/* Layout: 日系極簡。12 欄網格、左窄右寬的不對稱段落（標題 4 欄 / 內容 8 欄），髮絲線分隔取代卡片；明體大字＋細線插圖，唯一強調色為玉綠，人工步驟用琥珀色 */
:root {
  --paper: #FBFBFC;
  --tint: #F2F4F7;
  --surface: #FFFFFF;
  --ink: #151A21;
  --muted: #5D6671;
  --faint: #8A939E;
  --line: #E1E5EA;
  --brand: #2E5C85;
  --brand-ink: #FFFFFF;
  --brand-soft: #E4ECF4;
  --logo-dot: #C27A23;
  --amber: #A2660F;
  --amber-soft: #F5EAD9;

  --display: "Noto Serif TC", "Songti TC", "PMingLiU", serif;
  --body: "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;

  --fs-label: .75rem;
  --fs-xs: .875rem;
  --fs-sm: .9375rem;
  --fs-md: 1rem;
  --fs-lg: 1.1875rem;
  --fs-h3: clamp(1.25rem, 1.1rem + .5vw, 1.5rem);
  --fs-h2: clamp(1.625rem, 1.2rem + 1.6vw, 2.375rem);
  --fs-hero: clamp(2.375rem, 1.3rem + 4.2vw, 4.5rem);

  --wrap: 1200px;
  --gutter: clamp(20px, 5vw, 56px);
  --section: clamp(88px, 12vw, 160px);
  --ease: cubic-bezier(.2, .7, .2, 1);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0E1115;
    --tint: #151A20;
    --surface: #12161B;
    --ink: #E6EBF1;
    --muted: #A0A9B3;
    --faint: #6F7883;
    --line: #252C34;
    --brand: #8DB4DB;
    --brand-ink: #0B1726;
    --brand-soft: #172636;
    --amber: #E2A94E;
    --amber-soft: #33291A;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #0E1115;
  --tint: #151A20;
  --surface: #12161B;
  --ink: #E6EBF1;
  --muted: #A0A9B3;
  --faint: #6F7883;
  --line: #252C34;
  --brand: #8DB4DB;
  --brand-ink: #0B1726;
  --brand-soft: #172636;
  --amber: #E2A94E;
  --amber-soft: #33291A;
  color-scheme: dark;
}
html[lang="en"] {
  --display: "Source Serif 4", Georgia, serif;
  --body: "IBM Plex Sans", "Helvetica Neue", Arial, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 88px; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--body);
  font-size: var(--fs-md);
  line-height: 1.9;
  letter-spacing: .02em;
}
html[lang="en"] body { line-height: 1.65; letter-spacing: 0; }
a { color: inherit; }
h1, h2, h3 { margin: 0; font-weight: 500; text-wrap: balance; }
p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
figure { margin: 0; }
[hidden] { display: none !important; }
svg { max-width: 100%; }
:focus-visible { outline: 1.5px solid var(--brand); outline-offset: 4px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }

.wrap { max-width: var(--wrap); margin-inline: auto; padding-inline: var(--gutter); }

.label {
  display: inline-flex; align-items: center; gap: 12px;
  font-family: var(--mono);
  font-size: var(--fs-label);
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--faint);
}
.label::before { content: ""; width: 24px; height: 1px; background: currentColor; }

