:root, [data-theme="dark"] {
  --bg: #0b0e14;
  --bg-2: #0f131a;
  --panel: #161b22;
  --panel-2: #1c222c;
  --border: #2a313c;
  --border-2: #353d4a;
  --fg: #e6edf3;
  --muted: #8b949e;
  --muted-2: #6e7681;
  --accent: #ff8c42;
  --accent-2: #ffb877;
  --accent-3: #ff6f1f;
  --ok: #3fb950;
  --warn: #d29922;
  --err: #f85149;
  --info: #58a6ff;
  --shadow: 0 8px 24px rgba(0,0,0,0.45);
  --bg-grad: radial-gradient(1200px 600px at 50% -200px, #1a1f29 0%, var(--bg) 60%);
  --topbar-bg: rgba(11, 14, 20, 0.7);
  --log-bg: #06080c;
  --log-fg: #c9d1d9;
}

[data-theme="light"] {
  --bg: #f6f8fa;
  --bg-2: #ffffff;
  --panel: #ffffff;
  --panel-2: #f0f3f6;
  --border: #d1d9e0;
  --border-2: #b8c0c8;
  --fg: #1f2328;
  --muted: #59636e;
  --muted-2: #818b94;
  --accent: #ff7a1f;
  --accent-2: #ff9a55;
  --accent-3: #e76512;
  --ok: #1a7f37;
  --warn: #9a6700;
  --err: #cf222e;
  --info: #0969da;
  --shadow: 0 4px 14px rgba(31,35,40,0.10);
  --bg-grad: radial-gradient(1200px 600px at 50% -200px, #fff7f0 0%, var(--bg) 60%);
  --topbar-bg: rgba(255, 255, 255, 0.85);
  --log-bg: #0e1116;
  --log-fg: #e6edf3;
}

* { box-sizing: border-box; }
html, body {
  margin: 0;
  background: var(--bg-grad);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  font-size: 14px;
  min-height: 100vh;
  transition: background 0.25s, color 0.25s;
}
.hidden { display: none !important; }
.muted { color: var(--muted); }
.small { font-size: 12px; }

/* ========== Header ========== */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 32px;
  border-bottom: 1px solid var(--border);
  background: var(--topbar-bg);
  backdrop-filter: blur(8px);
  position: sticky; top: 0; z-index: 50;
}
.brand { display: flex; align-items: center; gap: 14px; }
.logo { width: 44px; height: 44px; filter: drop-shadow(0 2px 8px rgba(255,140,66,0.4)); }
.topbar h1 { margin: 0; font-size: 22px; letter-spacing: -0.02em; color: var(--fg); }
.tagline { margin: 2px 0 0; color: var(--muted); font-size: 13px; }
.actions { display: flex; align-items: center; gap: 12px; }
.who { color: var(--muted); font-size: 13px; }

/* ========== Layout ========== */
main { display: grid; gap: 20px; padding: 28px 32px 80px; max-width: 1100px; margin: 0 auto; }

/* ========== Stepper ========== */
.stepper {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  list-style: none;
  padding: 0;
  margin: 0;
}
.stepper li {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 16px;
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-areas: "num title" "num sub";
  column-gap: 12px;
  transition: all 0.2s;
}
.stepper li span {
  grid-area: num;
  align-self: center;
  width: 36px; height: 36px;
  border-radius: 50%;
  display: grid; place-items: center;
  background: var(--panel-2);
  border: 1px solid var(--border-2);
  color: var(--muted);
  font-weight: 700;
}
.stepper li b { grid-area: title; font-size: 14px; }
.stepper li i { grid-area: sub; font-style: normal; font-size: 12px; color: var(--muted); }
.stepper li.active { border-color: var(--accent); background: linear-gradient(180deg, rgba(255,140,66,0.08), transparent); }
.stepper li.active span { background: var(--accent); color: #1a1208; border-color: var(--accent); }
.stepper li.done span { background: var(--ok); color: #06210b; border-color: var(--ok); }
.stepper li.done span::before { content: "✓"; }
.stepper li.done span > * { display: none; }

/* ========== Cards ========== */
.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 22px 26px;
  box-shadow: var(--shadow);
}
.step.locked { opacity: 0.5; pointer-events: none; filter: grayscale(0.4); }
.step-head {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 16px; gap: 12px; flex-wrap: wrap;
}
.step-head h2 { margin: 0; font-size: 17px; display: flex; align-items: center; gap: 10px; }
.step-num {
  display: inline-grid; place-items: center;
  width: 26px; height: 26px;
  background: var(--accent); color: #1a1208;
  border-radius: 50%;
  font-size: 13px; font-weight: 700;
}
.head-actions { display: flex; align-items: center; gap: 10px; }

