:root {
  --bg: #07090d;
  --bg-2: #0c1017;
  --ink: #0a0d14;
  --panel: rgba(17, 21, 30, 0.78);
  --panel-solid: #11151e;
  --line: rgba(255, 255, 255, 0.08);
  --line-2: rgba(255, 255, 255, 0.14);
  --text: #e9edf4;
  --muted: #8b94a7;
  --faint: #5b6476;
  --cyan: #22d8ff;
  --pink: #ff3d9a;
  --amber: #ffd60a;
  --green: #2bdc74;
  --red: #ff5468;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 10px 40px rgba(0, 0, 0, 0.45);
  --font: ui-sans-serif, system-ui, -apple-system, 'SF Pro Text', 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB',
    'Microsoft YaHei', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --mono: ui-monospace, 'SF Mono', SFMono-Regular, Menlo, Consolas, monospace;
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
}

button,
input,
select,
textarea {
  font: inherit;
  color: inherit;
}

a {
  color: inherit;
}

.hidden {
  display: none !important;
}

/* ---------- brand mark: a tiny 3x3 code */
.mark {
  display: inline-grid;
  grid-template-columns: repeat(3, 7px);
  gap: 3px;
  padding: 6px;
  border-radius: 9px;
  background: var(--ink);
  border: 1px solid var(--line-2);
}
.mark i {
  width: 7px;
  height: 7px;
  border-radius: 2px;
  background: var(--faint);
}
.mark i:nth-child(1) { background: var(--cyan); }
.mark i:nth-child(3) { background: var(--pink); }
.mark i:nth-child(5) { background: #f2f4f8; }
.mark i:nth-child(6) { background: var(--amber); }
.mark i:nth-child(8) { background: var(--cyan); }
.mark i:nth-child(9) { background: var(--green); }
.mark i:nth-child(2),
.mark i:nth-child(4),
.mark i:nth-child(7) { background: #1b2130; }

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 650;
  letter-spacing: 0.01em;
  text-decoration: none;
}

/* ---------- buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 12px;
  border: 1px solid var(--line-2);
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  font-weight: 560;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s, border-color 0.15s, transform 0.1s;
  white-space: nowrap;
}
.btn:hover {
  background: rgba(255, 255, 255, 0.08);
}
.btn:active {
  transform: scale(0.98);
}
.btn.primary {
  background: #f2f4f8;
  color: #0a0d14;
  border-color: transparent;
}
.btn.primary:hover {
  background: #fff;
}
.btn.ghost {
  background: transparent;
  border-color: transparent;
}
.btn.icon {
  width: 44px;
  padding: 0;
}
.btn svg {
  width: 20px;
  height: 20px;
  flex: none;
}

/* ---------- segmented control */
.seg {
  display: inline-flex;
  padding: 3px;
  gap: 2px;
  border-radius: 11px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--line);
}
.seg button {
  min-height: 32px;
  padding: 0 11px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--muted);
  font-size: 13px;
  font-weight: 560;
  cursor: pointer;
}
.seg button[aria-pressed='true'] {
  background: rgba(255, 255, 255, 0.12);
  color: var(--text);
}

/* ---------- panels */
.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  backdrop-filter: blur(18px) saturate(1.2);
  -webkit-backdrop-filter: blur(18px) saturate(1.2);
  box-shadow: var(--shadow);
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--panel);
  border: 1px solid var(--line);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  font-size: 13px;
  color: var(--muted);
  max-width: 100%;
}
.chip b {
  color: var(--text);
  font-weight: 600;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--faint);
  flex: none;
}
.dot.live {
  background: var(--green);
  box-shadow: 0 0 0 4px rgba(43, 220, 116, 0.15);
}
.dot.warn {
  background: var(--amber);
}

