:root{--bg:#f5f6f8;--panel:#ffffff;--line:#e3e6ea;--text:#1c2530;--muted:#6b7684;--primary:#2563eb;--primary-dark:#1d4ed8;--danger:#dc2626;--unread:#eff6ff}*{box-sizing:border-box;margin:0;padding:0}body,html{height:100%}body{font-family:system-ui,-apple-system,Segoe UI,PingFang SC,Microsoft YaHei,sans-serif;background:var(--bg)}.btn,body{color:var(--text);font-size:14px}.btn{display:inline-block;padding:9px 16px;border-radius:8px;border:1px solid var(--line);background:#fff;cursor:pointer;text-decoration:none}.btn:hover{background:#f0f2f5}.btn-primary{background:var(--primary);border-color:var(--primary);color:#fff;font-weight:600}.btn-primary:hover{background:var(--primary-dark)}.btn-lg{padding:12px 20px;font-size:15px}.login-wrap{min-height:100vh;display:flex;align-items:center;justify-content:center}.login-card{width:380px;background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:36px;box-shadow:0 8px 30px rgba(20,30,50,.06)}.login-card h1{font-size:22px;margin-bottom:4px}.login-card .sub{color:var(--muted);font-size:13px;margin-bottom:24px}.field{margin-bottom:16px}.field label{display:block;font-size:13px;font-weight:600;margin-bottom:6px}.field input{width:100%;padding:10px 12px;border:1px solid var(--line);border-radius:8px;font-size:14px}.field input:focus{outline:2px solid #bfdbfe;border-color:var(--primary)}.app-shell{display:grid;grid-template-columns:220px 360px 1fr;height:100vh}.side{background:#101826;color:#cbd5e1;padding:18px 14px;display:flex;flex-direction:column;gap:4px}.side .logo{color:#fff;font-weight:700;font-size:17px;padding:6px 10px 18px}.side a{color:#cbd5e1;text-decoration:none;padding:9px 12px;border-radius:8px;font-size:13.5px}.side a.active,.side a:hover{background:rgba(255,255,255,.08);color:#fff}.side .spacer{flex:1 1}.side .whoami{font-size:12px;color:#94a3b8;padding:8px 12px;overflow:hidden;text-overflow:ellipsis}.list-pane{border-right:1px solid var(--line);overflow-y:auto}.list-head,.list-pane{background:var(--panel)}.list-head{padding:14px 16px;border-bottom:1px solid var(--line);display:flex;justify-content:space-between;align-items:center;position:-webkit-sticky;position:sticky;top:0;z-index:2}.list-head h2{font-size:15px}.mail-row{display:block;padding:12px 16px;border-bottom:1px solid var(--line);text-decoration:none;color:var(--text);cursor:pointer}.mail-row:hover{background:#f8fafc}.mail-row.active{border-right:3px solid var(--primary)}.mail-row.active,.mail-row.unread{background:var(--unread)}.mail-row.unread .subj{font-weight:700}.mail-row .top{display:flex;justify-content:space-between;gap:8px;margin-bottom:3px}.mail-row .from{font-size:13px;color:var(--text);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.mail-row .time{font-size:12px;color:var(--muted);white-space:nowrap}.mail-row .subj{font-size:13.5px;margin-bottom:2px}.mail-row .prev,.mail-row .subj{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.mail-row .prev{font-size:12.5px;color:var(--muted)}.read-pane{overflow-y:auto;background:var(--bg)}.read-head{padding:20px 28px;background:var(--panel);border-bottom:1px solid var(--line)}.read-head h2{font-size:17px;margin-bottom:10px}.read-meta{font-size:13px;color:var(--muted);display:grid;grid-gap:3px;gap:3px}.read-meta b{color:var(--text);font-weight:600}.read-body{padding:24px 28px;white-space:pre-wrap;word-break:break-word;font-size:14px;line-height:1.7}.read-actions{display:flex;gap:8px;margin-top:14px}.empty{display:flex;height:100%;align-items:center;justify-content:center;color:var(--muted)}.compose-card{margin:20px 28px;background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:20px}.compose-card h3{font-size:15px;margin-bottom:14px}.compose-card textarea{min-height:200px;font-family:inherit;resize:vertical}.compose-card input,.compose-card textarea{width:100%;padding:10px 12px;border:1px solid var(--line);border-radius:8px;font-size:14px}.err{background:#fef2f2;color:var(--danger);margin-bottom:12px}.err,.ok-note{padding:10px 12px;border-radius:8px;font-size:13px}.ok-note{background:#f0fdf4;color:#15803d;margin:0 28px 14px}