/* ==========================================================================
   解混淆 · xfqjiehunxiao.com
   设计语言：暖纸色、深咖啡墨色、锐角按钮、无阴影、大留白
   ========================================================================== */

/* ---------- 1. 设计变量 ---------- */
:root {
  --ink: #341103;
  --ink-soft: #4d1b08;
  --ink-2: #5a3522;
  --muted: #6d4c3a;
  --paper: #ffffff;
  --sand: #f5f5f5;
  --sand-deep: #efe9e4;
  --cream: #f7e8dd;
  --cream-soft: #fbf6f1;
  --cream-deep: #efdccd;
  --line: #e5dbd2;
  --line-strong: #cdbbae;
  --terra: #a84522;
  --white-70: rgba(255, 255, 255, 0.72);
  --white-40: rgba(255, 255, 255, 0.4);

  --font-body: "Geist", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    "Noto Sans SC", "Source Han Sans SC", system-ui, -apple-system, sans-serif;
  --font-display: "Geist", "Geist Sans", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", Menlo, "Roboto Mono", Consolas,
    monospace;

  --ease: cubic-bezier(0.19, 1, 0.22, 1);
  --ease-out: cubic-bezier(0.075, 0.82, 0.165, 1);
  --t-fast: 0.2s;
  --t-mid: 0.4s;
  --t-slow: 0.6s;

  --wrap: 1220px;
  --gutter: 40px;
  --radius: 10px;
  --head-h: 76px;
}

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

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body.is-locked {
  overflow: hidden;
}

[hidden] {
  display: none !important;
}

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

img {
  height: auto;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 500;
  line-height: 1.22;
  letter-spacing: -0.012em;
  color: var(--ink);
}

p {
  margin: 0 0 1.1em;
}

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

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

a:hover {
  color: var(--ink-soft);
}

strong {
  font-weight: 600;
}

ul,
ol {
  margin: 0;
  padding: 0;
}

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

button {
  cursor: pointer;
}

code,
kbd,
pre {
  font-family: var(--font-mono);
  font-size: 0.88em;
}

:focus-visible {
  outline: 3px solid #000000;
  outline-offset: 2px;
}

::selection {
  background: var(--cream-deep);
  color: var(--ink);
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 16px;
  z-index: 100;
  padding: 12px 18px;
  background: var(--ink);
  color: #fff;
  text-decoration: none;
}

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

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

/* ---------- 3. 布局工具 ---------- */
.wrap {
  width: min(var(--wrap), calc(100% - var(--gutter) * 2));
  margin-inline: auto;
}

.wrap--narrow {
  width: min(820px, calc(100% - var(--gutter) * 2));
}

.section {
  padding: 92px 0;
  border-bottom: 1px solid var(--line);
}

.section:last-of-type {
  border-bottom: 0;
}

.section--tight {
  padding: 64px 0;
}

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

.section--cream {
  background: var(--cream-soft);
}

.section__head {
  max-width: 780px;
  margin-bottom: 44px;
}

.section__head--center {
  margin-inline: auto;
  text-align: center;
}

.section__title {
  font-size: clamp(28px, 3.4vw, 40px);
  letter-spacing: -0.018em;
}

.section__desc {
  margin-top: 16px;
  font-size: 16.5px;
  line-height: 1.8;
  color: var(--ink-2);
  max-width: 720px;
}

.section__head--center .section__desc {
  margin-inline: auto;
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}

.kicker::before {
  content: "";
  width: 7px;
  height: 7px;
  background: var(--terra);
  transform: rotate(45deg);
}

.lede {
  font-size: 17px;
  line-height: 1.85;
  color: var(--ink-2);
}

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

.small {
  font-size: 13px;
  line-height: 1.65;
}

.mono {
  font-family: var(--font-mono);
}

.arrow-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
  border-bottom: 1px solid var(--ink);
  padding-bottom: 2px;
  transition: gap var(--t-mid) var(--ease), color var(--t-mid) var(--ease);
}

.arrow-link::after {
  content: "→";
  transition: transform var(--t-mid) var(--ease);
}

.arrow-link:hover::after {
  transform: translateX(4px);
}

/* ---------- 4. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 48px;
  padding: 0 20px;
  border: 1px solid var(--ink);
  border-radius: 0;
  background: transparent;
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 500;
  line-height: 1.2;
  text-decoration: none;
  white-space: nowrap;
  transition: background-color var(--t-mid) var(--ease),
    color var(--t-mid) var(--ease), border-color var(--t-mid) var(--ease),
    transform var(--t-fast) var(--ease-out);
}

.btn:hover {
  background: var(--ink);
  color: #fff;
}

.btn:active {
  transform: translateY(1px);
}

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

.btn--primary:hover {
  background: var(--ink-soft);
  color: #fff;
}

.btn--ghost {
  border-color: transparent;
  padding: 0 6px;
  min-height: 40px;
  color: var(--ink);
}

.btn--ghost:hover {
  background: transparent;
  color: var(--muted);
  text-decoration: underline;
}

.btn--light {
  background: var(--cream);
  border-color: var(--cream);
  color: var(--ink);
}

.btn--light:hover {
  background: #fff;
  border-color: #fff;
  color: var(--ink);
}

.btn--outline-light {
  border-color: rgba(255, 255, 255, 0.55);
  color: #fff;
}

.btn--outline-light:hover {
  background: #fff;
  border-color: #fff;
  color: var(--ink);
}

