:root {
  color-scheme: dark;
  --page: #07100e;
  --surface: #0c1715;
  --surface-2: #111e25;
  --ink: #f4f8f7;
  --muted: #aabbb7;
  --line: rgba(169, 205, 197, 0.2);
  --green: #6fd36f;
  --cyan: #59c9e8;
  --amber: #f0bd4f;
  --orange: #e9773d;
  --shadow: 0 28px 80px rgba(0, 0, 0, 0.36);
}

html.light {
  color-scheme: light;
  --page: #eef4f1;
  --surface: #ffffff;
  --surface-2: #e5efec;
  --ink: #12231f;
  --muted: #526761;
  --line: rgba(29, 82, 69, 0.2);
  --shadow: 0 24px 60px rgba(26, 68, 57, 0.16);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background-color: var(--page);
  background-image:
    linear-gradient(rgba(89, 201, 232, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(111, 211, 111, 0.045) 1px, transparent 1px);
  background-size: 64px 64px;
  font-family: "Segoe UI", "Noto Sans TC", "PingFang TC", Arial, sans-serif;
  letter-spacing: 0;
}

button, a { font: inherit; }
button { color: inherit; }
a { color: inherit; }

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 100;
  padding: 10px 14px;
  color: #07100e;
  background: var(--green);
  transform: translateY(-150%);
}

.skip-link:focus { transform: translateY(0); }

.card-site-header {
  min-height: 78px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 14px clamp(18px, 4vw, 64px);
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--page) 92%, transparent);
  backdrop-filter: blur(14px);
}

.brand-lockup {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
}

.brand-lockup img,
.mini-brand img {
  display: block;
  object-fit: cover;
  border: 1px solid rgba(89, 201, 232, 0.38);
  border-radius: 50%;
}

.brand-lockup span { display: grid; gap: 1px; }
.brand-lockup strong { font-size: 1.05rem; }
.brand-lockup small { color: var(--muted); font: 0.72rem/1.1 Consolas, monospace; }

.header-actions { display: flex; align-items: center; gap: 10px; }

.language-switch {
  display: grid;
  grid-template-columns: 1fr 1fr;
  padding: 3px;
  border: 1px solid var(--line);
  background: var(--surface);
}

.language-switch button,
.icon-button {
  min-width: 48px;
  min-height: 40px;
  border: 0;
  background: transparent;
  cursor: pointer;
}

.language-switch button.active {
  color: #07100e;
  background: var(--green);
  font-weight: 800;
}

.icon-button {
  border: 1px solid var(--line);
  background: var(--surface);
  font-size: 1.2rem;
}

.card-page {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: clamp(36px, 6vw, 74px) 0 48px;
}

.page-heading {
  width: min(880px, 100%);
  margin: 0 auto clamp(24px, 4vw, 38px);
}

.eyebrow {
  margin: 0 0 9px;
  color: var(--cyan);
  font: 700 0.82rem/1.2 Consolas, monospace;
}

.page-heading h1 {
  margin: 0;
  font-size: clamp(1.75rem, 4vw, 3rem);
  line-height: 1.15;
}

.page-heading > p:last-child {
  max-width: 740px;
  margin: 13px 0 0;
  color: var(--muted);
  line-height: 1.75;
}

.card-workspace { text-align: center; }

.card-stage {
  width: min(920px, 100%);
  margin: 0 auto;
  perspective: 1800px;
}

.business-card {
  width: 100%;
  aspect-ratio: 1.586 / 1;
  outline: none;
}

.business-card:focus-visible {
  box-shadow: 0 0 0 3px var(--page), 0 0 0 6px var(--cyan);
}

.card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 620ms cubic-bezier(.2, .75, .2, 1);
}

.business-card.is-flipped .card-inner { transform: rotateY(180deg); }

.card-face {
  position: absolute;
  inset: 0;
  overflow: hidden;
  border: 1px solid rgba(128, 195, 178, 0.32);
  border-radius: 8px;
  box-shadow: var(--shadow);
  backface-visibility: hidden;
  text-align: left;
}