/* ---------- Buttons & links ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 14px;
  padding: 15px 28px;
  border: 1px solid var(--ink);
  border-radius: 2px;
  background: var(--ink);
  color: var(--paper);
  font: inherit; font-size: var(--fs-sm); letter-spacing: .08em;
  text-decoration: none;
  cursor: pointer;
  transition: background-color .3s var(--ease), color .3s var(--ease);
}
.btn:hover { background: transparent; color: var(--ink); }
.btn .arrow { transition: transform .3s var(--ease); }
.btn:hover .arrow { transform: translateX(4px); }
.text-link {
  display: inline-flex; align-items: center; gap: 10px;
  font-size: var(--fs-sm); letter-spacing: .06em;
  text-decoration: none;
  padding-bottom: 4px;
  background: linear-gradient(currentColor, currentColor) left bottom / 100% 1px no-repeat;
  transition: background-size .35s var(--ease);
  cursor: pointer;
}
.text-link:hover { background-size: 0 1px; background-position: right bottom; }
.arrow { font-family: var(--mono); }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: env(safe-area-inset-top, 0px);
  z-index: 20;
  background: color-mix(in srgb, var(--paper) 90%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; gap: 24px; min-height: 72px; }
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; }
.brand svg { width: 32px; height: 32px; flex: none; }
.logo-tile { fill: #2E5C85; }
.logo-mark { fill: #FFFFFF; }
.logo-dot { fill: var(--logo-dot); }
.brand-name { font-family: "Noto Serif TC", serif; font-weight: 600; font-size: 1.1875rem; letter-spacing: .24em; }
.brand-en { font-family: var(--mono); font-size: .6875rem; letter-spacing: .18em; color: var(--muted); text-transform: uppercase; }
.brand-text { display: flex; flex-direction: column; line-height: 1.3; }
.nav { display: flex; align-items: center; gap: 32px; }
.nav a { text-decoration: none; font-size: .9375rem; font-weight: 500; letter-spacing: .06em; color: color-mix(in srgb, var(--ink) 80%, var(--paper)); transition: color .2s; }
.nav a:hover { color: var(--brand); }
.nav .lang { font-family: var(--mono); font-size: .8125rem; letter-spacing: .1em; }
.nav .nav-cta { color: var(--ink); border: 1px solid var(--ink); padding: 8px 16px; border-radius: 2px; }
.nav .nav-cta:hover { background: var(--ink); color: var(--paper); }

/* ---------- Hero ---------- */
.hero { position: relative; padding-block: clamp(72px, 11vw, 150px) clamp(56px, 7vw, 96px); overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 32px; align-items: end; }
.hero-copy { grid-column: 1 / span 7; display: flex; flex-direction: column; gap: 36px; min-width: 0; }
.hero h1 {
  font-family: var(--display);
  font-size: var(--fs-hero);
  font-weight: 500;
  line-height: 1.38;
  letter-spacing: .06em;
}
html[lang="en"] .hero h1 { letter-spacing: -.015em; line-height: 1.12; }
.hero h1 .accent { color: var(--brand); }
.lead { color: var(--muted); max-width: 30em; }
.hero-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 20px 36px; }
.hero-visual { grid-column: 9 / span 4; min-width: 0; }
.hero-copy > *, .hero-visual { animation: fadeUp .9s var(--ease) both; }
.hero-copy > *:nth-child(2) { animation-delay: .08s; }
.hero-copy > *:nth-child(3) { animation-delay: .16s; }
.hero-copy > *:nth-child(4) { animation-delay: .24s; }
.hero-visual { animation-delay: .3s; }
@keyframes fadeUp { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }
.vertical {
  position: absolute;
  right: max(16px, calc((100vw - var(--wrap)) / 2 - 8px));
  top: clamp(72px, 11vw, 150px);
  writing-mode: vertical-rl;
  font-family: "Noto Serif TC", serif;
  font-size: var(--fs-xs);
  letter-spacing: .5em;
  color: var(--faint);
}

/* Chat mock */
.chat-mock { border: 1px solid var(--line); background: var(--surface); }
.mock-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 14px 18px; border-bottom: 1px solid var(--line); font-size: var(--fs-xs); letter-spacing: .06em; }
.mock-title { display: flex; align-items: center; gap: 10px; }
.dot { width: 6px; height: 6px; border-radius: 50%; background: var(--brand); flex: none; }
.tag { font-family: var(--mono); font-size: .625rem; letter-spacing: .14em; color: var(--faint); text-transform: uppercase; }
.mock-body { display: flex; flex-direction: column; gap: 14px; padding: 22px 18px 24px; }
.msg { max-width: 90%; padding: 10px 14px; font-size: var(--fs-xs); line-height: 1.75; }
.msg.user { align-self: flex-end; background: var(--tint); }
.msg.bot { align-self: flex-start; border-left: 1.5px solid var(--brand); padding-left: 14px; }
.sources { display: flex; flex-wrap: wrap; gap: 6px 12px; margin-top: 6px; }
.source { font-family: var(--mono); font-size: .625rem; letter-spacing: .04em; color: var(--brand); }
.source::before { content: "↗ "; }
.handoff { display: block; margin-top: 4px; color: var(--amber); font-size: .6875rem; letter-spacing: .06em; }

