/* ============================================
   LeakSentinel — Styles
   Modern dark theme for data privacy project
   ============================================ */

/* ---------- CSS Variables ---------- */
:root {
  --bg-dark: #0a0a0f;
  --bg-card: #12121a;
  --bg-card-hover: #1a1a25;
  --bg-nav: rgba(10, 10, 15, 0.85);
  
  --text-primary: #f0f0f5;
  --text-secondary: #a0a0b0;
  --text-muted: #606070;
  
  --accent: #00d4aa;
  --accent-glow: rgba(0, 212, 170, 0.3);
  --accent-secondary: #7c3aed;
  --gradient: linear-gradient(135deg, #00d4aa 0%, #7c3aed 100%);
  
  --border: #2a2a35;
  --border-light: #3a3a45;
  
  --red: #ff6b6b;
  --yellow: #ffd93d;
  --green: #6bcb77;
  --blue: #4d96ff;
  
  --radius: 12px;
  --radius-sm: 8px;
  --radius-lg: 20px;
  
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 40px var(--accent-glow);
  
  --container: 1200px;
  --nav-height: 72px;
  
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
  --font-emoji: 'Noto Color Emoji', 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', sans-serif;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-dark);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--text-primary);
}

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

code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--bg-card);
  padding: 0.15em 0.4em;
  border-radius: 4px;
  border: 1px solid var(--border);
}

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

.section {
  padding: 100px 0;
}

.section-head {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 60px;
}

.eyebrow {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  margin-bottom: 12px;
}

.section-head h2 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 16px;
}

.lede {
  font-size: 1.125rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.gradient-text {
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  transition: all 0.25s ease;
  text-decoration: none;
}

.btn-primary {
  background: var(--gradient);
  color: var(--bg-dark);
  box-shadow: 0 4px 20px var(--accent-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px var(--accent-glow);
  color: var(--bg-dark);
}

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

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-light);
  color: var(--text-primary);
}

.btn-ghost {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border);
  padding: 10px 20px;
}

.btn-ghost:hover {
  background: var(--bg-card);
  border-color: var(--accent);
  color: var(--accent);
}

/* ---------- Navigation ---------- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: var(--bg-nav);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
}

.nav-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.brand:hover {
  color: var(--text-primary);
}

.brand-mark {
  font-size: 1.5rem;
  font-family: var(--font-emoji);
}

.brand-name .accent {
  color: var(--accent);
}

.nav-links {
  display: flex;
  gap: 32px;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s ease;
}

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

.nav-cta {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: var(--nav-height);
  overflow: hidden;
}

.hero-grid-bg {
  position: absolute;
  inset: 0;
  background-image: 
    linear-gradient(rgba(0, 212, 170, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 170, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, black 20%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, black 20%, transparent 70%);
}

.hero-inner {
  position: relative;
  text-align: center;
  padding: 80px 0;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 50px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

.hero-badge .dot {
  width: 8px;
  height: 8px;
  background: var(--green);
  border-radius: 50%;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.2); }
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 24px;
  letter-spacing: -0.02em;
}

.hero-sub {
  max-width: 680px;
  margin: 0 auto 40px;
  font-size: 1.2rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.hero-sub strong {
  color: var(--text-primary);
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 60px;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 60px;
  flex-wrap: wrap;
}

.stat {
  text-align: center;
}

.stat-num {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

.stat-label {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* ---------- Problem Section ---------- */
.problem {
  background: linear-gradient(180deg, var(--bg-dark) 0%, var(--bg-card) 100%);
}

.problem-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.problem-card {
  background: var(--bg-dark);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: all 0.3s ease;
}

.problem-card:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
}

.problem-icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
  font-family: var(--font-emoji);
}

.problem-card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.problem-card p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ---------- How It Works ---------- */
.how {
  background: var(--bg-dark);
}

.steps {
  list-style: none;
  display: grid;
  gap: 32px;
  max-width: 800px;
  margin: 0 auto;
}

.step {
  display: flex;
  gap: 24px;
  align-items: flex-start;
  padding: 32px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: all 0.3s ease;
}

.step:hover {
  border-color: var(--accent);
}

.step-num {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient);
  color: var(--bg-dark);
  font-size: 1.25rem;
  font-weight: 700;
  border-radius: 50%;
}

