/* ============================================================
   星游品牌站 · 共享样式 /assets/site.css
   夜间观测站：深夜蓝 + 星芒金，8px 蓝图网格，侧轨导航
   ============================================================ */

/* ---------- 01 重置 ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-padding-top: calc(var(--sy-topbar) + 8px);
}

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

ul, ol { padding: 0; list-style: none; }

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

button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }

input, textarea, select { font: inherit; }

/* ---------- 02 变量 ---------- */
:root {
  --sy-deep: #0B1330;
  --sy-deep-dot: #070D22;
  --sy-panel: #16224A;
  --sy-grid: #2A3557;
  --sy-gold: #F2B857;
  --sy-gold-soft: #F7C977;
  --sy-teal: #2FBFA6;
  --sy-orange: #F0733C;
  --sy-paper: #F4EDE1;
  --sy-ink: #14161C;
  --sy-mist: #A9B2C7;
  --sy-violet: #7C6BF2;

  --sy-rail: 88px;
  --sy-topbar: 60px;
  --sy-max: 1180px;
  --sy-gutter: clamp(18px, 4vw, 48px);
  --sy-radius: 16px;
  --sy-radius-sm: 10px;

  --sy-t1: clamp(30px, 6.4vw, 72px);
  --sy-t2: clamp(23px, 4.2vw, 44px);
  --sy-t3: clamp(19px, 2.6vw, 24px);
  --sy-t4: 17px;
  --sy-t5: 13px;

  --sy-line: rgba(42, 53, 87, 0.9);
  --sy-line-soft: rgba(42, 53, 87, 0.55);
  --sy-gold-line: rgba(242, 184, 87, 0.55);

  --sy-font: system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --sy-font-display: "Noto Sans SC", "Source Han Sans SC", system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;

  --sy-ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --sy-dur: 200ms;

  --sy-grid-pattern:
    linear-gradient(to right, var(--sy-line-soft) 1px, transparent 1px),
    linear-gradient(to bottom, var(--sy-line-soft) 1px, transparent 1px);
}

/* ---------- 03 基础排版 ---------- */
html { background-color: var(--sy-deep); }

@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

body {
  font-family: var(--sy-font);
  font-size: 16px;
  line-height: 1.75;
  color: var(--sy-paper);
  background-color: var(--sy-deep);
  min-height: 100vh;
  padding-top: var(--sy-topbar);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--sy-font-display);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.02em;
}

p { max-width: 34em; }

::selection {
  background: var(--sy-gold);
  color: var(--sy-deep);
}

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

/* ---------- 04 跳转链接 ---------- */
.sy-skip {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 400;
  display: inline-block;
  padding: 10px 18px;
  border-radius: 999px;
  background: var(--sy-gold);
  color: var(--sy-deep);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-decoration: none;
  transform: translateY(-180%);
  transition: transform var(--sy-dur) var(--sy-ease);
}

.sy-skip:focus,
.sy-skip:focus-visible { transform: translateY(0); }

/* ---------- 05 滚动进度 ---------- */
.sy-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 200;
  pointer-events: none;
  background: rgba(242, 184, 87, 0.12);
}

.sy-progress__bar {
  display: block;
  height: 100%;
  width: 100%;
  background: var(--sy-gold);
  transform: scaleX(0);
  transform-origin: 0 50%;
  will-change: transform;
}

/* ---------- 06 头部：移动端默认（顶部品牌行） ---------- */
.sy-header {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--sy-topbar);
  z-index: 120;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 var(--sy-gutter);
  background-color: var(--sy-deep);
  background-image: var(--sy-grid-pattern);
  background-size: 8px 8px;
  color: var(--sy-paper);
  border-bottom: 1px solid var(--sy-line);
}

/* 品牌 */
.sy-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  min-width: 0;
  color: inherit;
  text-decoration: none;
  padding: 4px 0;
}

.sy-brand__mark {
  width: 26px;
  height: 26px;
  flex: 0 0 auto;
  color: var(--sy-gold);
}

