/* ============ 1. Reset ============ */
*,
*::before,
*::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg, video, picture { max-width: 100%; }
ul, ol { margin: 0; padding: 0; list-style: none; }
h1, h2, h3, h4, p, figure, blockquote { margin: 0; }
a { color: inherit; text-decoration: none; }
button, input { font: inherit; color: inherit; }
button { background: none; border: 0; padding: 0; cursor: pointer; }

/* ============ 2. 变量 ============ */
:root {
  --paper: #FAF8F3;
  --ink: #12181A;
  --pine: #17453C;
  --moss: #66756E;
  --sand: #EDE8DC;
  --spring: #3FBF8F;
  --summer: #FF7A3D;
  --autumn: #E6B422;
  --winter: #2E5AAC;
  --wine: #8C3B4A;
  --line: #CFC8B8;

  --tone: var(--spring);

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

  --fs-display: clamp(2.6rem, 6.4vw, 4rem);
  --fs-h2: clamp(1.55rem, 3vw, 2.5rem);
  --fs-h3: clamp(1.15rem, 2vw, 1.75rem);
  --fs-lead: clamp(1.0625rem, 1.5vw, 1.25rem);
  --fs-body: 1.0625rem;
  --fs-small: .875rem;
  --fs-micro: .75rem;

  --dur: 210ms;
  --ease: cubic-bezier(.22, .61, .36, 1);

  --gutter: clamp(1.15rem, 4vw, 3.5rem);
  --maxw: 1320px;
}

/* ============ 3. 中文排版 ============ */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 400;
  line-height: 1.18;
  letter-spacing: .06em;
}

h1 { font-size: var(--fs-display); letter-spacing: .08em; }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); }

p { line-height: 1.75; }

strong { font-weight: 600; }

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

:focus-visible {
  outline: 2px solid var(--autumn);
  outline-offset: 3px;
  border-radius: 1px;
}

/* ============ 4. 布局与容器 ============ */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: clamp(2.5rem, 6vw, 5.5rem); }

.surface--sand { background: var(--sand); }
.surface--pine { background: var(--pine); color: var(--paper); }

.prose { max-width: 68ch; }
.prose p + p { margin-top: 1em; }
.prose h2, .prose h3 { margin-top: 1.9em; margin-bottom: .55em; }

.breadcrumb {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: .12em;
  color: var(--moss);
}
.breadcrumb ol { display: flex; flex-wrap: wrap; align-items: center; gap: .35rem; }
.breadcrumb li { display: inline-flex; align-items: center; }
.breadcrumb li + li::before { content: "/"; margin-right: .35rem; color: var(--line); }
.breadcrumb a { transition: color var(--dur) var(--ease); }
.breadcrumb a:hover { color: var(--pine); }
.breadcrumb [aria-current="page"] { color: var(--ink); }

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(1rem, 2.4vw, 1.6rem);
}
.grid--tight { gap: clamp(.6rem, 1.4vw, .9rem); }

@media (min-width: 901px) {
  .col-4 { grid-column: span 4; }
  .col-5 { grid-column: span 5; }
  .col-6 { grid-column: span 6; }
  .col-7 { grid-column: span 7; }
  .col-8 { grid-column: span 8; }
  .col-12 { grid-column: span 12; }
}
@media (max-width: 900px) {
  .grid { grid-template-columns: repeat(6, minmax(0, 1fr)); }
}
@media (max-width: 620px) {
  .grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* ============ 5. 通用按钮 ============ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .7rem 1.15rem;
  border: 1px solid currentColor;
  border-radius: 2px;
  font-size: var(--fs-small);
  letter-spacing: .08em;
  line-height: 1.4;
  transition: background-color var(--dur) var(--ease),
              color var(--dur) var(--ease),
              border-color var(--dur) var(--ease);
}
.btn::after { content: "→"; font-family: var(--font-mono); font-size: .85em; }

.btn--spring {
  background: var(--spring);
  border-color: var(--spring);
  color: var(--ink);
  font-weight: 500;
}
.btn--spring:hover,
.btn--spring:focus-visible { background: var(--autumn); border-color: var(--autumn); }

.btn--ghost {
  color: var(--paper);
  border-color: rgba(250, 248, 243, .38);
}
.btn--ghost:hover,
.btn--ghost:focus-visible {
  border-color: var(--winter);
  background: var(--winter);
  color: var(--paper);
}

/* ============ 6. 编号胶囊 ============ */
.chip {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  padding: .18rem .5rem;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--sand);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: .1em;
  line-height: 1.6;
  transition: border-color var(--dur) var(--ease),
              background-color var(--dur) var(--ease),
              color var(--dur) var(--ease);
}
.chip--mono { font-feature-settings: "tnum" 1; }
.chip:hover { border-color: var(--autumn); }
.chip.is-copied {
  background: var(--autumn);
  border-color: var(--autumn);
  color: var(--ink);
}

