/* ===== CSS Custom Properties ===== */
:root {
  --bg: #0f1117;
  --bg-alt: #13151e;
  --surface: #1a1d27;
  --surface-hover: #242836;
  --border: rgba(255, 255, 255, 0.06);
  --border-accent: rgba(26, 115, 232, 0.4);
  --text: #e8eaed;
  --text-secondary: #9aa0a6;
  --primary: #1a73e8;
  --primary-light: #4285f4;
  --primary-glow: rgba(26, 115, 232, 0.3);
  --grade-green: #63be7b;
  --grade-red: #f8696b;
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

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

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

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 16px;
  overflow-x: hidden;
}

a {
  color: var(--primary-light);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: #fff;
}

img {
  display: block;
}

/* ===== Container ===== */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Navigation ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 16px 0;
  transition: background var(--transition), padding var(--transition), box-shadow var(--transition);
}

.nav.scrolled {
  background: rgba(15, 17, 23, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  padding: 10px 0;
  box-shadow: 0 1px 0 var(--border);
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 600;
  font-size: 15px;
}

.nav-logo:hover {
  color: #fff;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

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

.nav-links a:hover {
  color: #fff;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font);
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  border: none;
  white-space: nowrap;
}

.btn-sm {
  font-size: 13px;
  padding: 8px 16px;
}

.btn-lg {
  font-size: 15px;
  padding: 14px 28px;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--primary-light);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 6px 24px var(--primary-glow);
}

.btn-outline {
  background: transparent;
  color: var(--text);
  border: 1.5px solid rgba(255, 255, 255, 0.15);
}

.btn-outline:hover {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.4);
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(255, 255, 255, 0.05);
}

/* ===== Hero ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 120px 24px 80px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 50% at 50% 0%, rgba(26, 115, 232, 0.15) 0%, transparent 70%),
    radial-gradient(ellipse 40% 40% at 30% 70%, rgba(99, 190, 123, 0.06) 0%, transparent 60%),
    radial-gradient(ellipse 40% 40% at 70% 80%, rgba(248, 105, 107, 0.06) 0%, transparent 60%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
}

.hero-icon {
  display: inline-flex;
  border-radius: 24px;
  padding: 4px;
  margin-bottom: 32px;
  animation: glow 3s ease-in-out infinite;
}

.hero-icon img {
  border-radius: 20px;
}

@keyframes glow {
  0%, 100% { box-shadow: 0 0 20px var(--primary-glow), 0 0 60px rgba(26, 115, 232, 0.1); }
  50% { box-shadow: 0 0 30px var(--primary-glow), 0 0 80px rgba(26, 115, 232, 0.25); }
}

.hero h1 {
  font-size: 56px;
  font-weight: 700;
  letter-spacing: -1.5px;
  line-height: 1.1;
  margin-bottom: 16px;
  background: linear-gradient(135deg, #fff 0%, var(--text) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-tagline {
  font-size: 19px;
  color: var(--text-secondary);
  max-width: 480px;
  margin: 0 auto 40px;
  line-height: 1.6;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.hero-meta {
  margin-top: 24px;
  font-size: 13px;
  color: var(--text-secondary);
}

.hero-meta a {
  text-decoration: underline;
  text-underline-offset: 2px;
}

.scroll-hint {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--text-secondary);
  opacity: 0.4;
  animation: bounce 2s ease-in-out infinite;
}

@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(8px); }
}

/* ===== Sections ===== */
.section {
  padding: 100px 0;
}

.section--alt {
  background: var(--bg-alt);
}

.section--cta {
  background: linear-gradient(180deg, var(--bg-alt) 0%, var(--bg) 100%);
  text-align: center;
}

.section-title {
  font-size: 36px;
  font-weight: 700;
  letter-spacing: -0.5px;
  margin-bottom: 56px;
  position: relative;
  display: inline-block;
}

