:root {
  color-scheme: dark;
  --bg: #071019;
  --panel: #0d1a26;
  --panel-2: #122536;
  --line: #20384a;
  --text: #edf7ff;
  --muted: #8fa8ba;
  --cyan: #4bd6d0;
  --blue: #4e8cff;
  --danger: #ff6f7d;
  --warning: #f2c15c;
  --good: #50d890;
}
* { box-sizing: border-box; }
html { min-height: 100%; background: var(--bg); }
body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background:
    radial-gradient(circle at 12% 8%, rgba(41, 126, 184, .2), transparent 32rem),
    linear-gradient(145deg, #071019 0%, #08131d 45%, #071018 100%);
  font-family: Inter, "Noto Sans TC", "Microsoft JhengHei", system-ui, sans-serif;
}
a { color: inherit; text-decoration: none; }
.topbar {
  height: 72px;
  border-bottom: 1px solid rgba(84, 139, 174, .22);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(20px, 4vw, 56px);
  background: rgba(7, 16, 25, .82);
  backdrop-filter: blur(18px);
}
.brand { display: flex; align-items: center; gap: 12px; font-weight: 700; letter-spacing: .02em; }
.brand-mark {
  border: 1px solid rgba(75, 214, 208, .45);
  background: rgba(75, 214, 208, .1);
  color: var(--cyan);
  padding: 8px 10px;
  border-radius: 10px;
  font-size: 13px;
  letter-spacing: .15em;
}
nav { display: flex; gap: 24px; color: var(--muted); font-size: 14px; }
nav a:hover { color: var(--text); }
.page-shell { width: min(1180px, calc(100% - 32px)); margin: 0 auto; padding: 56px 0 80px; }
.auth-card {
  width: min(460px, 100%);
  margin: 4vh auto 0;
  padding: clamp(26px, 5vw, 46px);
  background: linear-gradient(145deg, rgba(18, 37, 54, .96), rgba(10, 25, 37, .98));
  border: 1px solid rgba(97, 153, 188, .25);
  border-radius: 24px;
  box-shadow: 0 28px 90px rgba(0, 0, 0, .36);
}
.auth-card.wide { width: min(840px, 100%); }
.eyebrow { color: var(--cyan); font-size: 12px; letter-spacing: .18em; font-weight: 800; }
h1 { margin: 10px 0 8px; font-size: clamp(30px, 5vw, 48px); letter-spacing: -.04em; }
h2 { margin: 0 0 8px; font-size: 18px; }
.muted { color: var(--muted); line-height: 1.7; }
.stack { display: grid; gap: 10px; margin-top: 28px; }
.stack.compact { margin-top: 22px; }
label { color: #c9d9e5; font-size: 14px; font-weight: 650; margin-top: 8px; }
input, select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #08131d;
  color: var(--text);
  padding: 13px 14px;
  font: inherit;
  outline: none;
}
input:focus, select:focus { border-color: var(--cyan); box-shadow: 0 0 0 3px rgba(75, 214, 208, .1); }
button {
  border: 0;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--cyan), #40a8e0);
  color: #03131a;
  padding: 13px 18px;
  font: inherit;
  font-weight: 800;
  cursor: pointer;
  margin-top: 10px;
}
button:hover { filter: brightness(1.06); }
button:disabled { cursor: not-allowed; opacity: .45; }
button.secondary { background: transparent; border: 1px solid var(--line); color: var(--text); margin: 0; }
.alert { margin: 20px 0; padding: 13px 15px; border-radius: 12px; line-height: 1.5; }
.alert.danger { color: #ffd7db; background: rgba(255, 111, 125, .12); border: 1px solid rgba(255, 111, 125, .25); }
.alert.warning { color: #fff0ca; background: rgba(242, 193, 92, .1); border: 1px solid rgba(242, 193, 92, .24); }
.enrollment-grid { display: grid; grid-template-columns: minmax(240px, 320px) 1fr; gap: 42px; align-items: center; margin-top: 30px; }
.qr-panel { background: #fff; padding: 16px; border-radius: 18px; }
.qr-panel svg { display: block; width: 100%; height: auto; }
.steps { color: var(--muted); line-height: 1.8; padding-left: 22px; }
details { color: var(--muted); margin: 18px 0; }
.secret { display: block; color: var(--text); word-break: break-all; margin-top: 10px; }
.hero { display: flex; align-items: flex-end; justify-content: space-between; gap: 24px; margin-bottom: 36px; }
.status-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.status-card, .panel {
  background: rgba(13, 26, 38, .86);
  border: 1px solid rgba(70, 119, 151, .25);
  border-radius: 18px;
  padding: 24px;
}
.status-card { display: flex; gap: 14px; align-items: flex-start; }
.status-card p { margin: 0; color: var(--muted); line-height: 1.5; }
.status-dot { width: 10px; height: 10px; border-radius: 50%; margin-top: 5px; background: var(--muted); box-shadow: 0 0 16px currentColor; }
.status-dot.good { color: var(--good); background: var(--good); }
.status-dot.warn { color: var(--warning); background: var(--warning); }
.panel { margin-top: 20px; }
.roadmap { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 18px; }
