/* 素笺朱墨 · letter — shared design tokens */
:root{
  --paper:#F5F2E9;
  --paper-2:#E8E3D5;
  --paper-3:#DCD4BD;
  --paper-bright:#FCFAF1;
  --surface:#FFFFFF;
  --ink:#333333;
  --ink-2:#5C5547;
  --ink-3:#8A8270;
  --ink-4:#B5AC95;
  --vermillion:#C23531;
  --vermillion-deep:#9B2925;
  --vermillion-soft:#E89289;
  --vermillion-wash:#F5DCD7;
  --sage:#A8B69A;
  --line:rgba(51,51,51,.10);
  --line-2:rgba(51,51,51,.06);

  --shadow-paper:0 30px 80px -25px rgba(51,51,51,.30),0 6px 20px -8px rgba(51,51,51,.10);
  --shadow-card:0 1px 2px rgba(51,51,51,.04),0 12px 36px -12px rgba(51,51,51,.10);
  --shadow-soft:0 1px 2px rgba(51,51,51,.04),0 8px 24px -8px rgba(51,51,51,.06);

  --serif:'Literata',serif;
  --display:'Cormorant Garamond','Noto Serif SC',serif;
  --cjk:'Noto Serif SC',serif;
  --cjk-hand:'Ma Shan Zheng','LXGW WenKai',cursive;
  --hand:'Caveat',cursive;
  --mono:'JetBrains Mono',ui-monospace,monospace;
}
*{margin:0;padding:0;box-sizing:border-box}
*:focus-visible{outline:2px solid var(--vermillion);outline-offset:3px}
html{scroll-behavior:smooth}
body{
  font-family:var(--serif);font-size:15px;line-height:1.6;
  color:var(--ink);background:var(--paper);
  -webkit-font-smoothing:antialiased;min-height:100vh;
  font-feature-settings:'ss01','onum';
  background-image:
    radial-gradient(ellipse 1300px 900px at 80% 5%,rgba(194,53,49,.04),transparent 60%),
    radial-gradient(ellipse 800px 600px at 10% 95%,rgba(168,182,154,.04),transparent 60%);
}
body::before{
  content:'';position:fixed;inset:0;pointer-events:none;z-index:1;
  background-image:url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='1.1' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 .25 0 0 0 0 .22 0 0 0 0 .18 0 0 0 .12 0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  mix-blend-mode:multiply;opacity:.55;
}
main{position:relative;z-index:2}

/* ===== NAV ===== */
.nav{
  position:fixed;top:0;left:0;right:0;z-index:50;
  display:flex;justify-content:space-between;align-items:center;
  padding:22px clamp(24px,4vw,56px);
  background:linear-gradient(to bottom,rgba(245,242,233,.92),rgba(245,242,233,0));
  backdrop-filter:blur(8px);
}
.nav .brand{display:inline-flex;align-items:baseline;gap:14px;text-decoration:none;color:inherit}
.nav .brand:hover .en{color:var(--vermillion-deep)}
.nav .brand .en{
  font-family:var(--display);font-style:italic;font-weight:400;font-size:22px;
  color:var(--ink);letter-spacing:-.005em;transition:color .3s;
  position:relative;
}
/* tiny vermillion period after the brand "Linger." in nav */
.nav .brand .en::after{
  content:'.';color:var(--vermillion);font-weight:400;
}
.nav .brand .cn{
  font-family:var(--cjk);font-weight:300;font-size:13px;
  color:var(--ink-3);letter-spacing:.16em;
}
.nav .menu{display:flex;gap:32px;align-items:center}
.nav .menu a{
  font-family:var(--cjk);font-weight:300;font-size:14px;color:var(--ink-2);
  text-decoration:none;transition:color .3s;letter-spacing:.06em;
  position:relative;padding:4px 0;
}
.nav .menu a:hover,.nav .menu a.active{color:var(--ink)}
.nav .menu a.active::after{
  content:'';position:absolute;left:0;right:0;bottom:-2px;
  height:1px;background:var(--vermillion);
}

section{padding:140px clamp(24px,5vw,80px) 120px;position:relative}

/* ===== TYPE PRIMITIVES ===== */
.eyebrow{
  font-family:var(--mono);font-size:10px;letter-spacing:.20em;
  color:var(--ink-3);text-transform:uppercase;font-weight:400;
}
.eyebrow-cn{
  font-family:var(--cjk);font-weight:300;font-size:12px;
  color:var(--ink-3);letter-spacing:.32em;
  display:inline-flex;align-items:center;gap:14px;
}
.eyebrow-cn::before{content:'';width:32px;height:1px;background:var(--vermillion);opacity:.5}

