/* Suwu landing page — minimal design system
 * Tokens: text/primary #0C0C09 · secondary #312C85 · surface #F4F4F1
 * Fonts: Inter (display) · Open Sans (body) · Inconsolata (mono)
 * Spacing rhythm: 4 / 8 / 12 / 16 / 24 / 32 (×2 at section scale)
 */

:root {
  --color-text: #0c0c09;
  --color-text-muted: #52524c;
  --color-primary: #0c0c09;
  --color-secondary: #312c85;
  --color-secondary-strong: #232060;
  --color-surface: #f4f4f1;
  --color-surface-alt: #ebebe6;
  --color-border: #d6d6cf;
  --color-danger: #dc2626;
  --color-white: #ffffff;

  --font-display: "Inter", system-ui, sans-serif;
  --font-body: "Open Sans", system-ui, sans-serif;
  --font-mono: "Inconsolata", ui-monospace, monospace;

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-6: 24px;
  --space-8: 32px;
  --space-12: 48px;
  --space-16: 64px;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --measure: 62ch;
}

/* ---------- Reset & base ---------- */

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

html {
  scroll-behavior: smooth;
  /* fills the area outside the page column on ultra-wide screens */
  background: var(--color-surface);
}

body {
  margin: 0 auto;
  max-width: 80rem; /* 1280px — the whole page lives inside this column:
                       borders, bands, and backgrounds all stop here */
  border-inline: 1px solid var(--color-border); /* vertical page frame */
  background: var(--color-surface);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3 {
  font-family: var(--font-display);
  line-height: 1.12;
  margin: 0 0 var(--space-4);
  text-wrap: balance;
}

h2 {
  font-size: clamp(1.75rem, 1.2rem + 2.4vw, 2.625rem);
  font-weight: 800;
  letter-spacing: -0.02em;
}

h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--space-2);
}

p {
  margin: 0 0 var(--space-4);
}

a {
  color: var(--color-secondary);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

a:hover {
  color: var(--color-secondary-strong);
}

code,
kbd,
pre {
  font-family: var(--font-mono);
}

code {
  font-size: 0.875em;
  background: var(--color-surface-alt);
  border-radius: var(--radius-sm);
  padding: 0.1em 0.35em;
}

kbd {
  display: inline-block;
  min-width: 1.9em;
  text-align: center;
  font-size: 0.8125rem;
  font-weight: 500;
  padding: 2px 7px;
  border: 1px solid var(--color-border);
  border-bottom-width: 2px;
  border-radius: var(--radius-sm);
  background: var(--color-white);
  color: var(--color-text);
}

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

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-4);
  z-index: 10;
  padding: var(--space-2) var(--space-4);
  background: var(--color-primary);
  color: var(--color-white);
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  text-decoration: none;
}

.skip-link:focus-visible {
  top: 0;
  color: var(--color-white);
}

.container {
  max-width: 80rem; /* 1280px */
  margin-inline: auto;
  padding-inline: var(--space-6);
}

/* ---------- Header ---------- */

.site-header {
  border-bottom: 1px solid var(--color-border);
  background: var(--color-surface);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding-block: var(--space-3);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-text);
  text-decoration: none;
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.0625rem;
  letter-spacing: -0.01em;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-6);
}

.site-nav a {
  color: var(--color-text);
  text-decoration: none;
  font-size: 0.9375rem;
  font-weight: 500;
}

.site-nav a:hover {
  color: var(--color-secondary);
}

.site-nav a:focus-visible {
  outline-offset: 4px;
}

.nav-github {
  padding: 6px 14px;
  border: 1px solid var(--color-text);
  border-radius: 999px;
  transition: background-color 120ms ease, color 120ms ease;
}

.nav-github:hover {
  background: var(--color-primary);
  color: var(--color-white);
}

/* ---------- Hero ---------- */

.hero {
  position: relative;
  overflow: hidden;
  padding-block: var(--space-16) var(--space-16);
}

#hero-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  will-change: transform;
}

.hero-inner {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.hero-logo {
  width: 256px;
  height: 256px;
  margin-bottom: var(--space-8);
}

.hero h1 {
  font-size: clamp(3.5rem, 2rem + 6vw, 6.5rem);
  font-weight: 800;
  letter-spacing: -0.035em;
  margin-bottom: var(--space-4);
}

.hero-tagline {
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 1rem + 1.4vw, 1.75rem);
  font-weight: 500;
  font-style: italic;
  letter-spacing: -0.01em;
  color: var(--color-text);
  margin-bottom: var(--space-6);
}

.hero-sub {
  max-width: 46ch;
  font-size: 1.0625rem;
  color: var(--color-text-muted);
  margin-bottom: var(--space-8);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-3);
}

.btn {
  display: inline-block;
  padding: 12px 24px;
  border-radius: 999px;
  font-family: var(--font-display);
  font-size: 0.9375rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  transition: background-color 120ms ease, color 120ms ease, border-color 120ms ease;
}

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

.btn-primary:hover {
  background: #2a2a24;
  color: var(--color-white);
}

.btn-primary:focus-visible {
  outline-color: var(--color-primary);
}

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

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

/* ---------- Install band ---------- */

.install-band {
  background: var(--color-surface-alt);
  color: var(--color-text);
  border-block: 1px solid var(--color-border);
  padding-block: var(--space-12);
}

.install-lead {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--space-4);
}

.install-line {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  overflow-x: auto;
  max-width: 100%;
  background: var(--color-white);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-2) var(--space-2) var(--space-2) var(--space-4);
}

.install-line code {
  background: none;
  color: inherit;
  font-size: 0.875rem;
  white-space: nowrap;
  flex: 1;
  min-width: 0;
  padding-block: var(--space-1);
}

