

.checklist li {
  position: relative;
  margin-bottom: 10px;
  padding-left: 28px;
  font-size: 16px;
  line-height: 1.85;
}

.checklist li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 11px;
  width: 12px;
  height: 6px;
  border-left: 2px solid var(--c-primary);
  border-bottom: 2px solid var(--c-primary);
  transform: rotate(-45deg);
}

/* --------------------------------------------------------------------------
   17. 中间确认页
   -------------------------------------------------------------------------- */
.go-wrap {
  padding: 32px 0 64px;
}

.go-shell {
  max-width: 620px;
  margin: 0 auto;
}

.go-card {
  max-width: 620px;
  margin: 0 auto;
  padding: 24px;
  background-color: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
}

.go-card__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 16px;
}

.go-title {
  font-size: 24px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--c-text);
}

.go-domain {
  display: block;
  margin-top: 12px;
  font-family: var(--mono);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--c-text);
  word-break: break-all;
}

.go-lead {
  margin-top: 10px;
  font-size: 14px;
  line-height: 1.85;
  color: var(--c-text);
}

.go-target {
  margin-top: 24px;
  border-top: 1px solid var(--c-border);
  border-bottom: 1px solid var(--c-border);
}

.go-row {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 16px;
  padding: 12px 0;
  font-size: 14px;
}

.go-row + .go-row {
  border-top: 1px dashed var(--c-border);
}

.go-row__label {
  flex: 0 0 72px;
  color: var(--c-muted);
}

.go-row__value {
  flex: 1 1 240px;
  min-width: 0;
  font-family: var(--mono);
  line-height: 1.6;
  color: var(--c-text);
  word-break: break-all;
}

.go-row__value--text {
  font-family: var(--font);
  font-size: 14px;
}

.go-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.go-actions .btn {
  flex: 1 1 180px;
}

.go-note {
  margin-top: 20px;
  padding-top: 14px;
  border-top: 1px dashed var(--c-border);
  font-size: 14px;
  line-height: 1.8;
  color: var(--c-muted);
}

.go-back {
  margin-top: 24px;
  font-size: 14px;
}

.go-back a {
  font-weight: 700;
  color: var(--c-ink);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* 提示条 */
.toast {
  position: fixed;
  left: 50%;
  bottom: 24px;
  z-index: 1200;
  max-width: calc(100% - 32px);
  padding: 12px 20px;
  border-radius: var(--r-full);
  background-color: var(--c-text);
  color: var(--c-inverse);
  font-size: 14px;
  line-height: 1.5;
  text-align: center;
  opacity: 0;
  transform: translate(-50%, 16px);
  pointer-events: none;
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.toast.is-show {
  opacity: 1;
  transform: translate(-50%, 0);
}

/* --------------------------------------------------------------------------
   18. 站尾
   -------------------------------------------------------------------------- */
.site-footer {
  padding: 48px 0 32px;
  background-color: var(--c-surface);
  border-top: 1px solid var(--c-border);
}

.footer__grid {
  display: grid;
  gap: 32px;
}

.footer__brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.footer__brand .brand__mark {
  width: 36px;
  height: 36px;
  flex-basis: 36px;
}

.footer__brand .brand__text {
  font-size: 16px;
}

.footer__desc {
  max-width: 34em;
  font-size: 14px;
  line-height: 1.85;
  color: var(--c-text);
}

.footer__title {
  margin-bottom: 12px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--c-text);
}

.footer__list {
  display: grid;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 14px;
}

.footer__list a {
  display: inline-block;
  padding: 2px 0;
  color: var(--c-text);
  transition: color var(--dur) var(--ease);
}

.footer__list a:hover {
  color: var(--c-ink);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.footer__list li span {
  color: var(--c-text-soft);
}

.footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid var(--c-border);
  font-size: 10px;
  line-height: 1.8;
  color: var(--c-muted);
}

.footer__bottom p {
  margin: 0;
}

/* 悬浮返回顶部：仅图标，滚动一段距离后出现 */
.to-top {
  position: fixed;
  right: 20px;
  bottom: calc(20px + env(safe-area-inset-bottom, 0px));
  z-index: 900;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  padding: 0;
  border: 1px solid var(--c-primary);
  border-radius: 50%;
  background-color: var(--c-bg);
  color: var(--c-ink);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity var(--dur) var(--ease),
    visibility var(--dur) var(--ease), transform var(--dur) var(--ease),
    border-color var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.to-top.is-show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.to-top:hover {
  border-color: var(--c-primary);
  background-color: var(--c-primary-soft);
}

.to-top:active {
  background-color: #d8f2fb;
}

.to-top svg {
  width: 20px;
  height: 20px;
  pointer-events: none;
}

/* --------------------------------------------------------------------------
   19. 响应式
   -------------------------------------------------------------------------- */
@media (min-width: 640px) {
  .line-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .line-card {
    padding: 24px;
  }
}

@media (min-width: 768px) {
  .container {
    padding: 0 24px;
  }

  .hero {
    padding: 56px 0 56px;
  }

  .section {
    padding: 64px 0;
  }

  .step-grid,
  .type-grid,
  .why-grid,
  .notice-grid,
  .readmore {
    gap: 24px;
  }

  .check-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }

  .footer__grid {
    grid-template-columns: 1.5fr 1fr 1fr;
  }

  .go-card {
    padding: 40px;
  }

  .go-title {
    font-size: 24px;
  }
}

@media (min-width: 900px) {
  .nav-toggle {
    display: none;
  }

  .nav {
    display: block;
    position: static;
    padding: 0;
    background-color: transparent;
    border: 0;
  }

  .nav__list {
    flex-direction: row;
    align-items: center;
    gap: 4px;
  }

  .nav__link {
    padding: 8px 12px;
  }

  .hero__grid {
    grid-template-columns: 1.15fr 0.85fr;
    gap: 48px;
    align-items: start;
  }

  .step-grid,
  .type-grid,
  .why-grid,
  .notice-grid,
  .readmore {
    grid-template-columns: repeat(3, 1fr);
  }

  .panel {
    margin-top: 8px;
  }
}

@media (min-width: 1024px) {
  .line-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
  }

  .check-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* 窄屏表格改为卡片 */
@media (max-width: 767px) {
  .table-wrap {
    background-color: transparent;
    border: 0;
    border-radius: 0;
    overflow: visible;
  }

  .cmp thead {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0 0 0 0);
    white-space: nowrap;
  }

  .cmp,
  .cmp tbody,
  .cmp tr,
  .cmp td {
    display: block;
    width: 100%;
  }

  .cmp tr {
    margin-bottom: 12px;
    padding: 8px 16px;
    background-color: var(--c-bg);
    border: 1px solid var(--c-border);
    border-radius: var(--r-lg);
  }

  .cmp td {
    display: flex;
    gap: 12px;
    padding: 8px 0;
    border-bottom: 1px solid var(--c-border);
  }

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

  .cmp td::before {
    content: attr(data-label);
    flex: 0 0 76px;
    font-weight: 700;
    color: var(--c-muted);
  }
}

@media (max-width: 380px) {
  .hero__actions .btn {
    width: 100%;
  }
}

/* --------------------------------------------------------------------------
   20. 可访问性偏好
   -------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}