:root {
  --paper: #f2efe7;
  --paper-deep: #e8e3d8;
  --ink: #171714;
  --muted: #6e6b62;
  --line: #cbc6ba;
  --accent: #f04422;
  --accent-dark: #bd2e14;
  --signal: #b6d836;
  --black: #1c1c19;
  --mono: "DM Mono", Consolas, monospace;
  --sans: "Noto Sans TC", system-ui, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 18% 12%, rgba(255,255,255,.75), transparent 28%),
    repeating-linear-gradient(90deg, rgba(15,15,10,.018) 0, rgba(15,15,10,.018) 1px, transparent 1px, transparent 5px),
    var(--paper);
  font-family: var(--sans);
  min-width: 320px;
}

button, input { font: inherit; }
button { color: inherit; }
button:focus-visible, label:focus-within { outline: 3px solid rgba(240,68,34,.32); outline-offset: 3px; }
[hidden] { display: none !important; }

.app-shell { width: min(1280px, calc(100% - 48px)); margin: 0 auto; }
.topbar {
  height: 80px; display: flex; align-items: center; justify-content: space-between;
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 13px; color: inherit; text-decoration: none; font: 500 13px/1 var(--mono); letter-spacing: .12em; }
.brand strong { color: var(--accent); font-weight: 500; }
.brand-mark { width: 35px; height: 35px; background: var(--ink); display: flex; gap: 3px; align-items: center; justify-content: center; transform: rotate(-3deg); }
.brand-mark i { display: block; width: 3px; background: var(--paper); transform: skew(-18deg); }
.brand-mark i:nth-child(1) { height: 10px; }.brand-mark i:nth-child(2) { height: 17px; }.brand-mark i:nth-child(3) { height: 23px; background: var(--accent); }
.topbar-meta, .browser-state { display: flex; align-items: center; }
.topbar-meta { gap: 20px; }
.browser-state { gap: 8px; color: var(--muted); font: 11px/1 var(--mono); letter-spacing: .06em; text-transform: uppercase; }
.browser-state i { width: 7px; height: 7px; border-radius: 50%; background: #aaa59a; box-shadow: 0 0 0 4px rgba(0,0,0,.04); }
.browser-state.is-ready i { background: var(--signal); }
.browser-state.is-error i { background: var(--accent); }
.icon-button { width: 34px; height: 34px; border: 1px solid var(--line); border-radius: 50%; background: transparent; cursor: pointer; font: 500 13px var(--mono); }

main { padding: 74px 0 40px; }
.hero { display: flex; justify-content: space-between; align-items: flex-end; gap: 40px; margin-bottom: 64px; }
.eyebrow { display: flex; align-items: center; gap: 12px; margin: 0 0 22px; color: var(--muted); font: 500 10px/1 var(--mono); letter-spacing: .15em; }
.eyebrow span { color: var(--accent); }
.hero h1 { margin: 0; font-size: clamp(47px, 6.2vw, 90px); font-weight: 600; letter-spacing: -.07em; line-height: .98; }
.hero h1 em { color: var(--accent); font-style: normal; }
.hero-copy { margin: 0 0 8px; max-width: 430px; color: var(--muted); font-size: 14px; line-height: 2; }

.workspace { display: grid; grid-template-columns: .86fr 1.5fr; border: 1px solid var(--line); background: rgba(248,246,240,.6); box-shadow: 0 18px 45px rgba(43,39,29,.06); }
.device-panel, .update-panel { padding: 35px 38px 38px; }
.device-panel { border-right: 1px solid var(--line); background: rgba(228,223,211,.36); }
.section-heading, .section-heading > div, .activity-header, .activity-header > div { display: flex; align-items: center; justify-content: space-between; }
.section-heading > div, .activity-header > div { justify-content: flex-start; gap: 11px; }
.section-heading h2, .activity-header h2 { margin: 0; font-size: 14px; letter-spacing: .04em; }
.step-index { color: var(--accent); font: 500 10px var(--mono); }
.status-chip { padding: 7px 10px; border-radius: 30px; background: rgba(182,216,54,.16); color: #667d12; font: 500 9px/1 var(--mono); letter-spacing: .09em; }
.status-chip::before { content: ""; display: inline-block; width: 6px; height: 6px; margin-right: 6px; border-radius: 50%; background: var(--signal); }
.status-chip.is-offline { background: rgba(100,100,95,.08); color: #77736a; }
.status-chip.is-offline::before { background: #99948a; }

