/* ============================================================
   四季品牌 · 共享样式 /assets/site.css
   纸感底色 + 深墨绿稳定面 + 四季色带结构语言
   ============================================================ */

:root {
  --ink-green: #0E2B24;
  --ink: #101A17;
  --paper: #F4F0E6;
  --snow: #FBFBF8;
  --spring: #8FBF6A;
  --summer: #2E6F8E;
  --autumn: #C98B2E;
  --winter: #A9BFC6;
  --vermilion: #D4553A;
  --grid-line: #1C3A33;

  --line: rgba(16, 26, 23, 0.16);
  --line-strong: rgba(16, 26, 23, 0.34);
  --line-invert: rgba(169, 191, 198, 0.24);
  --body-soft: rgba(16, 26, 23, 0.74);

  --font-serif: "Songti SC", "Noto Serif CJK SC", "Source Han Serif SC", "STSong", SimSun, serif;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", "Heiti SC", sans-serif;
  --font-mono: "SFMono-Regular", Menlo, Consolas, "Liberation Mono", "Courier New", monospace;

  --shell: 1240px;
  --gutter: clamp(1.25rem, 4vw, 2.5rem);
  --radius: 4px;
  --ease: cubic-bezier(.22, .61, .36, 1);
  --dur: .42s;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  background: var(--paper);
}

body,
h1, h2, h3, h4, h5, h6,
p, ul, ol, li, figure, figcaption, blockquote, dl, dd {
  margin: 0;
}

ul, ol { padding: 0; list-style: none; }
img, svg, picture { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; }
main { display: block; }

/* ---------- 中文排版 ---------- */
body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: .01em;
  min-height: 100vh;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5 {
  font-family: var(--font-serif);
  font-weight: 600;
  line-height: 1.22;
  letter-spacing: -.01em;
}

strong { font-weight: 600; }

::selection { background: var(--spring); color: #0B211B; }

/* ---------- 焦点 ---------- */
:where(a, button, [tabindex]):focus-visible {
  outline: 2px solid var(--vermilion);
  outline-offset: 3px;
  border-radius: 2px;
}
.site-header :where(a, button):focus-visible,
.site-footer :where(a, button):focus-visible {
  outline-color: var(--spring);
}

/* ---------- 布局基础 ---------- */
.container {
  width: min(calc(100% - (var(--gutter) * 2)), var(--shell));
  margin-inline: auto;
}

.section { padding-block: clamp(3rem, 6vw, 5.5rem); }
.section--tight { padding-block: clamp(2rem, 4vw, 3rem); }

.page-hero { padding-top: clamp(7rem, 14vw, 10.5rem); }

.section__head {
  display: grid;
  gap: .7rem;
  max-width: 70ch;
  margin-bottom: clamp(1.5rem, 3vw, 2.5rem);
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: .6rem;
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--summer);
}
.eyebrow::before {
  content: "";
  width: 28px;
  height: 1px;
  background: currentColor;
  flex: none;
}

.section-title { font-size: clamp(1.6rem, 3.2vw, 2.4rem); }

.section-lead {
  max-width: 56ch;
  color: var(--body-soft);
  font-size: 1.02rem;
}

.rule {
  height: 1px;
  border: 0;
  background: var(--line);
}

.mono {
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .06em;
  font-variant-numeric: tabular-nums;
}

.layout-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, .56fr);
  gap: clamp(1.5rem, 4vw, 3.5rem);
  align-items: start;
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(1rem, 2vw, 1.5rem);
}

.index-rail {
  display: grid;
  gap: .9rem;
  align-content: start;
  padding-top: 1rem;
  border-top: 2px solid var(--ink-green);
  font-size: .88rem;
}

.prose { max-width: 68ch; }
.prose > * + * { margin-top: 1.1em; }
.prose h2 { font-size: 1.5rem; margin-top: 2em; }
.prose h3 { font-size: 1.2rem; margin-top: 1.7em; }
.prose a {
  color: var(--summer);
  border-bottom: 1px solid currentColor;
  padding-bottom: 1px;
}

