:root {
  --bg: #f1f4f8;
  --card: #ffffff;
  --text: #1b2230;
  --muted: #6b7686;
  --border: #e3e8ef;
  --accent: #14b8a6;
  --accent-strong: #0d9488;
  --accent-text: #ffffff;
  --danger: #e11d48;
  --unread: #effcfa;
  --hero: #1e2533;
  --hero-2: #283143;
  --hero-text: #e9eef5;
  --hero-muted: #9aa6b8;
  --hero-field: #141a25;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(16, 24, 40, .04), 0 4px 16px rgba(16, 24, 40, .06);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #11151d;
    --card: #181e29;
    --text: #e6eaf0;
    --muted: #94a0b2;
    --border: #273042;
    --accent: #2dd4bf;
    --accent-strong: #14b8a6;
    --accent-text: #08201d;
    --unread: #142a2b;
    --hero: #171c27;
    --hero-2: #1f2635;
    --hero-field: #0e121a;
    --shadow: none;
  }
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
button { font: inherit; cursor: pointer; }
svg { width: 20px; height: 20px; flex: none; }
.hidden { display: none !important; }

/* ---------- header ---------- */
.top { background: var(--hero); color: var(--hero-text); border-bottom: 1px solid rgba(255, 255, 255, .06); }
.top-inner { max-width: 1040px; margin: 0 auto; padding: 14px 16px; display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.brand { display: flex; align-items: center; gap: 8px; color: inherit; text-decoration: none; font-size: 19px; font-weight: 600; letter-spacing: -.01em; }
.brand svg { width: 26px; height: 26px; color: var(--accent); }
.brand b { color: var(--accent); font-weight: 700; }
.status { font-size: 13px; color: var(--hero-muted); display: inline-flex; align-items: center; gap: 6px; }
.status::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: #f59e0b; }
.status.live { color: var(--hero-text); }
.status.live::before { background: #22c55e; box-shadow: 0 0 0 3px rgba(34, 197, 94, .25); }

/* ---------- hero ---------- */
.hero { background: linear-gradient(180deg, var(--hero) 0%, var(--hero-2) 100%); color: var(--hero-text); }
.hero-inner { max-width: 760px; margin: 0 auto; padding: 36px 16px 32px; text-align: center; }
.hero-title { margin: 0 0 6px; font-size: 26px; line-height: 1.25; font-weight: 700; letter-spacing: -.015em; color: #fff; }
.label { margin: 0 0 12px; color: var(--hero-muted); font-size: 13px; text-transform: uppercase; letter-spacing: .08em; }
.address-box {
  display: flex; align-items: stretch; max-width: 560px; margin: 0 auto;
  background: var(--hero-field); border: 1.5px dashed rgba(45, 212, 191, .55); border-radius: 999px; overflow: hidden;
}
.address {
  flex: 1; min-width: 0; padding: 14px 22px; font: 600 20px/1.4 ui-monospace, "SF Mono", Menlo, monospace;
  color: #fff; text-align: center; overflow-wrap: anywhere; user-select: all;
}
.copy-btn {
  border: 0; background: var(--accent); color: var(--accent-text); padding: 0 22px;
  display: grid; place-items: center; transition: background .15s;
}
.copy-btn:hover { background: var(--accent-strong); }
.hero-sub { margin: 14px 0 0; color: var(--hero-muted); font-size: 14px; }
.hero-sub strong { color: var(--hero-text); font-variant-numeric: tabular-nums; }
#countdown.warn { color: #fb7185; }
.hero-note { margin: 10px auto 0; max-width: 520px; color: var(--hero-muted); font-size: 13px; }

.actions { display: flex; justify-content: center; flex-wrap: wrap; gap: 10px; margin-top: 24px; }
.action {
  display: inline-flex; align-items: center; gap: 8px; padding: 10px 18px; border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, .1); background: rgba(255, 255, 255, .06); color: var(--hero-text);
  transition: background .15s, border-color .15s;
}
.action svg { width: 18px; height: 18px; }
.action:hover, .action[aria-expanded="true"] { background: rgba(255, 255, 255, .12); border-color: rgba(255, 255, 255, .2); }
.action.danger:hover { background: rgba(225, 29, 72, .18); border-color: rgba(225, 29, 72, .45); color: #fecdd3; }
.action.spin svg { animation: spin .6s linear; }
@keyframes spin { to { transform: rotate(360deg); } }

