/* 随码 v0.2 · 纸白 / 墨 / 鼠尾草 的安静接收器
   只使用本地字体，无外链、无渐变。 */

:root {
  --paper: #fafaf8;
  --paper-raise: #fffefb;
  --ink: #242721;
  --muted: #646960;
  --rule: #dddfd7;
  --sage: #e9eee6;
  --accent: #486751;
  --accent-press: #3c5744;
  --warn: #8a4b2f;
  --warn-bg: #f5eae3;

  --serif: "Songti SC", "STSong", "Noto Serif CJK SC", Georgia, serif;
  --sans: "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, sans-serif;
  --ease: cubic-bezier(0.2, 0, 0, 1);

  --r-outer: 20px;
  --r-md: 14px;
  --r-sm: 10px;

  --shadow-1: 0 1px 0 rgba(0, 0, 0, 0.04), 0 2px 6px rgba(0, 0, 0, 0.04);
  --shadow-2: 0 1px 0 rgba(0, 0, 0, 0.05), 0 10px 30px rgba(0, 0, 0, 0.07);
}

* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-block-size: 100vh;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  text-align: start;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
}

.page {
  inline-size: 100%;
  max-inline-size: 660px;
  margin-inline: auto;
  padding-block-start: max(16px, env(safe-area-inset-top));
  padding-block-end: calc(44px + env(safe-area-inset-bottom));
  padding-inline: clamp(16px, 4vw, 28px);
}

/* ---------- header ---------- */
.site-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  padding-block-end: 14px;
  border-block-end: 1px solid var(--rule);
}

.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 0.06em;
}

.mark {
  inline-size: 26px;
  block-size: 26px;
  flex: 0 0 auto;
}

.head-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.offline-state {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.04em;
  padding-inline-end: 4px;
}

.dot {
  inline-size: 7px;
  block-size: 7px;
  border-radius: 50%;
  background: #b9bdb2;
  flex: 0 0 auto;
}

.offline-state[data-state="ready"] .dot { background: var(--accent); }
.offline-state[data-state="pending"] .dot { background: #b5903f; }
.offline-state[data-state="partial"] .dot,
.offline-state[data-state="insecure"] .dot { background: var(--warn); }
.offline-state[data-state="error"] .dot,
.offline-state[data-state="unsupported"] .dot { background: #8f2f24; }

.link-btn {
  appearance: none;
  background: transparent;
  border: 0;
  min-block-size: 44px;
  padding-block: 8px;
  padding-inline: 6px;
  font-family: var(--sans);
  font-size: 13px;
  color: var(--muted);
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: transparent;
  transition: color 140ms var(--ease), text-decoration-color 140ms var(--ease);
}

.link-btn:hover { color: var(--ink); text-decoration-color: var(--rule); }
.link-btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 6px; }

/* ---------- alerts / banner ---------- */
.alert {
  margin-block-start: 18px;
  padding-block: 12px;
  padding-inline: 16px;
  border-radius: var(--r-md);
  background: var(--warn-bg);
  color: var(--warn);
  border-inline-start: 3px solid var(--warn);
  font-size: 14px;
  overflow-wrap: anywhere;
}

.banner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  margin-block-start: 18px;
  padding-block: 12px;
  padding-inline: 16px;
  border-radius: var(--r-md);
  background: var(--sage);
  border: 1px solid var(--rule);
  font-size: 14px;
}

.banner p { margin: 0; }

/* ---------- instrument ---------- */
.instrument {
  padding-block-start: clamp(16px, 4vw, 28px);
}

.stage { display: block; }

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--muted);
}

.kicker::before {
  content: "";
  inline-size: 20px;
  block-size: 1px;
  background: var(--rule);
}

.display {
  margin: 0 0 12px;
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(30px, 7.4vw, 46px);
  line-height: 1.14;
  letter-spacing: 0.01em;
  text-wrap: balance;
}

.display-sm {
  font-size: clamp(28px, 6vw, 38px);
  margin-block: 6px 8px;
}

.lede {
  margin: 0 0 20px;
  max-inline-size: 34em;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.75;
  text-wrap: pretty;
}

/* ---------- scan target ---------- */
.scan-target {
  --corner: rgba(36, 39, 33, 0.34);
  position: relative;
  inline-size: clamp(240px, 72vw, 280px);
  max-inline-size: 100%;
  margin-inline: auto;
  aspect-ratio: 1 / 1;
  border-radius: var(--r-outer);
  border: 1px solid var(--rule);
  background: var(--paper-raise);
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, 0.015);
  overflow: hidden;
  display: grid;
  place-items: center;
}

.scan-target.is-live {
  --corner: rgba(250, 250, 248, 0.6);
  background: #1b1c17;
  border-color: #1b1c17;
}

.scan-target video {
  inline-size: 100%;
  block-size: 100%;
  object-fit: cover;
  display: block;
}

