/* Layered Launcher landing page
   テキストオンリーの美学に合わせて、白黒・大きい余白・等幅 + sans-serif 混在 */

:root {
  --fg: #0a0a0a;
  --bg: #ffffff;
  --muted: #666666;
  --border: #e5e5e5;
  --accent: #0a0a0a;
  --accent-fg: #ffffff;
  --dark-bg: #0a0a0a;
  --dark-fg: #f5f5f5;
  --max-width: 720px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic", "Meiryo", sans-serif;
  --font-mono: "SF Mono", "Menlo", "Monaco", "Consolas", monospace;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--fg);
  text-decoration: underline;
  text-underline-offset: 2px;
}

a:hover {
  text-decoration: none;
}

h1, h2, h3 {
  line-height: 1.3;
  letter-spacing: -0.01em;
}

h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  margin: 0 0 1.5rem;
  font-weight: 800;
}

h2 {
  font-size: clamp(1.5rem, 3.5vw, 2rem);
  margin: 0 0 1.5rem;
  font-weight: 700;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.5rem;
}

h3 {
  font-size: 1.15rem;
  margin: 1.5rem 0 0.75rem;
  font-weight: 700;
}

p {
  margin: 0 0 1rem;
}

ul {
  padding-left: 1.25rem;
  margin: 0 0 1rem;
}

li {
  margin-bottom: 0.5rem;
}

.muted {
  color: var(--muted);
}

.small {
  font-size: 0.875rem;
}

/* topnav */
.topnav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 10;
}

.topnav .brand {
  font-weight: 800;
  text-decoration: none;
  font-size: 1rem;
}

.topnav .nav-links {
  display: flex;
  gap: 1.25rem;
}

.topnav .nav-links a {
  text-decoration: none;
  font-size: 0.9rem;
  color: var(--muted);
}

.topnav .nav-links a:hover {
  color: var(--fg);
}

.topnav .nav-links a.lang-switch {
  border: 1px solid var(--border);
  padding: 0.15rem 0.5rem;
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

@media (max-width: 540px) {
  .topnav { padding: 0.75rem 1rem; }
  .topnav .nav-links { gap: 0.75rem; }
  .topnav .nav-links a { font-size: 0.8rem; }
}

/* hero */
.hero {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 4rem 1.5rem 3rem;
  text-align: left;
}

.hero .lead {
  font-size: 1.15rem;
  color: var(--fg);
  max-width: 38rem;
}

.cta {
  display: flex;
  gap: 0.75rem;
  margin-top: 2rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border: 1px solid var(--fg);
  border-radius: 2px;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  transition: all 0.15s ease;
}

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

.btn.primary:hover {
  background: var(--bg);
  color: var(--fg);
}

.btn.secondary {
  background: transparent;
  color: var(--fg);
}

.btn.secondary:hover {
  background: var(--fg);
  color: var(--accent-fg);
}

/* section */
.section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 3rem 1.5rem;
}

.section.dark {
  max-width: none;
  background: var(--dark-bg);
  color: var(--dark-fg);
  margin: 2rem 0;
  padding: 4rem 1.5rem;
}

.section.dark > * {
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
}

.section.dark h2 {
  border-bottom-color: rgba(255, 255, 255, 0.2);
}

.section.dark blockquote {
  margin: 0;
  border-left: 3px solid var(--dark-fg);
  padding-left: 1.5rem;
  font-size: 1.05rem;
}

.section.dark .signature {
  margin-top: 2rem;
  color: var(--muted);
  font-size: 0.9rem;
}

/* concept */
.point {
  margin-bottom: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}

.point:last-child {
  border-bottom: none;
  margin-bottom: 0;
}

.point h3 {
  margin-top: 0;
}

/* screenshots */
.screenshot-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.screenshot-grid figure {
  margin: 0;
}

.screenshot-placeholder {
  aspect-ratio: 9 / 19.5;
  background: #f0f0f0;
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  border-radius: 4px;
}

.screenshot-grid figcaption {
  font-size: 0.85rem;
  color: var(--muted);
  margin-top: 0.5rem;
}

/* feature list */
.feature-list {
  list-style: none;
  padding: 0;
}

.feature-list li {
  padding: 0.75rem 0;
  border-bottom: 1px dashed var(--border);
}

.feature-list li:last-child {
  border-bottom: none;
}

/* beta */
.beta-card {
  border: 1px solid var(--fg);
  padding: 1.5rem;
  margin-top: 1.5rem;
}

.signup-options {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: 0.5rem;
}

/* faq */
.faq details {
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
}

.faq details:last-child {
  border-bottom: none;
}

.faq summary {
  cursor: pointer;
  font-weight: 600;
  list-style: none;
  position: relative;
  padding-left: 1.5rem;
}

.faq summary::-webkit-details-marker {
  display: none;
}

.faq summary::before {
  content: "+";
  position: absolute;
  left: 0;
  font-family: var(--font-mono);
  font-weight: 700;
  transition: transform 0.15s;
}

.faq details[open] summary::before {
  content: "−";
}

.faq details p {
  margin-top: 0.75rem;
  margin-left: 1.5rem;
  color: var(--muted);
}

/* footer */
.footer {
  border-top: 1px solid var(--border);
  margin-top: 3rem;
  padding: 2rem 1.5rem;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  font-size: 0.85rem;
  color: var(--muted);
  text-align: center;
}

.footer-inner a {
  color: var(--muted);
}

.footer .copy {
  margin-top: 0.5rem;
  font-family: var(--font-mono);
}