.section-title::before {
  content: '';
  position: absolute;
  left: -20px;
  top: 6px;
  bottom: 6px;
  width: 4px;
  border-radius: 2px;
  background: var(--primary);
}

.section--cta .section-title::before,
.section--alt .section-title::before {
  display: none;
}

.section--cta .section-title,
.section--alt .section-title {
  display: block;
  text-align: center;
}

/* ===== Features Grid ===== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.feature-card {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: all var(--transition);
  overflow: hidden;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-accent);
  box-shadow: 0 8px 32px var(--primary-glow);
}

.feature-icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: rgba(26, 115, 232, 0.1);
  color: var(--primary-light);
  margin-bottom: 20px;
}

.feature-icon--disco {
  background: linear-gradient(135deg, rgba(248, 105, 107, 0.15), rgba(99, 190, 123, 0.15));
  color: #f0c040;
}

.feature-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}

.feature-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Disco strip */
.disco-strip {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #f8696b, #f0c040, #63be7b, #4285f4, #a259ff, #f8696b);
  background-size: 200% 100%;
  animation: disco 3s linear infinite;
}

@keyframes disco {
  0% { background-position: 0% 0%; }
  100% { background-position: 200% 0%; }
}

/* ===== Steps ===== */
.steps {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 0;
}

.step {
  text-align: center;
  flex: 0 0 200px;
}

.step-number {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  font-size: 22px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  box-shadow: 0 4px 20px var(--primary-glow);
}

.step h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}

.step p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.5;
}

.step-line {
  flex: 0 0 80px;
  height: 2px;
  margin-top: 28px;
  border-top: 2px dashed rgba(255, 255, 255, 0.12);
}

/* ===== CTA ===== */
.cta-sub {
  font-size: 18px;
  color: var(--text-secondary);
  margin-bottom: 40px;
}

.cta-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.cta-note {
  font-size: 13px;
  color: var(--text-secondary);
  max-width: 500px;
  margin: 0 auto;
  opacity: 0.7;
}

/* ===== Dropdown ===== */
.dropdown {
  position: relative;
}

.dropdown-toggle {
  position: relative;
}

.dropdown-chevron {
  transition: transform var(--transition);
}

.dropdown-toggle.open .dropdown-chevron {
  transform: rotate(180deg);
}

.dropdown-menu {
  position: absolute;
  top: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%);
  min-width: 220px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 8px;
  opacity: 0;
  visibility: hidden;
  transform: translateX(-50%) translateY(-8px);
  transition: opacity var(--transition), visibility var(--transition), transform var(--transition);
  z-index: 50;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
}

.dropdown-menu.open {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 14px;
  font-weight: 500;
  transition: background var(--transition);
  white-space: nowrap;
}

.dropdown-item:hover {
  background: var(--surface-hover);
  color: #fff;
}

.dropdown-divider {
  height: 1px;
  background: var(--border);
  margin: 6px 0;
}

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--border);
  padding: 24px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 13px;
  color: var(--text-secondary);
}

.footer a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-secondary);
}

.footer a:hover {
  color: #fff;
}

/* ===== Scroll Reveal ===== */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .hero h1 {
    font-size: 36px;
    letter-spacing: -1px;
  }

  .hero-tagline {
    font-size: 16px;
  }

  .hero {
    padding: 100px 20px 60px;
  }

  .section {
    padding: 64px 0;
  }

  .section-title {
    font-size: 28px;
    margin-bottom: 40px;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .steps {
    flex-direction: column;
    align-items: center;
    gap: 24px;
  }

  .step-line {
    width: 2px;
    height: 32px;
    flex: none;
    border-top: none;
    border-left: 2px dashed rgba(255, 255, 255, 0.12);
    margin-top: 0;
  }

  .nav-links a:not(.btn) {
    display: none;
  }

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

  .btn-lg {
    width: 100%;
    max-width: 280px;
    justify-content: center;
  }

  .cta-buttons {
    flex-direction: column;
    align-items: center;
  }
}