/* =========================================================
   鼎盛平台 PHVR · Site Kit 共享样式
   文件：/assets/site.css
   ========================================================= */

:root {
  --phvr-bg-deep: #0A0E1A;
  --phvr-bg-card: #10162B;
  --phvr-gold: #D4AF37;
  --phvr-gold-bright: #F0C75E;
  --phvr-ice: #A9DDEB;
  --phvr-snow: #F5F7FA;
  --phvr-slate: #3A4256;
  --phvr-silver: #2A3145;
  --phvr-snowfield: #E8EDF2;
  --phvr-gold-grad: linear-gradient(135deg, #F0C75E 0%, #D4AF37 60%, #8C6D1F 100%);
  --phvr-font-heading: "Montserrat", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --phvr-font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --phvr-shadow: 0 12px 28px rgba(0, 0, 0, .35);
  --phvr-shell: min(1280px, 100% - 48px);
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  min-height: 100vh;
  font-family: var(--phvr-font-body);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--phvr-snow);
  background:
    radial-gradient(1px 1px at 16% 24%, rgba(240, 199, 94, .4) 0%, transparent 100%),
    radial-gradient(1px 1px at 74% 12%, rgba(169, 221, 235, .32) 0%, transparent 100%),
    radial-gradient(1.5px 1.5px at 88% 58%, rgba(240, 199, 94, .28) 0%, transparent 100%),
    radial-gradient(1.2px 1.2px at 32% 84%, rgba(169, 221, 235, .25) 0%, transparent 100%),
    radial-gradient(ellipse 120% 55% at 50% -18%, rgba(16, 22, 43, .72) 0%, transparent 64%),
    var(--phvr-bg-deep);
}

::selection {
  background: rgba(212, 175, 55, .35);
  color: #fff;
}

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

a {
  color: inherit;
}

button {
  font: inherit;
}

:focus-visible {
  outline: 2px solid var(--phvr-gold);
  outline-offset: 3px;
}

#main-content {
  scroll-margin-top: 16px;
}

/* 布局 */
.shell {
  width: var(--phvr-shell);
  margin-inline: auto;
}

.section {
  padding: clamp(40px, 7vw, 96px) 0;
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px 24px;
  margin-bottom: 30px;
}

.eyebrow {
  display: block;
  font-family: var(--phvr-font-heading);
  font-size: .7rem;
  font-weight: 600;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--phvr-gold);
  margin-bottom: 8px;
}

.section-title {
  font-family: var(--phvr-font-heading);
  font-size: clamp(1.5rem, 3vw, 2.35rem);
  font-weight: 600;
  letter-spacing: .02em;
  line-height: 1.25;
  color: var(--phvr-snow);
}

.gold-rule {
  display: block;
  width: 64px;
  height: 3px;
  margin-top: 12px;
  border: 0;
  background: linear-gradient(90deg, var(--phvr-gold-bright), var(--phvr-gold));
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 8px 16px;
  border: 1px solid var(--phvr-silver);
  background: transparent;
  color: var(--phvr-snowfield);
  font-family: var(--phvr-font-heading);
  font-size: .74rem;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: .1em;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: color .25s ease, border-color .25s ease, background-color .25s ease, box-shadow .25s ease;
}

.btn:hover {
  border-color: var(--phvr-gold);
  color: var(--phvr-gold-bright);
}

.btn-gold {
  border-color: rgba(212, 175, 55, .6);
  background: linear-gradient(135deg, rgba(212, 175, 55, .16), rgba(212, 175, 55, .04));
  color: var(--phvr-gold);
}

.btn-gold:hover {
  border-color: var(--phvr-gold-bright);
  background: linear-gradient(135deg, rgba(240, 199, 94, .28), rgba(212, 175, 55, .08));
  color: var(--phvr-gold-bright);
  box-shadow: 0 0 0 3px rgba(212, 175, 55, .14);
}

.btn-ghost {
  border-color: var(--phvr-silver);
  color: var(--phvr-ice);
}

.btn-ghost:hover {
  border-color: var(--phvr-ice);
  background: rgba(169, 221, 235, .08);
  color: var(--phvr-snow);
}

