/* ============================================
   Courant — One-page website
   ============================================ */

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

:root {
  --bg-deep: #0a0a0f;
  --bg-primary: #12121a;
  --bg-secondary: #1a1a26;
  --accent: #26c6da;
  --accent-dim: #00838f;
  --secondary: #80deea;
  --secondary-dim: rgba(38, 198, 218, 0.15);
  --accent-light: #4dd0e1;
  --secondary-light: #b2ebf2;
  --text-primary: #f0f0f5;
  --text-secondary: #a0a0b8;
  --text-muted: #6b6b80;
  --glass-bg: rgba(255, 255, 255, 0.04);
  --glass-border: rgba(255, 255, 255, 0.08);
  --glass-bg-hover: rgba(255, 255, 255, 0.07);
  --radius-sm: 12px;
  --radius-md: 20px;
  --radius-lg: 28px;
  --radius-xl: 36px;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'SF Pro Display', sans-serif;
  background: var(--bg-deep);
  color: var(--text-primary);
  overflow-x: hidden;
  line-height: 1.6;
}

a { color: inherit; text-decoration: none; }

/* --- Nav --- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 0 2rem;
  transition: background 0.4s ease, backdrop-filter 0.4s ease, box-shadow 0.4s ease;
}

.nav.scrolled {
  background: rgba(10, 10, 15, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 1px 0 var(--glass-border);
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: -0.02em;
}

.nav-blob-icon {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: radial-gradient(circle at 40% 40%, var(--accent), var(--accent-dim));
  animation: glowPulse 3s ease-in-out infinite;
  box-shadow: 0 0 12px rgba(38, 198, 218, 0.3);
}

.nav-blob-icon.small { width: 20px; height: 20px; }

@keyframes glowPulse {
  0%, 100% { box-shadow: 0 0 12px rgba(38, 198, 218, 0.3); transform: scale(1); }
  50% { box-shadow: 0 0 20px rgba(38, 198, 218, 0.5); transform: scale(1.05); }
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-links a {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color 0.3s ease;
}

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

.nav-cta {
  background: linear-gradient(135deg, var(--accent-dim), var(--accent));
  padding: 7px 18px !important;
  border-radius: 100px;
  color: white !important;
  font-weight: 600 !important;
  font-size: 0.84rem !important;
  opacity: 0.6;
  cursor: default;
  pointer-events: none;
}

/* --- Hero --- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  padding: 6rem 2rem 4rem;
}

.hero-glow {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 800px; height: 800px;
  background: radial-gradient(circle, rgba(38, 198, 218, 0.1) 0%, rgba(38, 198, 218, 0.04) 40%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  text-align: center;
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
}

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

.visual-courant { width: 260px; height: 180px; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 16px; }
.courant-stream { width: 240px; height: 80px; position: relative; overflow: hidden; border-radius: 12px; }
.particle { position: absolute; width: 8px; height: 8px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 10px rgba(38,198,218,0.5); animation: particleFlow 2s linear infinite; }
.particle.p1 { top: 15%; animation-delay: 0s; width: 6px; height: 6px; }
.particle.p2 { top: 35%; animation-delay: 0.17s; width: 10px; height: 10px; }
.particle.p3 { top: 55%; animation-delay: 0.33s; }
.particle.p4 { top: 70%; animation-delay: 0.5s; width: 5px; height: 5px; }
.particle.p5 { top: 25%; animation-delay: 0.67s; width: 7px; height: 7px; }
.particle.p6 { top: 80%; animation-delay: 0.83s; }
.particle.p7 { top: 10%; animation-delay: 1s; width: 9px; height: 9px; }
.particle.p8 { top: 45%; animation-delay: 1.17s; width: 6px; height: 6px; }
.particle.p9 { top: 65%; animation-delay: 1.33s; }
.particle.p10 { top: 20%; animation-delay: 1.5s; width: 7px; height: 7px; }
.particle.p11 { top: 50%; animation-delay: 1.67s; width: 5px; height: 5px; }
.particle.p12 { top: 75%; animation-delay: 1.83s; width: 8px; height: 8px; }
.courant-bar { width: 200px; height: 6px; background: rgba(255,255,255,0.08); border-radius: 3px; overflow: hidden; }
.bar-fill { width: 65%; height: 100%; background: linear-gradient(90deg, var(--accent-dim), var(--accent)); border-radius: 3px; animation: barGrow 3s ease-in-out infinite; }
.courant-speed { font-size: 0.85rem; font-weight: 700; color: var(--accent); font-variant-numeric: tabular-nums; }
@keyframes particleFlow { 0% { left: -10px; opacity: 0; } 10% { opacity: 1; } 90% { opacity: 1; } 100% { left: 250px; opacity: 0; } }
@keyframes barGrow { 0% { width: 45%; } 50% { width: 75%; } 100% { width: 45%; } }


/* Title */
.hero-title {
  font-size: clamp(3.5rem, 8vw, 6rem);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 1;
  margin-bottom: 1.5rem;
}

.title-gradient {
  background: linear-gradient(135deg, var(--accent-light), var(--secondary-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-tagline {
  font-size: clamp(1.1rem, 2.5vw, 1.4rem);
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 2.5rem;
  font-weight: 400;
}