.btn--sm {
  min-height: 40px;
  padding: 0 15px;
  font-size: 13.5px;
}

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

.btn[disabled],
.btn[aria-disabled="true"] {
  border-color: var(--line-strong);
  background: var(--sand);
  color: #9b8375;
  cursor: not-allowed;
  transform: none;
}

.btn[disabled]:hover,
.btn[aria-disabled="true"]:hover {
  background: var(--sand);
  color: #9b8375;
}

.btn__icon {
  width: 17px;
  height: 17px;
  flex: none;
}

/* ---------- 5. 站点头部 ---------- */
.site-head {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: saturate(1.15) blur(12px);
  -webkit-backdrop-filter: saturate(1.15) blur(12px);
}

.site-head__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
  min-height: var(--head-h);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  flex: none;
  text-decoration: none;
}

.brand__mark {
  width: 31px;
  height: 31px;
  flex: none;
}

.brand__text {
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.brand__name {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 600;
  letter-spacing: 0.015em;
  line-height: 1;
}

.brand__note {
  padding-left: 10px;
  border-left: 1px solid var(--line-strong);
  font-size: 10px;
  letter-spacing: 0.12em;
  color: var(--muted);
  line-height: 1.4;
  white-space: nowrap;
}

.nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav__link {
  position: relative;
  padding: 10px 0;
  font-size: 14.5px;
  font-weight: 400;
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
}

.nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 2px;
  width: 0;
  height: 1px;
  background: var(--ink);
  transition: width var(--t-slow) var(--ease);
}

.nav__link:hover::after,
.nav__link[aria-current="page"]::after {
  width: 100%;
}

.nav__link[aria-current="page"] {
  font-weight: 600;
}

.site-head__cta {
  flex: none;
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid var(--line-strong);
  background: transparent;
}

.nav-toggle__box {
  display: flex;
  flex-direction: column;
  gap: 5px;
  width: 20px;
  margin-inline: auto;
}

.nav-toggle__bar {
  display: block;
  height: 1px;
  background: var(--ink);
  transition: transform var(--t-mid) var(--ease), opacity var(--t-fast);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) {
  transform: translateY(6px) 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(-6px) rotate(-45deg);
}

/* 移动端抽屉 */
.nav-drawer {
  position: fixed;
  inset: var(--head-h) 0 0;
  z-index: 39;
  display: none;
  overflow-y: auto;
  background: var(--paper);
  border-top: 1px solid var(--line);
  padding: 28px 0 48px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: opacity var(--t-mid) var(--ease),
    transform var(--t-mid) var(--ease), visibility var(--t-mid);
}

.nav-drawer[data-open="true"] {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.nav-drawer__group {
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.nav-drawer__label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.nav-drawer__group a {
  display: block;
  padding: 8px 0;
  font-size: 16px;
  text-decoration: none;
}

.nav-drawer__group a[aria-current="page"] {
  font-weight: 600;
}

.nav-drawer__note {
  margin-top: 24px;
  font-size: 12.5px;
  color: var(--muted);
}

/* ---------- 6. 首页 hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  padding: 74px 0 76px;
  border-bottom: 1px solid var(--line);
  background: radial-gradient(
      118% 130% at 16% -8%,
      #f6e4d7 0%,
      #fbf3ec 38%,
      #fffdfb 70%,
      #ffffff 100%
    );
}

.hero__inner {
  position: relative;
  z-index: 2;
  text-align: center;
}

.hero__copy {
  max-width: 880px;
  margin-inline: auto;
  animation: rise-in 0.9s var(--ease) both;
}

.hero__title {
  margin: 0 0 18px;
  font-size: clamp(48px, 6.6vw, 76px);
  font-weight: 500;
  line-height: 1.02;
  letter-spacing: -0.03em;
}

.hero__title em {
  display: block;
  margin-top: 16px;
  font-family: var(--font-body);
  font-size: clamp(13px, 1.7vw, 15px);
  font-style: normal;
  font-weight: 500;
  line-height: 1.5;
  letter-spacing: 0.2em;
  color: var(--muted);
}

.hero__lead {
  max-width: 780px;
  margin: 0 auto;
  font-size: 16.5px;
  line-height: 1.9;
  color: var(--ink-2);
}

.hero__tool {
  margin-top: 44px;
  animation: rise-in 0.95s 0.08s var(--ease) both;
}

.hero__ring {
  position: absolute;
  z-index: 0;
  width: 620px;
  height: 620px;
  top: -250px;
  right: -190px;
  border: 1px solid rgba(52, 17, 3, 0.12);
  border-radius: 50%;
  pointer-events: none;
}

.hero__ring::before {
  content: "";
  position: absolute;
  inset: 58px;
  border: 1px solid rgba(52, 17, 3, 0.07);
  border-radius: 50%;
}

.hero__ring--left {
  width: 380px;
  height: 380px;
  top: auto;
  right: auto;
  left: -190px;
  bottom: -160px;
}

.hero__star {
  position: absolute;
  z-index: 0;
  width: 124px;
  height: 124px;
  left: 4%;
  top: 68px;
  color: rgba(52, 17, 3, 0.16);
  animation: slow-spin 46s linear infinite;
  pointer-events: none;
}

