/* CSS Variables */
:root {
  --color-primary: #22c55e;
  --color-primary-dark: #16a34a;
  --color-text: #1f2937;
  --color-text-light: #6b7280;
  --color-bg: #ffffff;
  --color-bg-alt: #f9fafb;
  --color-border: #e5e7eb;
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --radius: 12px;
}

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

html {
  scroll-behavior: smooth;
}

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

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

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  font-size: 16px;
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius);
  transition: all 0.2s ease;
  cursor: pointer;
  border: none;
}

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

.btn-primary:hover {
  background-color: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-large {
  padding: 18px 36px;
  font-size: 18px;
}

/* Hero Section */
.hero {
  padding: 80px 0 100px;
  background: linear-gradient(180deg, var(--color-bg-alt) 0%, var(--color-bg) 100%);
}

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

.hero-title {
  font-size: 56px;
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 16px;
  color: var(--color-text);
}

.hero-tagline {
  font-size: 24px;
  color: var(--color-primary);
  font-weight: 600;
  margin-bottom: 20px;
}

.hero-description {
  font-size: 18px;
  color: var(--color-text-light);
  margin-bottom: 32px;
  max-width: 480px;
}

/* Phone Mockup */
.phone-mockup {
  width: 280px;
  height: 560px;
  background: #1f2937;
  border-radius: 40px;
  padding: 12px;
  margin: 0 auto;
  box-shadow: var(--shadow-lg);
}

.phone-screen {
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, #312e81 0%, #1e1b4b 100%);
  border-radius: 32px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 24px;
}

.mock-time {
  font-size: 64px;
  font-weight: 200;
  color: white;
  letter-spacing: -2px;
}

.mock-challenge {
  font-size: 28px;
  color: white;
  background: rgba(255, 255, 255, 0.1);
  padding: 16px 32px;
  border-radius: 16px;
}

.mock-input {
  width: 120px;
  height: 48px;
  background: white;
  border-radius: 12px;
}

/* Section Styles */
.section-title {
  font-size: 36px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 48px;
}

/* Features Section */
.features {
  padding: 100px 0;
}

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

.feature-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px;
  transition: all 0.2s ease;
}

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

.feature-icon {
  width: 56px;
  height: 56px;
  background: rgba(34, 197, 94, 0.1);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
  margin-bottom: 20px;
}

.feature-title {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 12px;
}

.feature-description {
  color: var(--color-text-light);
  font-size: 15px;
}

/* How It Works Section */
.how-it-works {
  padding: 100px 0;
  background: var(--color-bg-alt);
}

.steps {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 24px;
}

.step {
  text-align: center;
  max-width: 280px;
}

.step-number {
  width: 56px;
  height: 56px;
  background: var(--color-primary);
  color: white;
  font-size: 24px;
  font-weight: 700;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
}

.step-title {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 12px;
}

.step-description {
  color: var(--color-text-light);
  font-size: 15px;
}

.step-connector {
  width: 60px;
  height: 2px;
  background: var(--color-border);
  margin-top: 28px;
  flex-shrink: 0;
}

/* Download Section */
.download {
  padding: 100px 0;
  text-align: center;
}

.download-description {
  font-size: 18px;
  color: var(--color-text-light);
  margin-bottom: 32px;
}

.download-note {
  margin-top: 16px;
  font-size: 14px;
  color: var(--color-text-light);
}

/* Footer */
.footer {
  padding: 32px 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
  color: var(--color-text-light);
  font-size: 14px;
}

/* Responsive Design */
@media (max-width: 900px) {
  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-content {
    order: 1;
  }

  .hero-visual {
    order: 0;
  }

  .hero-description {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-title {
    font-size: 42px;
  }

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

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

  .step-connector {
    width: 2px;
    height: 40px;
    margin: 0;
  }
}

@media (max-width: 600px) {
  .hero {
    padding: 60px 0 80px;
  }

  .hero-title {
    font-size: 32px;
  }

  .hero-tagline {
    font-size: 18px;
  }

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

  .phone-mockup {
    width: 220px;
    height: 440px;
    border-radius: 32px;
  }

  .phone-screen {
    border-radius: 24px;
  }

  .mock-time {
    font-size: 48px;
  }

  .mock-challenge {
    font-size: 22px;
    padding: 12px 24px;
  }

  .section-title {
    font-size: 28px;
    margin-bottom: 36px;
  }

  .features, .how-it-works, .download {
    padding: 60px 0;
  }

  .feature-card {
    padding: 24px;
  }

  .btn-large {
    padding: 16px 28px;
    font-size: 16px;
  }
}