:root {
    color-scheme: light;
    --ink: #17212b;
    --muted: #647180;
    --line: #dbe3ea;
    --soft: #f4f7f9;
    --accent: #287f87;
    --accent-dark: #1f656c;
    --danger: #a52a2a;
    --success: #e8f7ef;
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
* { box-sizing: border-box; }
body { margin: 0; background: #eef3f5; color: var(--ink); }
a { color: var(--accent-dark); }
.shell { width: min(100% - 32px, 980px); margin: 42px auto 80px; }
.shell.narrow { max-width: 760px; }
.login-shell { max-width: 480px; margin-top: 14vh; }
.topbar { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 16px max(18px, calc((100vw - 980px) / 2)); background: #fff; border-bottom: 1px solid var(--line); }
.topbar strong, .topbar span { display: block; }
.topbar span { color: var(--muted); font-size: 13px; margin-top: 2px; }
.topbar nav { display: flex; gap: 16px; flex-wrap: wrap; }
.topbar nav a { text-decoration: none; font-weight: 650; }
.page-header { margin-bottom: 24px; }
.page-header h1 { margin: 4px 0 8px; font-size: clamp(30px, 6vw, 46px); letter-spacing: -0.035em; }
.page-header p { max-width: 68ch; color: var(--muted); line-height: 1.55; }
.eyebrow { color: var(--accent-dark); font-size: 12px; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
.card { background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 24px; box-shadow: 0 12px 40px rgba(26, 48, 63, .06); }
.grid { display: grid; gap: 18px; }
.grid.two { grid-template-columns: repeat(2, minmax(0, 1fr)); }
label { display: grid; gap: 7px; margin-bottom: 18px; font-weight: 700; font-size: 14px; }
input, select, textarea, button { font: inherit; }
input, select, textarea { width: 100%; border: 1px solid #bbc8d1; border-radius: 9px; padding: 11px 12px; background: #fff; color: var(--ink); }
textarea { resize: vertical; line-height: 1.5; }
input:focus, select:focus, textarea:focus { outline: 3px solid rgba(40, 127, 135, .18); border-color: var(--accent); }
button, .button { display: inline-block; border: 0; border-radius: 9px; padding: 11px 16px; background: var(--accent); color: #fff; font-weight: 750; text-decoration: none; cursor: pointer; }
button:hover, .button:hover { background: var(--accent-dark); }
button.danger { background: var(--danger); }
hr { border: 0; border-top: 1px solid var(--line); margin: 10px 0 22px; }
.hint { color: var(--muted); font-size: 13px; line-height: 1.45; }
.alert { border-radius: 10px; padding: 13px 15px; margin: 0 0 18px; }
.alert.error { background: #fff0f0; border: 1px solid #f0c3c3; color: #7d1d1d; }
.success { background: var(--success); border-color: #acd8be; }
.filters { display: grid; grid-template-columns: 220px 1fr auto; gap: 14px; align-items: end; }
.filters label { margin: 0; }
.mail-list { margin-top: 16px; display: grid; gap: 8px; }
.mail-row { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 16px 18px; background: #fff; border: 1px solid var(--line); border-radius: 11px; color: var(--ink); text-decoration: none; }
.mail-row:hover { border-color: #96b4ba; }
.mail-row strong, .mail-row span { display: block; }
.mail-row span, .mail-date { margin-top: 4px; color: var(--muted); font-size: 13px; }
.mail-date { white-space: nowrap; }
.empty { color: var(--muted); text-align: center; padding: 60px 20px; }
.message-meta { color: var(--muted); line-height: 1.6; border-bottom: 1px solid var(--line); padding-bottom: 16px; }
.message-body { white-space: pre-wrap; overflow-wrap: anywhere; font-family: inherit; line-height: 1.55; margin: 24px 0 0; }
.signature-preview { background: var(--soft); border-radius: 10px; padding: 14px; margin-bottom: 18px; }
.signature-preview pre, .signature-block { font-family: Arial, sans-serif; white-space: pre-wrap; margin: 10px 0 0; line-height: 1.35; }
.preview dl { display: grid; grid-template-columns: 90px 1fr; gap: 8px 16px; margin: 0; }
.preview dt { font-weight: 750; color: var(--muted); }
.preview dd { margin: 0; }
.preview-body { border-top: 1px solid var(--line); margin-top: 20px; padding-top: 20px; line-height: 1.55; }
.confirm-box { margin-top: 18px; padding: 18px; background: #fff5ea; border: 1px solid #f2c38d; border-radius: 12px; }
@media (max-width: 720px) {
    .grid.two, .filters { grid-template-columns: 1fr; }
    .topbar, .mail-row { align-items: flex-start; flex-direction: column; }
    .shell { margin-top: 24px; }
}