.device-visual { position: relative; height: 210px; display: grid; place-items: center; overflow: hidden; margin-top: 10px; }
.receiver-shape { position: relative; z-index: 2; width: 118px; height: 76px; border: 2px solid var(--ink); border-radius: 8px 16px 16px 8px; background: var(--paper); transform: rotate(-8deg); box-shadow: 9px 12px 0 rgba(23,23,20,.08); }
.receiver-shape::before { content: "WCH"; position: absolute; left: 37px; top: 26px; font: 500 12px var(--mono); letter-spacing: .12em; }
.receiver-port { position: absolute; left: -31px; top: 17px; width: 31px; height: 40px; border: 2px solid var(--ink); border-right: 0; border-radius: 4px 0 0 4px; background: linear-gradient(90deg,#aaa,#dedbd2); }
.receiver-port::before, .receiver-port::after { content: ""; position: absolute; left: 5px; width: 18px; height: 2px; background: #777; }.receiver-port::before { top: 9px; }.receiver-port::after { bottom: 9px; }
.receiver-led { position: absolute; right: 13px; top: 33px; width: 7px; height: 7px; border: 1px solid var(--ink); border-radius: 50%; background: #aaa; }
.receiver-led.is-on { background: var(--signal); box-shadow: 0 0 11px var(--signal); }
.receiver-ridges { position: absolute; left: 9px; top: 13px; display: flex; gap: 3px; }.receiver-ridges i { width: 2px; height: 50px; background: rgba(23,23,20,.18); }
.signal-ring { position: absolute; border: 1px solid rgba(240,68,34,.32); border-radius: 50%; transform: rotate(-8deg); }
.ring-one { width: 170px; height: 112px; }.ring-two { width: 225px; height: 155px; opacity: .48; }
.device-info { text-align: center; margin: -2px 0 22px; }
.device-info p { margin: 4px 0; }
.device-name { font-size: 14px; font-weight: 600; }
.device-info p:last-child { color: var(--muted); font: 10px var(--mono); }
.primary-button, .start-button, .secondary-button { border: 0; cursor: pointer; }
.primary-button { background: var(--ink); color: white; min-height: 48px; padding: 0 20px; font-size: 12px; font-weight: 600; }
.connect-button { width: 100%; display: flex; justify-content: center; align-items: center; gap: 10px; }
.connect-button:hover { background: #34342f; }.connect-button.is-connected { background: #dcd7cb; color: var(--ink); }
.button-icon { font: 18px var(--mono); transform: rotate(90deg); }
.privacy-note { text-align: center; color: var(--muted); font: 9px var(--mono); letter-spacing: .03em; margin: 14px 0 0; }.privacy-note span { color: #7f971d; margin-right: 5px; }