.hero__dot-grid {
  position: absolute;
  z-index: 0;
  right: 4%;
  bottom: 92px;
  width: 118px;
  height: 82px;
  opacity: 0.45;
  background-image: radial-gradient(
    circle,
    rgba(52, 17, 3, 0.32) 1px,
    transparent 1px
  );
  background-size: 14px 14px;
  pointer-events: none;
}

/* ---------- 7. 工具 ---------- */
.tool {
  position: relative;
  max-width: 1120px;
  margin-inline: auto;
  text-align: left;
  background: var(--paper);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  overflow: hidden;
}

.tool__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 16px 24px;
  border-bottom: 1px solid var(--line);
  background: #fff;
}

.tool__eyebrow {
  display: block;
  margin-bottom: 3px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}

.tool__title {
  margin: 0;
  font-size: 20px;
  font-weight: 500;
}

.tool__badges {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid var(--line);
  border-radius: 9999px;
  background: var(--cream-soft);
  font-size: 11.5px;
  line-height: 1.5;
  color: var(--ink-2);
  white-space: nowrap;
}

.chip::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--terra);
}

.tool__body {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(320px, 0.85fr);
}

.stage {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 466px;
  padding: 28px;
  background: #faf7f4;
  border-right: 1px solid var(--line);
  background-image: radial-gradient(
    circle at 1px 1px,
    rgba(52, 17, 3, 0.055) 1px,
    transparent 0
  );
  background-size: 18px 18px;
}

.stage.is-dragover {
  background-color: #f5e9df;
  outline: 2px solid var(--terra);
  outline-offset: -8px;
}

.stage__empty {
  max-width: 380px;
  text-align: center;
}

.stage__icon {
  width: 58px;
  height: 58px;
  margin: 0 auto 18px;
  color: var(--ink);
}

.stage__empty h3 {
  margin-bottom: 8px;
  font-size: 21px;
}

.stage__empty p {
  margin-bottom: 20px;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--muted);
}

.stage__empty-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.stage__frame {
  position: relative;
  display: none;
  max-width: 100%;
}

.stage.has-image {
  align-items: center;
  padding-bottom: 84px;
}

.stage.has-image .stage__empty {
  display: none;
}

.stage.has-image .stage__frame {
  display: inline-block;
}

.stage__image {
  display: block;
  max-width: 100%;
  max-height: 520px;
  width: auto;
  height: auto;
  border: 1px solid rgba(52, 17, 3, 0.14);
  background: #fff;
}

.stage__compare {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: contain;
  border: 1px solid rgba(52, 17, 3, 0.14);
  background: #fff;
  display: none;
}

.stage.is-comparing .stage__compare {
  display: block;
}

.stage__flag {
  position: absolute;
  top: 10px;
  left: 10px;
  z-index: 2;
  padding: 3px 8px;
  background: rgba(52, 17, 3, 0.82);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.stage__bar {
  position: absolute;
  left: 16px;
  right: 16px;
  bottom: 14px;
  z-index: 3;
  display: none;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 8px 10px 8px 14px;
  background: rgba(255, 255, 255, 0.94);
  border: 1px solid var(--line);
  backdrop-filter: blur(8px);
}

.stage.has-image .stage__bar {
  display: flex;
}

.stage__meta {
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.stage__bar-actions {
  display: flex;
  gap: 4px;
  flex: none;
}

.stage__busy {
  position: absolute;
  inset: 0;
  z-index: 8;
  display: grid;
  place-items: center;
  background: rgba(250, 247, 244, 0.82);
  backdrop-filter: blur(3px);
}

.busy-card {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 16px 22px;
  background: #fff;
  border: 1px solid var(--line-strong);
  font-size: 13.5px;
}

.spinner {
  width: 18px;
  height: 18px;
  border: 2px solid var(--cream-deep);
  border-top-color: var(--ink);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  flex: none;
}

.tool__panel {
  display: flex;
  flex-direction: column;
  gap: 18px;
  padding: 26px 24px;
  background: #fff;
}

.panel__label {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.action-stack {
  display: grid;
  gap: 9px;
}

.format-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}

.format-row label {
  font-size: 13px;
  color: var(--ink-2);
  white-space: nowrap;
}

.select {
  appearance: none;
  -webkit-appearance: none;
  width: 138px;
  height: 42px;
  padding: 0 32px 0 12px;
  border: 1px solid var(--line-strong);
  border-radius: 0;
  background-color: #fff;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1.5 6 6.5l5-5' fill='none' stroke='%23341103' stroke-width='1.4'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  font-size: 13px;
  cursor: pointer;
}

.select:focus-visible {
  outline: 3px solid #000;
  outline-offset: 1px;
}

.filemeta {
  display: grid;
  gap: 7px;
  margin: 0;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  font-size: 12.5px;
}

.filemeta__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 18px;
}

.filemeta dt {
  color: var(--muted);
  flex: none;
}

.filemeta dd {
  margin: 0;
  min-width: 0;
  text-align: right;
  word-break: break-all;
  color: var(--ink);
}

.state-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  margin-right: 5px;
  border-radius: 50%;
  background: #b3a094;
  vertical-align: 1px;
}

.state-dot.is-active {
  background: var(--terra);
}

.tool__privacy {
  display: flex;
  gap: 8px;
  margin-top: auto;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 11.5px;
  line-height: 1.65;
  color: var(--muted);
}

.tool__privacy svg {
  width: 14px;
  height: 14px;
  flex: none;
  margin-top: 3px;
}