.tagline-highlight { color: var(--text-primary); font-weight: 600; }

/* CTA */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: inherit;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-dim), var(--accent));
  color: white;
  padding: 16px 36px;
  border-radius: 100px;
  font-size: 1.05rem;
  box-shadow: 0 8px 32px rgba(38, 198, 218, 0.25), 0 2px 8px rgba(0,0,0,0.2);
  position: relative;
  overflow: hidden;
}

.btn-primary::before {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.15), transparent);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.btn-primary:hover::before { opacity: 1; }
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 40px rgba(38, 198, 218, 0.35), 0 4px 12px rgba(0,0,0,0.3);
}

.btn-disabled { opacity: 0.6; cursor: default; pointer-events: none; }
.btn-large { padding: 20px 48px; font-size: 1.15rem; }
.btn-icon { width: 20px; height: 20px; }

.hero-meta {
  margin-top: 1rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* Scroll indicator */
.scroll-indicator {
  position: absolute;
  bottom: 2rem; left: 50%;
  transform: translateX(-50%);
}

.scroll-line {
  width: 1px; height: 48px;
  background: linear-gradient(to bottom, var(--accent-dim), transparent);
  animation: scrollPulse 2s ease-in-out infinite;
}

@keyframes scrollPulse {
  0%, 100% { opacity: 0.3; transform: scaleY(1); }
  50% { opacity: 0.8; transform: scaleY(1.2); }
}

/* --- Section shared --- */
.section-inner { max-width: 1200px; margin: 0 auto; padding: 0 2rem; }

/* --- Download --- */
.download { padding: 4rem 0; }

.download-card {
  position: relative;
  text-align: center;
  padding: 5rem 3rem;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  overflow: hidden;
}

.download-glow {
  position: absolute;
  top: -100px; left: 50%;
  transform: translateX(-50%);
  width: 600px; height: 400px;
  background: radial-gradient(ellipse, rgba(38, 198, 218, 0.08) 0%, transparent 70%);
  pointer-events: none;
}

.download-title {
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 1rem;
  position: relative;
}

.download-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 2.5rem;
  position: relative;
}

.download-card .btn { position: relative; }

.download-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  margin-top: 2rem;
  position: relative;
  flex-wrap: wrap;
}

.download-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.82rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* --- Support --- */
.support { padding: 2rem 0 4rem; }

.support-card {
  text-align: center;
  max-width: 560px;
  margin: 0 auto;
  padding: 3.5rem 2.5rem;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  position: relative;
  overflow: hidden;
}

.support-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent-dim), var(--accent), transparent);
}

.support-icon { font-size: 2.5rem; margin-bottom: 1.25rem; }

.support-title {
  font-size: clamp(1.4rem, 3vw, 1.8rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

.support-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 2rem;
}

.btn-support {
  background: linear-gradient(135deg, rgba(38, 198, 218, 0.12), rgba(38, 198, 218, 0.12));
  border: 1px solid rgba(38, 198, 218, 0.2);
  color: var(--text-primary);
  padding: 14px 32px;
  border-radius: 100px;
  font-size: 0.95rem;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.btn-support:hover {
  background: linear-gradient(135deg, rgba(38, 198, 218, 0.22), rgba(38, 198, 218, 0.22));
  border-color: rgba(38, 198, 218, 0.35);
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(38, 198, 218, 0.15);
}

.btn-support .btn-icon { width: 18px; height: 18px; }

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

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1rem;
}

.footer-name {
  background: linear-gradient(135deg, var(--accent-light), var(--secondary-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.footer-credit { font-size: 0.82rem; color: var(--text-muted); }
.footer-credit strong { color: var(--text-secondary); font-weight: 600; }
.footer-credit a { transition: color 0.3s ease; }
.footer-credit a:hover, .footer-credit a:hover strong { color: var(--accent); }

/* --- Responsive --- */
@media (max-width: 600px) {
  .nav-links a:not(.nav-cta) { display: none; }
  .hero { padding: 6rem 1.5rem 3rem; }
  .blob-container { width: 160px; height: 160px; margin-bottom: 1.5rem; }
  .blob-pulse-ring { width: 180px; height: 180px; }
  .section-inner { padding: 0 1.25rem; }
  .download-card { padding: 3rem 1.5rem; }
  .btn-large { padding: 16px 32px; font-size: 1rem; }
  .support-card { padding: 2.5rem 1.5rem; }
}

.hero-content > *, .download-card > *, .support-card > * {
  will-change: transform, opacity;
}

/* --- Features --- */
.features {
  padding: 4rem 0;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.feature-card {
  text-align: center;
  padding: 2.5rem 2rem;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.feature-card:hover {
  background: var(--glass-bg-hover);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2);
}

.feature-icon {
  font-size: 2.2rem;
  margin-bottom: 1rem;
}

.feature-title {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
}

.feature-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

@media (max-width: 768px) {
  .features-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
    padding: 0 1.25rem;
  }
  .feature-card {
    padding: 2rem 1.5rem;
  }
}