:root {
  --bg-primary: #0a0a0a;
  --bg-secondary: #111111;
  --text-primary: #ffffff;
  --text-secondary: rgba(255, 255, 255, 0.6);
  --border-color: rgba(255, 255, 255, 0.1);
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.1);
  --frame-size: clamp(16px, 3vw, 40px);
}

[data-theme="light"] {
  --bg-primary: #ffffff;
  --bg-secondary: #f5f5f5;
  --text-primary: #0a0a0a;
  --text-secondary: rgba(10, 10, 10, 0.6);
  --border-color: rgba(0, 0, 0, 0.1);
  --glass-bg: rgba(0, 0, 0, 0.03);
  --glass-border: rgba(0, 0, 0, 0.08);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  transition: background 0.3s, color 0.3s;
}

/* Square Frame - 브라우저 테두리 */
.square-frame {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  border: var(--frame-size) solid var(--text-primary);
  pointer-events: none;
  z-index: 1000;
}

/* Main Content */
.content {
  padding: calc(var(--frame-size) + 40px);
  min-height: 100vh;
}

/* Logo */
.logo {
  width: 100px;
  height: 100px;
  border-radius: 24px;
  margin-bottom: 32px;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.logo:hover {
  transform: scale(1.05);
  box-shadow: 0 0 40px rgba(255, 255, 255, 0.15);
}

.logo:active {
  transform: scale(0.98);
}

[data-theme="light"] .logo:hover {
  box-shadow: 0 0 40px rgba(0, 0, 0, 0.1);
}

/* Hero Section */
.hero {
  min-height: calc(100vh - var(--frame-size) * 2);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 60px 20px;
}

.hero h1 {
  font-size: clamp(48px, 10vw, 80px);
  font-weight: 900;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.hero .tagline {
  font-size: clamp(16px, 3vw, 20px);
  color: var(--text-secondary);
  margin-bottom: 48px;
  max-width: 400px;
}

/* Store Buttons */
.store-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 80px;
}

.store-btn {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 28px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 16px;
  color: var(--text-primary);
  text-decoration: none;
  transition: all 0.3s;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

.store-btn:hover {
  background: var(--glass-border);
  transform: translateY(-2px);
}

.store-btn svg {
  width: 24px;
  height: 24px;
  opacity: 0.9;
}

.store-btn .text {
  text-align: left;
}

.store-btn .text small {
  font-size: 10px;
  opacity: 0.6;
  display: block;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.store-btn .text strong {
  font-size: 15px;
  font-weight: 600;
}

.store-btn.coming-soon {
  opacity: 0.5;
}

.store-btn.coming-soon:hover {
  transform: none;
}

/* Scroll Hint */
.scroll-hint {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--text-secondary);
  font-size: 12px;
  text-decoration: none;
  transition: color 0.3s;
}

.scroll-hint:hover {
  color: var(--text-primary);
}

.scroll-hint svg {
  width: 20px;
  height: 20px;
  animation: float 2s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(6px); }
}

/* Features Section */
.features {
  padding: 100px 20px;
  max-width: 1000px;
  margin: 0 auto;
}

.features h2 {
  text-align: center;
  font-size: clamp(28px, 5vw, 36px);
  font-weight: 700;
  margin-bottom: 60px;
  letter-spacing: -0.02em;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
  justify-content: center;
}

.feature-card {
  background: transparent;
  border: 1px solid var(--text-primary);
  border-radius: 20px;
  padding: 28px;
  transition: all 0.3s;
}

.feature-card:hover {
  background: var(--text-primary);
  transform: translateY(-4px);
}

.feature-card:hover h3,
.feature-card:hover p {
  color: var(--bg-primary);
}

.feature-card:hover .feature-icon svg {
  stroke: var(--bg-primary);
}

.feature-icon {
  margin-bottom: 20px;
}

.feature-icon svg {
  width: 28px;
  height: 28px;
  stroke: var(--text-primary);
  opacity: 0.6;
  transition: stroke 0.3s;
}

.feature-card:hover .feature-icon svg {
  opacity: 1;
}

.feature-card h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 8px;
  transition: color 0.3s;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.5;
  transition: color 0.3s;
}

/* Footer */
footer {
  padding: 60px 20px;
  text-align: center;
  border-top: 1px solid var(--border-color);
  margin: 0 calc(var(--frame-size) * -1 - 40px);
  padding-left: calc(var(--frame-size) + 40px);
  padding-right: calc(var(--frame-size) + 40px);
}

.footer-links {
  display: flex;
  gap: 32px;
  justify-content: center;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 13px;
  transition: color 0.3s;
}

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

.footer-info {
  color: var(--text-secondary);
  font-size: 12px;
  line-height: 1.8;
}

.footer-info a {
  color: inherit;
}

/* Responsive */
@media (max-width: 600px) {
  .store-buttons {
    flex-direction: column;
    align-items: center;
  }
  
  .store-btn {
    width: 100%;
    max-width: 260px;
    justify-content: center;
  }
  
  .hero {
    padding: 40px 16px;
  }
  
  .features {
    padding: 60px 16px;
  }
}