/* ========== Login ========== */
.login-card { max-width: 420px; margin: 60px auto; }
.login-card h2 { margin: 0 0 6px; }
.login-card form { display: grid; gap: 14px; margin-top: 18px; }

/* ========== Inputs / buttons ========== */
input, select, button {
  background: var(--bg-2);
  border: 1px solid var(--border);
  color: var(--fg);
  padding: 9px 12px;
  border-radius: 8px;
  font: inherit;
  outline: none;
  transition: border 0.15s, background 0.15s;
}
input:focus, select:focus { border-color: var(--accent); }
label { display: flex; flex-direction: column; gap: 4px; font-size: 12px; color: var(--muted); }
label input, label select { color: var(--fg); }

button { cursor: pointer; font-weight: 600; }
button.primary { background: var(--accent); color: #1a1208; border-color: transparent; }
button.primary:hover { background: var(--accent-2); }
button.primary:disabled { background: var(--panel-2); color: var(--muted-2); cursor: not-allowed; }
button.ghost { background: transparent; color: var(--fg); border: 1px solid var(--border); }
button.ghost:hover { background: var(--panel-2); border-color: var(--border-2); }
button.block { width: 100%; padding: 11px; }

/* ========== Empty state ========== */
.empty {
  display: grid;
  place-items: center;
  text-align: center;
  padding: 32px 20px;
  color: var(--muted);
}
.empty-icon { width: 56px; height: 56px; color: var(--muted-2); margin-bottom: 12px; animation: pulse 2s ease-in-out infinite; }
.empty h3 { margin: 6px 0 4px; color: var(--fg); font-size: 15px; }
.empty p { margin: 0 0 16px; font-size: 13px; }
.hint { max-width: 540px; margin-top: 8px; text-align: left; background: var(--bg-2); padding: 12px 16px; border-radius: 8px; border: 1px solid var(--border); }
.hint summary { cursor: pointer; font-weight: 600; color: var(--accent-2); }
.hint ul { margin: 10px 0 0; padding-left: 20px; font-size: 13px; line-height: 1.7; }

@keyframes pulse {
  0%, 100% { opacity: 0.4; transform: scale(1); }
  50% { opacity: 0.9; transform: scale(1.05); }
}

/* ========== Cards grid (boards / firmwares) ========== */
.grid-cards { list-style: none; padding: 0; margin: 0; display: grid; gap: 10px; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.grid-cards li {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 14px 16px;
  cursor: pointer;
  display: grid;
  gap: 6px;
  transition: all 0.15s;
}
.grid-cards li:hover { border-color: var(--accent); transform: translateY(-1px); }
.grid-cards li.selected { border-color: var(--accent); background: linear-gradient(180deg, rgba(255,140,66,0.1), var(--bg-2)); box-shadow: 0 0 0 2px rgba(255,140,66,0.25); }
.card-title { font-weight: 700; display: flex; align-items: center; gap: 8px; }
.card-meta { color: var(--muted); font-size: 12px; }

.badge {
  display: inline-block;
  font-size: 10px;
  padding: 2px 7px;
  border-radius: 999px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.badge.dfu { background: rgba(210, 153, 34, 0.18); color: var(--warn); border: 1px solid rgba(210, 153, 34, 0.4); }
.badge.serial { background: rgba(63, 185, 80, 0.18); color: var(--ok); border: 1px solid rgba(63, 185, 80, 0.4); }
.badge.stable { background: rgba(63, 185, 80, 0.18); color: var(--ok); }
.badge.beta { background: rgba(88, 166, 255, 0.18); color: var(--info); }

/* ========== Status pills ========== */
.status-pill {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 12px; padding: 4px 10px;
  border-radius: 999px;
  background: var(--panel-2); color: var(--muted);
  border: 1px solid var(--border);
}
.status-pill::before {
  content: ""; display: inline-block; width: 7px; height: 7px;
  border-radius: 50%; background: var(--muted);
}
.status-pill.ok { color: var(--ok); border-color: rgba(63,185,80,0.4); background: rgba(63,185,80,0.08); }
.status-pill.ok::before { background: var(--ok); animation: blink 1.4s ease-in-out infinite; }
.status-pill.busy { color: var(--accent); border-color: rgba(255,140,66,0.4); background: rgba(255,140,66,0.08); }
.status-pill.busy::before { background: var(--accent); animation: blink 0.8s ease-in-out infinite; }
.status-pill.err { color: var(--err); border-color: rgba(248,81,73,0.4); background: rgba(248,81,73,0.08); }
.status-pill.err::before { background: var(--err); }

