:root {
  --bg: #0e1116;
  --bg-elev: #161b22;
  --bg-list: #10141a;
  --panel: #0b0e13;
  --border: #232a34;
  --border-soft: #1a2029;
  --text: #e6edf3;
  --text-dim: #9aa7b4;
  --text-faint: #6b7787;
  --accent: #f5a524;
  --accent-soft: rgba(245, 165, 36, 0.14);
  --accent-line: rgba(245, 165, 36, 0.5);
  --hover: #1a212b;
  --sel: #1d2530;
  --danger: #f0616d;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.35);
  --radius: 12px;
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
  margin: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  font-size: 14px;
}

.app {
  display: grid;
  grid-template-rows: auto 1fr;
  height: 100vh;
}

/* ── Top bar ─────────────────────────────────────────────── */
.topbar {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px 18px;
  background: linear-gradient(180deg, var(--bg-elev), var(--bg));
  border-bottom: 1px solid var(--border);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  letter-spacing: 0.2px;
  white-space: nowrap;
}

.brand .logo {
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  background: var(--accent-soft);
  border: 1px solid var(--accent-line);
  border-radius: 9px;
  font-size: 17px;
}

.brand .sub {
  color: var(--text-faint);
  font-weight: 500;
  font-size: 12px;
}

.search {
  flex: 1;
  max-width: 420px;
  margin-left: 8px;
}

.search input {
  width: 100%;
  padding: 8px 12px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-size: 13px;
  outline: none;
}

.search input:focus { border-color: var(--accent-line); }

.spacer { flex: 1; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 12px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-dim);
  font-size: 13px;
  cursor: pointer;
  transition: all 0.12s ease;
}

.btn:hover { border-color: var(--accent-line); color: var(--text); }
.btn:active { transform: translateY(1px); }

.badge {
  padding: 2px 8px;
  font-size: 11px;
  border-radius: 20px;
  border: 1px solid var(--border);
  color: var(--text-faint);
}
.badge.demo { color: var(--accent); border-color: var(--accent-line); background: var(--accent-soft); }

/* ── Main split ──────────────────────────────────────────── */
.main {
  display: grid;
  grid-template-columns: minmax(300px, 380px) 1fr;
  overflow: hidden;
}

.list {
  background: var(--bg-list);
  border-right: 1px solid var(--border);
  overflow-y: auto;
}

.list-head {
  position: sticky;
  top: 0;
  z-index: 2;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding: 12px 16px 10px;
  background: var(--bg-list);
  border-bottom: 1px solid var(--border-soft);
}
.list-head h2 { margin: 0; font-size: 13px; text-transform: uppercase; letter-spacing: 0.8px; color: var(--text-dim); }
.list-head .count { font-size: 12px; color: var(--text-faint); }

.row {
  display: block;
  width: 100%;
  text-align: left;
  padding: 12px 16px;
  border: none;
  border-bottom: 1px solid var(--border-soft);
  border-left: 3px solid transparent;
  background: transparent;
  color: inherit;
  cursor: pointer;
  font: inherit;
}
.row:hover { background: var(--hover); }
.row.active { background: var(--sel); border-left-color: var(--accent); }

.row .r1 { display: flex; justify-content: space-between; gap: 10px; align-items: baseline; }
.row .r-key {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 12px;
  color: var(--text);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.row.opened .r-key { color: var(--text-dim); }
.row .r-date { font-size: 11px; color: var(--text-faint); white-space: nowrap; }
.row .r2 { margin-top: 5px; display: flex; gap: 8px; align-items: center; }
.row .r-meta { font-size: 11px; color: var(--text-faint); }
.row .tag {
  font-size: 10px;
  padding: 1px 6px;
  border-radius: 4px;
  border: 1px solid var(--border);
  color: var(--text-faint);
}
.row.opened .tag.cached { color: var(--accent); border-color: var(--accent-line); background: var(--accent-soft); }
.row .r-preview { margin-top: 5px; font-size: 12px; color: var(--text-dim); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* ── Reading pane ────────────────────────────────────────── */
.reader { overflow-y: auto; background: var(--bg); position: relative; }

.reader-inner { max-width: 860px; margin: 0 auto; padding: 26px 30px 60px; }

.msg-head { border-bottom: 1px solid var(--border); padding-bottom: 18px; margin-bottom: 6px; }
.msg-subject { font-size: 21px; font-weight: 700; margin: 0 0 14px; line-height: 1.3; }