.update-panel { min-width: 0; }
.session-id { color: var(--muted); font: 9px var(--mono); letter-spacing: .09em; }.session-id b { color: var(--ink); font-weight: 500; }
.mode-switch { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; margin: 28px 0 30px; }
.mode-button { display: flex; gap: 14px; align-items: center; min-height: 74px; padding: 12px 15px; border: 1px solid var(--line); background: transparent; text-align: left; cursor: pointer; }
.mode-button:hover { border-color: #969084; }.mode-button.is-active { border: 2px solid var(--ink); padding: 11px 14px; background: #fbfaf6; }
.mode-symbol { display: grid; place-items: center; flex: 0 0 38px; height: 38px; background: var(--accent); color: white; font: 500 13px var(--mono); transform: rotate(-3deg); }
.tracker-symbol { background: var(--ink); }.mode-button span:last-child { display: flex; flex-direction: column; gap: 2px; }.mode-button strong { font-size: 13px; }.mode-button small { color: var(--muted); font-size: 10px; }
.receiver-flow { display: grid; gap: 8px; margin: 28px 0; }
.flow-step { display: grid; grid-template-columns: 34px minmax(0,1fr) auto; align-items: center; gap: 12px; min-height: 68px; padding: 12px 14px; border: 1px solid var(--line); background: rgba(255,255,255,.28); }
.flow-step.is-current { border-color: var(--ink); background: #fbfaf6; }
.flow-step.is-complete { border-color: rgba(121,145,29,.55); background: rgba(182,216,54,.08); }
.flow-number { display: grid; place-items: center; width: 32px; height: 32px; background: #dfdbd1; color: var(--muted); font: 500 9px var(--mono); }
.flow-step.is-current .flow-number { background: var(--accent); color: white; }.flow-step.is-complete .flow-number { background: var(--signal); color: var(--ink); }
.flow-copy { display: flex; flex-direction: column; gap: 3px; min-width: 0; }.flow-copy strong { font-size: 11px; }.flow-copy small { color: var(--muted); font-size: 9px; line-height: 1.45; }
.flow-button { min-height: 35px; padding: 0 12px; border: 1px solid var(--ink); background: var(--ink); color: white; cursor: pointer; font-size: 9px; white-space: nowrap; }
.flow-button:hover:not(:disabled) { background: #34342f; }.flow-button:disabled { border-color: var(--line); background: transparent; color: #9a968c; cursor: not-allowed; }
.flow-connector { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 10px; color: #8a867c; font: 8px var(--mono); letter-spacing: .08em; }.flow-connector span { height: 1px; background: var(--line); }
.field-label-row { display: flex; justify-content: space-between; margin-bottom: 9px; }.field-label-row label { font-size: 11px; font-weight: 600; }.field-label-row span { color: var(--muted); font: 9px var(--mono); }
.firmware-sources { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.latest-firmware-card, .local-firmware-source { min-width: 0; min-height: 88px; padding: 8px 10px; border: 1px solid var(--line); background: rgba(255,255,255,.28); }
.latest-firmware-card { display: grid; grid-template-columns: minmax(0,1fr) auto; grid-template-rows: auto auto 1fr; column-gap: 12px; align-items: center; background: #e8e3d8; }
.source-label { display: block; margin-bottom: 4px; color: var(--accent); font: 500 7px var(--mono); letter-spacing: .12em; }.latest-firmware-card > .source-label { grid-column: 1 / -1; }.local-firmware-source .source-label { color: var(--muted); }
.latest-version { display: flex; flex-direction: column; gap: 1px; }.latest-version strong { font: 500 15px var(--mono); }.latest-version small { color: var(--muted); font-size: 8px; }
.latest-firmware-card p { grid-column: 1; margin: 5px 0 0; color: var(--muted); font-size: 8px; line-height: 1.4; }
.latest-load-button { grid-column: 2; grid-row: 2 / 4; width: 58px; min-height: 34px; padding: 0 8px; border: 0; background: var(--ink); color: white; cursor: pointer; font-size: 9px; font-weight: 600; }.latest-load-button:hover:not(:disabled) { background: #34342f; }.latest-load-button:disabled { background: #cbc6ba; color: #88847b; cursor: not-allowed; }
.latest-firmware-card.is-loaded { border-color: #8da51d; background: rgba(182,216,54,.12); }.latest-firmware-card.is-loaded .source-label { color: #687c16; }
.tracker-section { margin: 28px 0 27px; }
.tracker-list-header, .tracker-list-header > div { display: flex; align-items: center; justify-content: space-between; }
.tracker-list-header { margin-bottom: 10px; }.tracker-list-header > div { justify-content: flex-start; gap: 12px; }.tracker-list-header label { font-size: 11px; font-weight: 600; }.tracker-list-header > span { color: var(--muted); font: 9px var(--mono); }
.live-indicator { display: inline-flex; align-items: center; gap: 6px; color: #737067; font: 8px var(--mono); letter-spacing: .05em; }.live-indicator i { width: 6px; height: 6px; border-radius: 50%; background: #aaa59a; }.live-indicator.is-live i { background: var(--signal); box-shadow: 0 0 0 3px rgba(182,216,54,.13); }
.tracker-table-head, .tracker-row { display: grid; grid-template-columns: .8fr 1.35fr 1.6fr .55fr; gap: 10px; align-items: center; }
.tracker-table-head { padding: 0 12px 7px 48px; color: #8d887e; font: 8px var(--mono); letter-spacing: .04em; }
