/* KeyBase - Modern Professional Theme */

:root {
  --primary: #0891b2;       /* Cyan 600 - Darker Cyan for primary actions */
  --primary-dark: #0e7490;  /* Cyan 700 */
  --primary-light: #22d3ee; /* Cyan 400 */
  --accent: #06b6d4;        /* Cyan 500 */
  --bg: #f8fafc;            /* Slate 50 */
  --bg-top: #f8fafc;
  --bg-mid: #eef6ff;
  --bg-bottom: #0a0818;
  --bg-card: #ffffff;
  --text: #0f172a;          /* Slate 900 */
  --text-muted: #64748b;    /* Slate 500 */
  --border: #e2e8f0;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --radius: 12px;
  --max-width: 1100px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: linear-gradient(180deg, var(--bg-top) 0%, var(--bg-mid) 40%, rgba(10, 8, 24, 0.95) 100%);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  position: relative;
  min-height: 100vh;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.site-header,
.hero,
main,
.site-footer {
  position: relative;
  z-index: 1;
}

/* --- Header --- */
.site-header {
  background: rgba(8, 20, 45, 0.4);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  padding: 18px 0;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(16px) saturate(1.4);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.12);
}

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

.logo-section {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo {
  width: 48px;
  height: 48px;
  border-radius: 10px;
}

.brand h1 {
  font-size: 24px;
  font-weight: 800;
  color: #f8fafc;
  letter-spacing: -0.5px;
}

.tagline {
  display: none; /* Hidden on mobile/desktop for cleaner look, visible in hero */
}

.header-nav {
  display: flex;
  gap: 24px;
}

.header-nav a {
  color: #e2e8f0;
  text-decoration: none;
  font-weight: 600;
  font-size: 15px;
  transition: color 0.2s;
}

.header-nav a:hover {
  color: #60a5fa;
}

/* --- Hero Section --- */
.hero {
  background: transparent;
  padding: 120px 0 140px;
  text-align: center;
  border-bottom: none;
  position: relative;
  overflow: hidden;
}

.particle-surface {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: 0.9;
  background:
    radial-gradient(circle at 30% -10%, rgba(8, 145, 178, 0.25), transparent 55%),
    radial-gradient(circle at 70% 0%, rgba(8, 145, 178, 0.18), transparent 50%),
    radial-gradient(circle at 50% 110%, rgba(103, 78, 201, 0.35), transparent 55%),
    radial-gradient(circle at 20% 120%, rgba(66, 35, 143, 0.32), transparent 60%),
    radial-gradient(circle at 80% 115%, rgba(40, 20, 80, 0.25), transparent 50%);
}

.particle-surface canvas {
  width: 100%;
  height: 100%;
  display: block;
}

.hero h2 {
  font-size: 52px;
  font-weight: 800;
  line-height: 1.15;
  margin: 0 auto 28px;
  max-width: 880px;
  background: linear-gradient(135deg, var(--primary-dark), var(--accent), #5eb8d4);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: -1.2px;
  padding: 0 20px;
}

.hero-subtitle {
  font-size: 19px;
  color: #64748b;
  max-width: 640px;
  margin: 0 auto 48px;
  line-height: 1.65;
  padding: 0 24px;
}

.cta-buttons {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 16px 36px;
  border-radius: 50px;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  font-size: 16px;
  min-width: 200px;
  height: 56px;
  box-sizing: border-box;
}

.btn-primary {
  background: var(--primary);
  color: white;
  box-shadow: 0 6px 20px rgba(8, 145, 178, 0.35);
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-3px);
  box-shadow: 0 10px 28px rgba(8, 145, 178, 0.45);
}

.btn-secondary {
  background: rgba(241, 245, 249, 0.9);
  color: var(--text);
  border: 1.5px solid rgba(148, 163, 184, 0.2);
}

.btn-secondary:hover {
  background: #e2e8f0;
  border-color: rgba(148, 163, 184, 0.35);
  transform: translateY(-2px);
}