/* ---------- 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: .4em;
  padding: .26em .6em;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .06em;
  color: var(--body-soft);
  white-space: nowrap;
}
.tag--spring { color: #3C5C24; border-color: rgba(143, 191, 106, .7); background: rgba(143, 191, 106, .18); }
.tag--summer { color: var(--summer); border-color: rgba(46, 111, 142, .5); background: rgba(46, 111, 142, .1); }
.tag--autumn { color: #8B5D14; border-color: rgba(201, 139, 46, .55); background: rgba(201, 139, 46, .14); }
.tag--winter { color: #46626B; border-color: rgba(169, 191, 198, .8); background: rgba(169, 191, 198, .24); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: .5em;
  padding: .7em 1.2em;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-family: var(--font-sans);
  font-size: .95rem;
  font-weight: 500;
  letter-spacing: .02em;
  line-height: 1.4;
  cursor: pointer;
  transition: background-color .22s var(--ease), color .22s var(--ease),
              border-color .22s var(--ease), transform .22s var(--ease);
}
.btn:hover { transform: translateY(-1px); }

.btn--primary {
  background: var(--summer);
  border-color: var(--summer);
  color: var(--snow);
}
.btn--primary:hover { background: #255A73; border-color: #255A73; }

.btn--ghost {
  background: transparent;
  border-color: var(--line-strong);
  color: var(--ink);
}
.btn--ghost:hover { border-color: var(--ink); background: rgba(16, 26, 23, .05); }

.btn--sm { padding: .45em .85em; font-size: .82rem; }

.site-footer .btn--ghost {
  color: var(--snow);
  border-color: rgba(169, 191, 198, .48);
}
.site-footer .btn--ghost:hover {
  border-color: var(--spring);
  color: var(--spring);
  background: rgba(143, 191, 106, .1);
}

/* ---------- 面包屑 ---------- */
.breadcrumb {
  padding-block: .9rem;
  border-bottom: 1px solid var(--line);
}
.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .5rem;
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .05em;
  color: rgba(16, 26, 23, .58);
}
.breadcrumb__item { display: inline-flex; align-items: center; }
.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  margin-right: .5rem;
  color: var(--winter);
}
.breadcrumb__item a:hover { color: var(--summer); }
.breadcrumb__item[aria-current="page"] { color: var(--ink); }

/* ---------- 图片容器 ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  border-radius: 2px;
  background: var(--ink-green);
  isolation: isolate;
}
.media-frame img,
.media-frame picture,
.media-frame video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame--16x9 { aspect-ratio: 16 / 9; }
.media-frame--4x3 { aspect-ratio: 4 / 3; }
.media-frame--1x1 { aspect-ratio: 1 / 1; }
.media-frame--tall { aspect-ratio: 3 / 4; }

.media-frame__caption {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: .55rem .8rem;
  background: rgba(14, 43, 36, .74);
  color: var(--snow);
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .06em;
}
.media-watermark {
  position: absolute;
  top: .6rem;
  right: .8rem;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .12em;
  color: rgba(251, 251, 248, .58);
  pointer-events: none;
}

/* ---------- 显现 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease);
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   头部
   ============================================================ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 60;
  color: var(--snow);
  background-image: linear-gradient(
    180deg,
    rgba(10, 32, 27, .92) 0%,
    rgba(10, 32, 27, .74) 68%,
    rgba(10, 32, 27, .42) 100%
  );
  transition: background-color .34s var(--ease), box-shadow .34s var(--ease);
}
.site-header[data-scrolled] {
  background-color: var(--ink-green);
  background-image: none;
  box-shadow: 0 1px 0 rgba(169, 191, 198, .26);
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 80;
  width: 100%;
  height: 2px;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--spring), var(--summer), var(--autumn), var(--winter));
  transition: transform .12s linear;
  pointer-events: none;
}

.skip-link {
  position: absolute;
  left: var(--gutter);
  top: -120px;
  z-index: 100;
  padding: .55rem .95rem;
  background: var(--spring);
  color: #0B211B;
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: .8rem;
  letter-spacing: .06em;
  transition: top .2s var(--ease);
}
.skip-link:focus { top: .6rem; }

.header-top {
  width: min(calc(100% - (var(--gutter) * 2)), var(--shell));
  margin-inline: auto;
  display: flex;
  align-items: center;
  gap: clamp(.75rem, 2vw, 1.75rem);
  padding-block: 1rem;
  transition: padding .3s var(--ease);
}
.site-header[data-scrolled] .header-top { padding-block: .58rem; }

.brand {
  display: inline-flex;
  align-items: center;
  gap: .6rem;
  flex: none;
  white-space: nowrap;
}
.brand__mark {
  width: 14px;
  height: 14px;
  flex: none;
  background: conic-gradient(
    var(--spring) 0 25%,
    var(--summer) 0 50%,
    var(--autumn) 0 75%,
    var(--winter) 0 100%
  );
}
.brand__name {
  font-family: var(--font-serif);
  font-size: 1.04rem;
  font-weight: 700;
  letter-spacing: .1em;
}