.num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
}

/* ---------- landing */
.landing {
  min-height: 100%;
  display: flex;
  flex-direction: column;
  padding: max(20px, env(safe-area-inset-top)) 20px max(24px, env(safe-area-inset-bottom));
  max-width: 980px;
  margin: 0 auto;
}
.landing header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.hero {
  padding: 9vh 0 5vh;
}
.hero h1 {
  font-size: clamp(30px, 6vw, 52px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 0 0 14px;
  font-weight: 700;
}
.hero h1 em {
  font-style: normal;
  background: linear-gradient(90deg, var(--cyan), var(--pink) 55%, var(--amber));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero p {
  color: var(--muted);
  font-size: 17px;
  max-width: 560px;
  margin: 0;
}
.choices {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 14px;
}
.choice {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px;
  border-radius: 20px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.05), rgba(255, 255, 255, 0.02));
  border: 1px solid var(--line);
  text-decoration: none;
  transition: border-color 0.2s, transform 0.2s, background 0.2s;
}
.choice:hover {
  border-color: var(--line-2);
  transform: translateY(-2px);
}
.choice .ico {
  width: 46px;
  height: 46px;
  border-radius: 13px;
  display: grid;
  place-items: center;
  background: rgba(34, 216, 255, 0.12);
  color: var(--cyan);
}
.choice.recv .ico {
  background: rgba(255, 61, 154, 0.12);
  color: var(--pink);
}
.choice .ico svg {
  width: 24px;
  height: 24px;
}
.choice h2 {
  margin: 6px 0 0;
  font-size: 20px;
  font-weight: 650;
}
.choice p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}
.choice .go {
  margin-top: auto;
  padding-top: 8px;
  color: var(--text);
  font-weight: 560;
  font-size: 14px;
}
.facts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 18px 24px;
  margin: 7vh 0 4vh;
  padding-top: 26px;
  border-top: 1px solid var(--line);
}
.facts h3 {
  margin: 0 0 4px;
  font-size: 14px;
  font-weight: 620;
}
.facts p {
  margin: 0;
  font-size: 13px;
  color: var(--muted);
}
.foot {
  margin-top: auto;
  color: var(--faint);
  font-size: 12px;
}

.lang {
  border: 1px solid var(--line);
  background: transparent;
  color: var(--muted);
  border-radius: 9px;
  padding: 5px 10px;
  font-size: 12px;
  cursor: pointer;
}

/* ---------- full-screen stage (send + receive) */
.stage {
  position: fixed;
  inset: 0;
  overflow: hidden;
  background: var(--bg);
}
.topbar {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: max(12px, env(safe-area-inset-top)) 14px 10px;
  z-index: 5;
  pointer-events: none;
}
.topbar > * {
  pointer-events: auto;
}
.topbar .spacer {
  flex: 1;
}

/* ---------- empty state / drop zone */
.drop {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 80px 20px 40px;
}
.drop-card {
  width: min(520px, 100%);
  padding: 34px 26px 26px;
  text-align: center;
  border-radius: 24px;
  border: 1.5px dashed rgba(255, 255, 255, 0.16);
  background: rgba(255, 255, 255, 0.02);
  transition: border-color 0.2s, background 0.2s;
}
.drop.over .drop-card {
  border-color: var(--cyan);
  background: rgba(34, 216, 255, 0.05);
}
.tabs {
  margin: -8px auto 22px;
}
.tabs button {
  min-width: 84px;
}
.drop-card textarea {
  display: block;
  width: 100%;
  min-height: 190px;
  max-height: 50vh;
  resize: vertical;
  padding: 14px;
  border-radius: 14px;
  border: 1px solid var(--line-2);
  background: rgba(0, 0, 0, 0.3);
  font-size: 15px;
  line-height: 1.5;
  text-align: left;
  outline: none;
}
.drop-card textarea:focus {
  border-color: rgba(34, 216, 255, 0.55);
}
.text-meta {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin: 8px 2px 16px;
  font-size: 12px;
  color: var(--faint);
}
.btn:disabled {
  opacity: 0.4;
  cursor: default;
}
.drop-card h1 {
  margin: 16px 0 6px;
  font-size: 22px;
  font-weight: 650;
}
.drop-card p {
  margin: 0 0 22px;
  color: var(--muted);
}
.drop-card .row {
  display: flex;
  gap: 10px;
  justify-content: center;
  flex-wrap: wrap;
}
.drop-art {
  width: 64px;
  height: 64px;
  margin: 0 auto;
  border-radius: 18px;
  display: grid;
  place-items: center;
  background: rgba(34, 216, 255, 0.1);
  color: var(--cyan);
}
.drop-art svg {
  width: 30px;
  height: 30px;
}
.hint {
  margin-top: 18px;
  color: var(--faint);
  font-size: 12.5px;
}