/* --- Highlights (Overview) --- */
.highlights {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 28px;
  margin-top: 0;
  position: relative;
  z-index: 10;
  margin-bottom: 120px;
  padding-top: 60px;
}

.highlight-card {
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(10px);
  padding: 32px 24px;
  border-radius: 14px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06), 0 1px 4px rgba(0, 0, 0, 0.04);
  text-align: center;
  border: 1px solid rgba(226, 232, 240, 0.6);
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.3s ease;
}

.highlight-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.1), 0 2px 8px rgba(0, 0, 0, 0.06);
}

.highlight-icon {
  font-size: 32px;
  margin-bottom: 16px;
  background: #eff6ff;
  width: 64px;
  height: 64px;
  line-height: 64px;
  border-radius: 50%;
  margin-left: auto;
  margin-right: auto;
}

.highlight-card h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

.highlight-card p {
  font-size: 14px;
  color: var(--text-muted);
}

/* --- Features --- */
.content-section {
  margin-bottom: 120px;
}

.content-section h2 {
  font-size: 38px;
  text-align: center;
  margin-bottom: 64px;
  font-weight: 800;
  letter-spacing: -0.8px;
  padding-top: 20px;
}

/* --- Documentation Section --- */
#docs {
  position: relative;
  padding: 60px 24px;
  background: transparent;
  border-radius: 24px;
  margin: 80px auto 100px;
  max-width: 1000px;
}

#docs h2 {
  font-size: 28px;
  margin-bottom: 48px;
  letter-spacing: -0.6px;
  color: #0f172a;
}

.docs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
  max-width: 900px;
  margin: 0 auto;
}

.doc-card {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(8px);
  padding: 28px 24px;
  border-radius: 14px;
  border: 1px solid rgba(226, 232, 240, 0.5);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.doc-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
}

.doc-card h3 {
  font-size: 17px;
  font-weight: 700;
  color: #0f172a;
  margin: 0;
  display: flex;
  align-items: center;
  gap: 10px;
  line-height: 1.4;
}

.doc-card h3::before {
  content: attr(data-icon);
  font-size: 22px;
  line-height: 1;
  flex-shrink: 0;
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.doc-card p {
  color: #64748b;
  font-size: 13.5px;
  line-height: 1.6;
  margin: 0;
  flex-grow: 1;
}

.doc-card .btn {
  margin-top: 4px;
  padding: 10px 20px;
  font-size: 13px;
  min-width: auto;
  height: auto;
  align-self: flex-start;
}

.doc-card .btn-secondary {
  background: rgba(8, 145, 178, 0.08);
  color: var(--primary-dark);
  border: 1px solid rgba(8, 145, 178, 0.2);
  font-weight: 600;
}

.doc-card .btn-secondary:hover {
  background: rgba(8, 145, 178, 0.15);
  border-color: rgba(8, 145, 178, 0.35);
  color: var(--primary);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 32px;
}

.feature-item {
  background: white;
  padding: 32px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.feature-item h3 {
  font-size: 20px;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

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

kbd {
  background: #f1f5f9;
  border: 1px solid #cbd5e1;
  border-radius: 4px;
  padding: 2px 6px;
  font-size: 12px;
  font-family: monospace;
}

/* --- Tech Section --- */
.tech-section {
  margin-top: 140px;
  padding: 60px 24px;
  background: rgba(255, 255, 255, 0.4);
  backdrop-filter: blur(16px);
  border-radius: 20px;
  max-width: 1100px;
  margin-left: auto;
  margin-right: auto;
}

.tech-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  max-width: 800px;
  margin: 0 auto;
}

.badge {
  background: rgba(8, 145, 178, 0.1);
  color: var(--primary-dark);
  padding: 10px 20px;
  border-radius: 24px;
  font-size: 14px;
  font-weight: 600;
  border: 1px solid rgba(8, 145, 178, 0.2);
  transition: all 0.2s ease;
}