.header-hint {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  margin-left: auto;
  margin-right: auto;
  padding: .26rem .62rem;
  border: 1px solid rgba(169, 191, 198, .3);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .05em;
  color: rgba(251, 251, 248, .82);
  white-space: nowrap;
  min-width: 0;
  overflow: hidden;
}
.header-hint__dot {
  width: 6px;
  height: 6px;
  flex: none;
  border-radius: 50%;
  background: var(--spring);
  box-shadow: 0 0 0 3px rgba(143, 191, 106, .22);
}

.header-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-left: 0;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .05em;
  flex: none;
}
.header-phone {
  color: var(--snow);
  padding-bottom: 2px;
  border-bottom: 1px solid rgba(169, 191, 198, .42);
  transition: color .2s var(--ease), border-color .2s var(--ease);
}
.header-phone:hover { color: var(--spring); border-color: var(--spring); }
.header-lang { color: rgba(251, 251, 248, .58); letter-spacing: .1em; }

.header-nav { position: relative; }

.season-strip {
  display: grid;
  grid-template-columns: 1.7fr 1.35fr 1.05fr .8fr 1.1fr;
  width: min(calc(100% - (var(--gutter) * 2)), var(--shell));
  margin-inline: auto;
  height: 4px;
}
.season-strip__item {
  display: block;
  height: 100%;
  transform-origin: left center;
  animation: strip-in .7s var(--ease) both;
}
.season-strip__item:nth-child(even) { transform-origin: right center; }
.season-strip__item--spring { background: var(--spring); animation-delay: .06s; }
.season-strip__item--summer { background: var(--summer); animation-delay: .14s; }
.season-strip__item--autumn { background: var(--autumn); animation-delay: .22s; }
.season-strip__item--winter { background: var(--winter); animation-delay: .3s; }
.season-strip__item--rest { background: rgba(169, 191, 198, .26); animation-delay: .38s; }

@keyframes strip-in {
  from { transform: scaleX(0); opacity: .25; }
  to { transform: scaleX(1); opacity: 1; }
}

.header-nav__inner {
  position: relative;
  width: min(calc(100% - (var(--gutter) * 2)), var(--shell));
  margin-inline: auto;
  display: flex;
  align-items: center;
  gap: clamp(.5rem, 2vw, 1.5rem);
  padding-top: .5rem;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: .5rem;
  padding: .42rem .62rem;
  border: 1px solid rgba(169, 191, 198, .38);
  border-radius: var(--radius);
  color: var(--snow);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .1em;
  cursor: pointer;
}
.nav-toggle__icon { display: grid; gap: 3px; }
.nav-toggle__bar {
  display: block;
  width: 16px;
  height: 1.5px;
  background: currentColor;
}

.site-nav { flex: 1 1 auto; min-width: 0; }
.site-nav__list {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: clamp(.35rem, 1.6vw, 1.6rem);
}
.site-nav__item { display: block; }
.site-nav__link {
  position: relative;
  display: inline-block;
  padding: .55rem .15rem .7rem;
  font-size: .93rem;
  letter-spacing: .05em;
  color: rgba(251, 251, 248, .84);
  transition: color .2s var(--ease);
}
.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: .28rem;
  height: 2px;
  background: var(--autumn);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .28s var(--ease), background-color .2s var(--ease);
}
.site-nav__link:hover { color: var(--snow); }
.site-nav__link:hover::after { transform: scaleX(1); }
.site-nav__link[aria-current="page"] { color: var(--snow); }
.site-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--spring);
}

.nav-query {
  margin-left: auto;
  flex: none;
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  padding: .4rem .85rem;
  border: 1px solid rgba(143, 191, 106, .55);
  border-radius: var(--radius);
  background: rgba(143, 191, 106, .15);
  color: var(--spring);
  font-size: .82rem;
  letter-spacing: .06em;
  white-space: nowrap;
  transition: background-color .22s var(--ease), color .22s var(--ease), border-color .22s var(--ease);
}
.nav-query::before {
  content: "";
  width: 6px;
  height: 6px;
  flex: none;
  border-radius: 50%;
  background: currentColor;
}
.nav-query:hover {
  background: var(--spring);
  border-color: var(--spring);
  color: #0B211B;
}