.card-front {
  background:
    linear-gradient(100deg, #0b1715 0 61%, #11212b 61% 100%);
  color: #f4f8f7;
}

.card-back {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(190px, 30%);
  gap: clamp(20px, 4vw, 46px);
  align-items: center;
  padding: clamp(28px, 5vw, 58px);
  transform: rotateY(180deg);
  background: #101d22;
  color: #f4f8f7;
}

.card-grid {
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.42;
  background-image:
    linear-gradient(rgba(89, 201, 232, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(111, 211, 111, 0.065) 1px, transparent 1px);
  background-size: 44px 44px;
}

.corner {
  position: absolute;
  z-index: 2;
  width: 64px;
  height: 64px;
  pointer-events: none;
}

.corner::before,
.corner::after {
  content: "";
  position: absolute;
  background: var(--cyan);
}

.corner-top { top: 20px; left: 20px; }
.corner-top::before { width: 64px; height: 3px; }
.corner-top::after { width: 3px; height: 42px; }
.corner-bottom { right: 20px; bottom: 20px; transform: rotate(180deg); }
.corner-bottom::before { width: 64px; height: 3px; }
.corner-bottom::after { width: 3px; height: 42px; }

.front-content {
  position: relative;
  z-index: 1;
  width: 62%;
  height: 100%;
  display: flex;
  flex-direction: column;
  padding: clamp(32px, 5.2vw, 64px);
}

.mini-brand {
  display: flex;
  align-items: center;
  gap: 13px;
}

.mini-brand > div { display: grid; gap: 2px; }
.mini-brand strong { font-size: clamp(1.1rem, 2.2vw, 1.6rem); }
.mini-brand span { color: var(--cyan); font: 700 clamp(0.64rem, 1vw, 0.8rem)/1.2 Consolas, monospace; }

.identity-block {
  margin-top: auto;
  margin-bottom: auto;
}

.identity-label {
  margin: 0 0 6px;
  color: var(--green);
  font: 700 clamp(0.64rem, 1.1vw, 0.78rem)/1.2 Consolas, monospace;
}

.identity-block h2 {
  margin: 0;
  font-size: clamp(1.7rem, 4.2vw, 3.45rem);
  line-height: 1.08;
}

.role {
  margin: 8px 0 0;
  color: #d7e5e1;
  font-size: clamp(0.9rem, 1.8vw, 1.35rem);
  font-weight: 700;
}

.promise {
  max-width: 570px;
  margin: clamp(12px, 2vw, 20px) 0 0;
  color: #aebfbb;
  font-size: clamp(0.72rem, 1.25vw, 0.98rem);
  line-height: 1.65;
}

.service-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-bottom: clamp(12px, 2vw, 20px);
}

.service-strip span {
  min-height: 26px;
  display: inline-flex;
  align-items: center;
  padding: 4px 9px;
  border: 1px solid rgba(111, 211, 111, 0.32);
  color: #cce7d0;
  background: rgba(111, 211, 111, 0.07);
  font-size: clamp(0.6rem, 1vw, 0.72rem);
}

.front-contact {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  color: #8fb2aa;
  font: 700 clamp(0.62rem, 1vw, 0.75rem)/1.25 Consolas, monospace;
}

.language-signal {
  position: absolute;
  z-index: 1;
  top: 0;
  right: 0;
  width: 39%;
  height: 100%;
  padding: clamp(34px, 5.2vw, 64px) clamp(22px, 4vw, 48px);
}

.signal-kicker,
.signal-foot {
  margin: 0;
  color: var(--amber);
  font: 700 clamp(0.58rem, 1vw, 0.75rem)/1.2 Consolas, monospace;
}

.source-message {
  margin-top: clamp(40px, 6vw, 72px);
  padding: clamp(10px, 1.5vw, 15px);
  border-left: 3px solid var(--green);
  background: rgba(111, 211, 111, 0.11);
  font-size: clamp(0.68rem, 1.25vw, 0.9rem);
  font-weight: 700;
}

.signal-line {
  width: 1px;
  height: 22px;
  margin-left: 20px;
  background: var(--cyan);
}