/* ============ 7. Skip link ============ */
.skip-link {
  position: absolute;
  left: 1rem;
  top: -5rem;
  z-index: 300;
  padding: .65rem 1rem;
  background: var(--ink);
  color: var(--paper);
  font-size: var(--fs-small);
  letter-spacing: .08em;
  border-radius: 2px;
  transition: top var(--dur) var(--ease);
}
.skip-link:focus { top: 1rem; }

/* ============ 8. 页头 ============ */
.site-head {
  position: relative;
  z-index: 60;
  background: var(--paper);
}

.scroll-meter {
  position: fixed;
  inset: 0 0 auto 0;
  height: 2px;
  z-index: 200;
  pointer-events: none;
  background: transparent;
}
.scroll-meter > span {
  display: block;
  height: 100%;
  width: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--spring), var(--summer), var(--autumn), var(--winter));
}

/* 品牌行 */
.head-brandrow {
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}
.head-brandrow__inner {
  display: flex;
  align-items: center;
  gap: clamp(.9rem, 2.5vw, 2.25rem);
  min-height: 78px;
  padding-block: .7rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: .7rem;
  flex: 0 0 auto;
}
.brand__mark {
  display: grid;
  grid-template-columns: repeat(2, 7px);
  grid-template-rows: repeat(2, 7px);
  gap: 2px;
}
.brand__mark i { display: block; width: 7px; height: 7px; }
.brand__mark i:nth-child(1) { background: var(--spring); }
.brand__mark i:nth-child(2) { background: var(--summer); }
.brand__mark i:nth-child(3) { background: var(--autumn); }
.brand__mark i:nth-child(4) { background: var(--winter); }

.brand__text { display: flex; flex-direction: column; gap: .1rem; }
.brand__name {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 500;
  letter-spacing: .22em;
  line-height: 1.2;
  transition: color var(--dur) var(--ease);
}
.brand__tag {
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .24em;
  color: var(--moss);
  line-height: 1.3;
}
.brand:hover .brand__name { color: var(--pine); }

.brand--onDark .brand__name { color: var(--paper); }
.brand--onDark .brand__tag { color: rgba(250, 248, 243, .55); }
.brand--onDark:hover .brand__name { color: var(--spring); }

.head-status {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: .55rem;
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: .1em;
  color: var(--moss);
  white-space: nowrap;
}
.head-status__label { color: var(--moss); }
.head-status__time { font-size: .6875rem; letter-spacing: .06em; }

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: .5rem;
  padding: .45rem .7rem;
  border: 1px solid var(--line);
  border-radius: 2px;
  font-size: .8125rem;
  letter-spacing: .12em;
  color: var(--ink);
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}
.nav-toggle:hover { border-color: var(--pine); background: var(--sand); }
.nav-toggle__bars { display: grid; gap: 3px; }
.nav-toggle__bars i {
  display: block;
  width: 16px;
  height: 1.5px;
  background: var(--ink);
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}
.nav-toggle.is-open .nav-toggle__bars i:nth-child(1) { transform: translateY(4.5px) rotate(45deg); }
.nav-toggle.is-open .nav-toggle__bars i:nth-child(2) { opacity: 0; }
.nav-toggle.is-open .nav-toggle__bars i:nth-child(3) { transform: translateY(-4.5px) rotate(-45deg); }
.nav-toggle__text { font-family: var(--font-body); }

/* 命令栏 */
.site-nav { background: var(--pine); color: var(--paper); }

.site-nav__commands {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.command-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: clamp(.4rem, 1.7vw, 1.9rem);
}
.command-list a {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: .45rem;
  padding: .95rem 0 .85rem;
  font-size: .9375rem;
  letter-spacing: .06em;
  color: rgba(250, 248, 243, .7);
  transition: color var(--dur) var(--ease);
}
.command-list a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: .42rem;
  height: 2px;
  background: var(--spring);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform var(--dur) var(--ease), background-color var(--dur) var(--ease);
}
.command-list a:hover { color: var(--paper); }
.command-list a:hover::after { transform: scaleX(1); }
.command-list a[aria-current="page"] { color: var(--paper); }
.command-list a[aria-current="page"]::after { transform: scaleX(1); background: var(--autumn); }

.command-list__idx {
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .18em;
  color: var(--autumn);
  opacity: .88;
}

