/* Direction: dark tech platform — deep navy-black, vibrant green accent, modern sans */
:root {
  --color-bg: #06080f;
  --color-surface: #0f1520;
  --color-surface-raised: #161e2e;
  --color-border: #1e2a3a;
  --color-text: #e8ecf1;
  --color-text-muted: #8a9ab5;
  --color-primary: #00e68a;
  --color-primary-dim: #00b36b;
  --color-primary-glow: rgba(0, 230, 138, 0.15);
  --color-accent: #00d4aa;
  --color-success: #10b981;
  --color-danger: #ef4444;
  --font-heading: 'Space Grotesk', sans-serif;
  --font-body: 'Inter', sans-serif;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 40px rgba(0, 230, 138, 0.1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

a { color: var(--color-primary); text-decoration: none; }
a:hover { color: var(--color-accent); }

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--color-bg); }
::-webkit-scrollbar-thumb { background: var(--color-border); border-radius: 3px; }

/* Utility */
.container { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* Section spacing */
section { padding: 100px 0; }
@media (min-width: 768px) { section { padding: 120px 0; } }

/* Hero gradient bg */
.hero-bg {
  background: radial-gradient(ellipse 80% 60% at 50% 0%, rgba(0,230,138,0.08) 0%, transparent 60%),
              radial-gradient(ellipse 60% 40% at 80% 20%, rgba(0,212,170,0.05) 0%, transparent 50%),
              var(--color-bg);
}

/* Countdown digit styling */
.countdown-digit {
  background: var(--color-surface-raised);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  min-width: 80px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.countdown-digit::after {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(0,230,138,0.06) 0%, transparent 60%);
  pointer-events: none;
}
.countdown-value {
  font-family: var(--font-heading);
  font-size: 3rem;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1;
}
@media (min-width: 768px) { .countdown-value { font-size: 3.5rem; } }
.countdown-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-muted);
  margin-top: 4px;
}

/* Divider */
.divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-border), transparent);
  margin: 0 auto;
  max-width: 600px;
}

/* Learning point card */
.learn-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  transition: border-color 0.3s ease, box-shadow 0.3s ease, transform 0.3s ease;
}
.learn-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-glow);
  transform: translateY(-4px);
}

/* Speaker */
.speaker-img {
  width: 200px; height: 200px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--color-primary);
  box-shadow: var(--shadow-glow);
}

/* Agenda timeline */
.timeline-item { position: relative; padding-left: 40px; }
.timeline-item::before {
  content: '';
  position: absolute; left: 11px; top: 24px; bottom: -24px;
  width: 2px; background: var(--color-border);
}
.timeline-item:last-child::before { display: none; }
.timeline-dot {
  position: absolute; left: 3px; top: 16px;
  width: 20px; height: 20px;
  border-radius: 50%;
  background: var(--color-primary);
  border: 3px solid var(--color-bg);
  box-shadow: 0 0 0 3px var(--color-primary-dim);
}

/* FAQ accordion */
details { list-style: none; }
details[open] .faq-trigger .chevron { transform: rotate(180deg); }
summary::-webkit-details-marker { display: none; }
summary { list-style: none; }
.faq-item { border-bottom: 1px solid var(--color-border); }
.faq-trigger {
  width: 100%; text-align: left;
  background: none; border: none; cursor: pointer;
  padding: 24px 0;
  font-family: var(--font-heading);
  font-size: 1.125rem; font-weight: 600;
  color: var(--color-text);
  display: flex; justify-content: space-between; align-items: center;
  transition: color 0.3s;
}
.faq-trigger:hover { color: var(--color-primary); }
.faq-trigger:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 4px; border-radius: 4px; }
.faq-trigger .chevron {
  transition: transform 0.3s ease;
  flex-shrink: 0; margin-left: 16px;
}
.faq-item[open] .faq-trigger .chevron,
details[open] .faq-trigger .chevron { transform: rotate(180deg); }
.faq-content {
  padding-bottom: 24px;
  color: var(--color-text-muted);
  line-height: 1.7;
  animation: fadeUp 0.3s ease;
}
@keyframes fadeUp { from { opacity: 0; transform: translateY(-8px); } to { opacity: 1; transform: translateY(0); } }

/* Form */
.form-input {
  width: 100%;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 14px 18px;
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 1rem;
  transition: border-color 0.2s, box-shadow 0.2s;
  outline: none;
}
.form-input:focus { border-color: var(--color-primary); box-shadow: 0 0 0 3px var(--color-primary-glow); }
.form-input::placeholder { color: var(--color-text-muted); }
.form-input.error { border-color: var(--color-danger); box-shadow: 0 0 0 3px rgba(239,68,68,0.15); }
.form-error { color: var(--color-danger); font-size: 0.8rem; margin-top: 4px; display: none; }
.form-error.visible { display: block; }

.btn-primary {
  display: inline-flex; align-items: center; justify-content: center;
  background: var(--color-primary); color: var(--color-bg);
  font-family: var(--font-heading); font-weight: 700;
  font-size: 1rem; padding: 16px 36px;
  border-radius: var(--radius-sm); border: none; cursor: pointer;
  min-height: 48px;
  transition: background 0.2s, transform 0.15s, box-shadow 0.2s;
}
.btn-primary:hover { background: var(--color-accent); box-shadow: var(--shadow-glow); transform: translateY(-1px); }
.btn-primary:active { transform: translateY(0); }
.btn-primary:focus-visible { outline: 2px solid var(--color-text); outline-offset: 2px; }
.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

/* Success message */
.success-message {
  background: linear-gradient(135deg, rgba(0,230,138,0.1), rgba(0,230,138,0.05));
  border: 1px solid rgba(0,230,138,0.3);
  border-radius: var(--radius-md);
  padding: 32px;
  text-align: center;
}

/* Nav */
.nav-link {
  color: var(--color-text-muted);
  font-weight: 500;
  font-size: 0.9rem;
  transition: color 0.2s;
  padding: 4px 0;
  border-bottom: 2px solid transparent;
}
.nav-link:hover, .nav-link.active { color: var(--color-primary); border-bottom-color: var(--color-primary); }

/* Badge */
.badge {
  display: inline-block;
  background: var(--color-primary-glow);
  color: var(--color-primary);
  font-size: 0.75rem; font-weight: 700;
  padding: 6px 14px;
  border-radius: 100px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  border: 1px solid rgba(0,230,138,0.2);
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}