@media (prefers-reduced-motion: no-preference) {
  .sy-brand__mark { animation: sy-twinkle 7s var(--sy-ease) infinite; }
  @keyframes sy-twinkle {
    0%, 100% { opacity: 0.92; transform: rotate(0deg); }
    50% { opacity: 1; transform: rotate(4deg); }
  }
}

.sy-brand__name {
  font-family: var(--sy-font-display);
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 0.22em;
  white-space: nowrap;
}

.sy-brand__sub {
  display: none;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--sy-mist);
  white-space: nowrap;
}

@media (min-width: 520px) and (max-width: 899px) {
  .sy-brand__sub { display: inline; }
}

/* 抽屉开关 */
.sy-nav-toggle {
  margin-left: auto;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 9px 15px;
  border: 1px solid var(--sy-gold-line);
  border-radius: 999px;
  color: var(--sy-gold);
  font-size: 12px;
  letter-spacing: 0.14em;
  transition:
    background-color var(--sy-dur) var(--sy-ease),
    border-color var(--sy-dur) var(--sy-ease),
    color var(--sy-dur) var(--sy-ease);
}

.sy-nav-toggle:hover { background: rgba(242, 184, 87, 0.12); }

.sy-nav-toggle[aria-expanded="true"] {
  background: var(--sy-gold);
  border-color: var(--sy-gold);
  color: var(--sy-deep);
}

.sy-nav-toggle__text { line-height: 1; }

.sy-nav-toggle__bars {
  position: relative;
  display: block;
  width: 14px;
  height: 10px;
  flex: 0 0 auto;
}

.sy-nav-toggle__bars span {
  position: absolute;
  left: 0;
  right: 0;
  height: 1.5px;
  border-radius: 2px;
  background: currentColor;
  transition: transform var(--sy-dur) var(--sy-ease);
}

.sy-nav-toggle__bars span:nth-child(1) { top: 0; }
.sy-nav-toggle__bars span:nth-child(2) { bottom: 0; }

.sy-nav-toggle[aria-expanded="true"] .sy-nav-toggle__bars span:nth-child(1) {
  transform: translateY(4.25px) rotate(45deg);
}

.sy-nav-toggle[aria-expanded="true"] .sy-nav-toggle__bars span:nth-child(2) {
  transform: translateY(-4.25px) rotate(-45deg);
}

/* ---------- 07 导航：移动端抽屉 ---------- */
.sy-nav {
  position: fixed;
  inset: var(--sy-topbar) 0 0 0;
  z-index: 110;
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 22px var(--sy-gutter) 40px;
  overflow-y: auto;
  overscroll-behavior: contain;
  background-color: var(--sy-deep);
  background-image:
    linear-gradient(to right, var(--sy-line-soft) 1px, transparent 1px),
    linear-gradient(to bottom, var(--sy-line-soft) 1px, transparent 1px),
    radial-gradient(circle at 82% 8%, rgba(242, 184, 87, 0.14), transparent 42%);
  background-size: 8px 8px, 8px 8px, 100% 100%;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition:
    opacity var(--sy-dur) var(--sy-ease),
    transform var(--sy-dur) var(--sy-ease),
    visibility var(--sy-dur) var(--sy-ease);
}

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

.sy-nav__list {
  display: flex;
  flex-direction: column;
  margin: 0;
  padding: 0;
}

.sy-nav__item { display: block; }

.sy-nav__link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 15px 8px 15px 14px;
  color: var(--sy-paper);
  text-decoration: none;
  border-bottom: 1px solid var(--sy-line-soft);
  transition: background-color var(--sy-dur) var(--sy-ease);
}

.sy-nav__link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 2px;
  height: 0;
  background: var(--sy-gold);
  transform: translateY(-50%);
  transition: height var(--sy-dur) var(--sy-ease);
}

.sy-nav__link:hover,
.sy-nav__link:focus-visible { background: rgba(242, 184, 87, 0.07); }