.head-cta {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  padding: .45rem .85rem;
  border: 1px solid rgba(250, 248, 243, .32);
  border-radius: 2px;
  font-size: var(--fs-small);
  letter-spacing: .1em;
  color: var(--paper);
  transition: background-color var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              color var(--dur) var(--ease);
}
.head-cta::after { content: "→"; font-family: var(--font-mono); font-size: .85em; }
.head-cta:hover,
.head-cta:focus-visible {
  background: var(--spring);
  border-color: var(--spring);
  color: var(--ink);
}

/* 工具条 */
.site-nav__tools {
  background: var(--sand);
  color: var(--ink);
  border-top: 1px solid var(--line);
}
.tool-strip {
  display: flex;
  flex-wrap: wrap;
  align-items: stretch;
  gap: 0;
}
.tool-strip > li { display: flex; }
.tool {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: .4rem;
  padding: .62rem .8rem;
  border-right: 1px solid var(--line);
  transition: background-color var(--dur) var(--ease);
}
.tool-strip > li:first-child .tool { border-left: 1px solid var(--line); }
.tool:hover { background: rgba(255, 255, 255, .58); }
.tool__idx {
  font-family: var(--font-mono);
  font-size: .625rem;
  letter-spacing: .2em;
  color: var(--moss);
}
.tool__name {
  font-size: .8125rem;
  letter-spacing: .05em;
  color: var(--ink);
  white-space: nowrap;
}
.tool__ver {
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .04em;
  padding: .04rem .3rem;
  border-radius: 2px;
  background: rgba(230, 180, 34, .38);
  color: var(--ink);
  white-space: nowrap;
  transition: background-color var(--dur) var(--ease);
}
.tool:hover .tool__ver { background: var(--autumn); }

.tool__hint {
  position: absolute;
  left: .8rem;
  top: calc(100% + 6px);
  z-index: 40;
  padding: .3rem .55rem;
  border-radius: 2px;
  background: var(--pine);
  color: var(--paper);
  font-size: .75rem;
  letter-spacing: .04em;
  white-space: nowrap;
  opacity: 0;
  transform: translateY(-4px);
  pointer-events: none;
  transition: opacity 180ms var(--ease), transform 180ms var(--ease);
}
.tool:hover .tool__hint,
.tool:focus-visible .tool__hint { opacity: 1; transform: translateY(0); }

/* ============ 9. 页脚 ============ */
.site-foot {
  background: var(--pine);
  color: var(--paper);
}

.foot-grid {
  display: grid;
  grid-template-columns: 1.2fr .8fr;
  align-items: start;
  gap: clamp(2rem, 5vw, 4.5rem);
  padding-top: clamp(2.75rem, 6vw, 4.5rem);
  padding-bottom: clamp(2rem, 4vw, 3rem);
}

.foot-id__note {
  max-width: 34ch;
  margin-top: 1.1rem;
  color: rgba(250, 248, 243, .76);
  font-size: var(--fs-small);
}

.foot-contact {
  display: grid;
  gap: .35rem;
  margin-top: 1.6rem;
  font-size: .9375rem;
}
.foot-contact li {
  display: grid;
  grid-template-columns: 3.2rem 1fr;
  gap: .8rem;
  align-items: baseline;
}
.foot-contact__k {
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .16em;
  color: var(--spring);
}

.foot-hours {
  margin-top: 1.15rem;
  font-family: var(--font-mono);
  font-size: .8125rem;
  letter-spacing: .04em;
  color: rgba(250, 248, 243, .58);
}

.foot-anchor {
  margin-top: -2.5rem;
  padding: clamp(1.35rem, 3vw, 2.1rem);
  background: var(--paper);
  color: var(--ink);
  border-top: 4px solid var(--summer);
}
.foot-anchor__label {
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .24em;
  color: var(--moss);
}
.foot-anchor__title {
  margin-top: .5rem;
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 2.4vw, 1.6rem);
  letter-spacing: .1em;
  font-weight: 500;
}
.foot-anchor__text {
  margin-top: .6rem;
  font-size: var(--fs-small);
  color: var(--moss);
}
.foot-anchor__batch {
  display: flex;
  align-items: center;
  gap: .5rem;
  margin-top: 1rem;
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .1em;
  color: var(--moss);
}
.foot-anchor .btn { margin-top: 1.15rem; }

.foot-desk {
  display: grid;
  gap: clamp(1.5rem, 3vw, 2.25rem);
  padding-block: clamp(1.8rem, 4vw, 2.75rem);
  border-top: 1px solid rgba(250, 248, 243, .16);
}
.foot-desk__text {
  max-width: 60ch;
  margin-top: .35rem;
  font-size: var(--fs-small);
  color: rgba(250, 248, 243, .74);
}