.badge:hover {
  background: rgba(8, 145, 178, 0.18);
  transform: translateY(-2px);
}

/* --- Download & Install --- */
.download-section {
  text-align: center;
  background: white;
  padding: 60px 24px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.download-card h3 {
  font-size: 24px;
  margin-bottom: 8px;
}

.download-card p {
  color: var(--text-muted);
  margin-bottom: 24px;
}

.install-guide {
  max-width: 900px;
  margin: 0 auto 80px;
}

.safety-notice {
  background: #fffbeb;
  border: 1px solid #fcd34d;
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 40px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.notice-header {
  display: flex;
  align-items: center;
  gap: 12px;
}

.notice-header h3 {
  font-size: 18px;
  color: #92400e;
  margin: 0;
}

.notice-content p {
  font-size: 15px;
  color: #78350f;
  margin-bottom: 8px;
}

.trust-note {
  background: rgba(255,255,255,0.5);
  padding: 12px;
  border-radius: 6px;
  margin-top: 8px;
}

.steps-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-bottom: 24px;
}

.step-item {
  background: white;
  padding: 20px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.step-number {
  display: inline-block;
  background: var(--primary);
  color: white;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  text-align: center;
  line-height: 28px;
  font-weight: bold;
  font-size: 14px;
  margin-bottom: 12px;
}

.step-content h4 {
  font-size: 16px;
  margin-bottom: 4px;
}

.step-content p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.step-image {
  width: 100%;
  border-radius: 6px;
  border: 1px solid var(--border);
}

/* --- Footer --- */
.site-footer {
  background: #0e0e12;
  padding: 70px 0 30px;
  border-top: none;
  color: #e2e8f0;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.footer-logo {
  width: 42px;
  height: 42px;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.08);
  padding: 4px;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

.footer-brand-title {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.footer-brand-tagline {
  color: #cbd5e1;
  font-size: 14px;
  margin-top: 6px;
}

.footer-links h4, .footer-contact h4 {
  font-size: 17px;
  margin-bottom: 16px;
  color: #f8fafc;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.footer-links ul {
  list-style: none;
}

.footer-links li {
  margin-bottom: 8px;
}

.footer-contact p {
  color: #cbd5e1;
  font-size: 14px;
}

.footer-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: #cbd5e1;
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: color 0.2s ease, transform 0.2s ease;
}

.footer-icon {
  display: inline-flex;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: rgba(96, 165, 250, 0.15);
  justify-content: center;
  align-items: center;
  color: #93c5fd;
  transition: transform 0.2s ease, background 0.2s ease, color 0.2s ease;
}

.footer-link svg {
  width: 16px;
  height: 16px;
}

.footer-link:hover {
  color: #60a5fa;
}

.footer-link:hover .footer-icon {
  transform: translateY(-2px);
  background: rgba(96, 165, 250, 0.25);
  color: #bfdbfe;
}

.footer-distributor {
  color: #e2e8f0;
  font-size: 15px;
  margin-bottom: 12px;
}

.mk-logo {
  width: 48px;
  margin-top: 18px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
  padding: 6px;
}

.footer-bottom {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-small {
  color: #94a3b8;
  font-size: 12px;
}

/* --- Mobile Responsive --- */
@media (max-width: 768px) {
  .header-nav {
    display: none; /* Hide nav on mobile for simplicity */
  }
  
  .hero h2 {
    font-size: 36px;
  }
  
  .hero-subtitle {
    font-size: 18px;
  }
  
  .cta-buttons {
    flex-direction: column;
  }
  
  .btn {
    width: 100%;
  }
  
  .highlights {
    margin-top: 0;
    grid-template-columns: 1fr;
  }
  
  .steps-row {
    grid-template-columns: 1fr;
  }
  
  .feature-highlight {
    padding: 24px;
  }
}