/* ==========================================
   Lightning Tennis Landing Page
   Theme: Dark Mode with Lightning Yellow
   ========================================== */

/* CSS Variables */
:root {
  --color-bg-primary: #0A0A0A;
  --color-bg-secondary: #121212;
  --color-bg-card: #1E1E1E;
  --color-bg-elevated: #2A2A2A;

  --color-accent: #FFD700;
  --color-accent-light: #FFE44D;
  --color-accent-dark: #B89B00;

  --color-text-primary: #FFFFFF;
  --color-text-secondary: #B3B3B3;
  --color-text-muted: #666666;

  --color-border: #3A3A3C;
  --color-border-light: #505050;

  --font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  --section-padding: 100px 20px;
  --container-max-width: 1200px;

  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

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

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

a:hover {
  color: var(--color-accent-light);
}

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

/* Section Base */
.section {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--section-padding);
  position: relative;
}

/* ==========================================
   Hero Section
   ========================================== */
.hero-section {
  background: linear-gradient(135deg, var(--color-bg-primary) 0%, var(--color-bg-secondary) 50%, #1a1a0a 100%);
  text-align: center;
  flex-direction: column;
}

.hero-content {
  max-width: 800px;
  animation: fadeInUp 1s ease-out;
}

.lightning-icon {
  font-size: 80px;
  margin-bottom: 30px;
  animation: pulse 2s infinite;
  filter: drop-shadow(0 0 30px rgba(255, 215, 0, 0.5));
}

.app-logo {
  width: 120px;
  height: 120px;
  margin: 60px auto 30px auto;
  animation: pulse 2s infinite;
  filter: drop-shadow(0 0 30px rgba(255, 215, 0, 0.5));
  border-radius: 24px;
}

.hero-title {
  font-size: clamp(2.5rem, 8vw, 4.5rem);
  font-weight: 900;
  margin-bottom: 20px;
  background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-accent-light) 50%, var(--color-text-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
}

.hero-subtitle {
  font-size: clamp(1.2rem, 3vw, 1.8rem);
  color: var(--color-text-secondary);
  margin-bottom: 50px;
  font-weight: 300;
}

/* App Buttons */
.app-buttons {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 60px;
}

.app-button {
  display: flex;
  align-items: center;
  gap: 15px;
  padding: 15px 30px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 16px;
  color: var(--color-text-primary);
  transition: all var(--transition-normal);
  min-width: 200px;
}

.app-button:hover {
  background: var(--color-bg-elevated);
  border-color: var(--color-accent);
  transform: translateY(-3px);
  box-shadow: 0 10px 30px rgba(255, 215, 0, 0.15);
  color: var(--color-text-primary);
}

.app-icon {
  font-size: 36px;
}

.app-text {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.app-label {
  font-weight: 700;
  font-size: 1.1rem;
}

.app-status {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* Scroll Indicator */
.scroll-indicator {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  color: var(--color-text-muted);
  font-size: 0.9rem;
  animation: bounce 2s infinite;
}

.scroll-arrow {
  font-size: 24px;
  color: var(--color-accent);
}

/* ==========================================
   Feature Sections
   ========================================== */
.feature-section {
  background: var(--color-bg-secondary);
}

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

.section-container {
  max-width: var(--container-max-width);
  width: 100%;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.feature-section.alt .section-container {
  direction: rtl;
}

.feature-section.alt .section-container > * {
  direction: ltr;
}

/* Feature Image */
.feature-image {
  display: flex;
  justify-content: center;
  align-items: center;
}

.feature-image img {
  max-width: 441px;
  width: 100%;
  border-radius: 24px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
  transition: transform var(--transition-slow);
}

.feature-image img:hover {
  transform: scale(1.03);
}

/* Feature Content */
.feature-content {
  padding: 20px;
}

.feature-tag {
  display: inline-block;
  padding: 8px 16px;
  background: rgba(255, 215, 0, 0.1);
  border: 1px solid rgba(255, 215, 0, 0.3);
  border-radius: 20px;
  color: var(--color-accent);
  font-size: 0.9rem;
  font-weight: 500;
  margin-bottom: 20px;
}

.feature-title {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--color-text-primary);
  line-height: 1.3;
}

.feature-subtitle {
  font-size: clamp(1.2rem, 2.5vw, 1.6rem);
  font-weight: 500;
  color: var(--color-accent);
  margin-bottom: 25px;
}

.feature-description {
  font-size: 1.1rem;
  color: var(--color-text-secondary);
  line-height: 1.8;
}

/* ==========================================
   CTA Section
   ========================================== */
.cta-section {
  background: linear-gradient(135deg, #1a1a0a 0%, var(--color-bg-secondary) 50%, var(--color-bg-primary) 100%);
  text-align: center;
  min-height: auto;
  padding: 120px 20px;
}

.cta-content h2 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  margin-bottom: 15px;
  color: var(--color-accent);
}

.cta-content p {
  font-size: 1.2rem;
  color: var(--color-text-secondary);
  margin-bottom: 40px;
}

/* ==========================================
   Footer
   ========================================== */
.footer {
  background: var(--color-bg-primary);
  border-top: 1px solid var(--color-border);
  padding: 60px 20px;
  text-align: center;
}

.footer-content {
  max-width: 600px;
  margin: 0 auto;
}

.footer-logo {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.footer-logo .lightning-icon {
  font-size: 30px;
  margin-bottom: 0;
  animation: none;
}

.footer-tagline {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  margin-bottom: 25px;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 15px;
  margin-bottom: 30px;
}

.footer-links .divider {
  color: var(--color-text-muted);
}

.copyright {
  color: var(--color-text-muted);
  font-size: 0.85rem;
}

/* ==========================================
   Animations
   ========================================== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0%, 100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.1);
  }
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translateX(-50%) translateY(0);
  }
  40% {
    transform: translateX(-50%) translateY(-10px);
  }
  60% {
    transform: translateX(-50%) translateY(-5px);
  }
}

/* Scroll Animation */
.feature-section .section-container {
  opacity: 0;
  transform: translateY(50px);
  transition: all 0.8s ease-out;
}

.feature-section.visible .section-container {
  opacity: 1;
  transform: translateY(0);
}

/* ==========================================
   Responsive Design
   ========================================== */
@media (max-width: 968px) {
  .section-container {
    grid-template-columns: 1fr;
    gap: 40px;
    text-align: center;
  }

  .feature-section.alt .section-container {
    direction: ltr;
  }

  .feature-image {
    order: -1;
  }

  .feature-image img {
    max-width: 378px;
  }

  .feature-content {
    padding: 0;
  }
}

@media (max-width: 600px) {
  :root {
    --section-padding: 80px 16px;
  }

  .lightning-icon {
    font-size: 60px;
  }

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

  .app-button {
    width: 100%;
    max-width: 280px;
    justify-content: center;
  }

  .feature-image img {
    max-width: 353px;
  }

  .footer-links {
    flex-direction: column;
    gap: 10px;
  }

  .footer-links .divider {
    display: none;
  }
}

/* ==========================================
   Utility Classes
   ========================================== */
.text-gradient {
  background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-accent-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.glow {
  filter: drop-shadow(0 0 20px rgba(255, 215, 0, 0.4));
}