/* Base layer: reset, typography, header, footer, hero, buttons. Tokens only (tokens.css). */

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: var(--header-height); }
body {
  margin: 0;
  min-height: 100vh;
  background: var(--surface-0);
  color: var(--ink);
  font-family: var(--font-text);
  font-size: var(--step-0);
  line-height: 1.55;
  overflow-x: hidden;
}
body.lang-zh { font-family: var(--font-zh); line-height: 1.75; }
img, svg, video { display: block; max-width: 100%; }
a { color: inherit; text-underline-offset: 0.2em; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--signal); outline-offset: 3px; }
h1, h2, h3 { font-family: var(--font-display); font-stretch: 118%; font-weight: 750; line-height: 1.08; margin: 0 0 var(--space-4); letter-spacing: -0.01em; }
.lang-zh h1, .lang-zh h2, .lang-zh h3 { font-family: var(--font-zh); font-weight: 700; letter-spacing: 0; }
h1 { font-size: var(--step-5); }
h2 { font-size: var(--step-3); }
h3 { font-size: var(--step-1); }
p { margin: 0 0 var(--space-4); }
.mono { font-family: var(--font-mono); letter-spacing: 0.02em; }

.skip-link { position: absolute; left: var(--gutter); top: -100px; padding: var(--space-2) var(--space-4); background: var(--signal); color: var(--signal-ink); z-index: 100; }
.skip-link:focus { top: var(--space-2); }

/* Section index «01 / 11» with a leader line */
.section-index { display: flex; align-items: center; gap: var(--space-3); color: var(--ink-muted); font-size: var(--step--1); margin-bottom: var(--space-5); }
.section-index::after { content: ""; flex: 0 0 var(--space-8); height: 1px; background: var(--line); }

/* Buttons: cut corner, never rounded */
.btn {
  display: inline-flex; align-items: center; gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  font-family: var(--font-mono); font-size: var(--step--1); font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em;
  text-decoration: none; border: 0; cursor: pointer;
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, 0 100%);
  transition: transform var(--duration) var(--ease);
}
.btn { max-width: 100%; overflow-wrap: anywhere; }
.btn--signal { background: var(--signal); color: var(--signal-ink); }
.btn--signal:hover { transform: translateX(2px); }
.link-arrow { font-family: var(--font-mono); font-size: var(--step--1); text-transform: uppercase; letter-spacing: 0.08em; text-decoration: none; border-bottom: 1px solid var(--line); padding-bottom: 2px; }
.link-arrow::after { content: " →"; color: var(--signal-text); }
.link-arrow:hover { border-color: var(--signal); }

/* Header */
.site-header { position: sticky; top: 0; z-index: 50; background: var(--surface-0); border-bottom: var(--border); }
.site-header__bar { display: flex; align-items: center; gap: var(--space-5); max-width: var(--max-width); margin: 0 auto; padding: 0 var(--gutter); min-height: var(--header-height); }
.logo { display: inline-flex; align-items: center; gap: var(--space-2); text-decoration: none; color: var(--ink); }
.logo__mark { width: var(--mark-width); height: var(--mark-height); flex: none; color: var(--signal); }
.logo { flex: none; }
.logo__text { font-family: var(--font-display); font-stretch: 125%; font-weight: 800; font-size: var(--step-0); letter-spacing: 0.04em; text-transform: uppercase; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 18ch; }
/* Logo uploaded in the admin: fixed height, any width up to the header budget. */
.logo__image { display: block; height: var(--site-logo-height); width: auto; max-width: var(--site-logo-max-width); object-fit: contain; }
.site-nav { display: none; }
.site-nav__list { display: flex; gap: var(--space-5); list-style: none; margin: 0; padding: 0; }
.site-nav__link { font-family: var(--font-mono); font-size: var(--step--1); text-transform: uppercase; letter-spacing: 0.06em; text-decoration: none; color: var(--ink-muted); }
.site-nav__link:hover { color: var(--ink); }
.site-header__tools { display: flex; align-items: center; gap: var(--space-4); margin-left: auto; }
.lang-switch { display: flex; border: var(--border); font-family: var(--font-mono); font-size: var(--step--1); }
.lang-switch__item { padding: var(--space-1) var(--space-3); text-decoration: none; }
.lang-switch__item[aria-current="true"] { background: var(--ink); color: var(--surface-0); }
.theme-toggle { width: var(--tap); height: var(--tap); display: inline-grid; place-items: center; background: none; border: var(--border); color: var(--ink); cursor: pointer; }
.theme-toggle svg { width: 18px; height: 18px; }
.site-header__tools > .btn { display: none; }
.lang-switch__item { white-space: nowrap; }
.mobile-nav { position: static; }
.mobile-nav__toggle { white-space: nowrap; list-style: none; cursor: pointer; min-height: var(--tap); display: inline-flex; align-items: center; padding: 0 var(--space-3); border: var(--border); font-size: var(--step--1); text-transform: uppercase; letter-spacing: 0.06em; }
.mobile-nav__toggle::-webkit-details-marker { display: none; }
.mobile-nav[open] .mobile-nav__toggle { background: var(--ink); color: var(--surface-0); }
.mobile-nav__panel { position: absolute; left: 0; right: 0; top: 100%; background: var(--surface-0); border-bottom: var(--border); padding: var(--space-4) var(--gutter) var(--space-6); }
.mobile-nav__panel ul { list-style: none; margin: 0; padding: 0; display: grid; gap: var(--space-1); }
.mobile-nav__panel a:not(.btn) { display: block; padding: var(--space-3) 0; border-bottom: var(--border); text-decoration: none; font-family: var(--font-mono); text-transform: uppercase; letter-spacing: 0.06em; }
.mobile-nav__panel .btn { margin-top: var(--space-4); }
.mobile-nav:not([open]) .mobile-nav__panel { display: none; }
.site-header__tools { min-width: 0; gap: var(--space-2); }
@media (max-width: 479px) {
  .logo__text { font-size: var(--step--1); }
  .site-header__bar { gap: var(--space-3); }
  .site-header__tools > .theme-toggle { display: none; }
}
.mobile-nav__panel .theme-toggle { margin-top: var(--space-4); }
@media (max-width: 359px) {
  .logo__text { display: none; } /* the mark stays, the link keeps its aria-label */
  .lang-switch__item { padding: var(--space-1) var(--space-2); }
  .mobile-nav__toggle { padding: 0 var(--space-2); }
}
/* Full navigation needs ~1200px (6 items + tools); below that the compact menu is used (checked on 1024 screenshot). */
@media (min-width: 1200px) {
  .site-nav { display: block; }
  .site-header__tools > .btn { display: inline-flex; }
  .mobile-nav { display: none; }
}
.site-nav__link { white-space: nowrap; }
/* Services drop-down (<details>): opens below the bar, works without JS. */
.site-nav__group { position: relative; }
.site-nav__menu > summary { list-style: none; cursor: pointer; }
.site-nav__menu > summary::-webkit-details-marker { display: none; }
.site-nav__menu > summary::after { content: " ▾"; color: var(--signal-text); }
.site-nav__menu[open] > summary { color: var(--ink); }
.site-nav__sub { position: absolute; top: calc(100% + var(--space-3)); left: calc(-1 * var(--space-4)); z-index: 20; min-width: 16rem;
  list-style: none; margin: 0; padding: var(--space-2) 0; background: var(--surface-0); border: var(--border); }
.site-nav__sub a { display: block; padding: var(--space-3) var(--space-4); font-family: var(--font-mono); font-size: var(--step--1); text-transform: uppercase;
  letter-spacing: 0.06em; text-decoration: none; color: var(--ink-muted); }
.site-nav__sub a:hover, .site-nav__sub a:focus-visible { color: var(--ink); background: var(--surface-1); }