.roadmap span { border: 1px solid var(--line); color: var(--muted); border-radius: 999px; padding: 8px 12px; font-size: 13px; }
.roadmap span.done { color: var(--good); border-color: rgba(80, 216, 144, .35); background: rgba(80, 216, 144, .08); }
table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: 14px 10px; border-bottom: 1px solid var(--line); }
th { color: var(--muted); font-size: 12px; letter-spacing: .08em; text-transform: uppercase; }
@media (max-width: 760px) {
  .topbar { height: auto; min-height: 64px; padding: 12px 18px; }
  nav { gap: 12px; }
  .page-shell { padding-top: 30px; }
  .enrollment-grid, .status-grid { grid-template-columns: 1fr; }
  .hero { align-items: flex-start; flex-direction: column; }
  table { font-size: 13px; }
}

/* traffic-dashboard */
.dashboard-hero { align-items: center; }
.hero-actions { display: flex; align-items: center; gap: 14px; }
.connection-status {
  display: inline-flex; align-items: center; gap: 8px; color: var(--muted);
  border: 1px solid var(--line); border-radius: 999px; padding: 8px 12px; font-size: 13px;
}
.connection-status::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: currentColor; }
.connection-status.live { color: var(--good); }
.connection-status.reconnecting { color: var(--warning); }
.connection-status.offline { color: var(--danger); }
.period-toolbar {
  display: flex; align-items: center; flex-wrap: wrap; gap: 14px;
  margin-bottom: 18px; padding: 14px; border: 1px solid rgba(70,119,151,.25);
  border-radius: 16px; background: rgba(13,26,38,.72);
}
.period-buttons { display: flex; gap: 8px; overflow-x: auto; padding-bottom: 2px; }
.period-button { flex: 0 0 auto; margin: 0; padding: 9px 13px; background: transparent; color: var(--muted); border: 1px solid var(--line); }
.period-button.active { color: #03131a; background: var(--cyan); border-color: var(--cyan); }
.updated-at { margin-left: auto; color: var(--muted); font-size: 12px; }
.custom-period { width: 100%; display: grid; grid-template-columns: 1fr 1fr auto; gap: 10px; align-items: end; }
.custom-period[hidden] { display: none; }
.custom-period label { margin: 0; }
.custom-period input { margin-top: 6px; }
.custom-period button { margin: 0; }
.metric-grid { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 14px; }
.metric-card {
  min-width: 0; padding: 20px; border: 1px solid rgba(70,119,151,.25);
  border-radius: 18px; background: rgba(13,26,38,.88);
  box-shadow: inset 0 3px 0 var(--accent, var(--cyan));
}
.metric-card > span { display: block; color: var(--muted); font-size: 13px; }
.metric-card strong { display: block; margin: 10px 0 8px; font-size: clamp(26px,3vw,38px); letter-spacing: -.04em; }
.metric-card small { display: block; color: var(--muted); line-height: 1.45; }
.metric-card small b { color: var(--text); }
.accent-cyan { --accent: #4bd6d0; } .accent-blue { --accent: #4e8cff; }
.accent-violet { --accent: #aa7cff; } .accent-orange { --accent: #ffad5c; }
.accent-green { --accent: #50d890; }
.chart-panel { padding: 20px; }
.panel-heading { display: flex; justify-content: space-between; align-items: flex-start; gap: 18px; }
.panel-heading p { margin: 0; font-size: 13px; }
.chart-legend { display: flex; flex-wrap: wrap; gap: 12px; color: var(--muted); font-size: 12px; }
.chart-legend i { display: inline-block; width: 9px; height: 9px; margin-right: 5px; border-radius: 50%; background: var(--legend); }
.chart-wrap { position: relative; width: 100%; min-height: 310px; margin-top: 16px; }
#trafficChart { display: block; width: 100%; height: 310px; }
.chart-empty { position: absolute; inset: 0; display: grid; place-items: center; color: var(--muted); pointer-events: none; }
.chart-empty[hidden] { display: none; }
.compact-status { margin-top: 20px; }
@media (max-width: 980px) {
  .metric-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .metric-card:last-child { grid-column: span 2; }
}
@media (max-width: 620px) {
  .dashboard-hero, .panel-heading { align-items: stretch; }
  .hero-actions { justify-content: space-between; width: 100%; }
  .period-toolbar { align-items: stretch; }
  .period-buttons { width: 100%; }
  .updated-at { margin-left: 0; width: 100%; }
  .custom-period { grid-template-columns: 1fr; }
  .metric-grid { grid-template-columns: 1fr; }
  .metric-card:last-child { grid-column: auto; }
  .chart-legend { margin-top: 8px; }
  .chart-wrap, #trafficChart { min-height: 270px; height: 270px; }
}