.tool__warn {
  padding: 10px 12px;
  border-left: 2px solid var(--terra);
  background: #fdf6f1;
  font-size: 12px;
  line-height: 1.65;
  color: var(--ink-2);
}

/* 顶部提示 */
.toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  z-index: 120;
  transform: translate(-50%, 16px);
  padding: 12px 20px;
  background: var(--ink);
  color: #fff;
  font-size: 13px;
  line-height: 1.5;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--t-mid) var(--ease),
    transform var(--t-mid) var(--ease);
  max-width: calc(100% - 32px);
}

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

/* ---------- 8. 首页模块 ---------- */
.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  border-top: 1px solid var(--ink);
}

.stat {
  padding: 26px 28px 0 0;
  border-right: 1px solid var(--line);
}

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

.stat__value {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(38px, 4.6vw, 54px);
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.03em;
}

.stat__value small {
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0;
  margin-left: 4px;
  color: var(--muted);
}

.stat__label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
  gap: clamp(36px, 6vw, 80px);
  align-items: start;
}

.split__aside {
  position: sticky;
  top: calc(var(--head-h) + 32px);
}

.split__title {
  font-size: clamp(27px, 3.1vw, 38px);
  margin-bottom: 18px;
}

.split__note {
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: var(--muted);
}

.statement {
  font-size: clamp(23px, 2.7vw, 31px);
  line-height: 1.5;
  letter-spacing: -0.012em;
  color: var(--ink);
}

.statement em {
  font-style: normal;
  background: linear-gradient(transparent 70%, var(--cream-deep) 70%);
}

.prose {
  max-width: 800px;
}

.prose > p {
  font-size: 16px;
  line-height: 1.95;
  color: var(--ink-2);
}

.prose > p + p {
  margin-top: 1.05em;
}

.prose h2 {
  margin: 52px 0 16px;
  font-size: clamp(24px, 2.6vw, 31px);
}

.prose h3 {
  margin: 36px 0 12px;
  font-size: 20px;
}

.prose h2:first-child,
.prose h3:first-child {
  margin-top: 0;
}

.prose ul,
.prose ol {
  margin: 0 0 1.2em;
  padding-left: 1.3em;
}

.prose li {
  margin-bottom: 0.55em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink-2);
}

.prose li::marker {
  color: var(--terra);
}

.prose a {
  font-weight: 500;
}

.prose blockquote {
  margin: 28px 0;
  padding: 4px 0 4px 24px;
  border-left: 2px solid var(--ink);
  font-size: 18px;
  line-height: 1.8;
  color: var(--ink);
}

.prose code {
  padding: 2px 5px;
  background: var(--cream-soft);
  border: 1px solid var(--line);
  color: var(--ink);
}

.prose pre {
  margin: 24px 0;
  padding: 20px 22px;
  overflow-x: auto;
  background: var(--ink);
  color: #f8ede4;
  line-height: 1.7;
}

.prose pre code {
  padding: 0;
  border: 0;
  background: transparent;
  color: inherit;
  font-size: 13px;
}

.prose hr {
  margin: 40px 0;
  border: 0;
  border-top: 1px solid var(--line);
}

/* 卡片网格 */
.grid {
  display: grid;
  gap: 20px;
}

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

.grid--3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid--4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 30px;
  background: var(--sand);
  border-radius: var(--radius);
  transition: background-color var(--t-mid) var(--ease);
}

.card:hover {
  background: var(--sand-deep);
}

.card--link {
  color: var(--ink);
  text-decoration: none;
}

.card--outline {
  background: transparent;
  border: 1px solid var(--line);
}

.card--outline:hover {
  background: var(--cream-soft);
}

.card__icon {
  width: 34px;
  height: 34px;
  margin-bottom: 22px;
  color: var(--ink);
}

.card__num {
  margin-bottom: 22px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--muted);
}

.card__title {
  margin-bottom: 10px;
  font-size: 19px;
  line-height: 1.4;
}

.card__title a {
  text-decoration: none;
}

.card__title a:hover {
  text-decoration: underline;
}

.card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink-2);
}

.card__more {
  margin-top: auto;
  padding-top: 20px;
  font-size: 12.5px;
  font-weight: 500;
  color: var(--ink);
}

.card__more::after {
  content: " →";
}

.card--link:hover .card__more {
  text-decoration: underline;
}

/* 步骤 */
.steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--ink);
}

.step {
  padding: 26px 30px 4px 0;
  border-right: 1px solid var(--line);
}

.step:last-child {
  border-right: 0;
  padding-right: 0;
}

.step + .step {
  padding-left: 30px;
}

.step__num {
  display: block;
  margin-bottom: 48px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--muted);
}

.step h3 {
  margin-bottom: 10px;
  font-size: 21px;
}

.step p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink-2);
}

/* 提示块 */
.callout {
  margin: 32px 0;
  padding: 24px 28px;
  background: var(--cream-soft);
  border-left: 2px solid var(--ink);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.callout__title {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink);
}

.callout p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink-2);
}

.callout--warn {
  border-left-color: var(--terra);
  background: #fdf5ef;
}

.callout--plain {
  border-left-color: var(--line-strong);
  background: var(--sand);
}

.callout a {
  font-weight: 500;
}

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

.tbl {
  width: 100%;
  border-collapse: collapse;
  min-width: 620px;
  text-align: left;
}

.tbl caption {
  padding: 12px 0;
  font-size: 12px;
  color: var(--muted);
  text-align: left;
}