.language-output {
  display: grid;
  grid-template-columns: 32px 1fr;
  gap: 9px;
  align-items: center;
  margin: 7px 0;
  padding: 7px 9px;
  border: 1px solid rgba(89, 201, 232, 0.22);
  background: rgba(5, 12, 16, 0.52);
  font-size: clamp(0.56rem, 1vw, 0.72rem);
}

.language-output b { color: var(--cyan); font-family: Consolas, monospace; }
.language-output span { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.output-b { margin-left: 9%; }
.output-c { margin-left: 18%; }
.output-d { margin-left: 27%; }
.signal-foot { position: absolute; right: clamp(22px, 4vw, 48px); bottom: clamp(34px, 5.2vw, 64px); }

.back-copy { position: relative; z-index: 1; min-width: 0; }
.back-copy h2 { max-width: 560px; margin: clamp(24px, 4vw, 42px) 0 22px; font-size: clamp(1.25rem, 2.8vw, 2.25rem); line-height: 1.3; }

.contact-list { list-style: none; display: grid; gap: 10px; padding: 0; margin: 0; }
.contact-list li { display: grid; grid-template-columns: 54px minmax(0, 1fr); align-items: center; gap: 12px; }
.contact-list li > span { color: var(--green); font: 700 0.74rem/1.2 Consolas, monospace; }
.contact-list a { min-width: 0; overflow-wrap: anywhere; color: #d8e7e3; text-decoration-color: rgba(89, 201, 232, 0.52); text-underline-offset: 4px; }

.safety-note {
  max-width: 610px;
  margin: clamp(22px, 4vw, 40px) 0 0;
  padding-left: 13px;
  border-left: 3px solid var(--amber);
  color: #aebfbb;
  font-size: clamp(0.68rem, 1.15vw, 0.85rem);
  line-height: 1.65;
}

.qr-panel {
  position: relative;
  z-index: 1;
  display: grid;
  justify-items: center;
  gap: 9px;
  padding: clamp(14px, 2vw, 22px);
  border: 1px solid rgba(111, 211, 111, 0.36);
  background: #f8fbf9;
  color: #11231e;
  text-decoration: none;
}

.qr-panel img { display: block; width: min(100%, 220px); height: auto; image-rendering: pixelated; }
.qr-panel strong { font-size: clamp(0.72rem, 1.2vw, 0.9rem); }
.qr-panel span { color: #357c44; font: 800 0.78rem/1.2 Consolas, monospace; }

.card-toolbar {
  width: min(680px, 100%);
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  margin: 30px auto 0;
}

.card-toolbar button,
.card-toolbar a {
  min-width: 0;
  min-height: 72px;
  display: grid;
  place-items: center;
  align-content: center;
  gap: 5px;
  padding: 10px;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--ink);
  text-decoration: none;
  cursor: pointer;
}

.card-toolbar button:hover,
.card-toolbar a:hover,
.card-toolbar button:focus-visible,
.card-toolbar a:focus-visible {
  border-color: var(--cyan);
  background: var(--surface-2);
}

.button-icon { font-size: 1.16rem; font-weight: 800; line-height: 1; }
.line-mark { color: var(--green); font: 800 0.68rem/1 Consolas, monospace; }
.card-toolbar button > span:last-child,
.card-toolbar a > span:last-child { font-size: 0.78rem; }

.card-hint,
.action-status {
  min-height: 1.35em;
  margin: 14px auto 0;
  color: var(--muted);
  font-size: 0.82rem;
  line-height: 1.6;
}

.action-status { margin-top: 4px; color: var(--green); font-weight: 700; }

.card-footer {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding: 28px clamp(18px, 4vw, 64px);
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.8rem;
}

.card-footer nav { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 12px 22px; }
.card-footer a { text-underline-offset: 4px; }