.sy-nav__link:hover::before,
.sy-nav__link:focus-visible::before { height: 20px; }

.sy-nav__link[aria-current="page"]::before { height: 26px; }

.sy-nav__num {
  font-size: 12px;
  font-weight: 300;
  letter-spacing: 0.12em;
  font-variant-numeric: tabular-nums;
  color: var(--sy-mist);
}

.sy-nav__label {
  font-family: var(--sy-font-display);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--sy-paper);
}

.sy-nav__link[aria-current="page"] .sy-nav__num,
.sy-nav__link[aria-current="page"] .sy-nav__label { color: var(--sy-gold); }

/* CTA：移动端满宽按钮 */
.sy-nav__cta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-top: 8px;
  padding: 14px 22px;
  border-radius: 999px;
  background: var(--sy-gold);
  color: var(--sy-deep);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-decoration: none;
  text-align: center;
  transition:
    background-color var(--sy-dur) var(--sy-ease),
    transform var(--sy-dur) var(--sy-ease);
}

.sy-nav__cta:hover { background: var(--sy-gold-soft); transform: translateY(-1px); }

.sy-nav__cta-icon { font-size: 15px; line-height: 1; }

/* 抽屉打开时锁定背景滚动（仅移动端） */
@media (max-width: 899px) {
  html.sy-nav-open,
  html.sy-nav-open body { overflow: hidden; }
}

/* ---------- 08 头部：桌面端侧边轨道 ---------- */
@media (min-width: 900px) {
  body {
    padding-top: 0;
    padding-left: var(--sy-rail);
  }

  .sy-header {
    inset: 0 auto 0 0;
    width: var(--sy-rail);
    height: 100vh;
    height: 100dvh;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0;
    border-bottom: 0;
    border-right: 1px solid var(--sy-line);
    background-image:
      linear-gradient(to right, rgba(42, 53, 87, 0.42) 1px, transparent 1px),
      linear-gradient(to bottom, rgba(42, 53, 87, 0.42) 1px, transparent 1px);
    background-size: 8px 8px;
  }

  .sy-progress { left: var(--sy-rail); }

  .sy-brand {
    flex-direction: column;
    justify-content: center;
    gap: 8px;
    padding: 20px 6px 18px;
    border-bottom: 1px solid var(--sy-line);
  }

  .sy-brand__mark { width: 32px; height: 32px; }

  .sy-brand__name {
    font-size: 12px;
    letter-spacing: 0.34em;
    text-indent: 0.34em;
  }

  .sy-brand__sub {
    display: block;
    font-size: 9px;
    letter-spacing: 0.12em;
    text-align: center;
    line-height: 1.3;
  }

  .sy-nav-toggle { display: none; }

  .sy-nav {
    position: static;
    inset: auto;
    z-index: auto;
    flex: 1 1 auto;
    gap: 0;
    padding: 14px 0 18px;
    overflow-y: auto;
    overflow-x: hidden;
    background-image: none;
    background-color: transparent;
    opacity: 1;
    visibility: visible;
    transform: none;
    transition: none;
  }

  .sy-nav__list { flex-direction: column; }

  .sy-nav__link {
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
    padding: 12px 2px;
    border-bottom: 0;
  }

  .sy-nav__link::before {
    top: 0;
    bottom: 0;
    height: auto;
    width: 0;
    transform: none;
    transition: width var(--sy-dur) var(--sy-ease);
  }

  .sy-nav__link:hover::before,
  .sy-nav__link:focus-visible::before { height: auto; width: 2px; }

  .sy-nav__link[aria-current="page"]::before { height: auto; width: 3px; }

  .sy-nav__link[aria-current="page"] {
    background: rgba(242, 184, 87, 0.08);
  }

  .sy-nav__num {
    font-size: 13px;
    letter-spacing: 0.08em;
  }

  .sy-nav__label {
    font-size: 11px;
    letter-spacing: 0.04em;
    line-height: 1.3;
  }

