/* ==========================================================================
   源匣 · Origibox — official site design system
   Dark technical theme. No build step, no external fonts/icons.
   ========================================================================== */

:root {
  /* Color */
  --color-bg: #0a0d13;
  --color-bg-soft: #0d1119;
  --color-surface: #131826;
  --color-surface-2: #1a2033;
  --color-border: rgba(255, 255, 255, 0.08);
  --color-border-strong: rgba(255, 255, 255, 0.16);

  --color-text: #edf0f6;
  --color-text-secondary: #a2aac0;
  --color-text-tertiary: #6d7690;

  --color-accent: #ff9142;
  --color-accent-strong: #ffab6b;
  --color-accent-ink: #1c0f02;
  --color-accent-soft: rgba(255, 145, 66, 0.12);

  --color-teal: #5eead4;
  --color-teal-ink: #04211c;
  --color-teal-soft: rgba(94, 234, 212, 0.12);

  --color-focus: #7db8ff;

  /* Type */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "PingFang SC", "Microsoft YaHei", Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas,
    "Liberation Mono", monospace;

  --text-xs: 0.8rem;
  --text-sm: 0.9375rem;
  --text-base: clamp(1rem, 0.96rem + 0.2vw, 1.0625rem);
  --text-lg: clamp(1.125rem, 1.06rem + 0.3vw, 1.3rem);
  --text-xl: clamp(1.5rem, 1.3rem + 0.9vw, 2rem);
  --text-display: clamp(2.4rem, 1.9rem + 2.6vw, 4.2rem);

  /* Space */
  --space-section: clamp(4rem, 3.2rem + 3.8vw, 8rem);
  --space-lg: clamp(1.5rem, 1.3rem + 0.9vw, 2.5rem);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;

  /* Motion */
  --duration-fast: 150ms;
  --duration-normal: 320ms;
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);

  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

/* icon sprite: symbols carry no paint of their own — style is applied here so
   it correctly inherits across the <use> shadow-tree boundary via CSS */
svg {
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

html {
  background: var(--color-bg);
}

body {
  margin: 0;
  min-width: 320px;
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-text);
  background:
    radial-gradient(60vw 40vw at 82% -10%, rgba(255, 145, 66, 0.14), transparent 60%),
    radial-gradient(50vw 35vw at 8% 8%, rgba(94, 234, 212, 0.08), transparent 60%),
    var(--color-bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

a {
  color: inherit;
}

.container {
  width: 100%;
  max-width: 1120px;
  margin-inline: auto;
  padding-inline: clamp(1.25rem, 4vw, 2.5rem);
}

section {
  padding-block: var(--space-section);
}

:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 3px;
  border-radius: 4px;
}

::selection {
  background: var(--color-accent-soft);
  color: var(--color-accent-strong);
}

/* ---------- grain / atmosphere ---------- */
.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  opacity: 0.035;
  mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ---------- kicker / eyebrow ---------- */
.kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-tertiary);
}

/* ---------- nav ---------- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-block: 1rem;
  backdrop-filter: blur(14px) saturate(140%);
  background: rgba(10, 13, 19, 0.72);
  border-bottom: 1px solid transparent;
  transition: border-color var(--duration-normal) var(--ease-out-expo);
}

.site-nav.is-scrolled {
  border-bottom-color: var(--color-border);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 700;
  font-size: 1.05rem;
  text-decoration: none;
  letter-spacing: -0.01em;
}

.brand img {
  width: 30px;
  height: 30px;
  border-radius: 8px;
}

.brand-sub {
  font-family: var(--font-mono);
  font-weight: 400;
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: clamp(0.75rem, 2vw, 1.75rem);
}

.nav-link {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color var(--duration-fast) ease;
}

.nav-link:hover {
  color: var(--color-text);
}

/* language toggle */
.lang-toggle {
  display: inline-flex;
  border: 1px solid var(--color-border-strong);
  border-radius: 999px;
  padding: 3px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  background: var(--color-surface);
}