@media (max-width: 720px) {
  .card-page { width: min(100% - 22px, 620px); padding-top: 30px; }
  .page-heading { margin-bottom: 20px; }
  .page-heading > p:last-child { font-size: 0.9rem; }
  .business-card { aspect-ratio: 1.26 / 1; }
  .front-content { width: 64%; padding: 25px; }
  .mini-brand img { width: 46px; height: 46px; }
  .identity-block h2 { font-size: clamp(1.45rem, 6vw, 2.15rem); }
  .promise { line-height: 1.5; }
  .language-signal { width: 38%; padding: 25px 18px; }
  .source-message { margin-top: 24px; }
  .signal-line { height: 13px; }
  .language-output { grid-template-columns: 25px 1fr; gap: 4px; margin: 5px 0; padding: 5px 6px; }
  .output-b { margin-left: 5%; }
  .output-c { margin-left: 10%; }
  .output-d { margin-left: 15%; }
  .signal-foot { right: 18px; bottom: 24px; }
  .card-back { grid-template-columns: minmax(0, 1fr) minmax(130px, 31%); gap: 18px; padding: 28px; }
  .back-copy h2 { margin: 20px 0 14px; }
  .contact-list { gap: 7px; font-size: 0.74rem; }
  .contact-list li { grid-template-columns: 42px minmax(0, 1fr); gap: 7px; }
  .safety-note { margin-top: 17px; line-height: 1.45; }
  .qr-panel { padding: 10px; gap: 5px; }
  .card-toolbar { margin-top: 18px; }
}

@media (max-width: 520px) {
  .card-site-header { min-height: 68px; padding: 10px 12px; }
  .brand-lockup img { width: 38px; height: 38px; }
  .brand-lockup small { display: none; }
  .language-switch button { min-width: 43px; }
  .icon-button { min-width: 42px; }
  .business-card { aspect-ratio: 0.83 / 1; }
  .card-front { background: #0b1715; }
  .front-content { width: 100%; padding: 24px; }
  .identity-block { margin: 24px 0 16px; }
  .identity-block h2 { font-size: 2rem; }
  .role { font-size: 1rem; }
  .promise { max-width: 90%; font-size: 0.79rem; }
  .service-strip { max-width: 46%; margin-bottom: 12px; }
  .front-contact { max-width: 47%; display: grid; gap: 5px; }
  .language-signal {
    top: auto;
    right: 18px;
    bottom: 20px;
    width: 42%;
    height: auto;
    padding: 0;
  }
  .signal-kicker, .signal-foot, .signal-line { display: none; }
  .source-message { margin: 0 0 7px; padding: 7px; font-size: 0.58rem; }
  .language-output { grid-template-columns: 22px 1fr; margin: 4px 0; font-size: 0.53rem; }
  .output-b, .output-c, .output-d { margin-left: 0; }
  .card-back { grid-template-columns: 1fr; align-content: start; gap: 14px; padding: 24px; }
  .back-copy .mini-brand img { width: 42px; height: 42px; }
  .back-copy h2 { margin: 17px 0 12px; font-size: 1.18rem; }
  .contact-list { width: 47%; font-size: 0.7rem; }
  .contact-list li { grid-template-columns: 34px minmax(0, 1fr); gap: 5px; }
  .contact-list a { font-size: 0.6rem; line-height: 1.25; }
  .safety-note { width: 47%; max-width: 47%; margin-top: 14px; font-size: 0.56rem; }
  .qr-panel {
    position: absolute;
    right: 22px;
    bottom: 22px;
    width: 40%;
    padding: 9px;
  }
  .qr-panel strong { font-size: 0.61rem; }
  .qr-panel span { font-size: 0.64rem; }
  .card-toolbar { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .card-toolbar button, .card-toolbar a { min-height: 64px; }
  .card-footer { display: grid; text-align: center; }
  .card-footer nav { justify-content: center; }
}

@media (max-width: 370px) {
  .card-page { width: calc(100% - 16px); }
  .front-content { padding: 20px; }
  .promise { max-width: 94%; font-size: 0.7rem; }
  .service-strip { max-width: 43%; gap: 4px; }
  .front-contact { max-width: 44%; }
  .service-strip span { min-height: 22px; padding: 3px 6px; }
  .language-signal { right: 13px; bottom: 15px; width: 43%; }
  .source-message { display: none; }
  .card-back { padding: 20px; }
  .qr-panel { right: 18px; bottom: 18px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .card-inner { transition: none; }
}