/* 赛博梦想家 — Refero "AI for Business" tokens (Dayos-like) */
:root {
  --carbon: #000000;
  --paper: #ffffff;
  --canvas: #e5e5e5;
  --mist: #f3f3f3;
  --ash: #c6c6c6;
  --smoke: #979797;
  --slate: #444444;
  --graphite: #2f2f2f;
  --mint: #d1ffca;
  --voltage: #fff100;

  --font-display: "Barlow Condensed", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "DM Sans", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, monospace;

  --max: 1200px;
  --section-gap: 80px;
  --card-pad: 24px;
  --radius-card: 32px;
  --radius-card-lg: 64px;
  --radius-pill: 48px;
  --radius-btn: 8px;
  --radius-tag: 64px;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  .reveal {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
}

body {
  margin: 0;
  min-height: 100dvh;
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 500;
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--carbon);
  background: var(--canvas);
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.15em;
}

a:hover {
  color: var(--slate);
}

:focus-visible {
  outline: 2px solid var(--carbon);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  z-index: 100;
  background: var(--carbon);
  color: var(--paper);
  padding: 0.5rem 1rem;
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
}

.wrap {
  width: min(var(--max), calc(100% - 2.5rem));
  margin-inline: auto;
}

/* —— Header / nav pill —— */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: 5.5rem;
  display: flex;
  align-items: center;
  background: transparent;
}

@media (min-width: 900px) {
  .site-header {
    height: 8rem;
  }
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: min(var(--max), calc(100% - 2.5rem));
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  letter-spacing: -0.02em;
  color: var(--carbon);
  flex-shrink: 0;
}

.brand:hover {
  color: var(--carbon);
}

.brand-mark {
  width: 1.35rem;
  height: 1.35rem;
  border-radius: 6px;
  background: var(--carbon);
  position: relative;
}

.brand-mark::after {
  content: "";
  position: absolute;
  inset: 4px;
  border-radius: 2px;
  background: var(--mint);
}

.nav-cluster {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  min-width: 0;
}

.nav-pill {
  display: none;
  align-items: center;
  gap: 0.15rem;
  list-style: none;
  margin: 0;
  padding: 0.45rem 0.55rem;
  background: var(--paper);
  border-radius: var(--radius-pill);
}

@media (min-width: 900px) {
  .nav-pill {
    display: flex;
  }
}

.nav-pill a {
  text-decoration: none;
  color: var(--slate);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.55rem 0.9rem;
  border-radius: 999px;
  transition: background 0.2s, color 0.2s;
  white-space: nowrap;
}

.nav-pill a:hover {
  background: var(--mist);
  color: var(--carbon);
}

.lang-toggle {
  display: inline-flex;
  background: var(--paper);
  border-radius: var(--radius-pill);
  padding: 0.25rem;
  flex-shrink: 0;
}

.lang-toggle button {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--smoke);
  font: inherit;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  padding: 0.45rem 0.7rem;
  border-radius: 999px;
  cursor: pointer;
}

.lang-toggle button[aria-pressed="true"] {
  background: var(--mint);
  color: var(--carbon);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  min-height: 44px;
  padding: 0.85rem 1.35rem;
  border-radius: var(--radius-btn);
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 500;
  text-decoration: none;
  border: 0;
  cursor: pointer;
  transition: transform 0.15s var(--ease), filter 0.2s;
  white-space: nowrap;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--carbon);
  color: var(--paper);
}

.btn-primary:hover {
  color: var(--paper);
  filter: brightness(1.15);
}

.btn-ghost {
  background: transparent;
  color: var(--slate);
  border: 1.5px solid var(--slate);
  border-radius: 4px;
}

.btn-ghost:hover {
  color: var(--carbon);
  border-color: var(--carbon);
}

.header-cta {
  display: none;
}

@media (min-width: 900px) {
  .header-cta {
    display: inline-flex;
  }
}

/* —— Hero —— */
.hero {
  padding: 1.5rem 0 4rem;
  display: grid;
  gap: 2.5rem;
  align-items: end;
}

@media (min-width: 960px) {
  .hero {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 2rem;
    min-height: calc(100dvh - 8rem);
    padding: 0.5rem 0 5rem;
    align-items: center;
  }
}

.hero h1 {
  margin: 0 0 1.5rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(3.25rem, 11vw, 6.5rem);
  line-height: 0.9;
  letter-spacing: -0.03em;
  text-transform: uppercase;
  max-width: 10ch;
}

.hero .lede {
  margin: 0 0 1.75rem;
  max-width: 36ch;
  color: var(--slate);
  font-size: 1rem;
  font-weight: 500;
  line-height: 1.35;
  letter-spacing: -0.011em;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.hero-aside {
  background: var(--paper);
  border-radius: var(--radius-card-lg);
  padding: 1.5rem;
  min-height: 280px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 1.5rem;
}

@media (min-width: 960px) {
  .hero-aside {
    min-height: 420px;
    padding: 2rem;
    border-radius: 64px 64px 32px 32px;
  }
}

.hero-aside-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
}

.mono-label {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: -0.03em;
  color: var(--smoke);
  text-transform: none;
}

.stack-dots {
  display: flex;
  gap: 0.35rem;
}

.stack-dots span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--carbon);
}

.stack-dots span:nth-child(2) {
  background: var(--mint);
}

.stack-dots span:nth-child(3) {
  background: var(--voltage);
}

.hero-stat {
  margin: 0;
}

.hero-stat strong {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(3rem, 8vw, 5rem);
  font-weight: 700;
  line-height: 0.9;
  letter-spacing: -0.03em;
  text-transform: uppercase;
}

