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

:root {
  --color-primary: #1a56db;
  --color-primary-dark: #1244af;
  --color-primary-light: #e8effc;
  --color-accent: #0ea5e9;
  --color-accent-dark: #0284c7;
  --color-bg: #ffffff;
  --color-bg-alt: #f8fafc;
  --color-bg-dark: #0f172a;
  --color-text: #1e293b;
  --color-text-light: #64748b;
  --color-text-white: #f8fafc;
  --color-border: #e2e8f0;
  --color-success: #10b981;
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --container-width: 1200px;
  --header-height: 72px;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.12);
  --transition: 0.2s ease;
}

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

body {
  font-family: var(--font-family);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  font-size: 16px;
}

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

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

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

ul {
  list-style: none;
}

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

.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
}

.logo {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.logo-accent {
  color: var(--color-primary);
  font-weight: 600;
}

.nav-list {
  display: flex;
  gap: 32px;
  align-items: center;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text-light);
  padding: 8px 0;
  position: relative;
  transition: color var(--transition);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-primary);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-primary);
  border-radius: 1px;
}

.mobile-menu-btn {
  display: none;
  border: none;
  background: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--color-text);
  padding: 8px;
}

.hero {
  padding: 140px 0 80px;
  background: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-bg) 60%);
}

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

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: 20px;
}

.hero h1 strong {
  color: var(--color-primary);
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 32px;
}

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

.hero-cta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-image img {
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 600;
  font-family: var(--font-family);
  cursor: pointer;
  transition: all var(--transition);
  border: 2px solid transparent;
}

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

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

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

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

.btn-lg {
  padding: 16px 36px;
  font-size: 1.05rem;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  text-align: center;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--color-text-light);
  text-align: center;
  max-width: 680px;
  margin: 0 auto 48px;
  line-height: 1.8;
}

.features {
  padding: 100px 0;
  background: var(--color-bg);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 36px 28px;
  transition: all var(--transition);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
}

.feature-icon {
  font-size: 2.2rem;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--color-text);
}

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

.how-it-works {
  padding: 100px 0;
  background: var(--color-bg-alt);
}

.steps-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 28px;
}

.step-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  position: relative;
}

.step-number {
  width: 48px;
  height: 48px;
  background: var(--color-primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  font-weight: 700;
  margin: 0 auto 20px;
}

.step-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.step-card p {
  font-size: 0.9rem;
  color: var(--color-text-light);
  line-height: 1.7;
}

.platform-overview {
  padding: 100px 0;
  background: var(--color-bg);
}

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

.overview-content h2 {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.overview-content p {
  color: var(--color-text-light);
  margin-bottom: 24px;
  line-height: 1.8;
}

.overview-list {
  list-style: none;
}

.overview-list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 1rem;
  color: var(--color-text);
}

.overview-list li:last-child {
  border-bottom: none;
}

.overview-list li strong {
  color: var(--color-primary);
}

.overview-image img {
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
}

.login-guide {
  padding: 100px 0;
  background: var(--color-bg-alt);
}

.login-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.login-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px;
}

.login-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--color-primary);
}

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

.cta-section {
  padding: 80px 0;
  background: linear-gradient(135deg, var(--color-bg-dark) 0%, #1e3a5f 100%);
  text-align: center;
}

.cta-section h2 {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--color-text-white);
  margin-bottom: 12px;
}

.cta-section p {
  font-size: 1.1rem;
  color: #94a3b8;
  max-width: 600px;
  margin: 0 auto 32px;
  line-height: 1.7;
}

.footer {
  background: var(--color-bg-dark);
  color: #94a3b8;
  padding: 60px 0 0;
}

.footer-inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
}

.footer-col h4 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-text-white);
  margin-bottom: 16px;
}

.footer-col p {
  font-size: 0.9rem;
  line-height: 1.7;
}

.footer-col ul li {
  margin-bottom: 8px;
}

.footer-col ul li a {
  color: #94a3b8;
  font-size: 0.9rem;
  transition: color var(--transition);
}

.footer-col ul li a:hover {
  color: white;
}

.footer-bottom {
  margin-top: 40px;
  padding: 20px 0;
  border-top: 1px solid #1e293b;
  text-align: center;
}

.footer-bottom p {
  font-size: 0.85rem;
  color: #64748b;
}

.page-hero {
  padding: 140px 0 60px;
  background: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-bg) 60%);
  text-align: center;
}

.page-hero h1 {
  font-size: 2.6rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
}

.page-hero h1 strong {
  color: var(--color-primary);
}

.page-hero .hero-subtitle {
  max-width: 700px;
  margin: 0 auto;
}

.content-section {
  padding: 80px 0;
}

.content-main {
  max-width: 800px;
  margin: 0 auto;
}

.content-main h2 {
  font-size: 1.7rem;
  font-weight: 800;
  margin: 48px 0 16px;
  letter-spacing: -0.02em;
}

.content-main h2:first-child {
  margin-top: 0;
}

.content-main h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin: 28px 0 10px;
}

.content-main p {
  color: var(--color-text-light);
  margin-bottom: 16px;
  line-height: 1.8;
}

.content-main ul {
  margin: 16px 0;
  padding-left: 24px;
}

.content-main ul li {
  list-style: disc;
  color: var(--color-text-light);
  margin-bottom: 8px;
  line-height: 1.7;
}

.content-main a {
  color: var(--color-primary);
  text-decoration: underline;
}

.legal-content h2 {
  padding-top: 16px;
  border-top: 1px solid var(--color-border);
}

.legal-content h2:first-child {
  border-top: none;
  padding-top: 0;
}

.about-features {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin: 32px 0;
}

.about-feature {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
}

.about-feature h3 {
  color: var(--color-primary);
  margin-top: 0;
}

.about-feature p {
  font-size: 0.95rem;
  margin-bottom: 0;
}

.about-image-section {
  margin: 40px 0;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

@media (max-width: 968px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .hero h1 {
    font-size: 2.4rem;
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .steps-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 28px;
  }

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

@media (max-width: 640px) {
  .nav-list {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    padding: 20px 24px;
    gap: 0;
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
  }

  .nav-list.nav-open {
    display: flex;
  }

  .nav-link {
    padding: 12px 0;
    border-bottom: 1px solid var(--color-border);
    display: block;
    width: 100%;
  }

  .nav-link:last-child {
    border-bottom: none;
  }

  .mobile-menu-btn {
    display: block;
  }

  .hero {
    padding: 110px 0 60px;
  }

  .hero h1 {
    font-size: 1.9rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

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

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

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

  .section-title {
    font-size: 1.8rem;
  }

  .page-hero h1 {
    font-size: 2rem;
  }

  .content-main h2 {
    font-size: 1.4rem;
  }
}