/* Hero index */
.index { margin-top: clamp(64px, 9vw, 120px); display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); border-top: 1px solid var(--ink); }
.index a { display: flex; flex-direction: column; gap: 6px; padding: 20px 20px 0 0; text-decoration: none; min-width: 0; }
.index a + a { padding-left: 20px; border-left: 1px solid var(--line); }
.index .num { font-family: var(--mono); font-size: var(--fs-label); color: var(--faint); letter-spacing: .1em; }
.index .name { font-size: var(--fs-sm); letter-spacing: .06em; transition: color .2s; }
.index a:hover .name { color: var(--brand); }

/* ---------- Sections ---------- */
section { padding-block: var(--section); }
.rule { border-top: 1px solid var(--line); }
.tinted { background: var(--tint); }
.sec { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 32px; }
.sec-head { grid-column: 1 / span 4; display: flex; flex-direction: column; gap: 24px; min-width: 0; align-self: start; position: sticky; top: 120px; }
.sec-head h2 { font-family: var(--display); font-size: var(--fs-h2); font-weight: 500; line-height: 1.5; letter-spacing: .06em; }
html[lang="en"] .sec-head h2 { letter-spacing: -.01em; line-height: 1.2; }
.sec-head p { color: var(--muted); font-size: var(--fs-sm); }
.sec-body { grid-column: 6 / span 7; min-width: 0; }
.sec-wide { grid-column: 1 / -1; min-width: 0; }
.sec-head:has(+ .sec-wide) { grid-column: 1 / span 8; position: static; }

/* Pains */
.pains { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); border-top: 1px solid var(--line); }
.pain { display: flex; align-items: flex-start; gap: 20px; padding: 32px 24px 32px 0; border-bottom: 1px solid var(--line); min-width: 0; }
.pain:nth-child(even) { padding-left: 24px; border-left: 1px solid var(--line); }
.pain svg { width: 32px; height: 32px; flex: none; color: var(--brand); }
.pain p { font-size: var(--fs-lg); line-height: 1.7; letter-spacing: .04em; }
html[lang="en"] .pain p { letter-spacing: 0; line-height: 1.45; }

/* Services */
.services { display: flex; flex-direction: column; }
.svc { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 32px; align-items: center; padding-block: clamp(40px, 6vw, 72px); border-top: 1px solid var(--line); }
.svc:last-child { border-bottom: 1px solid var(--line); }
.svc-text { grid-column: 1 / span 5; display: flex; flex-direction: column; gap: 16px; min-width: 0; }
.svc-art { grid-column: 7 / span 6; min-width: 0; }
.svc:nth-child(even) .svc-text { grid-column: 8 / span 5; grid-row: 1; }
.svc:nth-child(even) .svc-art { grid-column: 1 / span 6; grid-row: 1; }
.svc-num { font-family: var(--mono); font-size: var(--fs-label); color: var(--brand); letter-spacing: .14em; }
.svc h3 { font-family: var(--display); font-size: var(--fs-h3); font-weight: 500; letter-spacing: .08em; line-height: 1.5; }
html[lang="en"] .svc h3 { letter-spacing: 0; }
.svc p { color: var(--muted); font-size: var(--fs-sm); }
.tags { display: flex; flex-wrap: wrap; gap: 6px 18px; }
.tags li { font-size: var(--fs-xs); color: var(--muted); display: inline-flex; align-items: center; gap: 8px; }
.tags li::before { content: ""; width: 4px; height: 4px; border-radius: 50%; background: var(--brand); }
.art-frame { background: var(--tint); aspect-ratio: 2 / 1; max-width: 100%; display: flex; align-items: center; justify-content: center; padding: 6%; }
.tinted .art-frame { background: var(--surface); }
.ill { width: 100%; height: auto; display: block; color: var(--ink); }
.ill .ln { stroke: currentColor; fill: none; stroke-width: 1.25; stroke-linecap: round; stroke-linejoin: round; vector-effect: non-scaling-stroke; }
.ill .lt { stroke: var(--faint); fill: none; stroke-width: 1; stroke-linecap: round; vector-effect: non-scaling-stroke; }
.ill .bg { fill: var(--paper); }
.tinted .ill .bg { fill: var(--tint); }
.ill .ac { stroke: var(--brand); fill: none; stroke-width: 1.75; stroke-linecap: round; stroke-linejoin: round; vector-effect: non-scaling-stroke; }
.ill .acf { fill: var(--brand); }
.ill .acs { fill: var(--brand-soft); }
.ill .hm { stroke: var(--amber); fill: none; stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; vector-effect: non-scaling-stroke; }
.ill .hmf { fill: var(--amber); }
.ill .dash { stroke-dasharray: 3 5; }
.ill .on-acf { stroke: var(--brand-ink); fill: none; stroke-width: 1.75; stroke-linecap: round; stroke-linejoin: round; vector-effect: non-scaling-stroke; }

