:root {
  --bg1: #6c5ce7;
  --bg2: #8e44ad;
  --card: #16181b;
  --accent: #ff4d4d;
  --muted: #97a0ad;
}
* { box-sizing: border-box; font-family: 'Segoe UI', Roboto, Arial; }
body, html { height: 100%; margin: 0; }
.page-bg {
  min-height: 100vh;
  background: linear-gradient(135deg, var(--bg1), #7b61ff 40%, #8f64c6);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.card {
  width: 100%;
  max-width: 480px;
  background: linear-gradient(180deg, rgba(20,20,22,0.98), rgba(10,10,12,0.98));
  border-radius: 16px;
  padding: 24px;
  box-shadow: 0 20px 40px rgba(13,12,20,0.45);
  color: #fff;
  text-align: center;
}
.card h1 {
  margin: 0 0 18px;
  font-size: 22px;
  font-weight: 700;
}
.note {
  background: rgba(51,102,153,0.14);
  color: #bfe0ff;
  padding: 14px;
  border-radius: 10px;
  margin: 8px 0 20px;
  font-size: 13px;
  line-height: 1.4;
  text-transform: uppercase;
}
.label { display:block; text-align:left; margin: 12px 0 6px; font-size: 12px; color: var(--muted); }
input#email {
  width: 100%;
  padding: 14px 16px;
  border-radius: 10px;
  border: 1px solid rgba(255,255,255,0.06);
  background: rgba(255,255,255,0.02);
  color: #fff;
  font-size: 15px;
  outline: none;
  margin-bottom: 14px;
}
.btn {
  width: 100%;
  padding: 14px;
  background: linear-gradient(180deg, #ff6b6b, var(--accent));
  border: none;
  border-radius: 12px;
  color: #fff;
  font-weight: 700;
  letter-spacing: 1px;
  cursor: pointer;
  font-size: 15px;
  box-shadow: 0 12px 22px rgba(255,77,77,0.16), inset 0 -6px 16px rgba(0,0,0,0.25);
}
.result {
  margin-top: 18px;
  text-align: left;
  background: rgba(255,255,255,0.03);
  padding: 12px;
  border-radius: 10px;
  min-height: 48px;
  color: #e5eefc;
  font-size: 14px;
}
.result .value { font-weight:700; word-break: break-all; }
.result .hint { color: #9fb0c8; font-size: 13px; margin-top:6px; display:block; }

/* card cho từng email */
.mail-card {
  background: rgba(255,255,255,0.05);
  border-radius: 10px;
  padding: 12px;
  margin: 10px 0;
}
.mail-card b { color: #fff; }
.mail-card .meta { color: var(--muted); font-size: 13px; margin-bottom: 6px; }
.mail-card details summary {
  cursor: pointer;
  color: var(--accent);
  margin-top: 8px;
}
.mail-card details[open] summary { color: #ff8888; }
.mail-body { margin-top: 8px; }
.mail-iframe {
  width: 100%;
  height: 320px;
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 8px;
  background: #fff;
}

/* responsive */
@media (max-width: 480px) {
  .card {
    padding: 20px;
  }
  .card h1 {
    font-size: 20px;
  }
  .btn {
    font-size: 14px;
    padding: 12px;
  }
  input#email {
    font-size: 14px;
  }
}
.mail-iframe { width: 100%; border: none; display: block; }