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

:root {
  --color-bg: #ffffff;
  --color-text: #111827;
  --color-muted: #6b7280;
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-alt-bg: #f9fafb;
  --color-dark-bg: #111827;
  --color-dark-text: #ffffff;
  --font: 'Segoe UI', system-ui, -apple-system, sans-serif;
  --radius: 12px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.07);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
}

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

.text-center {
  text-align: center;
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 10px 24px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
  border: 2px solid var(--color-primary);
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
}

.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

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

.btn-white {
  background: #fff;
  color: var(--color-primary);
  border: 2px solid #fff;
}

.btn-white:hover {
  background: transparent;
  color: #fff;
}

.btn-lg {
  padding: 14px 32px;
  font-size: 1.05rem;
}

/* Navigation */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid #e5e7eb;
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  gap: 32px;
}

.logo {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.5px;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 28px;
  margin-right: auto;
}

.nav-links a {
  text-decoration: none;
  color: var(--color-muted);
  font-weight: 500;
  font-size: 0.95rem;
  transition: color 0.2s;
}

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

/* Hero */
.hero {
  padding: 100px 24px 80px;
  text-align: center;
  background: linear-gradient(160deg, #f0f7ff 0%, #ffffff 60%);
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 900;
  letter-spacing: -1.5px;
  line-height: 1.1;
  color: var(--color-text);
  margin-bottom: 20px;
}

.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--color-muted);
  max-width: 560px;
  margin: 0 auto 40px;
}

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

/* Sections */
.section {
  padding: 80px 24px;
}

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

.section-dark {
  background: var(--color-dark-bg);
  color: var(--color-dark-text);
}

.section-dark .section-subtitle {
  color: #9ca3af;
}

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.5px;
  text-align: center;
  margin-bottom: 12px;
}

.section-subtitle {
  text-align: center;
  color: var(--color-muted);
  font-size: 1.05rem;
  margin-bottom: 56px;
}

/* Feature Grid */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.card {
  background: #fff;
  border: 1px solid #e5e7eb;
  border-radius: var(--radius);
  padding: 36px 28px;
  box-shadow: var(--shadow);
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.1);
}

.card-icon {
  font-size: 1.5rem;
  color: var(--color-primary);
  margin-bottom: 16px;
}

.card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.card p {
  color: var(--color-muted);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* About */
.about-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.about-text h2 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.5px;
  margin-bottom: 16px;
}

.about-text p {
  color: var(--color-muted);
  margin-bottom: 16px;
  font-size: 1rem;
  line-height: 1.75;
}

.about-text .btn {
  margin-top: 8px;
}

.about-visual {
  display: flex;
  justify-content: center;
}

.visual-box {
  width: 280px;
  height: 280px;
  background: linear-gradient(135deg, var(--color-primary), #7c3aed);
  border-radius: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 20px 60px rgba(37, 99, 235, 0.3);
}

.visual-text {
  color: #fff;
  font-size: 1.5rem;
  font-weight: 900;
  letter-spacing: -0.5px;
}

/* Footer */
.footer {
  background: #f3f4f6;
  border-top: 1px solid #e5e7eb;
  padding: 28px 24px;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-copy {
  color: var(--color-muted);
  font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .about-inner {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .about-visual {
    order: -1;
  }

  .visual-box {
    width: 200px;
    height: 200px;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }
}