.tracker-list { display: grid; gap: 6px; }
.tracker-row { position: relative; min-height: 62px; padding: 10px 12px 10px 48px; border: 1px solid var(--line); background: rgba(255,255,255,.28); cursor: pointer; transition: border-color .15s, background .15s, box-shadow .15s; }
.tracker-select { position: absolute; width: 1px; height: 1px; opacity: 0; pointer-events: none; }
.tracker-row:focus-within { outline: none; }.tracker-row:has(.tracker-select:focus-visible) { outline: 3px solid rgba(240,68,34,.32); outline-offset: 3px; }
.tracker-row.is-hovered:not(.is-offline):not(.is-ineligible) { border-color: var(--ink); box-shadow: inset 0 0 0 1px var(--ink); }.tracker-row.is-selected { border-color: var(--ink); background: #fbfaf6; box-shadow: inset 0 0 0 1px var(--ink); }.tracker-row.is-moving { border-color: #8ea91e; background: rgba(182,216,54,.16); box-shadow: inset 4px 0 0 var(--signal); }.tracker-row.is-selected.is-moving, .tracker-row.is-moving.is-hovered:not(.is-ineligible) { box-shadow: inset 0 0 0 1px var(--ink), inset 4px 0 0 var(--signal); }.tracker-row.is-offline, .tracker-row.is-ineligible { opacity: .48; cursor: not-allowed; }
.tracker-check { position: absolute; left: 14px; top: 50%; width: 20px; height: 20px; margin-top: -10px; display: grid; place-items: center; border: 1px solid #aaa59a; color: transparent; font: 11px var(--mono); }.tracker-row.is-selected .tracker-check { border-color: var(--ink); background: var(--ink); color: white; }
.tracker-cell { min-width: 0; display: flex; flex-direction: column; gap: 3px; }.tracker-cell b { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font: 500 10px var(--mono); }.tracker-cell small { color: var(--muted); font-size: 8px; }
.tracker-id b { font-size: 13px; }.tracker-id b::before { content: "#"; color: var(--accent); margin-right: 1px; }.tracker-tps b { color: #748b18; }
.tracker-empty { min-height: 88px; display: flex; align-items: center; justify-content: center; gap: 15px; padding: 18px; border: 1px dashed var(--line); color: var(--muted); }.tracker-empty strong, .tracker-empty small { display: block; }.tracker-empty strong { color: var(--ink); margin-bottom: 4px; font-size: 10px; }.tracker-empty small { font-size: 9px; line-height: 1.5; }
.tracker-radar { position: relative; width: 34px; height: 34px; flex: 0 0 34px; border: 1px solid var(--line); border-radius: 50%; }.tracker-radar::before, .tracker-radar::after { content: ""; position: absolute; border: 1px solid var(--line); border-radius: 50%; inset: 7px; }.tracker-radar::after { inset: 14px; background: var(--accent); border: 0; }.tracker-radar i { position: absolute; left: 50%; top: 50%; width: 15px; height: 1px; background: var(--accent); transform-origin: left; animation: radar-spin 2s linear infinite; }
@keyframes radar-spin { to { transform: rotate(360deg); } }
.dropzone { min-height: 54px; border: 1px dashed #aaa59a; display: flex; align-items: center; padding: 7px 9px; cursor: pointer; transition: background .15s, border-color .15s; }
.dropzone:hover, .dropzone.is-dragging { background: rgba(255,255,255,.55); border-color: var(--accent); }
.dropzone input { position: absolute; inline-size: 1px; block-size: 1px; opacity: 0; }
.upload-mark { display: grid; place-items: center; flex: 0 0 30px; height: 30px; margin-right: 8px; border: 1px solid var(--line); font: 17px var(--mono); }
.upload-copy { display: flex; flex-direction: column; gap: 5px; min-width: 0; }.upload-copy strong { font-size: 12px; }.upload-copy small { color: var(--muted); font-size: 10px; }
.browse-pill { margin-left: auto; padding: 8px 12px; border: 1px solid var(--line); font-size: 9px; white-space: nowrap; }
.file-card { min-height: 48px; border: 1px solid var(--ink); display: flex; align-items: center; padding: 6px 8px; background: #fbfaf6; }
.file-type { display: grid; place-items: center; width: 32px; height: 32px; margin-right: 8px; background: var(--accent); color: white; font: 500 8px var(--mono); }
.tracker-file-type { background: var(--ink); }
.file-card div { min-width: 0; display: flex; flex-direction: column; gap: 3px; }.file-card strong { max-width: 400px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: 11px; }.file-card small { color: var(--muted); font: 9px var(--mono); }
.file-card button { margin-left: auto; border: 0; background: transparent; cursor: pointer; color: var(--muted); font-size: 22px; }
.safety-note { display: flex; gap: 12px; align-items: flex-start; margin: 18px 0; }.safety-note > span { display: grid; place-items: center; flex: 0 0 19px; height: 19px; border-radius: 50%; background: #f4d995; font: 500 10px var(--mono); }.safety-note p { margin: 0; color: var(--muted); font-size: 9px; line-height: 1.6; }.safety-note strong { display: block; color: var(--ink); font-size: 10px; }
.start-button { width: 100%; min-height: 57px; padding: 0 22px; display: flex; align-items: center; justify-content: space-between; background: var(--accent); color: white; font-size: 12px; font-weight: 600; }
.start-button:hover:not(:disabled) { background: var(--accent-dark); }.start-button i { font: normal 22px var(--mono); }.start-button:disabled { background: #ccc7bc; color: #8c887f; cursor: not-allowed; }