.foot-h {
  display: flex;
  align-items: center;
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 500;
  letter-spacing: .16em;
  color: var(--paper);
}
.foot-h::before {
  content: "";
  display: inline-block;
  width: 3px;
  height: .92em;
  margin-right: .6rem;
  background: var(--winter);
}

.feedback .btn { margin-top: .9rem; }

.changelog__list { margin-top: .6rem; }
.changelog__item {
  display: grid;
  grid-template-columns: 5.2rem 4.6rem 1fr;
  gap: .9rem;
  align-items: baseline;
  padding: .65rem 0;
  border-bottom: 1px solid rgba(250, 248, 243, .1);
}
.changelog__batch {
  font-family: var(--font-mono);
  font-size: .8125rem;
  letter-spacing: .08em;
  color: var(--autumn);
}
.changelog__time {
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .04em;
  color: rgba(250, 248, 243, .5);
}
.changelog__text {
  font-size: var(--fs-small);
  color: rgba(250, 248, 243, .82);
}

.foot-legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .8rem 1.5rem;
  padding-block: 1.2rem 1.75rem;
  border-top: 1px solid rgba(250, 248, 243, .16);
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .08em;
  color: rgba(250, 248, 243, .6);
}
.foot-legal__copy { margin: 0; }
.foot-legal__links { display: flex; flex-wrap: wrap; gap: 1.25rem; }
.foot-legal__links a { transition: color var(--dur) var(--ease); }
.foot-legal__links a:hover { color: var(--autumn); }
.foot-legal__icp { margin: 0; }

/* ============ 10. 媒体容器基础规则 ============ */
.media-frame {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  border: 1px solid var(--line);
  background-color: var(--sand);
  background-image:
    repeating-linear-gradient(0deg, transparent 0 23px, rgba(207, 200, 184, .55) 23px 24px),
    repeating-linear-gradient(90deg, transparent 0 23px, rgba(207, 200, 184, .55) 23px 24px);
}
.media-frame::after {
  content: "";
  position: absolute;
  right: -12%;
  bottom: -28%;
  width: 62%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: var(--tone);
  opacity: .22;
  pointer-events: none;
}
.media-frame > img,
.media-frame > picture,
.media-frame > svg,
.media-frame > video {
  position: relative;
  z-index: 1;
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--tall { aspect-ratio: 3 / 4; }

.media-frame--spring { --tone: var(--spring); }
.media-frame--summer { --tone: var(--summer); }
.media-frame--autumn { --tone: var(--autumn); }
.media-frame--winter { --tone: var(--winter); }

/* ============ 11. 色调节点 ============ */
.tone-spring { --tone: var(--spring); }
.tone-summer { --tone: var(--summer); }
.tone-autumn { --tone: var(--autumn); }
.tone-winter { --tone: var(--winter); }

/* ============ 12. 响应式 ============ */
@media (max-width: 1080px) {
  .foot-grid { grid-template-columns: 1fr; }
  .foot-anchor { margin-top: 0; }
}

@media (max-width: 900px) {
  .nav-toggle { display: inline-flex; }

  .site-nav { display: none; }
  .site-nav[data-open] { display: block; }

  .site-nav__commands {
    flex-direction: column;
    align-items: stretch;
    gap: .5rem;
    padding-block: .25rem .9rem;
  }
  .command-list { flex-direction: column; gap: 0; }
  .command-list > li { border-bottom: 1px solid rgba(250, 248, 243, .14); }
  .command-list a { padding: .8rem 0; font-size: 1rem; }
  .command-list a::after { display: none; }
  .command-list a[aria-current="page"] { color: var(--autumn); }
  .head-cta { align-self: flex-start; margin-top: .35rem; }

  .tool-strip { flex-direction: column; padding-block: .25rem; }
  .tool-strip > li { border-bottom: 1px solid var(--line); }
  .tool {
    width: 100%;
    padding: .6rem 0;
    border-right: 0;
    border-left: 0;
  }
  .tool-strip > li:first-child .tool { border-left: 0; }
  .tool__hint { display: none; }

  .foot-desk { grid-template-columns: 1fr; }
  .changelog__item { grid-template-columns: 4.6rem 4.2rem 1fr; gap: .6rem; }
}

@media (max-width: 620px) {
  .head-status { font-size: .6875rem; gap: .4rem; }
  .head-brandrow__inner { min-height: 64px; }
  .foot-anchor { padding: 1.25rem; }
  .changelog__item { grid-template-columns: 1fr; gap: .15rem; }
  .foot-legal { flex-direction: column; align-items: flex-start; }
}

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

/* ============ 13. 减少动效 ============ */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }
  .scroll-meter > span { transition: none; }
}