  /* CTA：桌面端竖排金色胶囊 */
  .sy-nav__cta {
    display: block;
    width: -webkit-fit-content;
    width: fit-content;
    margin: 18px auto 0;
    padding: 16px 9px;
    writing-mode: vertical-rl;
    text-orientation: upright;
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.22em;
    line-height: 1.2;
    border-radius: 999px;
    background: var(--sy-gold);
    color: var(--sy-deep);
    transform: none;
  }

  .sy-nav__cta:hover {
    background: var(--sy-gold-soft);
    transform: none;
  }

  .sy-nav__cta-icon { display: none; }
}

/* ---------- 09 页脚 ---------- */
.sy-footer {
  position: relative;
  overflow: hidden;
  background-color: var(--sy-deep);
  background-image:
    linear-gradient(to right, rgba(42, 53, 87, 0.4) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(42, 53, 87, 0.4) 1px, transparent 1px);
  background-size: 8px 8px;
  color: var(--sy-paper);
  border-top: 1px solid var(--sy-line);
  padding: clamp(48px, 7vw, 84px) var(--sy-gutter) 28px;
}

.sy-footer::before {
  content: "";
  position: absolute;
  top: -140px;
  right: -140px;
  width: 360px;
  height: 360px;
  border-radius: 50%;
  border: 1px solid rgba(242, 184, 87, 0.2);
  box-shadow:
    inset 0 0 0 44px rgba(242, 184, 87, 0.035),
    inset 0 0 0 45px rgba(242, 184, 87, 0.14);
  pointer-events: none;
}

.sy-footer::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 96px;
  height: 1px;
  background: var(--sy-gold);
  pointer-events: none;
}

.sy-footer__inner {
  position: relative;
  z-index: 1;
  max-width: var(--sy-max);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(32px, 5vw, 64px);
}

.sy-footer__brand {
  display: inline-flex;
  align-items: baseline;
  gap: 12px;
  font-family: var(--sy-font-display);
  font-size: clamp(24px, 3.4vw, 34px);
  font-weight: 900;
  letter-spacing: 0.1em;
  color: var(--sy-paper);
  text-decoration: none;
}

.sy-footer__brand-sub {
  font-size: 11px;
  font-weight: 400;
  letter-spacing: 0.22em;
  color: var(--sy-mist);
}

.sy-footer__tagline {
  margin-top: 14px;
  max-width: 26em;
  font-size: 14px;
  line-height: 1.8;
  color: var(--sy-mist);
}

.sy-footer__contact {
  display: grid;
  gap: 10px;
  margin-top: 26px;
  padding-top: 20px;
  border-top: 1px solid var(--sy-line);
}

.sy-footer__contact li {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 12px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--sy-paper);
  word-break: break-word;
}

.sy-footer__label {
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--sy-gold);
  padding-top: 2px;
}

.sy-footer__links {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(128px, 1fr));
  gap: clamp(24px, 4vw, 40px);
  align-content: start;
}

.sy-footer__col-title {
  font-family: var(--sy-font);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.24em;
  color: var(--sy-gold);
  padding-bottom: 10px;
  margin-bottom: 14px;
  border-bottom: 1px solid var(--sy-line);
}

.sy-footer__list { display: grid; gap: 10px; }

.sy-footer__list a {
  display: inline-block;
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--sy-mist);
  text-decoration: none;
  transition:
    color var(--sy-dur) var(--sy-ease),
    transform var(--sy-dur) var(--sy-ease);
}

.sy-footer__list a:hover,
.sy-footer__list a:focus-visible {
  color: var(--sy-paper);
  transform: translateX(3px);
}

.sy-footer__meta {
  position: relative;
  z-index: 1;
  max-width: var(--sy-max);
  margin: clamp(32px, 5vw, 56px) auto 0;
  padding-top: 20px;
  border-top: 1px solid var(--sy-line);
  display: flex;
  flex-wrap: wrap;
  gap: 8px 26px;
  align-items: baseline;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--sy-mist);
}