.activity-panel { position: relative; margin-top: 24px; padding: 28px 38px; border: 1px solid var(--line); background: var(--black); color: #f5f1e8; }
.activity-header { margin-bottom: 23px; }.activity-header h2 { color: white; }.text-button { border: 0; background: transparent; color: #96958d; cursor: pointer; font: 9px var(--mono); letter-spacing: .08em; }
.progress-overview { display: grid; grid-template-columns: 160px 1fr; align-items: center; gap: 28px; margin-bottom: 22px; }
.progress-copy { display: flex; align-items: baseline; gap: 12px; }.progress-copy strong { font: 500 28px var(--mono); }.progress-copy span { color: #aaa89f; font-size: 10px; }
.progress-track { height: 5px; background: #363631; overflow: hidden; }.progress-track span { display: block; width: 0; height: 100%; background: var(--signal); transition: width .25s ease; }
.log-window { min-height: 74px; max-height: 150px; overflow-y: auto; padding-top: 16px; border-top: 1px solid #393934; scrollbar-color: #555 transparent; }
.log-window p { display: grid; grid-template-columns: 76px 62px 1fr; gap: 12px; margin: 0 0 9px; color: #b9b7af; font: 9px/1.55 var(--mono); }.log-window time { color: #6f6e68; }.log-window p > span:nth-child(2) { color: #8ba016; }.log-window .log-error { color: #ff7156 !important; }.log-window .log-info { color: #e9e7de !important; }
.cancel-button { position: absolute; right: 38px; top: 24px; border: 1px solid #53534d; background: transparent; color: #b4b1a9; padding: 8px 12px; font: 9px var(--mono); cursor: pointer; }.cancel-button:disabled { display: none; }.cancel-button:hover { border-color: var(--accent); color: white; }