.btn-star {
  font-size: 1rem;
  line-height: 1;
  color: var(--phvr-gold);
}

.btn-favorite[aria-pressed="true"],
.btn-favorite.is-saved {
  border-color: var(--phvr-gold);
  background: rgba(212, 175, 55, .1);
  color: var(--phvr-gold);
}

.btn-favorite[aria-pressed="true"] .btn-star {
  color: var(--phvr-gold-bright);
  text-shadow: 0 0 6px rgba(240, 199, 94, .6);
}

/* 跳转与进度 */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 300;
  padding: 9px 16px;
  background: var(--phvr-gold);
  color: var(--phvr-bg-deep);
  font-size: .76rem;
  font-weight: 600;
  letter-spacing: .06em;
  text-decoration: none;
  opacity: 0;
  transform: translateY(-180%);
  transition: opacity .25s ease, transform .25s ease;
}

.skip-link:focus-visible {
  opacity: 1;
  transform: translateY(0);
}

.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0;
  height: 3px;
  z-index: 210;
  background: linear-gradient(90deg, var(--phvr-gold), var(--phvr-gold-bright), var(--phvr-ice));
  box-shadow: 0 0 10px rgba(212, 175, 55, .55);
  pointer-events: none;
}

/* 页头 */
.site-header {
  position: relative;
  z-index: 80;
  background: var(--phvr-bg-deep);
  border-bottom: 1px solid var(--phvr-silver);
}

.site-header::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent 2%, rgba(212, 175, 55, .65) 22%, rgba(240, 199, 94, .92) 50%, rgba(212, 175, 55, .65) 78%, transparent 98%);
  pointer-events: none;
}

.masthead {
  background:
    radial-gradient(ellipse 55% 90% at 50% -20%, rgba(16, 22, 43, .9), transparent 70%),
    linear-gradient(180deg, rgba(10, 14, 26, 0), rgba(10, 14, 26, .4) 30%, transparent);
}

.masthead-shell {
  width: var(--phvr-shell);
  margin-inline: auto;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 24px;
  min-height: 92px;
  padding: 16px 0;
}

.masthead-edition {
  justify-self: start;
  display: inline-flex;
  align-items: center;
  margin: 0;
  font-family: var(--phvr-font-heading);
  font-size: .68rem;
  font-weight: 500;
  letter-spacing: .2em;
  text-transform: uppercase;
  white-space: nowrap;
  color: var(--phvr-ice);
}

.masthead-dot {
  width: 6px;
  height: 6px;
  margin-right: 9px;
  border-radius: 50%;
  background: var(--phvr-gold);
  box-shadow: 0 0 7px rgba(212, 175, 55, .75);
  flex: none;
}

.masthead-brand {
  justify-self: center;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  white-space: nowrap;
  text-decoration: none;
}

.masthead-brand::before,
.masthead-brand::after {
  content: "";
  width: 46px;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(212, 175, 55, .85));
}

.masthead-brand::before {
  margin-right: 14px;
}

.masthead-brand::after {
  margin-left: 14px;
  background: linear-gradient(90deg, rgba(212, 175, 55, .85), transparent);
}

.masthead-mark {
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  margin-right: 13px;
  background: linear-gradient(135deg, rgba(240, 199, 94, .16), rgba(16, 22, 43, .4));
  border: 1px solid rgba(212, 175, 55, .75);
  font-family: var(--phvr-font-heading);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--phvr-gold-bright);
  box-shadow: inset 0 0 0 3px rgba(10, 14, 26, .75), 0 0 14px rgba(212, 175, 55, .22);
}

.masthead-name {
  font-family: var(--phvr-font-heading);
  font-size: clamp(1.45rem, 2.6vw, 2.25rem);
  font-weight: 700;
  letter-spacing: .16em;
  line-height: 1;
  color: var(--phvr-snow);
  transition: color .25s ease;
}

.masthead-acronym {
  margin-left: 7px;
  font-size: clamp(.95rem, 1.5vw, 1.3rem);
  letter-spacing: .24em;
  color: transparent;
  background: linear-gradient(120deg, var(--phvr-gold-bright), var(--phvr-gold));
  -webkit-background-clip: text;
  background-clip: text;
}

.masthead-brand:hover .masthead-name {
  color: var(--phvr-gold-bright);
}

.masthead-actions {
  justify-self: end;
  display: flex;
  align-items: center;
  gap: 10px;
}