.tbl th,
.tbl td {
  padding: 15px 18px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
  font-size: 14.5px;
  line-height: 1.7;
}

.tbl thead th {
  padding-top: 13px;
  padding-bottom: 13px;
  background: var(--cream-soft);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-2);
}

.tbl tbody th {
  font-weight: 500;
  color: var(--ink);
  width: 26%;
}

.tbl tbody td {
  color: var(--ink-2);
}

.tbl tbody tr:hover {
  background: #fcf9f6;
}

.tbl code {
  font-size: 12.5px;
}

/* FAQ */
.faq-list {
  border-top: 1px solid var(--ink);
}

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

.faq summary {
  position: relative;
  display: block;
  padding: 22px 48px 22px 0;
  font-size: 16.5px;
  font-weight: 500;
  line-height: 1.55;
  color: var(--ink);
  cursor: pointer;
  list-style: none;
}

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

.faq summary::after {
  content: "";
  position: absolute;
  right: 4px;
  top: 29px;
  width: 13px;
  height: 13px;
  background: linear-gradient(var(--ink), var(--ink)) center / 13px 1px
      no-repeat,
    linear-gradient(var(--ink), var(--ink)) center / 1px 13px no-repeat;
  transition: transform var(--t-mid) var(--ease);
}

.faq[open] summary::after {
  background: linear-gradient(var(--ink), var(--ink)) center / 13px 1px no-repeat;
  transform: rotate(180deg);
}

.faq__body {
  padding: 0 60px 24px 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink-2);
}

.faq__body p {
  margin-bottom: 0.8em;
}

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

.faq__body ul {
  padding-left: 1.2em;
  margin-bottom: 1em;
}

/* 延伸阅读 */
.read-list {
  border-top: 1px solid var(--ink);
}

.read-item {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 28px;
  padding: 24px 0;
  border-bottom: 1px solid var(--line);
  text-decoration: none;
}

.read-item__main {
  min-width: 0;
}

.read-item__tag {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.read-item h3 {
  font-size: 19px;
  transition: color var(--t-fast);
}

.read-item p {
  margin: 6px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

.read-item__arrow {
  flex: none;
  font-size: 20px;
  transition: transform var(--t-mid) var(--ease);
}

.read-item:hover .read-item__arrow {
  transform: translateX(6px);
}

.read-item:hover h3 {
  text-decoration: underline;
  text-underline-offset: 4px;
}

/* 兜底 CTA */
.cta-wrap {
  padding: 0 0 92px;
}

.cta {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 48px;
  padding: 54px 56px;
  background: var(--ink);
  color: #fff;
  border-radius: var(--radius);
  background-image: radial-gradient(
      circle at 86% 10%,
      rgba(247, 232, 221, 0.14) 0,
      transparent 42%
    ),
    radial-gradient(circle at 8% 100%, rgba(247, 232, 221, 0.08) 0, transparent 46%);
}

.cta__title {
  margin: 0 0 14px;
  max-width: 640px;
  font-size: clamp(28px, 3.4vw, 42px);
  color: #fff;
  letter-spacing: -0.02em;
}

.cta__desc {
  max-width: 620px;
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--white-70);
}

.cta__actions {
  display: flex;
  gap: 10px;
  flex: none;
}

/* ---------- 9. 内页 ---------- */
.page-hero {
  position: relative;
  overflow: hidden;
  padding: 50px 0 54px;
  border-bottom: 1px solid var(--line);
  background: radial-gradient(
    110% 150% at 10% 0%,
    #f7e9de 0%,
    #fbf6f1 45%,
    #fff 100%
  );
}

.page-hero::after {
  content: "";
  position: absolute;
  right: -90px;
  bottom: -210px;
  width: 420px;
  height: 420px;
  border: 1px solid rgba(52, 17, 3, 0.1);
  border-radius: 50%;
  pointer-events: none;
}

.page-hero__inner {
  position: relative;
  z-index: 1;
  max-width: 850px;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: 28px;
  font-size: 11.5px;
  color: var(--muted);
}

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

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

.breadcrumb span[aria-current] {
  color: var(--ink);
}

.page-hero h1 {
  margin: 0 0 18px;
  font-size: clamp(34px, 4.7vw, 52px);
  line-height: 1.1;
  letter-spacing: -0.025em;
}

.page-hero .lede {
  max-width: 760px;
  margin: 0;
}

.page-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 24px;
}

.doc-grid {
  display: grid;
  grid-template-columns: 210px minmax(0, 1fr);
  gap: clamp(36px, 6vw, 78px);
  align-items: start;
}

.toc {
  position: sticky;
  top: calc(var(--head-h) + 28px);
  padding-left: 18px;
  border-left: 1px solid var(--line-strong);
}

.toc__label {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.toc a {
  display: block;
  padding: 5px 0;
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
  text-decoration: none;
}

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

/* 数字标注块 */
.numbered-list {
  counter-reset: n;
  list-style: none;
  padding: 0;
  margin: 0;
  border-top: 1px solid var(--ink);
}

.numbered-list li {
  position: relative;
  padding: 22px 0 22px 54px;
  border-bottom: 1px solid var(--line);
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-2);
  counter-increment: n;
}

.numbered-list li::before {
  content: counter(n, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 24px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--muted);
}

