:root{
  --paper:      #f7f1e6;
  --paper-deep: #efe6d4;
  --paper-lift: #fbf7ee;
  --ink:        #2a2419;
  --ink-soft:   #6f6555;
  --ink-faint:  #a89b85;
  --rule:       #cdbfa5;
  --rule-soft:  #ded2ba;
  --brown:      #7a5c3e;
  --cinnabar:   #a8382f;
  --jade:       #4a6b52;
  --serif: Georgia, "Times New Roman", "Songti SC", "STSong", "SimSun", serif;
  --shadow-plate:
    0 0 0 7px var(--paper-lift),
    0 0 0 8px var(--rule-soft),
    0 26px 60px rgba(72,56,34,.18);
}

*{ box-sizing: border-box; }
html, body{ height: 100%; }

body{
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* 纸张肌理 + 暗角 */
.grain{
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)' opacity='1'/%3E%3C/svg%3E");
  opacity: .16; mix-blend-mode: multiply;
}
.vignette{
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background: radial-gradient(130% 95% at 46% 38%, rgba(255,252,244,0) 52%, rgba(94,74,48,.14) 100%);
}

/* 顶部导航条 */
.topbar{
  position: relative; z-index: 2;
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 40px;
  border-bottom: 1px solid var(--rule-soft);
}
.brand{
  font-size: 15px; letter-spacing: .28em; color: var(--ink);
  text-decoration: none;
}
.brand .dot{ color: var(--cinnabar); }
.nav{ display: flex; align-items: center; gap: 28px; }
.nav a{
  font-size: 13px; letter-spacing: .16em; color: var(--ink-soft);
  text-decoration: none; padding-bottom: 3px;
  border-bottom: 1px solid transparent;
  transition: color .2s ease, border-color .2s ease;
}
.nav a:hover{ color: var(--ink); }
.nav a.active{ color: var(--cinnabar); border-bottom-color: var(--cinnabar); }

.eyebrow{
  margin: 0 0 18px; font-size: 11px; letter-spacing: .32em; text-transform: uppercase;
  color: var(--ink-faint);
}
h1{ margin: 0 0 10px; font-size: 30px; font-weight: 400; letter-spacing: .12em; }
.lede{
  margin: 0 0 40px; font-size: 14px; line-height: 1.9; color: var(--ink-soft);
  padding-left: 14px; border-left: 2px solid var(--rule);
}

.field label{
  display: block; margin-bottom: 10px;
  font-size: 12px; letter-spacing: .22em; color: var(--brown);
}
.field input, .field textarea{
  width: 100%;
  padding: 12px 2px 11px;
  font-family: var(--serif); font-size: 21px; color: var(--ink);
  background: transparent; border: 0; border-bottom: 1px solid var(--rule);
  border-radius: 0; outline: none; transition: border-color .25s ease;
}
.field select{
  width: 100%;
  padding: 12px 2px 11px;
  font-family: var(--serif); font-size: 21px; color: var(--ink);
  background: transparent; border: 0; border-bottom: 1px solid var(--rule);
  border-radius: 0; outline: none; cursor: pointer;
  appearance: none; -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' fill='none' stroke='%237a5c3e' stroke-width='1.5'/%3E%3C/svg%3E");
  background-repeat: no-repeat; background-position: right 4px center;
  transition: border-color .25s ease;
}
.field select:focus{ border-bottom-color: var(--ink); }
.field textarea{ font-size: 15px; resize: vertical; min-height: 44px; line-height: 1.6; }
.field input::placeholder, .field textarea::placeholder{ color: var(--ink-faint); font-size: 17px; }
.field input:focus, .field textarea:focus{ border-bottom-color: var(--ink); }
.field input.is-error, .field textarea.is-error{ border-bottom-color: var(--cinnabar); }

.hint{
  margin: 8px 0 0; min-height: 17px;
  font-size: 12.5px; letter-spacing: .04em; color: var(--cinnabar);
  opacity: 0; transition: opacity .2s ease;
}
.hint.on{ opacity: 1; }

.btn{
  font-family: var(--serif); cursor: pointer; border-radius: 0;
  letter-spacing: .4em; text-indent: .4em;
  transition: background .25s ease, color .25s ease, letter-spacing .25s ease, border-color .25s ease;
}
.btn-solid{
  width: 100%; padding: 15px 20px; font-size: 16px;
  color: var(--paper-lift); background: var(--ink); border: 1px solid var(--ink);
}
.btn-solid:hover{ background: var(--brown); border-color: var(--brown); letter-spacing: .52em; text-indent: .52em; }
.btn-solid:disabled{ opacity: .55; cursor: progress; }
.btn-ghost{
  padding: 12px 18px; font-size: 13px;
  color: var(--ink); background: transparent; border: 1px solid var(--rule);
  letter-spacing: .2em; text-indent: .2em;
}
.btn-ghost:hover{ border-color: var(--brown); background: var(--paper-deep); }
.btn-danger{ color: var(--cinnabar); border-color: rgba(168,56,47,.4); }
.btn-danger:hover{ background: rgba(168,56,47,.08); border-color: var(--cinnabar); }

@media (max-width: 900px){
  .topbar{ padding: 16px 22px; }
  .nav{ gap: 18px; }
}