.sy-footer__meta p { max-width: none; }

.sy-footer__year {
  color: var(--sy-gold);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.06em;
}

@media (min-width: 760px) {
  .sy-footer__inner {
    grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.3fr);
    align-items: start;
  }
}

/* ---------- 10 容器 / 网格 / 章节 ---------- */
.sy-container {
  width: 100%;
  max-width: var(--sy-max);
  margin: 0 auto;
  padding-left: var(--sy-gutter);
  padding-right: var(--sy-gutter);
}

.sy-section { padding: clamp(56px, 8vw, 104px) 0; }

.sy-grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2.4vw, 28px);
}

.sy-grid > * { grid-column: span 12; }

@media (min-width: 760px) {
  .sy-span-4 { grid-column: span 4; }
  .sy-span-5 { grid-column: span 5; }
  .sy-span-6 { grid-column: span 6; }
  .sy-span-7 { grid-column: span 7; }
  .sy-span-8 { grid-column: span 8; }
}

/* ---------- 11 文本零件 ---------- */
.sy-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.24em;
  color: var(--sy-gold);
}

.sy-eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: currentColor;
  flex: 0 0 auto;
}

.sy-num {
  display: block;
  font-family: var(--sy-font-display);
  font-weight: 200;
  font-size: clamp(44px, 8vw, 96px);
  line-height: 0.9;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  color: rgba(242, 184, 87, 0.42);
}

/* ---------- 12 按钮 ---------- */
.sy-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 24px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-decoration: none;
  transition:
    background-color var(--sy-dur) var(--sy-ease),
    color var(--sy-dur) var(--sy-ease),
    border-color var(--sy-dur) var(--sy-ease),
    transform var(--sy-dur) var(--sy-ease);
}

.sy-btn--gold {
  background: var(--sy-gold);
  color: var(--sy-deep);
}

.sy-btn--gold:hover {
  background: var(--sy-gold-soft);
  transform: translateY(-1px);
}

.sy-btn--ghost {
  border-color: var(--sy-gold-line);
  color: var(--sy-gold);
  background: transparent;
}

.sy-btn--ghost:hover {
  background: rgba(242, 184, 87, 0.12);
  transform: translateY(-1px);
}

/* ---------- 13 面包屑 ---------- */
.sy-breadcrumb {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--sy-mist);
}

.sy-breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

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

.sy-breadcrumb li + li::before {
  content: "/";
  color: rgba(169, 178, 199, 0.45);
}

.sy-breadcrumb a {
  color: var(--sy-mist);
  text-decoration: none;
  transition: color var(--sy-dur) var(--sy-ease);
}

.sy-breadcrumb a:hover,
.sy-breadcrumb a:focus-visible { color: var(--sy-gold); }

.sy-breadcrumb [aria-current="page"] { color: var(--sy-paper); }

/* ---------- 14 标签 ---------- */
.sy-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 11px;
  border: 1px solid currentColor;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.14em;
  line-height: 1.6;
  white-space: nowrap;
}

.sy-tag--gold { color: var(--sy-gold); }
.sy-tag--teal { color: var(--sy-teal); }
.sy-tag--orange { color: var(--sy-orange); }

/* ---------- 15 暖纸正文 ---------- */
.sy-prose {
  max-width: 38em;
  padding: clamp(22px, 4vw, 44px);
  border-radius: var(--sy-radius);
  background: var(--sy-paper);
  color: var(--sy-ink);
  font-size: 16px;
  line-height: 1.8;
}

.sy-prose > * + * { margin-top: 1em; }

.sy-prose h2,
.sy-prose h3 {
  color: var(--sy-ink);
  font-size: var(--sy-t3);
  font-weight: 800;
  letter-spacing: 0;
  line-height: 1.4;
  margin-top: 1.8em;
}