footer { min-height: 82px; display: flex; justify-content: space-between; align-items: center; color: #8a867c; font: 8px var(--mono); letter-spacing: .1em; }
footer span { color: var(--accent); }

dialog { border: 0; padding: 0; background: transparent; max-width: calc(100% - 32px); }
dialog::backdrop { background: rgba(12,12,10,.66); backdrop-filter: blur(4px); }
.dialog-card { position: relative; width: min(490px, calc(100vw - 32px)); padding: 38px; background: var(--paper); box-shadow: 0 24px 80px rgba(0,0,0,.3); }
.dialog-kicker { color: var(--accent); font: 500 9px var(--mono); letter-spacing: .16em; }.dialog-card h2 { margin: 10px 0 14px; font-size: 27px; letter-spacing: -.04em; }.dialog-card > p { color: var(--muted); font-size: 12px; line-height: 1.8; }
.dialog-warning { display: flex; flex-direction: column; gap: 4px; margin: 24px 0; padding: 14px; border-left: 3px solid #e3bb4f; background: #ebe4d2; }.dialog-warning b { font-size: 11px; }.dialog-warning span { color: var(--muted); font-size: 10px; }
.dialog-actions { display: flex; justify-content: flex-end; gap: 8px; }.secondary-button { padding: 0 18px; background: transparent; border: 1px solid var(--line); font-size: 11px; }
.dialog-close { position: absolute; right: 20px; top: 18px; border: 0; background: transparent; font-size: 24px; cursor: pointer; }
.help-card ol { list-style: none; padding: 0; margin: 26px 0; counter-reset: guide; }.help-card li { position: relative; padding: 0 0 22px 43px; counter-increment: guide; }.help-card li::before { content: "0" counter(guide); position: absolute; left: 0; top: 0; color: var(--accent); font: 500 10px var(--mono); }.help-card li:not(:last-child)::after { content: ""; position: absolute; left: 9px; top: 20px; bottom: 5px; border-left: 1px solid var(--line); }.help-card li b, .help-card li span { display: block; }.help-card li b { font-size: 12px; margin-bottom: 4px; }.help-card li span { color: var(--muted); font-size: 10px; line-height: 1.6; }.help-footnote { margin-bottom: 0; padding-top: 16px; border-top: 1px solid var(--line); font-family: var(--mono) !important; font-size: 9px !important; }
.toast { position: fixed; z-index: 10; left: 50%; bottom: 24px; transform: translate(-50%, 20px); padding: 11px 16px; background: var(--ink); color: white; opacity: 0; pointer-events: none; transition: .2s; font-size: 11px; box-shadow: 0 10px 30px rgba(0,0,0,.2); }.toast.is-visible { opacity: 1; transform: translate(-50%, 0); }

@media (max-width: 820px) {
  .app-shell { width: min(100% - 28px, 680px); }
  main { padding-top: 46px; }
  .hero { display: block; margin-bottom: 42px; }.hero-copy { margin-top: 25px; }
  .workspace { grid-template-columns: 1fr; }.device-panel { border-right: 0; border-bottom: 1px solid var(--line); }.device-visual { height: 170px; }
  .firmware-sources { grid-template-columns: 1fr; }
  .tracker-table-head { display: none; }.tracker-row { grid-template-columns: repeat(2, minmax(0,1fr)); row-gap: 12px; }
}

@media (max-width: 520px) {
  .app-shell { width: 100%; }.topbar { margin: 0 18px; height: 68px; }.browser-state { display: none; }
  main { padding: 36px 14px 20px; }.hero h1 { font-size: 45px; }.hero-copy br { display: none; }
  .device-panel, .update-panel { padding: 27px 22px; }.mode-switch { grid-template-columns: 1fr; }.browse-pill { display: none; }
  .latest-firmware-card { grid-template-columns: 1fr; }.latest-load-button { grid-column: 1; grid-row: auto; width: 100%; margin-top: 9px; }
  .flow-step { grid-template-columns: 32px 1fr; }.flow-button { grid-column: 1 / -1; min-height: 40px; }
  .activity-panel { padding: 25px 22px; }.progress-overview { grid-template-columns: 1fr; gap: 12px; }.log-window p { grid-template-columns: 58px 52px 1fr; }
  footer { padding: 0 18px; } footer p:last-child { display: none; }
  .dialog-card { padding: 30px 24px; }.dialog-actions { flex-direction: column-reverse; }.dialog-actions button { min-height: 46px; }
}

@media (prefers-reduced-motion: reduce) { * { scroll-behavior: auto !important; transition: none !important; animation: none !important; } }