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

/* 检查清单 */
.check-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.check-list li {
  position: relative;
  padding: 7px 0 7px 26px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink-2);
}

.check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 13px;
  width: 11px;
  height: 6px;
  border-left: 1.5px solid var(--ink);
  border-bottom: 1.5px solid var(--ink);
  transform: rotate(-45deg);
}

/* 术语表 */
.glossary {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0 48px;
  border-top: 1px solid var(--ink);
}

.glossary__item {
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}

.glossary__item dt {
  margin-bottom: 7px;
  font-size: 17px;
  font-weight: 600;
  color: var(--ink);
}

.glossary__item dt span {
  display: inline-block;
  margin-left: 6px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 400;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.glossary__item dd {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-2);
}

/* 时间线 */
.timeline {
  margin: 0;
  padding: 0 0 0 26px;
  list-style: none;
  border-left: 1px solid var(--line-strong);
}

.timeline li {
  position: relative;
  padding: 0 0 30px;
}

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

.timeline li::before {
  content: "";
  position: absolute;
  left: -31px;
  top: 8px;
  width: 9px;
  height: 9px;
  background: var(--paper);
  border: 1px solid var(--ink);
  border-radius: 50%;
}

.timeline__date {
  display: block;
  margin-bottom: 5px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.timeline h3 {
  margin-bottom: 6px;
  font-size: 17px;
}

.timeline p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-2);
}

/* 网站地图 */
.sitemap-groups {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 44px 64px;
}

.sitemap-group {
  border-top: 1px solid var(--ink);
  padding-top: 18px;
}

.sitemap-group h2 {
  margin-bottom: 14px;
  font-size: 13px;
  font-family: var(--font-mono);
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

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

.sitemap-group li {
  padding: 7px 0;
  border-bottom: 1px solid var(--line);
}

.sitemap-group a {
  font-size: 15px;
  text-decoration: none;
}

.sitemap-group a:hover {
  text-decoration: underline;
}

.sitemap-group span {
  display: block;
  margin-top: 2px;
  font-size: 12.5px;
  color: var(--muted);
}

/* ---------- 10. 批量处理页 ---------- */
.batch {
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  overflow: hidden;
  background: #fff;
}

.batch__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 24px;
  border-bottom: 1px solid var(--line);
}

.batch__head h2 {
  font-size: 20px;
}

.batch__controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.batch__drop {
  margin: 24px;
  padding: 34px 24px;
  border: 1px dashed var(--line-strong);
  background: var(--cream-soft);
  text-align: center;
  transition: background-color var(--t-fast), border-color var(--t-fast);
  cursor: pointer;
}

.batch__drop.is-dragover {
  background: var(--cream);
  border-color: var(--ink);
}

.batch__drop h3 {
  margin-bottom: 6px;
  font-size: 19px;
}

.batch__drop p {
  margin: 0 0 16px;
  font-size: 13px;
  color: var(--muted);
}

.batch__progress {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 0 24px 18px;
}

.progress {
  flex: 1;
  height: 3px;
  background: var(--line);
  overflow: hidden;
}

.progress__bar {
  width: 0;
  height: 100%;
  background: var(--ink);
  transition: width var(--t-mid) var(--ease);
}

.batch__count {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--muted);
  white-space: nowrap;
}

.batch__empty {
  padding: 20px 24px 34px;
  font-size: 13px;
  color: var(--muted);
  text-align: center;
  border-top: 1px solid var(--line);
}

.batch__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.batch-row {
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr) auto;
  align-items: center;
  gap: 16px;
  padding: 14px 24px;
  border-bottom: 1px solid var(--line);
}

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

.batch-row__thumb {
  width: 54px;
  height: 54px;
  object-fit: cover;
  background: var(--sand);
  border: 1px solid var(--line);
}

.batch-row__name {
  font-size: 14px;
  font-weight: 500;
  line-height: 1.5;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.batch-row__meta {
  margin-top: 3px;
  font-size: 11.5px;
  color: var(--muted);
  line-height: 1.5;
}

.batch-row__status {
  display: flex;
  align-items: center;
  gap: 10px;
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 3px 8px;
  border: 1px solid var(--line);
  background: var(--cream-soft);
  font-size: 11px;
  line-height: 1.5;
  color: var(--ink-2);
  white-space: nowrap;
}

.badge--done {
  border-color: #b7c4ae;
  background: #f1f5ed;
  color: #3e5a31;
}

.badge--error {
  border-color: #dbb4a6;
  background: #fbf0eb;
  color: #8d3218;
}

.batch-row__actions {
  display: flex;
  gap: 4px;
}

.batch-row__remove {
  width: 32px;
  height: 32px;
  border: 1px solid transparent;
  background: transparent;
  color: var(--muted);
  font-size: 18px;
  line-height: 1;
}

.batch-row__remove:hover {
  border-color: var(--line);
  color: var(--ink);
}

.batch__note {
  padding: 16px 24px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 11. 曲线演示 ---------- */
.curve-figure {
  margin: 0;
  padding: 22px;
  background: var(--cream-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.curve-figure canvas {
  display: block;
  width: 100%;
  height: auto;
  background: #fff;
  border: 1px solid var(--line);
}

.curve-figure figcaption {
  margin-top: 12px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--muted);
}

.demo {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(260px, 0.65fr);
  gap: 32px;
  padding: 24px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: #fff;
}