.step-content {
  flex: 1;
}

.step h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.step p {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ---------- Features ---------- */
.features {
  background: linear-gradient(180deg, var(--bg-dark) 0%, var(--bg-card) 50%, var(--bg-dark) 100%);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.feature {
  padding: 32px;
  background: var(--bg-dark);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: all 0.3s ease;
}

.feature:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.feature-icon {
  font-size: 2rem;
  margin-bottom: 16px;
  font-family: var(--font-emoji);
}

.feature h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.feature p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* ---------- Use Case ---------- */
.usecase {
  background: var(--bg-dark);
}

.usecase-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.usecase-copy p {
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.7;
}

.check-list {
  list-style: none;
  margin: 24px 0;
}

.check-list li {
  position: relative;
  padding-left: 28px;
  margin-bottom: 12px;
  color: var(--text-secondary);
}

.check-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}

/* Terminal */
.terminal {
  background: #1a1a24;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.terminal-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  background: #0d0d12;
  border-bottom: 1px solid var(--border);
}

.terminal-bar .dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.terminal-bar .dot.red { background: var(--red); }
.terminal-bar .dot.yellow { background: var(--yellow); }
.terminal-bar .dot.green { background: var(--green); }

.terminal-title {
  margin-left: auto;
  font-size: 0.8rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.terminal-body {
  padding: 20px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.8;
  color: var(--text-secondary);
  overflow-x: auto;
}

.t-muted { color: var(--text-muted); }
.t-ok { color: var(--green); }
.t-info { color: var(--blue); }
.t-warn { color: var(--yellow); }

/* ---------- Community ---------- */
.community {
  background: linear-gradient(180deg, var(--bg-dark) 0%, #0d1a15 100%);
}

.community-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.community h2 {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  margin-bottom: 16px;
}

.community .lede {
  margin-bottom: 32px;
}

.community-cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.comm-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  transition: all 0.3s ease;
}

.comm-card:hover {
  border-color: var(--accent);
}

.comm-num {
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 4px;
}

.comm-card > div:last-child {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* ---------- FAQ ---------- */
.faq {
  background: var(--bg-dark);
}

.qa {
  max-width: 800px;
  margin: 0 auto 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color 0.3s ease;
}

.qa:hover,
.qa[open] {
  border-color: var(--accent);
}

.qa summary {
  padding: 20px 24px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: background 0.2s ease;
}

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

.qa summary::after {
  content: '+';
  font-size: 1.5rem;
  color: var(--accent);
  transition: transform 0.3s ease;
}

.qa[open] summary::after {
  transform: rotate(45deg);
}

.qa summary:hover {
  background: var(--bg-card-hover);
}

.qa p {
  padding: 0 24px 20px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ---------- Footer ---------- */
.footer {
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  padding-top: 60px;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.5fr 2fr;
  gap: 60px;
  padding-bottom: 40px;
}

.footer-brand p {
  color: var(--text-secondary);
  margin-top: 16px;
  max-width: 280px;
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
}

.footer-cols h4 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.footer-cols a {
  display: block;
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 10px;
  transition: color 0.2s ease;
}

.footer-cols a:hover {
  color: var(--accent);
}

.footer-bottom {
  border-top: 1px solid var(--border);
  padding: 20px 0;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .usecase-grid,
  .community-inner {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  
  .terminal {
    max-width: 100%;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  
  .hero-stats {
    gap: 30px;
  }
  
  .stat-num {
    font-size: 2rem;
  }
  
  .footer-inner {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  
  .footer-cols {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .step {
    flex-direction: column;
    text-align: center;
  }
  
  .step-num {
    margin: 0 auto;
  }
  
  .step-content {
    text-align: center;
  }
  
  .community-cards {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 480px) {
  .hero-actions {
    flex-direction: column;
    align-items: center;
  }
  
  .btn {
    width: 100%;
    justify-content: center;
  }
  
  .hero-stats {
    flex-direction: column;
    gap: 24px;
  }
  
  .footer-cols {
    grid-template-columns: 1fr;
  }
  
  .community-cards {
    grid-template-columns: 1fr;
  }
}