/* ---------- Works ---------- */
.work-feature { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 32px; align-items: center; padding-bottom: clamp(56px, 8vw, 96px); }
.work-visual { grid-column: 1 / span 7; position: relative; aspect-ratio: 16 / 11; overflow: hidden; background: var(--tint); min-width: 0; }
.work-bg { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; filter: saturate(.85); }
.work-visual .tag { position: absolute; left: 16px; bottom: 14px; background: color-mix(in srgb, var(--paper) 85%, transparent); padding: 3px 8px; }
.phones { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; gap: 3%; }
.shot { height: 76%; width: auto; aspect-ratio: 540 / 1168; border-radius: 16px; border: 3px solid #1F1A22; background: #fff; box-shadow: 0 24px 48px -18px rgba(0, 0, 0, .45); object-fit: cover; }
.shot.main { height: 90%; position: relative; z-index: 1; }
.phones.pair { gap: 5%; }
.phones.pair .shot { height: 86%; aspect-ratio: 540 / 1170; }
.work-text { grid-column: 9 / span 4; display: flex; flex-direction: column; gap: 18px; min-width: 0; }
.work-meta { display: flex; align-items: center; gap: 14px; }
.status { display: inline-flex; align-items: center; gap: 6px; font-family: var(--mono); font-size: .625rem; letter-spacing: .12em; text-transform: uppercase; color: var(--amber); border: 1px solid currentColor; padding: 2px 8px; }
html[lang="zh-Hant-TW"] .status { font-family: var(--body); letter-spacing: .1em; font-size: .6875rem; }
.work-text h3 { font-family: var(--display); font-size: var(--fs-h2); font-weight: 500; line-height: 1.3; display: flex; flex-direction: column; gap: 6px; }
.work-text h3 small { font-family: var(--body); font-size: var(--fs-sm); color: var(--muted); letter-spacing: .08em; }
.work-text > p { color: var(--muted); font-size: var(--fs-sm); }
.work-points { display: flex; flex-direction: column; border-top: 1px solid var(--line); }
.work-points li { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 4px 16px; padding-block: 12px; border-bottom: 1px solid var(--line); font-size: var(--fs-sm); }
.work-points strong { font-weight: 500; }
.work-points span { color: var(--muted); }
.work-note { font-size: var(--fs-xs) !important; color: var(--brand) !important; }