.sy-prose p,
.sy-prose li {
  max-width: 34em;
  color: #2A2F3A;
}

.sy-prose ul,
.sy-prose ol {
  padding-left: 1.25em;
  list-style: disc;
}

.sy-prose ol { list-style: decimal; }

.sy-prose li + li { margin-top: 0.4em; }

.sy-prose a {
  color: #8A5A12;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.sy-prose strong { font-weight: 700; color: var(--sy-ink); }

/* ---------- 16 响应式图片容器 ---------- */
.sy-media {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  border: 1px solid var(--sy-line);
  border-radius: var(--sy-radius);
  background-color: var(--sy-panel);
}

.sy-media--wide { aspect-ratio: 21 / 9; }
.sy-media--tall { aspect-ratio: 3 / 4; }
.sy-media--square { aspect-ratio: 1 / 1; }

.sy-media img,
.sy-media > picture,
.sy-media > picture > img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.sy-media__ph {
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(45deg, rgba(42, 53, 87, 0.75) 0 1px, transparent 1px 12px),
    radial-gradient(circle at 28% 24%, rgba(242, 184, 87, 0.18), transparent 58%),
    radial-gradient(circle at 76% 78%, rgba(47, 191, 166, 0.14), transparent 55%);
}

.sy-media__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 12px 16px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--sy-paper);
  background: linear-gradient(to top, rgba(11, 19, 48, 0.92), rgba(11, 19, 48, 0));
}

/* ---------- 17 可展开组 ---------- */
.sy-collapse {
  border: 1px solid var(--sy-line);
  border-left: 3px solid var(--sy-grid);
  border-radius: var(--sy-radius-sm);
  background: rgba(22, 34, 74, 0.62);
  overflow: hidden;
  transition: border-left-color var(--sy-dur) var(--sy-ease);
}

.sy-collapse:hover { border-left-color: rgba(242, 184, 87, 0.55); }

.sy-collapse[data-open="true"] { border-left-color: var(--sy-teal); }

.sy-collapse__btn {
  width: 100%;
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 16px 18px;
  text-align: left;
  font-family: var(--sy-font-display);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.6;
  color: var(--sy-paper);
  transition: background-color var(--sy-dur) var(--sy-ease);
}

.sy-collapse__btn:hover { background: rgba(242, 184, 87, 0.07); }

.sy-collapse__icon {
  position: relative;
  flex: 0 0 auto;
  margin-left: auto;
  width: 18px;
  height: 18px;
  margin-top: 3px;
  border: 1px solid var(--sy-gold-line);
  border-radius: 50%;
}

.sy-collapse__icon::before,
.sy-collapse__icon::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  background: var(--sy-gold);
  transition:
    transform var(--sy-dur) var(--sy-ease),
    opacity var(--sy-dur) var(--sy-ease);
}

.sy-collapse__icon::before {
  width: 8px;
  height: 1px;
  transform: translate(-50%, -50%);
}

.sy-collapse__icon::after {
  width: 1px;
  height: 8px;
  transform: translate(-50%, -50%);
}

.sy-collapse[data-open="true"] .sy-collapse__icon::after {
  transform: translate(-50%, -50%) scaleY(0);
  opacity: 0;
}

.sy-collapse__panel {
  display: grid;
  grid-template-rows: 0fr;
  visibility: hidden;
  transition:
    grid-template-rows var(--sy-dur) var(--sy-ease),
    visibility var(--sy-dur) var(--sy-ease);
}

.sy-collapse__panel > div { overflow: hidden; }

.sy-collapse[data-open="true"] .sy-collapse__panel {
  grid-template-rows: 1fr;
  visibility: visible;
}

.sy-collapse__body {
  padding: 0 18px 18px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--sy-mist);
}

.sy-collapse__body > * + * { margin-top: 0.7em; }

.sy-collapse__body p { max-width: 36em; }

/* ---------- 18 动效降级 ---------- */
@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;
  }

  .sy-skip { transition: none; }
  .sy-nav { transition: none; }
  .sy-progress__bar { transition: none; }
  .sy-collapse__panel { transition: none; }
}