.corner-frame {
  position: absolute;
  inset: 14px;
  pointer-events: none;
}

.corner {
  position: absolute;
  inline-size: 26px;
  block-size: 26px;
  border: 0 solid var(--corner);
}

.corner-tl { inset-block-start: 0; inset-inline-start: 0; border-block-start-width: 2px; border-inline-start-width: 2px; border-start-start-radius: 8px; }
.corner-tr { inset-block-start: 0; inset-inline-end: 0; border-block-start-width: 2px; border-inline-end-width: 2px; border-start-end-radius: 8px; }
.corner-bl { inset-block-end: 0; inset-inline-start: 0; border-block-end-width: 2px; border-inline-start-width: 2px; border-end-start-radius: 8px; }
.corner-br { inset-block-end: 0; inset-inline-end: 0; border-block-end-width: 2px; border-inline-end-width: 2px; border-end-end-radius: 8px; }

.scan-empty {
  position: relative;
  text-align: center;
  padding: 28px;
  color: var(--muted);
}

.scan-mark {
  inline-size: 52px;
  block-size: 52px;
  color: var(--accent);
  opacity: 0.85;
  margin-block-end: 10px;
}

.scan-empty p {
  margin: 0;
  font-size: 13px;
  letter-spacing: 0.14em;
}

/* ---------- buttons ---------- */
.actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.actions-scan { margin-block-start: 18px; }
.actions-result { margin-block-start: 4px; }

.btn {
  appearance: none;
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.2;
  min-block-size: 48px;
  padding-block: 13px;
  padding-inline: 20px;
  border-radius: 12px;
  border: 1px solid transparent;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  text-align: center;
  color: var(--ink);
  background: transparent;
  transition: background-color 140ms var(--ease), border-color 140ms var(--ease),
    color 140ms var(--ease), transform 140ms var(--ease), box-shadow 140ms var(--ease);
}

.btn:active { transform: scale(0.96); }
.btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #ffffff;
  box-shadow: var(--shadow-1);
}

.btn-primary:hover { background: var(--accent-press); border-color: var(--accent-press); }

.btn-secondary {
  background: var(--paper-raise);
  border-color: var(--rule);
  color: var(--ink);
}

.btn-secondary:hover { background: var(--sage); }

.btn-quiet {
  background: transparent;
  border-color: transparent;
  color: var(--muted);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--rule);
  padding-inline: 8px;
}

.btn-quiet:hover { color: var(--ink); text-decoration-color: var(--ink); }

.btn-small { min-block-size: 44px; padding-block: 10px; padding-inline: 14px; font-size: 14px; }

.actions-scan .btn-primary { flex: 0 0 auto; min-inline-size: 132px; }

/* copy icon crossfade */
.btn-copy { padding-inline: 18px 22px; }

.ico-swap {
  position: relative;
  inline-size: 20px;
  block-size: 20px;
  flex: 0 0 auto;
}

.ico {
  position: absolute;
  inset: 0;
  inline-size: 20px;
  block-size: 20px;
  transition: opacity 300ms var(--ease), transform 300ms var(--ease), filter 300ms var(--ease);
}

.ico-check { opacity: 0; transform: scale(0.25); filter: blur(4px); }

.btn-copy.is-copied .ico-copy { opacity: 0; transform: scale(0.25); filter: blur(4px); }
.btn-copy.is-copied .ico-check { opacity: 1; transform: scale(1); filter: blur(0); }

/* ---------- status / notes / fields ---------- */
.status-line {
  margin-block: 10px 0;
  font-size: 13px;
  color: var(--muted);
  line-height: 1.6;
}

.note {
  margin-block: 10px 0;
  font-size: 13px;
  color: var(--muted);
  line-height: 1.65;
}

.exp-note {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.exp-label {
  display: inline-flex;
  align-items: center;
  min-block-size: 22px;
  padding-inline: 8px;
  border-radius: 999px;
  background: var(--sage);
  border: 1px solid var(--rule);
  color: var(--accent);
  font-size: 11px;
  letter-spacing: 0.08em;
}

.field-label {
  display: block;
  margin-block-end: 8px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

textarea {
  inline-size: 100%;
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  color: var(--ink);
  background: var(--paper-raise);
  border: 1px solid var(--rule);
  border-radius: 12px;
  padding-block: 14px;
  padding-inline: 14px;
  min-block-size: 96px;
  resize: vertical;
}

textarea:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
  border-color: var(--accent);
}

.row {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

/* ---------- disclosures ---------- */
.disclosures {
  margin-block-start: 20px;
  display: grid;
  gap: 0;
}

.disclosure {
  border-block-start: 1px solid var(--rule);
}

.disclosures .disclosure:last-child {
  border-block-end: 1px solid var(--rule);
}

.disclosure > summary {
  list-style: none;
  min-block-size: 54px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-block: 15px;
  cursor: pointer;
  font-size: 15px;
  color: var(--ink);
}

.disclosure > summary::-webkit-details-marker { display: none; }

.disclosure > summary::after {
  content: "展开";
  flex: 0 0 auto;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.disclosure[open] > summary::after { content: "收起"; }