/* 导航 */
.nav-rule {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 48px;
  border-top: 1px solid var(--phvr-silver);
  border-bottom: 1px solid var(--phvr-silver);
  background: linear-gradient(180deg, rgba(212, 175, 55, .06), rgba(212, 175, 55, 0) 80%);
}

.nav-rule::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent 4%, rgba(212, 175, 55, .65) 24%, rgba(240, 199, 94, .85) 50%, rgba(212, 175, 55, .65) 76%, transparent 96%);
  pointer-events: none;
}

.site-nav {
  flex: 1 1 auto;
  min-width: 0;
}

.nav-list {
  display: flex;
  justify-content: center;
  align-items: stretch;
  list-style: none;
  counter-reset: phvr-nav;
}

.nav-item {
  counter-increment: phvr-nav;
  display: flex;
}

.nav-link {
  display: flex;
  align-items: center;
  padding: 15px 18px;
  border-bottom: 2px solid transparent;
  font-family: var(--phvr-font-heading);
  font-size: .78rem;
  font-weight: 600;
  letter-spacing: .14em;
  color: var(--phvr-snowfield);
  text-decoration: none;
  transition: color .25s ease, border-color .25s ease, background-color .25s ease;
}

.nav-link::before {
  content: "0" counter(phvr-nav) " /";
  margin-right: 6px;
  font-size: .66rem;
  font-weight: 400;
  letter-spacing: .1em;
  color: var(--phvr-gold);
}

.nav-link:hover {
  background: rgba(212, 175, 55, .05);
  color: var(--phvr-gold-bright);
}

.nav-link[aria-current="page"] {
  border-bottom-color: var(--phvr-gold);
  color: var(--phvr-gold);
}

.nav-link[aria-current="page"]::before {
  color: var(--phvr-gold-bright);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border: 1px solid var(--phvr-silver);
  background: transparent;
  color: var(--phvr-snowfield);
  cursor: pointer;
  transition: border-color .25s ease, color .25s ease;
}

.nav-toggle:hover {
  border-color: var(--phvr-gold);
  color: var(--phvr-gold);
}

.nav-toggle-label {
  font-family: var(--phvr-font-heading);
  font-size: .72rem;
  font-weight: 600;
  letter-spacing: .14em;
  text-transform: uppercase;
}

.nav-toggle-box {
  position: relative;
  display: inline-block;
  width: 18px;
  height: 14px;
  flex: none;
}

.nav-toggle-bar,
.nav-toggle-bar::before,
.nav-toggle-bar::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: top .25s ease, transform .25s ease, background-color .2s ease;
}

.nav-toggle-bar {
  top: 6px;
}

.nav-toggle-bar::before {
  top: 0;
}

.nav-toggle-bar::after {
  top: 12px;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar {
  background-color: transparent;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar::before {
  top: 6px;
  transform: rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar::after {
  top: 6px;
  transform: rotate(-45deg);
}

/* 页脚 */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 8vw, 120px);
  background: #070B14;
  border-top: 1px solid var(--phvr-silver);
  color: var(--phvr-snowfield);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, transparent 2%, var(--phvr-gold) 24%, var(--phvr-gold-bright) 50%, var(--phvr-gold) 76%, transparent 98%);
  pointer-events: none;
}

.footer-shell {
  width: var(--phvr-shell);
  margin-inline: auto;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1.2fr;
  gap: 44px;
  padding: 64px 0 52px;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 12px;
}

.footer-brand-mark {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--phvr-gold);
  background: linear-gradient(135deg, rgba(240, 199, 94, .12), transparent);
  color: var(--phvr-gold);
  font-family: var(--phvr-font-heading);
  font-size: 1.3rem;
  font-weight: 700;
}

.footer-brand-name {
  font-family: var(--phvr-font-heading);
  font-size: 1.2rem;
  font-weight: 600;
  letter-spacing: .1em;
  color: var(--phvr-snow);
}

.footer-brand-slogan {
  font-size: .76rem;
  letter-spacing: .06em;
  color: var(--phvr-ice);
}