.msg-from { display: flex; align-items: center; gap: 12px; }
.avatar {
  width: 42px; height: 42px; border-radius: 50%;
  display: grid; place-items: center;
  font-weight: 700; font-size: 17px; color: #12161c;
  background: var(--accent);
  flex: 0 0 auto;
}
.msg-from .who { min-width: 0; }
.msg-from .name { font-weight: 600; }
.msg-from .addr { font-size: 12px; color: var(--text-faint); }
.msg-from .when { margin-left: auto; font-size: 12px; color: var(--text-faint); white-space: nowrap; text-align: right; }
.msg-to { margin-top: 8px; font-size: 12px; color: var(--text-faint); }

.msg-toolbar {
  display: flex; align-items: center; gap: 8px;
  margin: 16px 0 10px;
}
.msg-toolbar .note { font-size: 12px; color: var(--text-faint); margin-left: auto; }

.msg-body { margin-top: 10px; }
.msg-frame { width: 100%; border: none; background: #fff; border-radius: var(--radius); min-height: 200px; }
pre.msg-text {
  white-space: pre-wrap;
  word-break: break-word;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 13px;
  line-height: 1.6;
  color: var(--text);
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  margin: 0;
}

/* ── States ──────────────────────────────────────────────── */
.center-state {
  height: 100%;
  display: grid;
  place-items: center;
  text-align: center;
  color: var(--text-faint);
  padding: 40px;
}
.center-state .big { font-size: 46px; margin-bottom: 12px; opacity: 0.7; }
.center-state h3 { color: var(--text-dim); margin: 0 0 6px; font-weight: 600; }
.center-state p { margin: 4px 0; max-width: 460px; line-height: 1.5; font-size: 13px; }
.center-state code { background: var(--panel); padding: 2px 6px; border-radius: 5px; border: 1px solid var(--border); font-size: 12px; }
.center-state.error h3 { color: var(--danger); }

.spinner {
  width: 26px; height: 26px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto 14px;
}
@keyframes spin { to { transform: rotate(360deg); } }

.list-msg { padding: 24px 16px; text-align: center; color: var(--text-faint); font-size: 13px; line-height: 1.5; }

/* ── Light mode ──────────────────────────────────────────── */
@media (prefers-color-scheme: light) {
  :root {
    --bg: #f6f8fa; --bg-elev: #ffffff; --bg-list: #ffffff; --panel: #ffffff;
    --border: #d8dee4; --border-soft: #eaeef2; --text: #1f2328; --text-dim: #57606a;
    --text-faint: #8a93a0; --hover: #f3f5f8; --sel: #fff5e6; --shadow: 0 8px 30px rgba(140,149,159,0.2);
  }
  .avatar { color: #fff; }
}

/* ── Lock screen ─────────────────────────────────────────── */
.lock-overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: grid;
  place-items: center;
  padding: 24px;
  background: radial-gradient(1200px 600px at 50% -10%, rgba(245,165,36,0.08), transparent), var(--bg);
  transition: opacity 0.25s ease;
}
.lock-overlay.unlocked { opacity: 0; pointer-events: none; }
.lock-card {
  width: 100%;
  max-width: 360px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow);
  padding: 30px 28px;
  text-align: center;
}
.lock-card .lock-logo {
  width: 54px; height: 54px; margin: 0 auto 16px;
  display: grid; place-items: center; font-size: 26px;
  background: var(--accent-soft); border: 1px solid var(--accent-line); border-radius: 14px;
}
.lock-card h1 { font-size: 18px; margin: 0 0 4px; }
.lock-card p { font-size: 13px; color: var(--text-faint); margin: 0 0 20px; }
.lock-card input {
  width: 100%; padding: 11px 13px; text-align: center;
  background: var(--panel); border: 1px solid var(--border);
  border-radius: 9px; color: var(--text); font-size: 15px; outline: none;
  letter-spacing: 1px;
}
.lock-card input:focus { border-color: var(--accent-line); }
.lock-card .lock-btn {
  width: 100%; justify-content: center; margin-top: 12px; padding: 11px;
  background: var(--accent); border: none; color: #12161c; font-weight: 700; font-size: 14px;
}
.lock-card .lock-btn:hover { filter: brightness(1.05); color: #12161c; }
.lock-card .lock-btn:disabled { opacity: 0.6; cursor: default; }
.lock-err { color: var(--danger); font-size: 12px; min-height: 15px; margin-top: 12px; }
.lock-card.shake { animation: shake 0.35s; }
@keyframes shake {
  0%,100% { transform: translateX(0); }
  20%,60% { transform: translateX(-7px); }
  40%,80% { transform: translateX(7px); }
}

@media (max-width: 720px) {
  .main { grid-template-columns: 1fr; }
  .reader { display: none; }
  .main.reading .list { display: none; }
  .main.reading .reader { display: block; }
  .main.reading #back { display: inline-flex !important; }
  .reader-inner { padding-top: 52px; }
}