.concepts { display: flex; flex-direction: column; gap: 28px; padding-top: clamp(40px, 6vw, 64px); border-top: 1px solid var(--line); }
.concepts-note { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 14px; font-size: var(--fs-xs); color: var(--muted); }
.concept-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 32px; }
.concept { display: flex; flex-direction: column; gap: 12px; min-width: 0; }
.concept h3 { font-family: var(--display); font-size: var(--fs-h3); font-weight: 500; letter-spacing: .06em; margin-top: 8px; }
html[lang="en"] .concept h3 { letter-spacing: 0; }
.concept p { font-size: var(--fs-sm); color: var(--muted); }
.concept-grid.two { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 40px; }
.concept-grid.one { grid-template-columns: minmax(0, 1fr); }
.concept-grid.one .concept { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); grid-template-rows: 1fr auto auto auto 1fr; column-gap: clamp(32px, 5vw, 64px); row-gap: 12px; }
.concept-grid.one .art { grid-column: 1; grid-row: 1 / -1; }
.concept-grid.one .concept > :not(.art) { grid-column: 2; }
.concept-grid.one .concept h3 { grid-row: 2; margin-top: 0; }
.concept-grid.one .concept p { grid-row: 3; }
.concept-grid.one .concept .tags { grid-row: 4; }
.art { aspect-ratio: 16 / 9; background: var(--tint); overflow: hidden; }
.art img { width: 100%; height: 100%; object-fit: cover; display: block; transition: transform .8s var(--ease); }
.concept:hover .art img { transform: scale(1.03); }

/* ---------- Tabs ---------- */
.tabs { display: flex; gap: 32px; border-bottom: 1px solid var(--line); margin-bottom: clamp(40px, 6vw, 64px); flex-wrap: wrap; }
.tab { font: inherit; font-size: var(--fs-sm); letter-spacing: .06em; padding: 0 0 14px; border: 0; border-bottom: 1.5px solid transparent; margin-bottom: -1px; background: transparent; color: var(--faint); cursor: pointer; }
.tab:hover { color: var(--ink); }
.tab[aria-selected="true"] { color: var(--ink); border-bottom-color: var(--ink); }

/* ---------- Flow diagrams ---------- */
.flow-figure { display: flex; flex-direction: column; gap: 36px; }
.flow { display: flex; align-items: flex-start; }
.step { flex: 0 0 auto; width: 148px; display: flex; flex-direction: column; align-items: center; text-align: center; gap: 6px; min-width: 0; }
.step-mark {
  width: 64px; height: 64px; border-radius: 50%;
  display: grid; place-items: center;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--ink);
  margin-bottom: 10px;
  position: relative;
}
.tinted .step-mark { background: var(--tint); }
.step-mark svg { width: 24px; height: 24px; }
.step-mark .n { font-family: var(--display); font-size: 1.375rem; }
.step.ai .step-mark { border-color: var(--brand); color: var(--brand); }
.step.human .step-mark { border-color: var(--amber); color: var(--amber); }
.step-badge { position: absolute; top: -4px; right: -10px; font-family: var(--mono); font-size: .5625rem; letter-spacing: .1em; padding: 1px 6px; background: var(--brand); color: var(--brand-ink); }
.step.human .step-badge { background: var(--amber); color: var(--paper); }
.step-title { font-size: var(--fs-sm); font-weight: 500; letter-spacing: .06em; line-height: 1.5; }
.step-sub { font-size: var(--fs-xs); color: var(--muted); line-height: 1.6; }
.step-note { margin-top: 6px; font-size: .6875rem; color: var(--amber); letter-spacing: .04em; line-height: 1.5; }
.step-time { font-family: var(--mono); font-size: .6875rem; color: var(--faint); letter-spacing: .06em; }
.link { flex: 1 1 0; min-width: 24px; position: relative; height: 64px; display: flex; align-items: center; justify-content: center; }
.link::before { content: ""; position: absolute; left: 6px; right: 10px; top: 50%; height: 1px; background: var(--faint); }
.link::after { content: ""; position: absolute; right: 6px; top: calc(50% - 3.5px); border-left: 7px solid var(--faint); border-top: 3.5px solid transparent; border-bottom: 3.5px solid transparent; }
.link span { position: relative; top: -16px; font-family: var(--mono); font-size: .625rem; letter-spacing: .1em; color: var(--muted); background: var(--paper); padding-inline: 6px; white-space: nowrap; }
.tinted .link span { background: var(--tint); }
.link.gate::before { background: var(--amber); }
.link.gate::after { border-left-color: var(--amber); }
.link.gate span { color: var(--amber); }
.flow-caption { display: flex; flex-wrap: wrap; gap: 8px 28px; font-size: var(--fs-xs); color: var(--muted); padding-top: 24px; border-top: 1px solid var(--line); }
.legend { display: inline-flex; align-items: center; gap: 8px; }
.legend i { width: 10px; height: 10px; border-radius: 50%; border: 1px solid var(--brand); }
.legend.h i { border-color: var(--amber); }