.disclosure > summary:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 6px;
}

.disclosure-body {
  display: grid;
  gap: 12px;
  padding-block: 4px 24px;
}

/* ---------- LAN ---------- */
.lan-status:empty { display: none; }

.lan-answer {
  display: grid;
  gap: 12px;
  margin-block-start: 8px;
}

.answer-viewport {
  inline-size: min(100%, 300px);
  margin-inline: auto;
  aspect-ratio: 1 / 1;
  background: var(--paper-raise);
  border: 1px solid var(--rule);
  border-radius: var(--r-md);
  padding: 12px;
  display: grid;
  place-items: center;
}

.answer-viewport canvas {
  inline-size: 100%;
  block-size: 100%;
  display: block;
}

.answer-caption,
.answer-counter {
  margin: 0;
  text-align: center;
  font-size: 13px;
  color: var(--muted);
}

.answer-counter { font-size: 12px; letter-spacing: 0.06em; }

/* ---------- result ---------- */
.result-head { margin-block-end: 22px; }

.result-meta {
  margin: 0;
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.result-text {
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1.8;
  background: var(--paper-raise);
  border: 1px solid var(--rule);
  border-radius: var(--r-outer);
  padding-block: 18px;
  padding-inline: 20px;
  /* 随内容自适应，短文本不浪费空间，长文本在 360px 内滚动。 */
  field-sizing: content;
  min-block-size: 160px;
  max-block-size: 360px;
  overflow: auto;
  box-shadow: var(--shadow-1);
}

.copy-note { min-block-size: 1.4em; }

/* ---------- footer ---------- */
.foot {
  margin-block-start: 56px;
  padding-block-start: 16px;
  border-block-start: 1px solid var(--rule);
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.04em;
}

.foot p { margin: 0; }
.foot-mark { font-family: var(--serif); }

/* ---------- help dialog ---------- */
.dialog {
  border: 0;
  padding: 0;
  background: transparent;
  color: var(--ink);
  inline-size: min(92vw, 560px);
  max-inline-size: 560px;
}

.dialog::backdrop {
  background: rgba(20, 22, 18, 0.36);
}

.dialog-inner {
  background: var(--paper);
  border: 1px solid var(--rule);
  border-radius: var(--r-outer);
  box-shadow: var(--shadow-2);
  max-block-size: 86vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.dialog-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-block: 18px;
  padding-inline: 22px;
  border-block-end: 1px solid var(--rule);
}

.dialog-head h2 {
  margin: 0;
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 600;
}

.dialog-head h2:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 6px; }

.dialog-close {
  appearance: none;
  inline-size: 44px;
  block-size: 44px;
  flex: 0 0 auto;
  border-radius: 50%;
  border: 1px solid var(--rule);
  background: transparent;
  color: var(--muted);
  font-size: 22px;
  line-height: 1;
  cursor: pointer;
  transition: background-color 140ms var(--ease), color 140ms var(--ease);
}

.dialog-close:hover { background: var(--sage); color: var(--ink); }
.dialog-close:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.dialog-body {
  padding-block: 6px 26px;
  padding-inline: 22px;
  overflow: auto;
  display: grid;
  gap: 18px;
}

.help-block h3 {
  margin: 14px 0 8px;
  font-family: var(--serif);
  font-size: 17px;
  font-weight: 600;
}

.help-block h3:first-child { margin-block-start: 6px; }

.help-list {
  margin: 0;
  padding-inline-start: 1.25em;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.help-list li { margin-block: 5px; }

.dialog details {
  border-block-start: 1px solid var(--rule);
  padding-block: 4px;
}

.dialog summary {
  list-style: none;
  min-block-size: 44px;
  display: flex;
  align-items: center;
  cursor: pointer;
  font-size: 14px;
  color: var(--ink);
}

.dialog summary::-webkit-details-marker { display: none; }

.dialog summary::after {
  content: "＋";
  margin-inline-start: auto;
  color: var(--muted);
}

.dialog details[open] summary::after { content: "－"; }

.dialog summary:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 6px; }

/* ---------- utilities ---------- */
.sr-only {
  position: absolute;
  inline-size: 1px;
  block-size: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

[hidden] { display: none !important; }

/* ---------- responsive ---------- */
@media (max-width: 420px) {
  .actions .btn { flex: 1 1 100%; }
  .actions-scan .btn-primary { min-inline-size: 0; }
}

@media (min-width: 640px) {
  .page { padding-inline: 32px; }
  .instrument { padding-block-start: clamp(28px, 5vw, 44px); }
  .scan-target { inline-size: min(100%, 320px); }
  .display { font-size: clamp(40px, 5.4vw, 56px); }
}

@media (min-width: 960px) {
  .page { max-inline-size: 700px; }
}

@media (prefers-reduced-motion: reduce) {
  .btn,
  .ico,
  .link-btn,
  .dialog-close {
    transition: none !important;
  }
  .btn:active { transform: none; }
}