/* ---------- code display */
.codewrap {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
}
.codewrap {
  cursor: pointer;
}
#code {
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  display: block;
}

/* ---------- floating dock */
.dock {
  position: absolute;
  left: 50%;
  bottom: max(12px, env(safe-area-inset-bottom));
  transform: translateX(-50%);
  width: min(720px, calc(100% - 16px));
  padding: 10px;
  z-index: 6;
  transition: opacity 0.25s, transform 0.25s;
}
.dock.away {
  opacity: 0;
  transform: translate(-50%, 16px);
  pointer-events: none;
}
.dock .row {
  display: flex;
  align-items: center;
  gap: 8px;
}
.dock .grow {
  flex: 1;
  min-width: 0;
}
.fileinfo .fname {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  min-width: 0;
}
.fileinfo .fname b {
  font-weight: 620;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  min-width: 0;
}
.fileinfo .fname span.num {
  color: var(--muted);
  font-size: 12.5px;
  white-space: nowrap;
}
.dock .stats {
  font-size: 12px;
  color: var(--muted);
  display: flex;
  gap: 12px;
  overflow: hidden;
  white-space: nowrap;
}
.dock .stats b {
  color: var(--text);
  font-weight: 600;
}
.settings {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--line);
}
#setBtn[aria-expanded='true'] {
  background: rgba(255, 255, 255, 0.12);
}
.field {
  display: flex;
  align-items: center;
  gap: 8px;
}
.field > span {
  font-size: 12px;
  color: var(--faint);
}
input[type='range'] {
  accent-color: var(--cyan);
  width: 110px;
}

/* ---------- modal */
.modal {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: grid;
  place-items: center;
  padding: 20px;
  background: rgba(0, 0, 0, 0.55);
}
.modal .panel {
  width: min(560px, 100%);
  padding: 20px;
}
.modal h2 {
  margin: 0 0 12px;
  font-size: 18px;
}
.modal textarea {
  width: 100%;
  min-height: 180px;
  resize: vertical;
  padding: 12px;
  border-radius: 12px;
  border: 1px solid var(--line-2);
  background: rgba(0, 0, 0, 0.3);
  outline: none;
}
.modal .row {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  margin-top: 14px;
}

/* ---------- receiver */
#video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  background: #000;
}
#overlay {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}
.viewfinder {
  position: absolute;
  inset: 0;
  pointer-events: none;
  display: grid;
  place-items: center;
}
.viewfinder i {
  position: absolute;
  width: 34px;
  height: 34px;
  border: 3px solid rgba(255, 255, 255, 0.55);
}
.recv-bottom {
  position: absolute;
  left: 50%;
  bottom: max(14px, env(safe-area-inset-bottom));
  transform: translateX(-50%);
  width: min(560px, calc(100% - 20px));
  padding: 16px;
  z-index: 6;
}
.progress {
  height: 8px;
  border-radius: 99px;
  background: rgba(255, 255, 255, 0.08);
  overflow: hidden;
}
.progress > div {
  height: 100%;
  width: 0;
  border-radius: 99px;
  background: linear-gradient(90deg, var(--cyan), var(--pink), var(--amber));
  transition: width 0.25s ease-out;
}
.recv-title {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}
.recv-title .name {
  font-weight: 620;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.recv-title .pct {
  font-family: var(--mono);
  font-size: 22px;
  font-weight: 650;
}
.metrics {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin-top: 12px;
}
.metrics div {
  font-size: 11.5px;
  color: var(--faint);
}
.metrics b {
  display: block;
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
}
.tip {
  margin-top: 10px;
  font-size: 13px;
  color: var(--amber);
  min-height: 1.2em;
}
.tip.ok {
  color: var(--muted);
}
.diag {
  margin-top: 6px;
  font-size: 11px;
  color: var(--faint);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.side-tools {
  position: absolute;
  right: max(12px, env(safe-area-inset-right));
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  gap: 10px;
  z-index: 6;
}
.side-tools .btn {
  background: var(--panel);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}
.zoom {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  bottom: calc(max(14px, env(safe-area-inset-bottom)) + 190px);
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 14px;
  z-index: 6;
  font-size: 12px;
  color: var(--muted);
}