/* ---------- FAQ ---------- */
.faq details { border-bottom: 1px solid var(--line); }
.faq details:first-of-type { border-top: 1px solid var(--line); }
.faq summary { list-style: none; cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 24px; padding-block: 24px; letter-spacing: .04em; }
html[lang="en"] .faq summary { letter-spacing: 0; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: ""; width: 11px; height: 11px; flex: none; background: linear-gradient(var(--ink), var(--ink)) center / 100% 1px no-repeat, linear-gradient(var(--ink), var(--ink)) center / 1px 100% no-repeat; transition: transform .3s var(--ease); }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { padding-bottom: 28px; color: var(--muted); font-size: var(--fs-sm); max-width: 38em; }

/* ---------- Contact ---------- */
.contact { background: var(--ink); color: var(--paper); -webkit-font-smoothing: antialiased; }
.contact .label { color: color-mix(in srgb, var(--paper) 55%, var(--ink)); }
.contact .sec-head h2 { color: var(--paper); }
.contact .sec-head p { color: color-mix(in srgb, var(--paper) 65%, var(--ink)); }
.channels { display: flex; flex-direction: column; border-top: 1px solid color-mix(in srgb, var(--paper) 18%, var(--ink)); }
.channel { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding-block: 14px; border-bottom: 1px solid color-mix(in srgb, var(--paper) 18%, var(--ink)); min-width: 0; }
.channel-text { min-width: 0; display: flex; flex-direction: column; }
.channel-label { font-family: var(--mono); font-size: .625rem; letter-spacing: .14em; text-transform: uppercase; color: color-mix(in srgb, var(--paper) 50%, var(--ink)); }
.channel-value { font-size: var(--fs-sm); user-select: all; word-break: break-all; letter-spacing: .04em; }
.copy { flex: none; font: inherit; font-size: var(--fs-label); letter-spacing: .1em; padding: 4px 0; border: 0; border-bottom: 1px solid currentColor; background: transparent; color: color-mix(in srgb, var(--paper) 75%, var(--ink)); cursor: pointer; }
.copy:hover { color: var(--paper); }

.form { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 28px 32px; }
.field { display: flex; flex-direction: column; gap: 4px; min-width: 0; }
.field.full { grid-column: 1 / -1; }
.field label, .field legend { font-family: var(--mono); font-size: .6875rem; letter-spacing: .12em; text-transform: uppercase; color: color-mix(in srgb, var(--paper) 55%, var(--ink)); }
html[lang="zh-Hant-TW"] .field label, html[lang="zh-Hant-TW"] .field legend { font-family: var(--body); letter-spacing: .1em; }
.field label b { color: var(--brand); font-weight: 400; }
.field input, .field textarea {
  font: inherit; font-size: var(--fs-md);
  color: var(--paper);
  background: transparent;
  border: 0;
  border-bottom: 1px solid color-mix(in srgb, var(--paper) 28%, var(--ink));
  border-radius: 0;
  padding: 10px 0;
  width: 100%;
  transition: border-color .3s var(--ease);
}
.field textarea { min-height: 96px; resize: vertical; }
.field input:focus, .field textarea:focus { outline: none; border-bottom-color: var(--paper); }
.field input::placeholder, .field textarea::placeholder { color: color-mix(in srgb, var(--paper) 35%, var(--ink)); }
.topics { display: flex; flex-wrap: wrap; gap: 10px; border: 0; padding: 0; margin: 0; }
.topics legend { margin-bottom: 12px; padding: 0; }
.topic { position: relative; }
.topic input { position: absolute; opacity: 0; width: 1px; height: 1px; }
.topic span { display: inline-block; font-size: var(--fs-xs); letter-spacing: .04em; padding: 7px 14px; border: 1px solid color-mix(in srgb, var(--paper) 25%, var(--ink)); border-radius: 2px; cursor: pointer; color: color-mix(in srgb, var(--paper) 80%, var(--ink)); transition: background-color .2s, color .2s; }
.topic input:checked + span { background: var(--paper); border-color: var(--paper); color: var(--ink); }
.topic input:focus-visible + span { outline: 1.5px solid var(--brand); outline-offset: 3px; }
.hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
.form-foot { grid-column: 1 / -1; display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 16px; }
.form-status { font-size: var(--fs-sm); min-height: 1.5em; }
.form-status.ok { color: var(--brand); }
.form-status.err { color: var(--amber); }
.contact .btn { background: var(--paper); color: var(--ink); border-color: var(--paper); }
.contact .btn:hover { background: transparent; color: var(--paper); }
.contact-side { display: flex; flex-direction: column; gap: 40px; }

