/* ═══════════════════════════════════════════
   CommandOS — Minimalist Design System
   ═══════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* ── Reset & Base ── */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg:       #fafafa;
  --surface:  #ffffff;
  --border:   #e5e5e5;
  --text:     #111111;
  --text-2:   #555555;
  --text-3:   #999999;
  --accent:   #111111;
  --accent-light: #f5f5f5;
  --radius:   8px;
  --max-w:    1120px;
  --nav-h:    64px;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', -apple-system, system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* ── Layout ── */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: 96px 0;
}

/* ── Typography ── */
h1 {
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 800;
  letter-spacing: -1.5px;
  line-height: 1.1;
}

h2 {
  font-size: clamp(28px, 3.5vw, 40px);
  font-weight: 700;
  letter-spacing: -1px;
  line-height: 1.2;
}

h3 {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.3px;
}

p { color: var(--text-2); }

.label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 12px;
}

/* ── Navigation ── */
nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-h);
  background: rgba(250, 250, 250, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
  display: flex;
  align-items: center;
}

nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.5px;
}

.nav-logo img {
  width: 32px;
  height: 32px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-2);
  transition: color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text);
}

.nav-links .cta-link {
  background: var(--accent);
  color: white;
  padding: 8px 20px;
  border-radius: 6px;
  font-weight: 600;
  transition: opacity 0.2s;
}

.nav-links .cta-link:hover {
  opacity: 0.85;
  color: white;
}

/* Mobile menu */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  width: 24px;
  height: 24px;
  position: relative;
}

.nav-toggle span,
.nav-toggle span::before,
.nav-toggle span::after {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text);
  border-radius: 1px;
  position: absolute;
  transition: 0.3s;
}

.nav-toggle span { top: 11px; left: 2px; }
.nav-toggle span::before { content: ''; top: -6px; }
.nav-toggle span::after { content: ''; top: 6px; }

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
  font-family: inherit;
}

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

.btn-primary:hover {
  opacity: 0.85;
  transform: translateY(-1px);
}

.btn-secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: var(--accent-light);
  border-color: var(--text-3);
}

/* ── Cards ── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: border-color 0.2s;
}

.card:hover {
  border-color: var(--text-3);
}

/* ── Grid ── */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

/* ── Hero ── */
.hero {
  padding-top: calc(var(--nav-h) + 80px);
  padding-bottom: 80px;
  text-align: center;
}

.hero h1 {
  max-width: 720px;
  margin: 0 auto 24px;
}

.hero p {
  font-size: 18px;
  max-width: 560px;
  margin: 0 auto 40px;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
}

/* ── Section Header ── */
.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-header h2 {
  margin-bottom: 16px;
}

.section-header p {
  font-size: 16px;
  max-width: 520px;
  margin: 0 auto;
}

/* ── Feature Card ── */
.feature-card {
  padding: 32px;
}

.feature-icon {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  background: var(--accent-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  margin-bottom: 20px;
}

.feature-card h3 {
  margin-bottom: 10px;
}

.feature-card p {
  font-size: 14px;
  line-height: 1.7;
}

/* ── Stats Row ── */
.stats-row {
  display: flex;
  justify-content: center;
  gap: 64px;
  padding: 48px 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.stat {
  text-align: center;
}

.stat-number {
  font-size: 40px;
  font-weight: 800;
  letter-spacing: -1px;
  color: var(--text);
}

.stat-label {
  font-size: 13px;
  color: var(--text-3);
  margin-top: 4px;
}

/* ── CTA Banner ── */
.cta-banner {
  text-align: center;
  padding: 80px 0;
}

.cta-banner h2 {
  margin-bottom: 16px;
}

.cta-banner p {
  font-size: 16px;
  margin-bottom: 32px;
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}

/* ── Footer ── */
footer {
  border-top: 1px solid var(--border);
  padding: 48px 0;
}

footer .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 16px;
  font-weight: 700;
}

