* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: #f5f7fb;
  color: #222;
  line-height: 1.5;
}
a { color: #2563eb; text-decoration: none; }

.topbar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 24px;
  background: #1e293b; color: #fff;
  box-shadow: 0 2px 4px rgba(0,0,0,.1);
}
.logo { font-size: 18px; font-weight: 600; }
.nav a { color: #cbd5e1; margin-left: 16px; }
.nav a:hover { color: #fff; }
.user span { margin-right: 12px; }

.container { max-width: 1000px; margin: 24px auto; padding: 0 16px; }

.btn-primary, .btn-secondary, .btn-text {
  display: inline-block; padding: 8px 16px; border-radius: 6px;
  border: none; cursor: pointer; font-size: 14px;
}
.btn-primary { background: #2563eb; color: #fff; }
.btn-secondary { background: #e5e7eb; color: #374151; }
.btn-text { background: transparent; color: #cbd5e1; }

label { display: block; margin: 12px 0; font-size: 14px; color: #4b5563; }
input, textarea {
  display: block; width: 100%; padding: 8px 10px; margin-top: 4px;
  border: 1px solid #d1d5db; border-radius: 6px; font-size: 14px; font-family: inherit;
}
input:focus, textarea:focus { border-color: #2563eb; outline: none; }

.login-card { max-width: 360px; margin: 80px auto; background: #fff; padding: 32px; border-radius: 8px; box-shadow: 0 4px 12px rgba(0,0,0,.05); }
.login-card h1 { margin-bottom: 16px; }

.error { background: #fee2e2; color: #b91c1c; padding: 10px 14px; border-radius: 6px; margin: 12px 0; }
.hint { background: #dbeafe; color: #1e40af; padding: 8px 12px; border-radius: 6px; margin: 8px 0; font-size: 13px; }
code { background: #1e293b; color: #fbbf24; padding: 2px 6px; border-radius: 4px; font-size: 13px; }
.empty { text-align: center; color: #9ca3af; padding: 48px 0; font-size: 16px; }

.mail-list { list-style: none; }
.mail-item { background: #fff; border-radius: 8px; margin-bottom: 8px; border: 1px solid #e5e7eb; transition: all .15s; }
.mail-item:hover { border-color: #2563eb; }
.mail-item a { display: block; padding: 12px 16px; color: inherit; }
.mail-item.unseen { border-left: 4px solid #2563eb; background: #eff6ff; }
.row1 { display: flex; justify-content: space-between; font-size: 14px; }
.from { font-weight: 600; }
.date { color: #6b7280; font-size: 12px; }
.subject { font-size: 14px; margin-top: 4px; }
.to { font-size: 12px; color: #9ca3af; margin-top: 4px; }

.read-head { background: #fff; padding: 16px; border-radius: 8px; margin-bottom: 16px; }
.read-head h1 { font-size: 20px; margin-bottom: 12px; }
.meta div { font-size: 14px; color: #4b5563; margin: 4px 0; }
.meta strong { color: #1f2937; }
.attachment { display: inline-block; background: #f3f4f6; padding: 2px 8px; border-radius: 4px; margin-right: 6px; font-size: 12px; }
.read-body { background: #fff; padding: 16px; border-radius: 8px; min-height: 200px; }
.html-frame { width: 100%; min-height: 400px; border: none; background: #fff; }
.text-body { white-space: pre-wrap; font-family: inherit; font-size: 14px; }
.read-actions { margin-top: 16px; display: flex; gap: 8px; }

.compose form { background: #fff; padding: 24px; border-radius: 8px; }
.compose-actions { margin-top: 16px; }