/* ---------- Footer ---------- */
.site-footer { padding-block: 56px calc(40px + 72px); font-size: var(--fs-xs); color: var(--muted); }
.foot { display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between; gap: 24px; }
.foot-mark { font-family: "Noto Serif TC", serif; font-size: clamp(2.5rem, 1.5rem + 4vw, 4.5rem); letter-spacing: .3em; color: var(--ink); line-height: 1; }
.foot-meta { display: flex; flex-direction: column; gap: 4px; text-align: right; letter-spacing: .06em; }

/* ---------- Chat widget ---------- */
.cw-launch {
  position: fixed;
  right: 24px;
  bottom: calc(24px + env(safe-area-inset-bottom, 0px));
  z-index: 40;
  display: inline-flex; align-items: center; gap: 10px;
  padding: 13px 20px 13px 16px;
  border: 1px solid var(--ink);
  border-radius: 2px;
  background: var(--ink);
  color: var(--paper);
  font: inherit; font-size: var(--fs-xs); letter-spacing: .08em;
  cursor: pointer;
  box-shadow: 0 12px 32px -12px rgba(0, 0, 0, .35);
}
.cw-launch svg { width: 18px; height: 18px; }
.cw-launch .dot { box-shadow: 0 0 0 3px color-mix(in srgb, var(--brand) 30%, transparent); }
.cw-panel {
  position: fixed;
  right: 24px;
  bottom: calc(88px + env(safe-area-inset-bottom, 0px));
  z-index: 41;
  width: min(380px, calc(100vw - 32px));
  height: min(560px, calc(100vh - 128px));
  display: flex; flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--line);
  box-shadow: 0 24px 64px -24px rgba(0, 0, 0, .35);
}
.cw-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 16px 18px; border-bottom: 1px solid var(--line); }
.cw-title { display: flex; flex-direction: column; line-height: 1.5; }
.cw-title strong { font-weight: 500; font-size: var(--fs-sm); display: flex; align-items: center; gap: 8px; letter-spacing: .06em; }
.cw-title small { font-size: .6875rem; color: var(--faint); }
.cw-close { border: 0; background: transparent; color: var(--muted); font-size: 1.375rem; line-height: 1; cursor: pointer; padding: 4px 6px; }
.cw-close:hover { color: var(--ink); }
.cw-log { flex: 1; overflow-y: auto; padding: 18px; display: flex; flex-direction: column; gap: 14px; }
.cw-log .msg { white-space: pre-wrap; }
.cw-log .msg a { color: var(--brand); }
.cw-typing { display: inline-flex; gap: 4px; }
.cw-typing i { width: 5px; height: 5px; border-radius: 50%; background: var(--faint); animation: blink 1s infinite; }
.cw-typing i:nth-child(2) { animation-delay: .15s; }
.cw-typing i:nth-child(3) { animation-delay: .3s; }
@keyframes blink { 0%, 100% { opacity: .25; } 50% { opacity: 1; } }
.cw-suggest { display: flex; flex-wrap: wrap; gap: 6px; padding: 0 18px 14px; }
.cw-suggest button { font: inherit; font-size: .75rem; padding: 5px 10px; border: 1px solid var(--line); border-radius: 2px; background: transparent; color: var(--ink); cursor: pointer; }
.cw-suggest button:hover { border-color: var(--brand); color: var(--brand); }
.cw-form { display: flex; gap: 8px; padding: 12px 14px; border-top: 1px solid var(--line); }
.cw-form input { flex: 1; min-width: 0; font: inherit; font-size: var(--fs-sm); padding: 8px 0; border: 0; border-bottom: 1px solid var(--line); background: transparent; color: var(--ink); }
.cw-form input:focus { outline: none; border-bottom-color: var(--ink); }
.cw-form button { flex: none; width: 40px; height: 40px; border: 1px solid var(--ink); border-radius: 2px; background: var(--ink); color: var(--paper); display: grid; place-items: center; cursor: pointer; }
.cw-form button:disabled { opacity: .4; cursor: default; }
.cw-form button svg { width: 16px; height: 16px; }