.hero-stat span {
  display: block;
  margin-top: 0.65rem;
  color: var(--slate);
  font-size: 0.95rem;
  line-height: 1.3;
  max-width: 22ch;
}

/* —— Sections —— */
.section {
  padding: var(--section-gap) 0;
}

.section-head {
  margin-bottom: 2rem;
  display: grid;
  gap: 0.85rem;
  max-width: 40rem;
}

.section-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2.5rem, 6vw, 4rem);
  line-height: 0.9;
  letter-spacing: -0.03em;
  text-transform: uppercase;
}

.section-head p {
  margin: 0;
  color: var(--slate);
  font-size: 1rem;
  line-height: 1.35;
  max-width: 42ch;
}

/* —— Project cards —— */
.project-grid {
  display: grid;
  gap: 1rem;
}

@media (min-width: 720px) {
  .project-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (min-width: 1000px) {
  .project-grid {
    grid-template-columns: 1.15fr 1fr;
    grid-template-rows: auto auto;
  }

  .project-grid .project:first-child {
    grid-row: span 2;
  }
}

.project {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 1.5rem;
  background: var(--paper);
  border-radius: var(--radius-card);
  padding: var(--card-pad);
  text-decoration: none;
  color: var(--carbon);
  min-height: 200px;
  transition: transform 0.2s var(--ease), background 0.2s;
}

.project:hover {
  color: var(--carbon);
  transform: translateY(-2px);
}

.project:first-child {
  background: var(--carbon);
  color: var(--paper);
  min-height: 280px;
  border-radius: var(--radius-card-lg);
}

.project:first-child:hover {
  color: var(--paper);
}

.project:first-child .project-desc,
.project:first-child .project-meta {
  color: var(--ash);
}

.project:first-child .tag {
  background: var(--mint);
  color: var(--carbon);
}

.project-top {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
}

.tag {
  display: inline-flex;
  align-items: center;
  background: var(--mint);
  color: var(--carbon);
  border-radius: var(--radius-tag);
  padding: 0.35rem 0.75rem;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: -0.03em;
  line-height: 1.3;
}

.tag-muted {
  background: var(--mist);
}

.project:first-child .tag-muted {
  background: var(--graphite);
  color: var(--ash);
}

.project h3 {
  margin: 0.85rem 0 0.55rem;
  font-family: var(--font-body);
  font-weight: 500;
  font-size: clamp(1.35rem, 2.5vw, 1.75rem);
  line-height: 1.15;
  letter-spacing: -0.02em;
  text-transform: uppercase;
}

.project-desc {
  margin: 0;
  color: var(--slate);
  font-size: 0.95rem;
  line-height: 1.4;
  font-weight: 500;
}

.project-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--smoke);
  letter-spacing: -0.03em;
}

.project-meta .arrow {
  font-size: 1.1rem;
  color: inherit;
  transition: transform 0.2s var(--ease);
}

.project:hover .arrow {
  transform: translateX(3px);
}

/* —— About band (inverted) —— */
.about-band {
  background: var(--carbon);
  color: var(--paper);
  border-radius: var(--radius-card-lg) var(--radius-card-lg) 0 0;
  padding: 4rem 0 4.5rem;
  margin-top: 1rem;
}

.about-band .section-head h2 {
  color: var(--paper);
}

.about-band .section-head p {
  color: var(--smoke);
}

.about-grid {
  display: grid;
  gap: 1rem;
}

@media (min-width: 800px) {
  .about-grid {
    grid-template-columns: 1.2fr 1fr;
    gap: 1.25rem;
  }
}

.about-card {
  background: var(--graphite);
  border-radius: var(--radius-card);
  padding: 1.5rem;
}

.about-card p {
  margin: 0 0 1rem;
  color: var(--ash);
  font-size: 1rem;
  line-height: 1.4;
  font-weight: 500;
}

.about-card p:last-child {
  margin-bottom: 0;
}

.fact-list {
  list-style: none;
  margin: 0;
  padding: 1.5rem;
  background: var(--paper);
  color: var(--carbon);
  border-radius: var(--radius-card);
  display: grid;
  gap: 0;
}

.fact-list li {
  display: grid;
  grid-template-columns: 7rem 1fr;
  gap: 0.75rem;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--ash);
  font-size: 0.95rem;
  line-height: 1.3;
}

.fact-list li:first-child {
  padding-top: 0;
}

.fact-list li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.fact-k {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--smoke);
  letter-spacing: -0.03em;
  padding-top: 0.15rem;
}

/* —— Footer —— */
.site-footer {
  background: var(--carbon);
  color: var(--smoke);
  padding: 2rem 0 2.5rem;
  font-size: 0.875rem;
  font-weight: 500;
}

.footer-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 1.5rem;
  justify-content: space-between;
  align-items: flex-start;
}

.site-footer a {
  color: var(--ash);
  text-decoration: none;
}

.site-footer a:hover {
  color: var(--mint);
}

.beian {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  align-items: center;
}

/* —— Lang —— */
html[lang="zh-CN"] [data-lang="en"],
html[lang="en"] [data-lang="zh"] {
  display: none !important;
}

/* —— Reveal —— */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.65s var(--ease), transform 0.65s var(--ease);
}

.reveal.is-in {
  opacity: 1;
  transform: none;
}

/* Mobile nav links fallback */
.mobile-nav {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}

@media (min-width: 900px) {
  .mobile-nav {
    display: none;
  }
}

.mobile-nav a {
  text-decoration: none;
  font-size: 0.85rem;
  color: var(--slate);
  background: var(--paper);
  padding: 0.4rem 0.75rem;
  border-radius: 999px;
}