.demo__canvas-wrap {
  min-width: 0;
}

.demo canvas {
  display: block;
  width: 100%;
  height: auto;
  background: #faf7f4;
  border: 1px solid var(--line);
}

.demo__controls {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.demo__readout {
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.8;
  color: var(--ink-2);
}

.demo__readout b {
  color: var(--ink);
}

.field {
  display: block;
}

.field__label {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 7px;
  font-size: 12px;
  color: var(--muted);
}

.field__value {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ink);
}

input[type="range"] {
  width: 100%;
  accent-color: var(--ink);
  cursor: pointer;
}

.demo__legend {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  font-size: 11.5px;
  color: var(--muted);
}

.demo__legend span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.demo__swatch {
  width: 9px;
  height: 9px;
  display: inline-block;
}

.demo__swatch--i {
  background: var(--ink);
}

.demo__swatch--j {
  background: var(--terra);
}

.formula {
  display: inline-block;
  padding: 8px 14px;
  background: var(--cream-soft);
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.7;
}

/* ---------- 12. 联系与说明块 ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.contact-card {
  padding: 30px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.contact-card h2 {
  margin-bottom: 10px;
  font-size: 20px;
}

.contact-card p {
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-2);
}

.contact-card code {
  padding: 3px 7px;
  background: var(--cream-soft);
  border: 1px solid var(--line);
  font-size: 12.5px;
}

.copy-box {
  position: relative;
  margin: 18px 0;
  padding: 18px 20px;
  background: var(--ink);
  color: #f8ede4;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.8;
  overflow-x: auto;
}

.copy-box button {
  position: absolute;
  right: 8px;
  top: 8px;
  padding: 5px 10px;
  border: 1px solid rgba(255, 255, 255, 0.35);
  background: transparent;
  color: #fff;
  font-size: 11px;
}

.copy-box button:hover {
  background: rgba(255, 255, 255, 0.12);
}

/* ---------- 13. 页脚 ---------- */
.site-footer {
  background: var(--cream-soft);
  border-top: 1px solid var(--line);
  padding-top: 66px;
  overflow: hidden;
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.6fr);
  gap: 64px;
}

.footer-brand__name {
  display: flex;
  align-items: center;
  gap: 11px;
  margin-bottom: 16px;
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.footer-brand__name img {
  width: 28px;
  height: 28px;
}

.footer-brand p {
  max-width: 360px;
  font-size: 13.5px;
  line-height: 1.85;
  color: var(--muted);
}

.footer-note {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 20px;
  padding: 7px 12px;
  border: 1px solid var(--line);
  border-radius: 9999px;
  background: #fff;
  font-size: 11px;
  color: var(--ink-2);
}

.footer-note::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--terra);
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 32px;
}

.footer-col h2 {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.footer-col a {
  display: block;
  padding: 5px 0;
  font-size: 13.5px;
  color: var(--ink);
  text-decoration: none;
}

.footer-col a:hover {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.footer-word {
  margin-top: 54px;
  font-family: var(--font-display);
  font-size: clamp(86px, 17vw, 230px);
  font-weight: 600;
  line-height: 0.72;
  letter-spacing: -0.05em;
  color: rgba(52, 17, 3, 0.055);
  white-space: nowrap;
  user-select: none;
  pointer-events: none;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px 28px;
  margin-top: 28px;
  padding: 20px 0 28px;
  border-top: 1px solid var(--line);
  font-size: 11.5px;
  line-height: 1.7;
  color: var(--muted);
}

.footer-bottom nav {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

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

.footer-bottom a:hover {
  color: var(--ink);
  text-decoration: underline;
}

/* ---------- 14. 404 ---------- */
.error-page {
  display: grid;
  place-items: center;
  min-height: 62vh;
  padding: 80px 0;
  text-align: center;
  background: radial-gradient(
    100% 100% at 50% 0%,
    #f7e9de 0%,
    #fff 70%
  );
}

.error-code {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(70px, 14vw, 150px);
  font-weight: 500;
  line-height: 0.9;
  letter-spacing: -0.06em;
  color: var(--ink);
}

.error-page h1 {
  margin: 18px 0 10px;
  font-size: clamp(24px, 3vw, 32px);
}

.error-page p {
  max-width: 560px;
  margin: 0 auto 26px;
  color: var(--ink-2);
  font-size: 15px;
}

.error-page__links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

/* ---------- 15. 动画 ---------- */
@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@keyframes slow-spin {
  to {
    transform: rotate(360deg);
  }
}

@keyframes rise-in {
  from {
    opacity: 0;
    transform: translateY(18px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

/* ---------- 16. 响应式 ---------- */
@media (max-width: 1080px) {
  :root {
    --gutter: 28px;
  }

  .nav {
    gap: 20px;
  }

  .brand__note {
    display: none;
  }

  .site-head__cta {
    display: none;
  }

  .tool__body {
    grid-template-columns: minmax(0, 1.35fr) minmax(300px, 0.8fr);
  }
}

@media (max-width: 991px) {
  :root {
    --gutter: 24px;
    --head-h: 68px;
  }

  .nav {
    display: none;
  }

  .nav-toggle {
    display: block;
  }

  .nav-drawer {
    display: block;
  }

  .section {
    padding: 72px 0;
  }

  .hero {
    padding-top: 58px;
    padding-bottom: 58px;
  }

  .hero__star {
    width: 92px;
    height: 92px;
    left: 2%;
    top: 40px;
  }