/* ---------- Responsive ---------- */
@media (max-width: 1080px) {
  .vertical { display: none; }
}
@media (max-width: 960px) {
  .hero-grid, .sec, .svc { grid-template-columns: minmax(0, 1fr); }
  .hero-copy, .hero-visual { grid-column: 1 / -1; }
  .hero-visual { max-width: 460px; }
  .index { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .index a:nth-child(4) { padding-left: 0; border-left: 0; }
  .index a { padding-bottom: 16px; }
  .sec-head, .sec-body, .sec-head:has(+ .sec-wide) { grid-column: 1 / -1; position: static; }
  .svc-text, .svc-art, .svc:nth-child(even) .svc-text, .svc:nth-child(even) .svc-art { grid-column: 1 / -1; grid-row: auto; }
  .flow { flex-direction: column; align-items: stretch; max-width: 520px; }
  .work-feature { grid-template-columns: minmax(0, 1fr); }
  .work-visual, .work-text { grid-column: 1 / -1; }
  .concept-grid, .concept-grid.two { grid-template-columns: minmax(0, 1fr); max-width: 560px; }
  .concept-grid.one .concept { grid-template-columns: minmax(0, 1fr); grid-template-rows: none; }
  .concept-grid.one .art, .concept-grid.one .concept > :not(.art) { grid-column: 1; grid-row: auto; }
  .step { width: auto; flex-direction: row; align-items: center; text-align: left; gap: 18px; flex-wrap: wrap; }
  .step-mark { margin-bottom: 0; width: 52px; height: 52px; flex: none; }
  .step-text { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: 2px; }
  .step-note { flex-basis: 100%; padding-left: 70px; margin-top: 0; }
  .link { height: 44px; flex: none; justify-content: flex-start; padding-left: 70px; }
  .link::before { left: 26px; right: auto; top: 4px; bottom: 10px; width: 1px; height: auto; }
  .link::after { left: 22.5px; right: auto; top: auto; bottom: 4px; border-left: 3.5px solid transparent; border-right: 3.5px solid transparent; border-top: 7px solid var(--faint); border-bottom: 0; }
  .link.gate::after { border-left-color: transparent; border-top-color: var(--amber); }
  .link span { top: 0; padding-inline: 0; }
}
@media (min-width: 961px) {
  .step-text { display: flex; flex-direction: column; gap: 4px; align-items: center; }
}
@media (max-width: 720px) {
  .nav a:not(.nav-cta):not(.lang) { display: none; }
  .nav { gap: 16px; }
  .brand-en { display: none; }
  .index { grid-template-columns: minmax(0, 1fr); }
  .index a, .index a + a { flex-direction: row; gap: 16px; padding: 14px 0; border-left: 0; border-bottom: 1px solid var(--line); }
  .pains, .form { grid-template-columns: minmax(0, 1fr); }
  .pain, .pain:nth-child(even) { padding-left: 0; border-left: 0; }
  .work-visual { aspect-ratio: 1 / 1; }
  .phones { gap: 2%; }
  .shot { height: 58%; border-width: 2px; border-radius: 12px; }
  .shot.main { height: 72%; }
  .phones.pair .shot { height: 70%; }
  .cw-launch .cw-launch-text { display: none; }
  .cw-launch { padding: 14px; right: 16px; }
  .cw-panel { right: 16px; bottom: calc(80px + env(safe-area-inset-bottom, 0px)); }
  .foot-meta { text-align: left; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .hero-copy > *, .hero-visual, .cw-typing i { animation: none; }
  .btn, .text-link, .btn .arrow { transition: none; }
}