/* Hero with blueprint grid and toolpath */
.hero { position: relative; overflow: hidden; border-bottom: var(--border); min-height: calc(100vh - var(--header-height)); display: flex; align-items: center; }
.hero__grid {
  position: absolute; inset: 0; pointer-events: none;
  /* fine blueprint grid only — no axis lines across the text */
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 8px 8px, 8px 8px;
}
.hero__inner { position: relative; z-index: 1; max-width: var(--max-width); width: 100%; margin: 0 auto; padding: var(--space-7) var(--gutter) var(--space-6); }
.hero__title { font-size: clamp(2rem, 1.2rem + 3.4vw, 4.4rem); max-width: 20ch; overflow-wrap: break-word; hyphens: auto; }
.lang-zh .hero__title { max-width: 16em; font-size: var(--step-5); }
.hero__lead { font-size: var(--step-1); color: var(--ink-muted); max-width: 46ch; }
.hero__actions { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-5); margin-top: var(--space-6); }
/* Toolpath strip below the actions, in normal flow (never overlays content) */
.toolstrip { margin-top: var(--space-6); }
.toolstrip__label { display: flex; justify-content: space-between; gap: var(--space-4); margin: 0 0 var(--space-2); font-size: 0.7rem; color: var(--ink-muted); letter-spacing: 0.08em; }
.toolstrip__track { position: relative; height: 56px; border-top: 1px dashed var(--line); }
/* 6px inset on both sides: the 10px cutter dot stays inside the content box at both ends */
.toolstrip__svg { display: block; width: calc(100% - 12px); height: calc(100% - 6px); margin: 0 6px; overflow: visible; }
.toolstrip__stock { fill: none; stroke: var(--line); stroke-width: 1; vector-effect: non-scaling-stroke; }
@media (min-width: 768px) { .toolstrip__track { height: 72px; } }
.toolpath { fill: none; stroke: var(--signal); stroke-width: 1.5; vector-effect: non-scaling-stroke; opacity: 0.55; }

/* Generic page section */
.page-section { max-width: var(--max-width); margin: 0 auto; padding: var(--space-7) var(--gutter); }
@media (min-width: 1024px) { .page-section { padding-top: var(--space-9); padding-bottom: var(--space-9); } }

/* Footer */
.site-footer { border-top: var(--border); padding: var(--space-8) var(--gutter) var(--space-6); max-width: var(--max-width); margin: 0 auto; }
.site-footer__grid { display: grid; gap: var(--space-6); }
.site-footer__name { display: block; font-family: var(--font-display); font-stretch: 125%; font-weight: 800; font-size: var(--step-2); }
.site-footer__tagline { color: var(--ink-muted); }
.site-footer__links { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--space-2) var(--space-5); font-family: var(--font-mono); font-size: var(--step--1); text-transform: uppercase; }
.site-footer__links a { text-decoration: none; color: var(--ink-muted); }
.site-footer__links a:hover { color: var(--ink); }
.site-footer__legal { color: var(--ink-muted); font-size: var(--step--1); margin-top: var(--space-5); max-width: 80ch; }
@media (min-width: 768px) {
  .site-footer__grid { grid-template-columns: 1fr 2fr; }
  .site-footer__links { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}