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

  .stage {
    border-right: 0;
    border-bottom: 1px solid var(--line);
    min-height: 400px;
  }

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

  .split__aside {
    position: static;
  }

  .grid--4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .toc {
    display: none;
  }

  .cta {
    padding: 44px 40px;
  }

  .footer-top {
    grid-template-columns: 1fr;
    gap: 44px;
  }

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

  .footer-word {
    margin-top: 44px;
  }
}

@media (max-width: 767px) {
  :root {
    --gutter: 18px;
  }

  body {
    font-size: 15.5px;
  }

  .section {
    padding: 58px 0;
  }

  .section--tight {
    padding: 46px 0;
  }

  .section__head {
    margin-bottom: 32px;
  }

  .section__desc {
    font-size: 15px;
  }

  .hero {
    padding: 44px 0 50px;
  }

  .hero__title {
    font-size: clamp(42px, 12vw, 56px);
  }

  .hero__title em {
    margin-top: 12px;
    letter-spacing: 0.14em;
  }

  .hero__lead {
    font-size: 15px;
    line-height: 1.85;
  }

  .hero__tool {
    margin-top: 30px;
  }

  .hero__star {
    width: 68px;
    height: 68px;
    opacity: 0.7;
  }

  .hero__ring {
    width: 380px;
    height: 380px;
    top: -190px;
    right: -160px;
  }

  .hero__dot-grid {
    display: none;
  }

  .tool__head {
    padding: 14px 16px;
    align-items: flex-start;
  }

  .tool__title {
    font-size: 18px;
  }

  .tool__badges {
    gap: 4px;
  }

  .chip {
    padding: 3px 7px;
    font-size: 10.5px;
  }

  .stage {
    min-height: 330px;
    padding: 18px 16px 58px;
  }

  .stage.has-image {
    padding-bottom: 70px;
  }

  .stage__image {
    max-height: 380px;
  }

  .stage__bar {
    left: 12px;
    right: 12px;
    bottom: 10px;
    padding-left: 10px;
  }

  .stage__meta {
    max-width: 120px;
  }

  .tool__panel {
    padding: 22px 16px;
  }

  .stats {
    grid-template-columns: 1fr;
    border-top: 1px solid var(--ink);
  }

  .stat {
    display: flex;
    align-items: baseline;
    gap: 18px;
    padding: 18px 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .stat:last-child {
    border-bottom: 0;
  }

  .stat__value {
    font-size: 36px;
    flex: none;
    min-width: 120px;
  }

  .stat__label {
    margin-top: 0;
  }

  .grid--2,
  .grid--3,
  .grid--4 {
    grid-template-columns: 1fr;
  }

  .card {
    padding: 24px;
  }

  .steps {
    grid-template-columns: 1fr;
    border-top: 1px solid var(--ink);
  }

  .step {
    padding: 22px 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .step + .step {
    padding-left: 0;
  }

  .step:last-child {
    border-bottom: 0;
  }

  .step__num {
    margin-bottom: 16px;
  }

  .page-hero {
    padding: 34px 0 40px;
  }

  .page-hero h1 {
    font-size: 32px;
  }

  .breadcrumb {
    margin-bottom: 20px;
  }

  .cta-wrap {
    padding-bottom: 58px;
  }

  .cta {
    flex-direction: column;
    align-items: flex-start;
    gap: 24px;
    padding: 34px 24px;
  }

  .cta__actions {
    flex-wrap: wrap;
  }

  .cta__title {
    font-size: 27px;
  }

  .table-wrap {
    margin-inline: calc(var(--gutter) * -1);
    padding-inline: var(--gutter);
  }

  .tbl {
    min-width: 560px;
  }

  .tbl th,
  .tbl td {
    padding: 12px 14px;
    font-size: 13.5px;
  }

  .faq summary {
    padding: 18px 40px 18px 0;
    font-size: 15.5px;
  }

  .faq summary::after {
    top: 24px;
  }

  .faq__body {
    padding-right: 20px;
    font-size: 14.5px;
  }

  .read-item {
    gap: 16px;
    padding: 20px 0;
  }

  .read-item h3 {
    font-size: 17px;
  }

  .glossary,
  .sitemap-groups,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .footer-nav {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 24px 20px;
  }

  .footer-word {
    font-size: 26vw;
  }

  .footer-bottom {
    margin-top: 20px;
  }

  .batch__drop {
    margin: 16px;
    padding: 26px 16px;
  }

  .batch__head {
    padding: 16px;
  }

  .batch__controls {
    width: 100%;
  }

  .batch-row {
    grid-template-columns: 44px minmax(0, 1fr);
    gap: 12px;
    padding: 12px 16px;
  }

  .batch-row__thumb {
    width: 44px;
    height: 44px;
  }

  .batch-row__status {
    grid-column: 1 / -1;
    justify-content: space-between;
    padding-top: 4px;
  }

  .batch__note,
  .batch__progress {
    padding-left: 16px;
    padding-right: 16px;
  }

  .demo {
    padding: 16px;
    gap: 22px;
  }

  .copy-box {
    font-size: 11px;
  }
}

@media (max-width: 420px) {
  .brand__name {
    font-size: 17px;
  }

  .hero__title {
    font-size: 42px;
  }

  .stage {
    min-height: 300px;
  }

  .tool__badges .chip:nth-child(3) {
    display: none;
  }

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

  .btn {
    padding: 0 16px;
  }
}