.footer-logo img {
  width: 28px;
  height: 28px;
}

.footer-links {
  display: flex;
  gap: 24px;
  list-style: none;
}

.footer-links a {
  font-size: 13px;
  color: var(--text-3);
  transition: color 0.2s;
}

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

.footer-copy {
  font-size: 13px;
  color: var(--text-3);
}

/* ── Page Header (inner pages) ── */
.page-header {
  padding-top: calc(var(--nav-h) + 64px);
  padding-bottom: 48px;
  border-bottom: 1px solid var(--border);
}

.page-header h1 {
  font-size: clamp(32px, 4vw, 48px);
  margin-bottom: 12px;
}

.page-header p {
  font-size: 17px;
  max-width: 560px;
}

/* ── Feature Detail (features page) ── */
.feature-detail {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  padding: 64px 0;
  border-bottom: 1px solid var(--border);
}

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

.feature-detail.reverse .feature-detail-text { order: 2; }
.feature-detail.reverse .feature-detail-visual { order: 1; }

.feature-detail-text .label { margin-bottom: 8px; }
.feature-detail-text h3 {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.5px;
  margin-bottom: 16px;
}
.feature-detail-text p {
  font-size: 15px;
  line-height: 1.7;
  margin-bottom: 24px;
}

.feature-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.feature-list li {
  font-size: 14px;
  color: var(--text-2);
  padding-left: 20px;
  position: relative;
}

.feature-list li::before {
  content: '—';
  position: absolute;
  left: 0;
  color: var(--text-3);
}

.feature-detail-visual {
  background: var(--accent-light);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 40px;
  min-height: 280px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Courier New', monospace;
  font-size: 13px;
  color: var(--text-2);
  line-height: 1.8;
  white-space: pre;
}

/* ── About Page ── */
.about-story {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
  padding: 64px 0;
}

.about-story h2 {
  font-size: 32px;
  margin-bottom: 24px;
}

.about-story p {
  font-size: 15px;
  line-height: 1.8;
  margin-bottom: 16px;
}

.principle-card {
  padding: 24px;
}

.principle-card .num {
  font-size: 32px;
  font-weight: 800;
  color: var(--border);
  margin-bottom: 12px;
}

.principle-card h3 { margin-bottom: 8px; }
.principle-card p { font-size: 14px; }

.team-card {
  text-align: center;
  padding: 32px 24px;
}

.team-avatar {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--accent-light);
  margin: 0 auto 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  font-weight: 700;
  color: var(--text-3);
}

.team-card h3 { font-size: 16px; margin-bottom: 4px; }
.team-card p { font-size: 13px; }

/* ── Contact Page ── */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  padding: 64px 0;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.form-group { display: flex; flex-direction: column; gap: 6px; }

.form-group label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
}

.form-group input,
.form-group textarea,
.form-group select {
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
  font-family: inherit;
  color: var(--text);
  background: var(--surface);
  transition: border-color 0.2s;
  outline: none;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  border-color: var(--text);
}

.form-group textarea {
  min-height: 120px;
  resize: vertical;
}

.contact-info h3 {
  font-size: 24px;
  margin-bottom: 24px;
}

.contact-info-item {
  margin-bottom: 24px;
}

.contact-info-item .ci-label {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-3);
  margin-bottom: 6px;
}

.contact-info-item p {
  font-size: 15px;
  color: var(--text);
}

/* ── Responsive ── */
@media (max-width: 768px) {
  section { padding: 64px 0; }

  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }

  .feature-detail,
  .about-story,
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .feature-detail.reverse .feature-detail-text { order: 1; }
  .feature-detail.reverse .feature-detail-visual { order: 2; }

  .stats-row {
    flex-direction: column;
    gap: 32px;
  }

  .hero-actions { flex-direction: column; align-items: center; }

  .nav-links { display: none; }
  .nav-toggle { display: block; }

  footer .container { flex-direction: column; gap: 16px; text-align: center; }
}