@import url(/assets/fonts.css);

:root {
  --field: #140c5c;      /* icon background: hero band, code panels */
  --field-2: #1f1480;
  --signal: #f2546a;     /* icon arcs: packets, primary buttons */
  --signal-ink: #c8304b; /* coral that holds contrast on paper */
  --lens: #9c8cff;       /* icon lens: schematic lines */
  --paper: #f4f3fb;
  --ink: #17123f;
  --muted: #5b5680;
  --line: #d9d6ee;
  --card: #ffffff;
  --link: #4b33e0;
  /* names used by the studio and watch pages */
  --bg: var(--paper);
  --brand: var(--signal);
  --brand-ink: var(--field);
  --sans: "IBM Plex Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans TC", "PingFang TC", sans-serif;
  --cond: "IBM Plex Sans Condensed", "IBM Plex Sans", "Arial Narrow", "Noto Sans TC", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #0f0a3a; --ink: #eeebff; --muted: #a9a3d6; --line: #2a2366;
    --card: #17104a; --link: #b3a8ff; --signal-ink: #ff8296;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 17px/1.6 var(--sans); }
a { color: var(--link); text-underline-offset: 3px; }
:focus-visible { outline: 2px solid var(--signal); outline-offset: 3px; border-radius: 4px; }
code { font-family: var(--mono); font-size: .9em; }
.wrap { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* ---------- header / footer ---------- */
header.site { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 20px 0; }
header.site .logo { display: inline-flex; align-items: center; gap: 10px; color: inherit; text-decoration: none; font: 700 22px/1 var(--cond); letter-spacing: .01em; }
header.site .logo::before { content: ""; width: 30px; height: 30px; border-radius: 8px; background: url(/icon.png) center / cover; }
header.site nav { display: flex; gap: 22px; }
header.site nav a { color: var(--muted); text-decoration: none; font-size: 15px; }
header.site nav a:hover { color: var(--ink); }
@media (max-width: 520px) { header.site nav { gap: 16px; } header.site nav .wide { display: none; } }
footer.site { display: flex; flex-wrap: wrap; gap: 8px 22px; border-top: 1px solid var(--line); margin-top: 72px; padding: 28px 0 48px; color: var(--muted); font-size: 14px; }
footer.site a { color: var(--muted); }
footer.site span { margin-left: auto; }

/* ---------- buttons, forms (shared with studio) ---------- */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 46px; padding: 0 20px; border-radius: 10px; border: 0; background: var(--brand); color: var(--brand-ink); font: 600 16px/1 var(--sans); text-decoration: none; cursor: pointer; }
.btn:hover { filter: brightness(1.06); }
.btn.secondary { background: transparent; color: var(--ink); box-shadow: inset 0 0 0 1px var(--line); }
.btn:disabled { opacity: .5; cursor: default; }
input { width: 100%; min-height: 46px; padding: 0 14px; border-radius: 10px; border: 1px solid var(--line); background: var(--card); color: var(--ink); font: inherit; }
label { display: block; margin: 14px 0 6px; font-size: 14px; color: var(--muted); }
.error { color: var(--signal-ink); min-height: 1.4em; font-size: 14px; }

/* ---------- home: hero band with the signal path ---------- */
.band { background:
    linear-gradient(rgba(156,140,255,.07) 1px, transparent 1px) 0 0 / 32px 32px,
    linear-gradient(90deg, rgba(156,140,255,.07) 1px, transparent 1px) 0 0 / 32px 32px,
    linear-gradient(160deg, var(--field-2), var(--field) 60%);
  color: #f1eeff; }
.band header.site nav a { color: #c9c2ff; }
.band header.site nav a:hover { color: #fff; }
.band .btn.secondary { color: #fff; box-shadow: inset 0 0 0 1px rgba(201,194,255,.45); }
.hero { padding: 64px 0 40px; }
.hero h1 { font: 700 clamp(44px, 7.4vw, 88px)/.98 var(--cond); letter-spacing: -.012em; margin: 0; max-width: 13ch; text-wrap: balance; }
.hero .lede { font-size: 19px; color: #cfc9f5; max-width: 58ch; margin: 24px 0 0; }
.hero .actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }

/* Schematic: node, link, node … ; the links between zones carry the protocol name. */
.path { margin: 56px 0 0; padding: 0 0 72px; }
.path .lanes { display: grid; grid-template-columns: 1fr 64px 1fr minmax(120px, 1fr) 1fr 64px 1fr; margin-bottom: 14px; font-size: 14px; color: #a9a1e6; }
.path .lanes span { border-top: 1px solid rgba(156,140,255,.4); padding-top: 8px; }
.path .lanes span:first-child { grid-column: 1 / 4; }
.path .lanes span:last-child { grid-column: 5 / 8; }
.path ol { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: 1fr 64px 1fr minmax(120px, 1fr) 1fr 64px 1fr; align-items: center; }
.node { border: 1px solid rgba(156,140,255,.55); border-radius: 12px; padding: 14px 16px; background: rgba(20,12,92,.6); min-height: 88px; display: flex; flex-direction: column; justify-content: center; }
.node b { font: 600 20px/1.2 var(--cond); color: #fff; }
.node span { font-size: 14px; color: #b8b0ef; margin-top: 4px; }
.node.hot { border-color: var(--signal); box-shadow: 0 0 0 4px rgba(242,84,106,.12); }
.link { position: relative; height: 88px; display: flex; align-items: center; justify-content: center; }
.link::before { content: ""; position: absolute; left: 0; right: 0; top: 50%; border-top: 2px dashed rgba(156,140,255,.6); }
.link i { position: absolute; top: calc(50% - 4px); left: 0; width: 8px; height: 8px; border-radius: 50%; background: var(--signal); box-shadow: 0 0 10px var(--signal); animation: packet 2.4s linear infinite; }
.link i:nth-of-type(2) { animation-delay: -1.2s; }
.link em { position: relative; z-index: 1; font: 500 14px/1 var(--mono); font-style: normal; color: #fff; background: var(--field); border: 1px solid var(--signal); border-radius: 999px; padding: 6px 12px; }
@keyframes packet { from { left: 0; opacity: 0; } 10% { opacity: 1; } 90% { opacity: 1; } to { left: calc(100% - 8px); opacity: 0; } }
@keyframes packet-y { from { top: 0; opacity: 0; } 15% { opacity: 1; } 85% { opacity: 1; } to { top: calc(100% - 8px); opacity: 0; } }