.copy-btn {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-text);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 6px 14px;
  cursor: pointer;
  transition: background-color 120ms ease, border-color 120ms ease;
}

.copy-btn:hover {
  border-color: var(--color-text);
}

.copy-btn:active {
  background: var(--color-surface-alt);
}

.copy-btn-done {
  color: #166534;
  border-color: #166534;
}

.install-line-lg code {
  font-size: 0.9375rem;
}

.install-note {
  margin: var(--space-4) 0 0;
  color: var(--color-text-muted);
  font-size: 0.9375rem;
}

.install-note code {
  background: var(--color-white);
  color: var(--color-text);
}

/* ---------- Sections ---------- */

.section {
  padding-block: var(--space-16);
}

/* The page body is capped at 80rem, so banded sections simply fill the
 * column — their edges stop where the page stops. */
.section-alt {
  background: var(--color-surface-alt);
  border-block: 1px solid var(--color-border);
}

.section-sub {
  max-width: var(--measure);
  color: var(--color-text-muted);
  font-size: 1.0625rem;
}

/* ---------- Demo ---------- */

.demo-figure {
  margin: var(--space-8) 0 0;
}

.demo-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
  aspect-ratio: 16 / 9;
  background: var(--color-primary);
  border-radius: var(--radius-lg);
  color: var(--color-surface);
}

.demo-play {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 64px;
  height: 64px;
  border: 1px solid #3a3a33;
  border-radius: 50%;
  background: #1d1d18;
  color: var(--color-surface);
}

.demo-label {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: #b3b3ab;
}

.demo-caption {
  margin-top: var(--space-3);
  color: var(--color-text-muted);
  font-size: 0.875rem;
}

/* ---------- Features, one by one ---------- */

.feature-list {
  list-style: none;
  margin: var(--space-12) 0 0;
  padding: 0;
  counter-reset: feature;
}

.feature-row {
  display: grid;
  grid-template-columns: 96px minmax(0, 1.1fr) minmax(0, 1fr);
  gap: var(--space-6);
  align-items: center;
  padding-block: var(--space-8);
  border-top: 1px solid var(--color-border);
}

.feature-row:last-child {
  border-bottom: 1px solid var(--color-border);
}

.feature-num {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--color-secondary);
  line-height: 1.2;
}

.feature-body p {
  max-width: var(--measure);
  color: var(--color-text-muted);
  margin: 0;
}

.feature-media {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  aspect-ratio: 16 / 9;
  background: var(--color-white);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
}

.feature-media-icon {
  display: inline-flex;
  color: #8a8a82;
}

.feature-media-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: #8a8a82;
}

.feature-media-video {
  display: block;
  width: 100%;
  height: auto;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

@media (max-width: 60rem) {
  .feature-row {
    grid-template-columns: 96px minmax(0, 1fr);
    align-items: start;
  }

  .feature-media {
    grid-column: 2;
    max-width: 28rem;
  }
}

@media (max-width: 40rem) {
  .feature-row {
    grid-template-columns: 1fr;
    gap: var(--space-2);
  }

  .feature-num {
    font-size: 1.5rem;
  }

  .feature-media {
    grid-column: 1;
    width: 100%;
    max-width: none;
  }
}

/* ---------- Shortcuts ---------- */

.shortcut-table {
  width: 100%;
  margin-top: var(--space-8);
  border-collapse: collapse;
  font-size: 0.9375rem;
}

.shortcut-table th,
.shortcut-table td {
  text-align: left;
  padding: var(--space-3) var(--space-2);
  border-bottom: 1px solid var(--color-border);
}

.shortcut-table th {
  font-family: var(--font-display);
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-muted);
}

.shortcut-table td:first-child {
  font-weight: 600;
}

@media (min-width: 48rem) {
  .shortcut-table tbody tr td:nth-child(2) {
    width: 55%;
  }
}

/* ---------- Thanks ---------- */

.thanks {
  background: transparent;
  border-block: none;
}

.thanks-inner {
  max-width: 46rem;
  text-align: center;
}

.thanks-copy {
  max-width: 52ch;
  margin-inline: auto;
  color: var(--color-text-muted);
  font-size: 1.0625rem;
}

/* ---------- Footer ---------- */

.site-footer {
  border-top: 1px solid var(--color-border);
  padding-block: var(--space-8);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-4) var(--space-6);
}

.footer-left,
.footer-right {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-2) var(--space-6);
}

.footer-brand {
  font-family: var(--font-display);
  font-weight: 700;
}

.footer-note,
.footer-year {
  color: var(--color-text-muted);
  font-size: 0.875rem;
}

.footer-credit,
.footer-github {
  font-size: 0.875rem;
  font-weight: 500;
}

/* ---------- Lightbox ---------- */

.lightbox {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgb(12 12 9 / 0.82);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  padding: var(--space-8);
  opacity: 0;
  visibility: hidden;
  transition: opacity 200ms ease, visibility 200ms;
}

.lightbox.is-open {
  opacity: 1;
  visibility: visible;
}

.lightbox-close {
  position: absolute;
  top: var(--space-4);
  right: var(--space-4);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: none;
  background: var(--color-white);
  color: var(--color-text);
  cursor: pointer;
  box-shadow: 0 2px 8px rgb(0 0 0 / 0.15);
  transition: background-color 120ms ease;
}

.lightbox-close:hover {
  background: var(--color-surface-alt);
}

.lightbox-video-wrap {
  max-width: 1120px;
  max-height: calc(100vh - var(--space-8) * 2);
}

.lightbox-video-wrap video {
  display: block;
  width: 100%;
  max-height: calc(100vh - var(--space-8) * 2);
  border-radius: var(--radius-md);
  background: #000;
  object-fit: contain;
}

/* ---------- Reduced motion ---------- */

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}