h1.hero-cn{
  font-family:var(--cjk);font-weight:200;
  font-size:clamp(56px,7vw,108px);line-height:1.15;letter-spacing:.04em;
  color:var(--ink);
}
h1.hero-cn b{color:var(--vermillion);font-weight:400}
h2.section{
  font-family:var(--cjk);font-weight:300;
  font-size:clamp(40px,5.5vw,76px);line-height:1.1;letter-spacing:.04em;
  color:var(--ink);
}
h2.section b{color:var(--vermillion);font-weight:400}
h2.section em{font-family:var(--display);font-style:italic;font-weight:400;letter-spacing:-.02em;color:var(--vermillion)}
.lead{
  font-family:var(--display);font-style:italic;font-weight:400;
  font-size:clamp(18px,1.5vw,22px);line-height:1.5;color:var(--ink-2);
  letter-spacing:-.005em;
}
.cn-body{font-family:var(--cjk);font-weight:300;font-size:15px;color:var(--ink-2);line-height:1.85;letter-spacing:.04em}

/* ===== STAMP ===== */
.stamp-square{
  background:var(--vermillion);color:var(--paper-bright);
  display:inline-flex;align-items:center;justify-content:center;
  font-family:var(--cjk);font-weight:500;
  position:relative;letter-spacing:.04em;line-height:1;
  box-shadow:0 4px 10px rgba(194,53,49,.30);
}
.stamp-square::before{
  content:'';position:absolute;inset:4px;
  border:1px solid rgba(255,255,255,.35);
}

/* ===== BUTTONS — primary (vermillion) reserved for the most important action only ===== */
.btn{
  display:inline-flex;align-items:center;gap:10px;
  background:var(--vermillion);color:var(--paper-bright);border:1px solid var(--vermillion);
  padding:14px 36px;font-family:var(--cjk);font-weight:500;font-size:13px;
  letter-spacing:.18em;cursor:pointer;
  transition:all .3s;min-height:44px;
  box-shadow:0 4px 12px rgba(194,53,49,.30);
  text-decoration:none;
}
.btn:hover{background:var(--vermillion-deep);border-color:var(--vermillion-deep);transform:translateY(-2px);box-shadow:0 8px 20px rgba(194,53,49,.40)}
.btn:disabled{opacity:.5;cursor:not-allowed;transform:none}

/* secondary actions — outlined, no shadow, neutral ink */
.btn-outline{
  background:transparent;color:var(--ink);border:1px solid var(--ink);
  box-shadow:none;
}
.btn-outline:hover{background:var(--ink);color:var(--paper);transform:translateY(-2px);box-shadow:none}

/* tertiary — soft outlined, low emphasis */
.btn-soft{
  background:var(--paper-bright);color:var(--ink-2);border:1px solid var(--line);
  box-shadow:none;font-weight:400;
}
.btn-soft:hover{border-color:var(--ink-2);color:var(--ink);background:var(--paper-bright);transform:none;box-shadow:none}

/* link-style ghost button */
.btn-ghost{
  background:transparent;border:none;color:var(--ink-2);
  font-family:var(--display);font-style:italic;font-size:14px;
  padding:8px 14px;cursor:pointer;text-decoration:none;
}
.btn-ghost:hover{color:var(--vermillion)}

/* danger button */
.btn-danger{
  background:transparent;color:var(--vermillion);border:1px solid var(--vermillion-soft);
  box-shadow:none;
}
.btn-danger:hover{background:var(--vermillion);color:var(--paper-bright);border-color:var(--vermillion);box-shadow:none}

/* ===== ICON BUTTONS ===== */
.icon-btn{
  width:38px;height:38px;border-radius:50%;
  border:1px solid var(--line);background:var(--paper-bright);
  display:inline-flex;align-items:center;justify-content:center;
  cursor:pointer;color:var(--ink-2);transition:all .3s;
}
.icon-btn:hover{border-color:var(--ink);color:var(--ink)}
.icon-btn svg{width:15px;height:15px}

/* ===== TOAST ===== */
.toast{
  position:fixed;bottom:32px;left:50%;transform:translateX(-50%) translateY(20px);
  background:var(--ink);color:var(--paper-bright);
  padding:14px 24px;font-family:var(--cjk);font-size:13px;letter-spacing:.06em;
  z-index:200;opacity:0;pointer-events:none;
  transition:all .4s cubic-bezier(.22,1,.36,1);
  box-shadow:0 12px 36px -12px rgba(0,0,0,.30);
}
.toast.on{opacity:1;transform:translateX(-50%) translateY(0)}

/* ===== INK ILLUSTRATIONS (small SVGs) ===== */
.ink-bird,.ink-leaf{position:absolute;pointer-events:none}

@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.01ms !important;transition-duration:.01ms !important}
}