/* ══════════════════════════════════════════════════════════
   Landing 系静态页公共样式
   被 landing.html / about.html / apply.html / privacy.html 共用
   原则：最保守 CSS · 不依赖 system-v1/v2 · 避免 GPU 重负担
   ══════════════════════════════════════════════════════════ */

*{margin:0;padding:0;box-sizing:border-box;-webkit-tap-highlight-color:transparent}

:root{
  --bg-deep: #070A14;
  --bg-0:    #0A0E1A;
  --ink-0:   #F2EEE4;
  --ink-1:   #B8B3A5;
  --ink-2:   #6B6558;
  --moon:    #E8D9B6;
  --line-1:  rgba(232,217,182,0.12);
  --line-2:  rgba(232,217,182,0.20);
  --moon-faint: rgba(232,217,182,0.10);
  --glass-bg:     rgba(255,255,255,0.045);
  --glass-border: rgba(232,217,182,0.12);
  --serif: 'LXGW WenKai Screen','Noto Serif SC','Source Han Serif SC','Songti SC','STSong','SimSun','Georgia',serif;
  --sans:  -apple-system,'PingFang SC','Noto Sans SC','Helvetica Neue',sans-serif;
  --mono:  'SF Mono','Cascadia Code','Menlo',monospace;
  --ease:  cubic-bezier(0.16,1,0.3,1);
}

html{
  background: var(--bg-deep);
  -webkit-text-size-adjust: 100%;
}
body{
  background: var(--bg-deep);
  color: var(--ink-1);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
  line-height: 1.7;
}

/* 中央容器 · ambient 用 stage 自己的 background · 不用 fixed 元素 */
.stage{
  max-width: 640px;
  margin: 0 auto;
  padding: 80px 24px;
  background:
    radial-gradient(ellipse 55% 12% at 50% 0%,  rgba(117,145,168,0.12) 0%, transparent 55%),
    radial-gradient(ellipse 60% 15% at 50% 100%,rgba(232,217,182,0.04) 0%, transparent 55%),
    var(--bg-0);
  box-shadow: 0 0 0 1px rgba(232,217,182,0.04);
  min-height: 100vh;
}
.stage *{ max-width:100%; box-sizing:border-box }

/* 左上回链 · 4 页通用 */
.back{
  position: absolute;
  top: 20px; left: 20px;
  z-index: 5;
  color: var(--ink-2);
  font-size: 12px;
  letter-spacing: 0.04em;
  text-decoration: none;
  padding: 8px 12px;
  opacity: 0.62;
  transition: color .22s, opacity .22s;
}
.back:hover, .back:active{ opacity: 1; color: var(--moon) }

/* 章节小标 */
.kicker{
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.28em;
  color: var(--moon);
  opacity: 0.55;
  margin-bottom: 24px;
}

/* 标题 / 副标 / 段落 */
h1{
  font-family: var(--serif);
  font-weight: 300;
  font-size: 30px;
  line-height: 1.55;
  letter-spacing: 0.015em;
  color: var(--ink-0);
  margin-bottom: 22px;
  word-break: keep-all;
}
.lead{
  font-family: var(--serif);
  font-weight: 300;
  font-size: 17px;
  line-height: 2;
  color: var(--ink-1);
  opacity: 0.82;
  margin-bottom: 48px;
  max-width: 22em;
  word-break: keep-all;
}
h2{
  font-family: var(--serif);
  font-weight: 300;
  font-size: 19px;
  line-height: 1.6;
  letter-spacing: 0.01em;
  color: var(--ink-0);
  margin: 44px 0 14px;
}
p{
  font-size: 14.5px;
  line-height: 1.95;
  color: var(--ink-1);
  opacity: 0.85;
  margin-bottom: 14px;
  /* 长中文段落 · 不能 keep-all（会整段溢出）· 默认允许字间断行 */
  overflow-wrap: break-word;
}

/* 邮件卡（about + apply 用） */
.mail-card{
  margin: 32px 0;
  padding: 30px 24px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--line-1);
  border-radius: 14px;
  text-align: center;
  position: relative;
}
.mail-card::after{
  content: '';
  position: absolute; top: 0; left: 12%; right: 12%;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(232,217,182,0.4), transparent);
  pointer-events: none;
}
.mail-card .label{
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.22em;
  color: var(--moon);
  opacity: 0.55;
  margin-bottom: 16px;
}
.mail-card .mail{
  font-family: var(--mono);
  font-size: 20px;
  letter-spacing: 0.02em;
  color: var(--ink-0);
  overflow-wrap: anywhere;
  margin-bottom: 20px;
}
.mail-card .actions{
  display: flex; gap: 10px;
  justify-content: center;
  flex-wrap: wrap;
}
.mail-card button, .mail-card a{
  padding: 9px 18px;
  font-size: 13px;
  background: transparent;
  border: 1px solid var(--line-1);
  color: var(--ink-1);
  border-radius: 8px;
  cursor: pointer;
  font-family: inherit;
  text-decoration: none;
  transition: color .22s, border-color .22s;
}
.mail-card button:hover, .mail-card a:hover{
  color: var(--moon);
  border-color: rgba(232,217,182,0.45);
}
.copy-ok{
  height: 16px;
  margin-top: 12px;
  font-size: 11.5px;
  letter-spacing: 0.04em;
  color: var(--moon);
  opacity: 0;
  transition: opacity .3s;
}
.copy-ok.show{ opacity: 1 }

/* 引述卡 · about + apply + privacy 都用 */
.callout{
  margin: 44px 0;
  padding: 22px 24px;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--line-1);
  border-radius: 10px;
  font-size: 14px;
  line-height: 1.95;
  color: var(--ink-1);
  font-family: var(--serif);
  font-weight: 300;
  overflow-wrap: break-word;
}

/* 底部 meta · 4 页通用 */
.meta{
  margin-top: 64px;
  padding-top: 24px;
  border-top: 1px solid rgba(232,217,182,0.08);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--ink-2);
  opacity: 0.8;
  line-height: 2.2;
  display: flex;
  flex-wrap: wrap;
  gap: 14px 22px;
}
.meta a{
  color: var(--ink-1);
  text-decoration: none;
  border-bottom: 1px dotted rgba(232,217,182,0.18);
  padding-bottom: 2px;
  transition: color .22s, border-color .22s;
}
.meta a:hover{ color: var(--moon); border-bottom-color: rgba(232,217,182,0.5) }

/* 桌面尺寸 · 字号上调 */
@media (min-width: 640px){
  h1{ font-size: 38px }
  .lead{ font-size: 19px }
  h2{ font-size: 22px }
  p{ font-size: 15.5px }
  .mail-card .mail{ font-size: 26px }
  .callout{ font-size: 15.5px }
}