.panel {
  margin: 18px auto 0; max-width: 560px; padding: 14px; border-radius: var(--radius);
  background: rgba(0, 0, 0, .18); border: 1px solid rgba(255, 255, 255, .08); text-align: left;
}
.new-form { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.new-form input, .new-form select {
  padding: 9px 12px; border-radius: 10px; border: 1px solid rgba(255, 255, 255, .12);
  background: var(--hero-field); color: var(--hero-text); font: inherit;
}
.new-form input { flex: 1 1 180px; min-width: 0; }
.new-form input:focus, .new-form select:focus { outline: 2px solid var(--accent); outline-offset: -1px; }
.at { color: var(--hero-muted); }
.history { margin-top: 10px; display: flex; flex-wrap: wrap; gap: 6px; }
.history:empty { display: none; }
.history::before { content: "Recent:"; color: var(--hero-muted); font-size: 13px; padding: 3px 2px; }
.history button {
  border: 1px solid rgba(255, 255, 255, .12); background: transparent; color: var(--hero-text);
  border-radius: 999px; padding: 3px 12px; font-size: 13px;
}
.history button:hover { border-color: var(--accent); }

/* ---------- buttons ---------- */
.btn {
  border: 1px solid var(--border); background: var(--card); color: var(--text);
  padding: 9px 16px; border-radius: 10px;
}
.btn:hover { border-color: var(--muted); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-text); font-weight: 600; }
.btn.primary:hover { background: var(--accent-strong); }
.btn.small { padding: 5px 12px; font-size: 13px; }
.btn.danger { color: var(--danger); }
.btn.ghost { border-color: transparent; background: none; padding-left: 4px; color: var(--muted); }
.btn.ghost:hover { color: var(--text); }

/* ---------- main ---------- */
.wrap { flex: 1; width: 100%; max-width: 1040px; margin: -1px auto 0; padding: 24px 16px 32px; display: grid; gap: 16px; align-content: start; }
.card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); }

.list { overflow: hidden; }
.list-head, #messages li { display: grid; grid-template-columns: minmax(0, 240px) minmax(0, 1fr) 64px; gap: 16px; align-items: center; }
.list-head {
  padding: 12px 20px; background: var(--bg); border-bottom: 1px solid var(--border);
  color: var(--muted); font-size: 12px; font-weight: 600; text-transform: uppercase; letter-spacing: .06em;
}
.col-view { text-align: right; }
#messages { list-style: none; margin: 0; padding: 0; }
#messages li { padding: 14px 20px; border-bottom: 1px solid var(--border); cursor: pointer; transition: background .12s; }
#messages li:last-child { border-bottom: 0; }
#messages li:hover { background: var(--bg); }
#messages li.unread { background: var(--unread); box-shadow: inset 3px 0 0 var(--accent); }
#messages li.unread .subj, #messages li.unread .name { font-weight: 700; }
.sender { display: flex; align-items: center; gap: 12px; min-width: 0; }
.sender-text { min-width: 0; }
.name, .addr, .subj, .prev { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.name { font-weight: 500; }
.addr, .prev, .time { font-size: 13px; color: var(--muted); }
.subj-line { display: flex; align-items: center; gap: 8px; min-width: 0; }
.subj { min-width: 0; }
.view { display: flex; flex-direction: column; align-items: flex-end; gap: 2px; }
.view svg { width: 18px; height: 18px; color: var(--muted); }
#messages li:hover .view svg { color: var(--accent); }

.avatar {
  width: 38px; height: 38px; border-radius: 50%; flex: none; display: grid; place-items: center;
  color: #fff; font-weight: 600; font-size: 15px; text-transform: uppercase; background: var(--accent);
}

.empty { padding: 56px 16px; color: var(--muted); text-align: center; }
.empty p { margin: 0; }
.empty-title { color: var(--text); font-weight: 600; font-size: 17px; margin-bottom: 4px !important; }
.empty-icon { position: relative; width: 72px; height: 72px; margin: 0 auto 16px; color: var(--accent); display: grid; place-items: center; }
.empty-icon svg { width: 56px; height: 56px; position: relative; }
.pulse { position: absolute; inset: 0; border-radius: 50%; background: var(--accent); opacity: .12; animation: pulse 2s ease-out infinite; }
@keyframes pulse { 0% { transform: scale(.7); opacity: .25; } 100% { transform: scale(1.35); opacity: 0; } }

.otp {
  display: inline-block; flex: none; padding: 1px 8px; border-radius: 6px; cursor: pointer;
  font: 600 13px ui-monospace, monospace; letter-spacing: .08em;
  background: var(--unread); border: 1px solid var(--accent); color: var(--accent-strong);
}
.otp:hover { background: var(--accent); color: var(--accent-text); }
.otp.big { font-size: 20px; padding: 4px 14px; border-radius: 8px; }