.lang-toggle button {
  border: 0;
  background: transparent;
  color: var(--color-text-tertiary);
  padding: 0.3rem 0.7rem;
  border-radius: 999px;
  cursor: pointer;
  font-family: inherit;
  font-size: inherit;
  transition: background var(--duration-fast) ease, color var(--duration-fast) ease;
}

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

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.8rem 1.4rem;
  border-radius: 999px;
  font-size: var(--text-sm);
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform var(--duration-fast) var(--ease-out-expo),
    background var(--duration-fast) ease, border-color var(--duration-fast) ease,
    box-shadow var(--duration-fast) ease;
  will-change: transform;
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: var(--color-accent);
  color: var(--color-accent-ink);
  box-shadow: 0 8px 24px -8px rgba(255, 145, 66, 0.55);
}

.btn-primary:hover {
  background: var(--color-accent-strong);
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  border-color: var(--color-border-strong);
  color: var(--color-text);
}

.btn-ghost:hover {
  border-color: var(--color-accent);
  color: var(--color-accent-strong);
  transform: translateY(-1px);
}

.btn-block {
  width: 100%;
}

.btn-disabled {
  cursor: default;
  opacity: 0.72;
  pointer-events: none;
  box-shadow: none;
}

/* ---------- hero ---------- */
.hero {
  padding-top: clamp(3.5rem, 3rem + 3vw, 6rem);
  position: relative;
}

.hero-grid {
  display: grid;
  gap: clamp(2rem, 4vw, 3rem);
  align-items: center;
}

.hero h1 {
  font-size: var(--text-display);
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin: 0.6em 0 0.4em;
}

.hero .accent-word {
  color: var(--color-accent);
}

.hero p.lede {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 46ch;
  margin: 0 0 2rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem;
  margin-bottom: 2.5rem;
}

.badge-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border-strong);
  border-radius: 999px;
  padding: 0.4rem 0.75rem;
  background: var(--color-surface);
}

.badge svg {
  width: 13px;
  height: 13px;
  color: var(--color-teal);
  flex-shrink: 0;
}

/* ---------- stat / bento ---------- */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--color-border);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-top: clamp(2.5rem, 4vw, 4rem);
}

.stat-card {
  background: var(--color-surface);
  padding: clamp(1.5rem, 3vw, 2.25rem);
}

.stat-card .stat-value {
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 1.3rem + 1.4vw, 2.4rem);
  color: var(--color-accent);
  letter-spacing: -0.01em;
}

.stat-card .stat-label {
  font-weight: 600;
  margin-top: 0.5rem;
}

.stat-card .stat-desc {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  margin-top: 0.4rem;
}

/* ---------- section heading ---------- */
.section-head {
  max-width: 60ch;
  margin-bottom: clamp(2.5rem, 4vw, 3.5rem);
}

.section-head h2 {
  font-size: var(--text-xl);
  letter-spacing: -0.01em;
  margin: 0.5em 0 0.4em;
}

.section-head p {
  color: var(--color-text-secondary);
  margin: 0;
}

/* ---------- feature bento grid ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
}

.feature-card {
  grid-column: span 2;
  border: 1px solid var(--color-border);
  background: linear-gradient(160deg, var(--color-surface), var(--color-surface-2));
  border-radius: var(--radius-md);
  padding: clamp(1.4rem, 2vw, 1.9rem);
  transition: transform var(--duration-normal) var(--ease-out-expo),
    border-color var(--duration-normal) ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--color-border-strong);
}

.feature-card.span-full {
  grid-column: span 4;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: clamp(1.5rem, 3vw, 3rem);
  align-items: center;
}

.feature-card.is-compact {
  grid-column: span 2;
}

.feature-icon {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-soft);
  color: var(--color-accent);
  margin-bottom: 1.1rem;
}

.feature-card.is-teal .feature-icon {
  background: var(--color-teal-soft);
  color: var(--color-teal);
}