.start {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 24px;
  text-align: center;
  z-index: 8;
  background: radial-gradient(ellipse at 50% 30%, rgba(255, 61, 154, 0.08), transparent 60%), var(--bg);
}
.start .inner {
  max-width: 420px;
}
.start h1 {
  font-size: 24px;
  margin: 18px 0 8px;
}
.start p {
  color: var(--muted);
  margin: 0 0 22px;
}
.start .drop-art {
  background: rgba(255, 61, 154, 0.12);
  color: var(--pink);
}
.err {
  color: var(--red);
  font-size: 13px;
  margin-top: 14px;
}

.done {
  position: absolute;
  inset: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: max(14px, env(safe-area-inset-top)) 14px max(14px, env(safe-area-inset-bottom));
  background: rgba(4, 6, 10, 0.7);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
/* the panel never exceeds the screen; a long preview scrolls inside it */
.done .panel {
  width: min(460px, 100%);
  max-height: 100%;
  display: flex;
  flex-direction: column;
  padding: 24px;
  text-align: center;
}
.done .panel.wide {
  width: min(760px, 100%);
}
.done .panel > * {
  flex: none;
}
.done .badge {
  width: 58px;
  height: 58px;
  margin: 0 auto 14px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: rgba(43, 220, 116, 0.14);
  color: var(--green);
}
.done .badge svg {
  width: 28px;
  height: 28px;
}
.done h2 {
  margin: 0 0 4px;
  font-size: 19px;
  word-break: break-all;
}
.done .sub {
  color: var(--muted);
  font-size: 13.5px;
}
.done .panel > .preview {
  flex: 0 1 auto;
  min-height: 72px;
  margin: 16px 0 4px;
  overflow: auto;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
  border-radius: 12px;
  border: 1px solid var(--line);
  text-align: left;
}
.done .preview img {
  display: block;
  max-width: 100%;
  max-height: 55vh;
  margin: 0 auto;
  object-fit: contain;
}
.done .preview.text {
  background: rgba(0, 0, 0, 0.28);
}
/* fade at the bottom while there is more text below */
.done .preview.fade {
  -webkit-mask-image: linear-gradient(to bottom, #000 calc(100% - 44px), transparent);
  mask-image: linear-gradient(to bottom, #000 calc(100% - 44px), transparent);
}
.done .more-hint {
  margin-top: 6px;
  font-size: 12px;
  color: var(--faint);
}
.done .preview.text pre {
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.55;
  user-select: text;
  -webkit-user-select: text;
}
.done .preview pre {
  margin: 0;
  padding: 12px;
  font-family: var(--mono);
  font-size: 12.5px;
  white-space: pre-wrap;
  word-break: break-word;
  overflow-wrap: anywhere;
}
.done .row {
  display: flex;
  gap: 10px;
  justify-content: center;
  margin-top: 18px;
  flex-wrap: wrap;
}

@media (max-width: 560px) {
  .dock .stats span.wide {
    display: none;
  }
  .metrics b {
    font-size: 13px;
  }
}