@media (max-width: 860px) {
  .path .lanes { display: none; }
  .path ol { grid-template-columns: 1fr; max-width: 420px; }
  .node { min-height: 0; }
  .link { height: 52px; }
  .link::before { left: 50%; right: auto; top: 0; bottom: 0; border-top: 0; border-left: 2px dashed rgba(156,140,255,.6); }
  .link i { left: calc(50% - 3px); top: 0; animation-name: packet-y; }
}
@media (prefers-reduced-motion: reduce) {
  .link i { animation: none; opacity: 1; left: calc(50% - 4px); top: calc(50% - 4px); }
  .link:has(em) i { display: none; }
}

/* ---------- home: content sections ---------- */
.section { padding-top: 88px; }
.section h2 { font: 600 clamp(30px, 4vw, 40px)/1.1 var(--cond); margin: 0 0 12px; max-width: 24ch; }
.section .intro { color: var(--muted); max-width: 62ch; margin: 0; }

.steps { list-style: none; counter-reset: step; margin: 40px 0 0; padding: 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 32px; }
.steps li { counter-increment: step; border-top: 2px solid var(--ink); padding-top: 16px; }
.steps li::before { content: counter(step); display: block; font: 700 44px/1 var(--cond); color: var(--signal-ink); margin-bottom: 14px; }
.steps h3 { font: 600 20px/1.25 var(--cond); margin: 0 0 6px; }
.steps p { margin: 0; color: var(--muted); font-size: 16px; }
@media (max-width: 860px) { .steps { grid-template-columns: 1fr 1fr; } }
@media (max-width: 520px) { .steps { grid-template-columns: 1fr; gap: 24px; } }

.bridge { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: 48px; align-items: start; margin-top: 40px; }
.bridge p { margin: 0; color: var(--muted); }
.bridge dl { margin: 24px 0 0; display: grid; grid-template-columns: max-content 1fr; gap: 10px 18px; font-size: 15px; }
.bridge dt { font: 500 14px/1.6 var(--mono); }
.bridge dd { margin: 0; color: var(--muted); }
.code { margin: 0; background: var(--field); color: #e6e2ff; border-radius: 14px; padding: 22px 24px; overflow-x: auto; font: 14px/1.7 var(--mono); border: 1px solid #2a1f8f; }
.code .c { color: #8f88c4; }
.code .k { color: var(--lens); }
.code .s { color: #ff98a8; }
.code-caption { font-size: 14px; color: var(--muted); margin: 10px 0 0; }
@media (max-width: 860px) { .bridge { grid-template-columns: minmax(0, 1fr); gap: 28px; } }
.bridge p code { overflow-wrap: anywhere; }
@media (max-width: 420px) { .bridge dl { grid-template-columns: 1fr; gap: 2px; } .bridge dd { margin-bottom: 10px; } }

.spec { width: 100%; max-width: 860px; border-collapse: collapse; margin-top: 32px; font-size: 16px; }
.spec th, .spec td { text-align: left; vertical-align: top; padding: 14px 0; border-bottom: 1px solid var(--line); }
.spec th { width: 30%; font-weight: 600; padding-right: 24px; }
.spec td { color: var(--muted); }
@media (max-width: 520px) {
  .spec th, .spec td { display: block; width: auto; padding: 0; border: 0; }
  .spec tr { display: block; padding: 14px 0; border-bottom: 1px solid var(--line); }
  .spec th { margin-bottom: 4px; }
}

.demo { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 32px; align-items: center; border: 1px solid var(--line); border-radius: 16px; padding: 32px; background: var(--card); margin-top: 88px; }
.demo h2 { font: 600 clamp(28px, 3.6vw, 36px)/1.1 var(--cond); margin: 0 0 8px; }
.demo p { margin: 0; color: var(--muted); max-width: 60ch; }
.demo .addr { display: inline-block; font: 500 20px/1 var(--mono); color: var(--ink); background: var(--paper); border: 1px dashed var(--lens); border-radius: 8px; padding: 14px 18px; white-space: nowrap; }
@media (max-width: 720px) { .demo { grid-template-columns: 1fr; padding: 24px; } }

.zh { margin-top: 88px; max-width: 62ch; }
.zh h2 { font: 600 24px/1.3 var(--sans); margin: 0 0 8px; }
.zh p { color: var(--muted); line-height: 1.85; margin: 0; }

/* ---------- documents: privacy, terms, support ---------- */
.doc { padding: 40px 0 0; max-width: 70ch; }
.doc h1 { font: 700 clamp(36px, 5vw, 52px)/1.05 var(--cond); margin: 0 0 8px; }
.doc h2 { font: 600 24px/1.25 var(--cond); margin: 40px 0 8px; }
.doc .meta { color: var(--muted); font-size: 15px; margin: 0 0 24px; }
.doc li { margin-bottom: 6px; }
.doc code { background: var(--card); border: 1px solid var(--line); border-radius: 6px; padding: 1px 6px; }