/* ---------- viewer ---------- */
.placeholder { display: none; }
.mail.reading .list { display: none; }
.viewer { display: flex; flex-direction: column; min-width: 0; padding: 12px 20px 20px; }
.viewer-bar { display: flex; justify-content: space-between; align-items: center; gap: 8px; flex-wrap: wrap; padding-bottom: 12px; border-bottom: 1px solid var(--border); }
.viewer-actions { display: flex; gap: 6px; align-items: center; flex-wrap: wrap; }
.viewer-head { display: flex; gap: 14px; align-items: flex-start; margin-top: 16px; }
.viewer-head .avatar { width: 44px; height: 44px; font-size: 17px; }
.viewer-meta { min-width: 0; }
.viewer-meta h3 { margin: 0 0 2px; font-size: 19px; overflow-wrap: anywhere; }
.meta { color: var(--muted); font-size: 13px; margin: 0; overflow-wrap: anywhere; }
.otp-row { margin: 14px 0 0; color: var(--muted); font-size: 14px; display: flex; align-items: center; gap: 8px; }
.otp-row:empty { display: none; }
.tab { border: 1px solid var(--border); background: none; color: var(--muted); padding: 5px 12px; border-radius: 8px; font-size: 13px; }
.tab.active { color: var(--text); border-color: var(--text); }
#v-frame { flex: 1; width: 100%; min-height: 480px; margin-top: 16px; border: 1px solid var(--border); border-radius: 10px; background: #fff; }
.textbody { flex: 1; white-space: pre-wrap; overflow-wrap: anywhere; margin: 16px 0 0; padding: 14px; background: var(--bg); border-radius: 10px; font-size: 14px; }
.attachments { list-style: none; padding: 0; margin: 14px 0 0; display: flex; flex-wrap: wrap; gap: 8px; }
.attachments:empty { display: none; }
.attachments a { display: inline-block; padding: 7px 12px; border: 1px solid var(--border); border-radius: 10px; color: var(--text); text-decoration: none; font-size: 13px; }
.attachments a:hover { border-color: var(--accent); }

/* ---------- nội dung SEO + trang tĩnh ---------- */
.content { padding: 8px 4px 0; max-width: 820px; width: 100%; justify-self: center; }
.content h2 { font-size: 22px; letter-spacing: -.01em; margin: 32px 0 10px; }
.content h2:first-child { margin-top: 8px; }
.content h3 { font-size: 15px; margin: 0 0 4px; }
.content p, .content li { color: var(--muted); }
.content p { margin: 0 0 10px; }
.content strong { color: var(--text); }
.steps { padding-left: 22px; margin: 0; display: grid; gap: 8px; }
.uses { padding-left: 20px; margin: 0; display: grid; gap: 4px; }
.features { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 12px; }
.features > div { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px 16px; }
.features p { margin: 0; font-size: 14px; }
.faq { display: grid; gap: 8px; }
.faq details { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 12px 16px; }
.faq summary { cursor: pointer; font-weight: 600; }
.faq details p { margin: 8px 0 0; }

.doc { padding: 24px 28px; max-width: 820px; width: 100%; justify-self: center; }
.doc h1 { font-size: 26px; margin: 0 0 4px; }
.doc h2 { font-size: 18px; margin: 24px 0 8px; }
.doc p, .doc li { color: var(--muted); }
.doc a, .foot a { color: var(--accent-strong); }

.foot { text-align: center; color: var(--muted); font-size: 12px; padding: 8px 16px 24px; }
.foot nav { font-size: 13px; margin-bottom: 4px; }
.foot p { margin: 0; }

.toast {
  position: fixed; left: 50%; bottom: 24px; transform: translateX(-50%) translateY(20px);
  background: var(--text); color: var(--bg); padding: 10px 16px; border-radius: 10px;
  opacity: 0; transition: .2s; pointer-events: none; max-width: calc(100% - 32px); z-index: 10;
}
.toast.show { opacity: 1; transform: translateX(-50%); }

@media (max-width: 720px) {
  .hero-inner { padding: 24px 16px; }
  .hero-title { font-size: 20px; }
  .content h2 { font-size: 19px; }
  .doc { padding: 18px 16px; }
  .address { font-size: 16px; padding: 12px 16px; }
  .copy-btn { padding: 0 16px; }
  .action { padding: 9px 14px; }
  .action span { font-size: 14px; }
  .list-head { display: none; }
  #messages li { grid-template-columns: minmax(0, 1fr) auto; gap: 6px 12px; padding: 14px 16px; }
  #messages li .content { grid-column: 1 / -1; grid-row: 2; padding-left: 50px; }
  #messages li .view { grid-column: 2; grid-row: 1; }
  .viewer { padding: 10px 14px 16px; }
  #v-frame { min-height: 360px; }
}

/* ---------- language ---------- */
.top-right { display: flex; align-items: center; gap: 14px; }
.lang-select {
  padding: 5px 8px; border-radius: 8px; border: 1px solid rgba(255, 255, 255, .14);
  background: var(--hero-field); color: var(--hero-text); font: inherit; font-size: 13px; max-width: 140px;
}
.lang-select:focus { outline: 2px solid var(--accent); outline-offset: -1px; }
.foot .langs { margin: 6px auto 8px; max-width: 720px; line-height: 1.9; }
.foot .langs span { color: var(--text); font-weight: 600; }
@media (max-width: 560px) {
  .top-right { gap: 10px; min-width: 0; }
  .status { font-size: 0; gap: 0; } /* chỉ giữ chấm trạng thái */
  .lang-select { max-width: 120px; }
}