@keyframes blink { 0%, 100% { opacity: 1; } 50% { opacity: 0.3; } }

/* ========== Firmware controls ========== */
.fw-controls { display: grid; gap: 12px; margin-bottom: 14px; }
.seg {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 4px;
  background: var(--bg-2); padding: 4px; border-radius: 10px;
  border: 1px solid var(--border);
}
.seg button {
  background: transparent; border: none; padding: 10px 12px;
  border-radius: 7px; text-align: center; color: var(--muted); cursor: pointer;
  display: grid; gap: 2px;
}
.seg button:hover { background: var(--panel-2); color: var(--fg); }
.seg button.active { background: var(--accent); color: #1a1208; }
.seg-name { font-weight: 700; font-size: 13px; }
.seg-sub { font-size: 10px; opacity: 0.85; }

.fw-search { display: grid; grid-template-columns: 1fr auto; gap: 10px; }

/* ========== Flash ========== */
.flash-summary {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 12px; margin-bottom: 14px;
}
.flash-summary > div {
  background: var(--bg-2); border: 1px solid var(--border); border-radius: 8px;
  padding: 10px 14px; display: grid; gap: 4px;
}
.flash-summary b { color: var(--muted); font-size: 11px; text-transform: uppercase; letter-spacing: 0.05em; font-weight: 600; }

.progress-wrap { background: var(--bg-2); border-radius: 6px; height: 6px; overflow: hidden; margin-bottom: 12px; border: 1px solid var(--border); }
.progress { width: 0%; height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent-2)); transition: width 0.4s; }
.progress.indeterminate {
  width: 30%;
  animation: indeterminate 1.4s ease-in-out infinite;
}
@keyframes indeterminate {
  0% { transform: translateX(-100%); width: 30%; }
  50% { width: 50%; }
  100% { transform: translateX(380%); width: 30%; }
}

.log {
  background: var(--log-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px;
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 12px;
  line-height: 1.5;
  max-height: 360px;
  overflow: auto;
  white-space: pre-wrap;
  color: var(--log-fg);
}

/* ========== Boot test ========== */
.boot-form {
  display: grid; gap: 12px;
  grid-template-columns: 2fr 1fr 1fr auto auto;
  align-items: end;
  margin-bottom: 14px;
}
.boot-form button { padding: 10px 18px; }

.boot-result {
  background: var(--bg-2); border: 1px solid var(--border); border-radius: 10px;
  padding: 16px; min-height: 60px; font-size: 13px;
}
.boot-result.ok { border-color: rgba(63,185,80,0.5); background: rgba(63,185,80,0.06); }
.boot-result.err { border-color: rgba(248,81,73,0.5); background: rgba(248,81,73,0.06); }
.boot-result h4 { margin: 0 0 10px; display: flex; align-items: center; gap: 8px; font-size: 14px; }
.boot-result table { width: 100%; border-collapse: collapse; font-size: 13px; }
.boot-result td { padding: 4px 0; }
.boot-result td:first-child { color: var(--muted); width: 40%; }

/* ========== Toasts ========== */
#toasts {
  position: fixed; top: 80px; right: 24px;
  display: grid; gap: 8px; z-index: 100;
  pointer-events: none;
}
.toast {
  background: var(--panel); border: 1px solid var(--border);
  border-radius: 10px; padding: 12px 16px;
  box-shadow: var(--shadow);
  display: flex; align-items: center; gap: 10px;
  min-width: 260px;
  animation: slide-in 0.25s ease-out;
  pointer-events: auto;
}
.toast.ok { border-left: 4px solid var(--ok); }
.toast.err { border-left: 4px solid var(--err); }
.toast.info { border-left: 4px solid var(--info); }
.toast .icon { font-size: 18px; }

@keyframes slide-in { from { opacity: 0; transform: translateX(20px); } to { opacity: 1; transform: none; } }

.error { color: var(--err); margin: 8px 0 0; font-size: 13px; }

/* ========== Theme + lang toggles in header ========== */
.icon-btn { padding: 7px 11px; font-size: 16px; line-height: 1; }
.theme-sun, .theme-moon { display: inline-block; }
[data-theme="dark"] .theme-sun { display: inline-block; }
[data-theme="dark"] .theme-moon { display: none; }
[data-theme="light"] .theme-sun { display: none; }
[data-theme="light"] .theme-moon { display: inline-block; }

.seg-mini {
  display: inline-flex;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 2px;
  gap: 2px;
}
.seg-mini button {
  background: transparent;
  border: none;
  color: var(--muted);
  padding: 5px 10px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
}
.seg-mini button:hover { color: var(--fg); }
.seg-mini button.active { background: var(--accent); color: #1a1208; }

@media (max-width: 720px) {
  .stepper { grid-template-columns: 1fr 1fr; }
  .seg { grid-template-columns: 1fr 1fr; }
  .boot-form { grid-template-columns: 1fr; }
  main { padding: 20px 16px 60px; }
  .topbar { padding: 14px 18px; }
}