.footer-trust {
  max-width: 46ch;
  font-size: .76rem;
  line-height: 1.8;
  color: var(--phvr-snowfield);
  opacity: .72;
}

.footer-links {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 8px;
}

.footer-col-title {
  margin: 0 0 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--phvr-silver);
  font-family: var(--phvr-font-heading);
  font-size: .68rem;
  font-weight: 600;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--phvr-gold);
}

.footer-links a {
  padding: 2px 0;
  border-bottom: 1px solid transparent;
  color: var(--phvr-snowfield);
  font-size: .85rem;
  text-decoration: none;
  transition: color .2s ease, border-color .2s ease;
}

.footer-links a:hover {
  border-bottom-color: rgba(212, 175, 55, .5);
  color: var(--phvr-gold-bright);
}

.footer-contact {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.footer-contact p {
  margin: 0;
  font-size: .78rem;
  line-height: 1.7;
  color: var(--phvr-snowfield);
  opacity: .92;
}

.footer-contact-note {
  color: var(--phvr-ice);
  opacity: .72;
}

.footer-base {
  border-top: 1px solid var(--phvr-silver);
  background: rgba(10, 14, 26, .72);
}

.footer-base-shell {
  width: var(--phvr-shell);
  margin-inline: auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 20px;
  padding: 16px 0;
}

.footer-copy,
.footer-icp,
.footer-route {
  font-size: .74rem;
}

.footer-copy {
  color: var(--phvr-snowfield);
}

.footer-icp {
  color: var(--phvr-ice);
}

.footer-route a {
  border-bottom: 1px solid rgba(212, 175, 55, .4);
  color: var(--phvr-snowfield);
  text-decoration: none;
  transition: color .2s ease, border-color .2s ease;
}

.footer-route a:hover {
  border-bottom-color: var(--phvr-gold);
  color: var(--phvr-gold);
}

/* 面包屑 */
.breadcrumb {
  font-size: .8rem;
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  list-style: none;
}

.breadcrumb li {
  display: inline-flex;
  align-items: center;
  color: var(--phvr-ice);
}

.breadcrumb li + li::before {
  content: "›";
  margin-right: 6px;
  color: var(--phvr-gold);
}

.breadcrumb a {
  color: var(--phvr-ice);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s ease, border-bottom-color .2s ease;
}

.breadcrumb a:hover {
  border-bottom-color: rgba(212, 175, 55, .4);
  color: var(--phvr-gold);
}

.breadcrumb .is-current,
.breadcrumb [aria-current="page"] {
  color: var(--phvr-snow);
}

/* 正文 */
.prose {
  font-size: .96rem;
  line-height: 1.85;
  color: var(--phvr-snowfield);
}

.prose p {
  margin-bottom: 1em;
}

.prose a {
  color: var(--phvr-ice);
  text-decoration: underline;
  text-decoration-color: rgba(169, 221, 235, .4);
  text-underline-offset: 3px;
}

.prose a:hover {
  color: var(--phvr-gold-bright);
}

.prose strong {
  color: var(--phvr-snow);
}

.prose h2,
.prose h3,
.prose h4 {
  font-family: var(--phvr-font-heading);
  line-height: 1.3;
  color: var(--phvr-snow);
  margin: 1.6em 0 .55em;
}

.prose h2 {
  font-size: 1.4rem;
}

.prose h3 {
  font-size: 1.1rem;
  color: var(--phvr-gold-bright);
}

.prose h4 {
  font-size: 1rem;
}

.prose ul,
.prose ol {
  margin: 0 0 1em;
  padding-left: 1.25em;
}

.prose blockquote {
  margin: 1.4em 0;
  padding: 14px 20px;
  border-left: 3px solid var(--phvr-gold);
  background: var(--phvr-bg-card);
  color: var(--phvr-snowfield);
}

.prose code {
  padding: .18em .45em;
  background: var(--phvr-slate);
  font-family: ui-monospace, SFMono-Regular, "Segoe UI Mono", Consolas, monospace;
  font-size: .85em;
}

.prose img {
  max-width: 100%;
  height: auto;
  border: 1px solid var(--phvr-silver);
}

/* 表格 */
.table-wrap {
  overflow-x: auto;
}

.table {
  width: 100%;
  border-collapse: collapse;
  font-size: .86rem;
  color: var(--phvr-snowfield);
}