/* ============================================================
   页脚
   ============================================================ */
.site-footer {
  background: var(--ink-green);
  color: var(--snow);
}
.footer-strip {
  display: grid;
  grid-template-columns: 1.7fr 1.35fr 1.05fr .8fr 1.1fr;
  height: 4px;
}
.footer-strip__item { display: block; height: 100%; }
.footer-strip__item--spring { background: var(--spring); }
.footer-strip__item--summer { background: var(--summer); }
.footer-strip__item--autumn { background: var(--autumn); }
.footer-strip__item--winter { background: var(--winter); }
.footer-strip__item--rest { background: rgba(169, 191, 198, .3); }

.footer-inner {
  width: min(calc(100% - (var(--gutter) * 2)), var(--shell));
  margin-inline: auto;
  padding-block: clamp(2.5rem, 5vw, 4rem) 1.5rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.5fr;
  gap: clamp(1.5rem, 3vw, 3rem);
}

.footer-col { min-width: 0; }
.footer-col--brand {
  display: grid;
  gap: .5rem;
  align-content: start;
}

.footer-brand {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: .12em;
}
.footer-tagline {
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .22em;
  color: var(--spring);
}

.footer-col__title {
  margin-bottom: .95rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  font-weight: 400;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--winter);
}

.footer-list {
  display: grid;
  gap: .55rem;
  font-size: .9rem;
}
.footer-list a {
  color: rgba(251, 251, 248, .82);
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}
.footer-list a:hover {
  color: var(--snow);
  border-color: var(--autumn);
}

.footer-contact {
  font-size: .84rem;
  color: rgba(251, 251, 248, .82);
  gap: .6rem;
}
.footer-contact__row {
  display: grid;
  grid-template-columns: 3.1rem minmax(0, 1fr);
  gap: .6rem;
  align-items: baseline;
  line-height: 1.6;
  overflow-wrap: anywhere;
}
.footer-contact__row .mono {
  color: var(--winter);
  font-size: .68rem;
  letter-spacing: .1em;
}

.footer-bottom {
  margin-top: clamp(2rem, 4vw, 3rem);
  padding-top: 1.1rem;
  border-top: 1px solid var(--line-invert);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .75rem 1.5rem;
  font-size: .78rem;
  color: rgba(251, 251, 248, .62);
}
.footer-bottom__note { line-height: 1.7; }
.footer-bottom__links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.2rem;
}
.footer-bottom__links a {
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}
.footer-bottom__links a:hover {
  color: var(--snow);
  border-color: var(--winter);
}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1079px) {
  .header-hint { display: none; }
  .header-meta { margin-left: auto; }
  .site-nav__link { font-size: .88rem; }
}

@media (max-width: 899px) {
  .header-top { padding-block: .78rem; gap: .75rem; }
  .header-lang { display: none; }
  .brand__name { font-size: .98rem; letter-spacing: .08em; }

  .header-nav__inner { padding-top: .45rem; gap: .6rem; }
  .nav-toggle { display: inline-flex; }

  .site-nav {
    flex: 0 0 auto;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: block;
    background: var(--ink-green);
    box-shadow: 0 1px 0 rgba(169, 191, 198, .22);
    max-height: 0;
    visibility: hidden;
    overflow: hidden;
    transition: max-height .34s var(--ease), visibility .34s var(--ease);
  }
  .site-nav[data-open] {
    max-height: 72vh;
    overflow-y: auto;
    visibility: visible;
  }
  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: .35rem 0 1rem;
  }
  .site-nav__item { border-bottom: 1px solid rgba(169, 191, 198, .16); }
  .site-nav__link {
    display: block;
    padding: .95rem .2rem;
    font-size: 1rem;
  }
  .site-nav__link::after { bottom: .5rem; }

  .nav-query { margin-left: auto; }

  .layout-split { grid-template-columns: minmax(0, 1fr); }
  .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
}

@media (max-width: 760px) {
  body { font-size: 16px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-col--brand { grid-column: 1 / -1; }
  .footer-col--contact { grid-column: 1 / -1; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
  .grid-12 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .media-frame--tall { aspect-ratio: 4 / 5; }
}

@media (max-width: 460px) {
  .footer-grid { grid-template-columns: 1fr; }
  .header-phone { font-size: .68rem; }
  .nav-query { padding: .38rem .6rem; font-size: .76rem; }
}

/* ============================================================
   动效降级
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-delay: 0ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    transition-delay: 0ms !important;
  }
  .reveal { opacity: 1; transform: none; }
  .season-strip__item, .footer-strip__item { transform: none; opacity: 1; }
  .btn:hover { transform: none; }
  .scroll-progress { transition: none; }
}