.feature-icon svg {
  width: 22px;
  height: 22px;
}

.feature-card h3 {
  font-size: 1.05rem;
  margin: 0 0 0.45rem;
  letter-spacing: -0.01em;
}

.feature-card p {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  margin: 0;
}

.feature-card code {
  font-family: var(--font-mono);
  background: rgba(255, 255, 255, 0.06);
  padding: 0.1em 0.4em;
  border-radius: 5px;
  font-size: 0.9em;
}

/* ---------- flow steps ---------- */
.flow-visual {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: clamp(1.5rem, 2.5vw, 2.25rem);
  background: var(--color-surface);
  display: flex;
  flex-direction: column;
  gap: 1.4rem;
}

.flow-step {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}

.flow-step-num {
  flex-shrink: 0;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: var(--color-accent-soft);
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.flow-step p {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  padding-top: 0.35rem;
}

.flow-step strong {
  color: var(--color-text);
}

/* ---------- download ---------- */
.download-panel {
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-lg);
  padding: clamp(2rem, 4vw, 3.5rem);
  background: linear-gradient(160deg, var(--color-surface), var(--color-bg-soft));
  display: grid;
  gap: clamp(1.75rem, 3vw, 2.5rem);
  grid-template-columns: 1.3fr 1fr;
  align-items: center;
}

.download-panel h2 {
  font-size: var(--text-xl);
  margin: 0.4em 0 0.5em;
  letter-spacing: -0.01em;
}

.download-panel p {
  color: var(--color-text-secondary);
  margin: 0 0 1.6rem;
  max-width: 42ch;
}

.download-meta {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.download-actions {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

/* ---------- footer ---------- */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding-block: clamp(2.5rem, 4vw, 3.5rem);
}

.footer-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: flex-start;
  gap: 2rem;
}

.footer-links {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: var(--text-sm);
}

.footer-links a:hover {
  color: var(--color-text);
}

.footer-meta {
  color: var(--color-text-tertiary);
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  margin-top: 1.5rem;
}

/* ---------- reveal-on-scroll ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s var(--ease-out-expo), transform 0.7s var(--ease-out-expo);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .btn,
  .feature-card {
    transition: none !important;
  }
}

/* ---------- mobile ---------- */
.nav-toggle {
  display: none;
  border: 1px solid var(--color-border-strong);
  background: var(--color-surface);
  color: var(--color-text);
  border-radius: 8px;
  width: 38px;
  height: 38px;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

@media (max-width: 860px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .feature-card.span-full {
    grid-column: span 2;
    grid-template-columns: 1fr;
  }

  .download-panel {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .stat-grid {
    grid-template-columns: 1fr;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .feature-card,
  .feature-card.is-compact,
  .feature-card.span-full {
    grid-column: span 1;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .nav-links {
    position: fixed;
    inset: 64px 0 auto 0;
    flex-direction: column;
    align-items: stretch;
    padding: 1.25rem clamp(1.25rem, 4vw, 2.5rem);
    background: var(--color-bg-soft);
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-8px);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--duration-normal) ease, transform var(--duration-normal) ease;
  }

  .nav-links.is-open {
    opacity: 1;
    transform: none;
    pointer-events: auto;
  }

  .nav-links .lang-toggle {
    align-self: flex-start;
    margin-top: 0.5rem;
  }
}

/* ---------- generic content page (privacy) ---------- */
.doc {
  max-width: 74ch;
  margin-inline: auto;
}

.doc h1 {
  font-size: var(--text-xl);
  margin-bottom: 0.3em;
}

.doc .doc-updated {
  color: var(--color-text-tertiary);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  margin-bottom: 2.5rem;
}

.doc h2 {
  font-size: 1.15rem;
  margin-top: 2.2em;
  letter-spacing: -0.01em;
}

.doc p {
  color: var(--color-text-secondary);
}

.doc a {
  color: var(--color-accent);
}

.doc hr {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: 3rem 0;
}

.lang-jump {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 2.5rem;
}