.table th,
.table td {
  padding: 10px 14px;
  border: 1px solid var(--phvr-silver);
  text-align: left;
  vertical-align: top;
}

.table th {
  background: var(--phvr-bg-card);
  color: var(--phvr-gold);
  font-family: var(--phvr-font-heading);
  font-size: .78rem;
  font-weight: 600;
  letter-spacing: .06em;
  white-space: nowrap;
}

/* Bento 网格 */
.bento-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 20px;
}

.bento {
  position: relative;
  padding: 26px;
  background: var(--phvr-bg-card);
  border: 1px solid var(--phvr-silver);
  box-shadow: var(--phvr-shadow);
}

.bento--3 {
  grid-column: span 3;
}

.bento--4 {
  grid-column: span 4;
}

.bento--6 {
  grid-column: span 6;
}

.bento--8 {
  grid-column: span 8;
}

.bento--12 {
  grid-column: span 12;
}

/* 卡片 */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 22px;
}

.card-grid--compact {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
}

.card {
  position: relative;
  padding: 26px;
  background: var(--phvr-bg-card);
  border: 1px solid var(--phvr-silver);
  box-shadow: var(--phvr-shadow);
}

.card::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 22px;
  height: 22px;
  border-top: 2px solid rgba(212, 175, 55, .65);
  border-right: 2px solid rgba(212, 175, 55, .65);
  pointer-events: none;
}

/* 图片占位 */
.phvr-figure {
  position: relative;
  overflow: hidden;
  display: grid;
  align-items: end;
  aspect-ratio: 16 / 9;
  min-height: 160px;
  padding: 20px;
  border: 1px solid var(--phvr-silver);
  background: linear-gradient(180deg, rgba(10, 14, 26, .25), rgba(10, 14, 26, .68) 86%), var(--phvr-bg-card);
}

.phvr-figure::before {
  content: "";
  position: absolute;
  inset: 10px;
  z-index: 1;
  border: 1px solid rgba(212, 175, 55, .4);
  pointer-events: none;
}

.phvr-figure::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  z-index: 2;
  border-style: solid;
  border-width: 0 34px 34px 0;
  border-color: transparent rgba(212, 175, 55, .55) transparent transparent;
  pointer-events: none;
}

.phvr-figure--wide {
  aspect-ratio: 21 / 9;
}

.phvr-figure--tall {
  aspect-ratio: 3 / 4;
}

.phvr-figure--square {
  aspect-ratio: 1 / 1;
}

.phvr-figure-caption {
  position: relative;
  z-index: 3;
  align-self: end;
  font-size: .72rem;
  letter-spacing: .14em;
  color: var(--phvr-snow);
  opacity: .78;
}

/* 装饰 */
.tech-grid {
  background-image:
    linear-gradient(rgba(169, 221, 235, .14) 1px, transparent 1px),
    linear-gradient(90deg, rgba(169, 221, 235, .14) 1px, transparent 1px);
  background-size: 28px 28px;
}

.corner-frame {
  position: relative;
}

.corner-frame::before,
.corner-frame::after {
  content: "";
  position: absolute;
  width: 18px;
  height: 18px;
  z-index: 2;
  border: 0 solid var(--phvr-gold);
  pointer-events: none;
}

.corner-frame::before {
  top: 12px;
  left: 12px;
  border-top-width: 2px;
  border-left-width: 2px;
}

.corner-frame::after {
  right: 12px;
  bottom: 12px;
  border-right-width: 2px;
  border-bottom-width: 2px;
}

/* 标签与提示 */
.chip {
  display: inline-block;
  padding: 3px 10px;
  border: 1px solid var(--phvr-silver);
  border-radius: 999px;
  background: rgba(169, 221, 235, .06);
  color: var(--phvr-ice);
  font-size: .7rem;
  font-weight: 500;
  letter-spacing: .08em;
}

.chip--gold {
  border-color: rgba(212, 175, 55, .5);
  background: rgba(212, 175, 55, .08);
  color: var(--phvr-gold);
}

.callout {
  margin: 24px 0;
  padding: 20px 24px;
  border: 1px solid var(--phvr-silver);
  border-left: 3px solid var(--phvr-ice);
  background: rgba(169, 221, 235, .06);
  color: var(--phvr-snowfield);
  font-size: .92rem;
}

.callout--gold {
  border-left-color: var(--phvr-gold);
  background: linear-gradient(135deg, rgba(212, 175, 55, .12), rgba(212, 175, 55, .03));
}

/* 滚动显现 */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .5s ease, transform .5s ease;
}

html.js [data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}

/* 返回顶部 */
.back-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 90;
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  width: 54px;
  height: 54px;
  border: 1px solid rgba(212, 175, 55, .55);
  background: rgba(10, 14, 26, .94);
  color: var(--phvr-gold);
  text-decoration: none;
  box-shadow: 0 8px 24px rgba(0, 0, 0, .5);
  opacity: 0;
  transform: translateY(14px);
  pointer-events: none;
  transition: opacity .3s ease, transform .3s ease, border-color .3s ease, color .3s ease;
}

.back-top.is-visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.back-top:hover,
.back-top:focus-visible {
  border-color: var(--phvr-gold-bright);
  color: var(--phvr-gold-bright);
}

.back-top-arrow {
  font-size: 1.1rem;
  line-height: 1;
}

.back-top-text {
  font-family: var(--phvr-font-heading);
  font-size: .62rem;
  letter-spacing: .12em;
}

/* 响应式 */
@media (max-width: 960px) {
  .bento--3,
  .bento--4 {
    grid-column: span 6;
  }

  .bento--6,
  .bento--8 {
    grid-column: span 12;
  }

  .footer-shell {
    grid-template-columns: 1.2fr 1fr;
    gap: 32px;
    padding-top: 48px;
    padding-bottom: 40px;
  }

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

@media (max-width: 880px) {
  .masthead-shell {
    grid-template-columns: auto 1fr auto;
    gap: 12px;
    min-height: 72px;
  }

  .masthead-brand {
    justify-self: start;
  }

  .masthead-brand::before,
  .masthead-brand::after {
    display: none;
  }

  .masthead-edition {
    display: none;
  }

  .nav-rule {
    justify-content: flex-end;
    padding: 0 16px;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex: 0 0 auto;
    display: none;
    width: 100%;
    background: var(--phvr-bg-card);
    border-top: 1px solid var(--phvr-silver);
    border-bottom: 1px solid var(--phvr-silver);
    box-shadow: 0 16px 30px rgba(0, 0, 0, .48);
  }

  .site-nav[data-open] {
    display: block;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .nav-list {
    display: block;
    width: 100%;
    padding: 8px 0;
  }

  .nav-item {
    display: block;
  }

  .nav-link {
    display: flex;
    width: 100%;
    padding: 13px 22px;
    border-bottom: 1px solid var(--phvr-silver);
    border-left: 3px solid transparent;
  }

  .nav-link[aria-current="page"] {
    border-bottom-color: var(--phvr-silver);
    border-left-color: var(--phvr-gold);
  }

  .site-nav .nav-item:last-child .nav-link {
    border-bottom: 0;
  }
}

@media (max-width: 640px) {
  .bento-grid {
    display: block;
  }

  .bento {
    margin-bottom: 16px;
  }

  .footer-shell {
    grid-template-columns: 1fr;
    padding-top: 40px;
    padding-bottom: 32px;
  }

  .footer-brand {
    grid-column: auto;
  }

  .footer-base-shell {
    flex-direction: column;
    align-items: flex-start;
  }

  .masthead-actions {
    gap: 6px;
  }

  .masthead-actions .btn {
    padding: 7px 11px;
    font-size: .66rem;
  }

  .masthead-mark {
    width: 38px;
    height: 38px;
    margin-right: 10px;
    font-size: 1.1rem;
  }

  .masthead-name {
    font-size: 1.15rem;
    letter-spacing: .12em;
  }

  .masthead-acronym {
    font-size: .95rem;
    letter-spacing: .14em;
  }

  .btn-star {
    display: none;
  }

  .back-top {
    right: 14px;
    bottom: 14px;
    width: 46px;
    height: 46px;
  }

  .back-top-text {
    display: none;
  }
}

/* 减少动态效果 */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    transition-delay: 0ms !important;
  }

  html.js [data-reveal],
  [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }
}