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

:root {
  --bg-light: #f8f8f8;
  --fg-light: #1a1a1a;
  --bg-dark: #303030;
  --fg-dark: #e3e3e3;
  --accent-light: #e8e8e8;
  --accent-dark: #505050;
  --muted-light: #999999;
  --muted-dark: #b0b0b0;
}

html {
  scroll-behavior: smooth;
}

html.dark {
  background-color: var(--bg-dark);
  color: var(--fg-dark);
}

html.light {
  background-color: var(--bg-light);
  color: var(--fg-light);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Helvetica Neue', sans-serif;
  line-height: 1.6;
  transition: background-color 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
}

/* 다크 모드 전체 그라데이션 */
html.dark body {
  background: linear-gradient(180deg, #303030 0%, #282828 30%, #252525 60%, #1e1e1e 100%);
  background-attachment: fixed;
}

/* 라이트 모드 전체 그라데이션 */
html.light body {
  background: linear-gradient(180deg, #f8f8f8 0%, #efefef 30%, #e8e8e8 60%, #e0e0e0 100%);
  background-attachment: fixed;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== STICKY HEADER ===== */
.sticky-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  backdrop-filter: blur(12px);
  transition: all 0.3s ease;
  padding: 16px 0;
}

html.dark .sticky-header {
  background: rgba(48, 48, 48, 0.9);
  border-bottom: 1px solid rgba(80, 80, 80, 0.3);
}

html.light .sticky-header {
  background: rgba(248, 248, 248, 0.9);
  border-bottom: 1px solid rgba(232, 232, 232, 0.8);
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo-icon {
  height: 70px;
  width: auto;
  display: block;
}


html.dark .header-logo {
  color: var(--fg-dark);
}

html.light .header-logo {
  color: var(--fg-light);
}

.header-right {
  display: flex;
  align-items: center;
  gap: 32px;
}

.header-nav {
  display: flex;
  gap: 32px;
}

.header-nav a {
  text-decoration: none;
  font-size: 15px;
  font-weight: 500;
  transition: color 0.2s;
}

html.dark .header-nav a {
  color: var(--muted-dark);
}

html.dark .header-nav a:hover {
  color: var(--fg-dark);
}

html.light .header-nav a {
  color: var(--muted-light);
}

html.light .header-nav a:hover {
  color: var(--fg-light);
}

.theme-toggle {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
  position: relative;
}

html.dark .theme-toggle {
  background: var(--accent-dark);
  color: var(--fg-dark);
}

html.light .theme-toggle {
  background: var(--accent-light);
  color: var(--fg-light);
}

/* 데스크톱에서만 hover */
@media (hover: hover) {
  .theme-toggle:hover {
    transform: scale(1.1);
  }
}

/* 모바일 터치 */
.theme-toggle:active {
  transform: scale(0.95);
}

.sun-icon,
.moon-icon {
  position: absolute;
  transition: all 0.3s ease;
}

html.dark .sun-icon {
  opacity: 0;
  transform: rotate(-90deg) scale(0.5);
}

html.dark .moon-icon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

html.light .sun-icon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

html.light .moon-icon {
  opacity: 0;
  transform: rotate(90deg) scale(0.5);
}

/* ===== HERO SECTION ===== */
.hero-section {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 120px 20px 80px;
  position: relative;
}

.hero-section .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}

.hero-content {
  animation: fadeInUp 0.8s ease-out;
}

.hero-icon {
  height: 120px;
  width: auto;
  display: block;
  margin-bottom: 20px;
  animation: fadeInUp 0.8s ease-out;
}

.hero-subtitle {
  font-size: 40px;
  font-weight: 600;
  letter-spacing: 1px;
  margin-bottom: 24px;
  opacity: 0.8;
}

.hero-description {
  font-size: 20px;
  line-height: 1.7;
  margin-bottom: 40px;
  max-width: 500px;
}

html.dark .hero-description {
  color: var(--muted-dark);
}

html.light .hero-description {
  color: var(--muted-light);
}

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

.btn-primary,
.btn-secondary {
  padding: 14px 32px;
  border-radius: 12px;
  font-size: 16px;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s ease;
  display: inline-block;
}

.btn-primary {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
}

html.dark .btn-primary {
  background: var(--fg-dark);
  color: var(--bg-dark);
}

html.light .btn-primary {
  background: var(--fg-light);
  color: var(--bg-light);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
}

html.dark .btn-secondary {
  background: var(--accent-dark);
  color: var(--fg-dark);
}

html.light .btn-secondary {
  background: var(--accent-light);
  color: var(--fg-light);
}

/* 데스크톱에서만 hover */
@media (hover: hover) {
  .btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
  }

  .btn-secondary:hover {
    transform: translateY(-2px);
  }
}

/* 모바일 터치 */
.btn-primary:active,
.btn-secondary:active {
  transform: scale(0.98);
  opacity: 0.9;
}

.hero-image {
  display: flex;
  justify-content: center;
  animation: fadeIn 1s ease-out;
}

.iphone-frame {
  position: relative;
  width: 320px;
  animation: float 4s ease-in-out infinite;
}

.iphone-frame-small {
  position: relative;
  width: 240px;
}

.phone-screen {
  width: 100%;
  height: auto;
  border-radius: 40px;
  transition: all 0.3s ease;
}

html.dark .phone-screen {
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.6),
    0 0 30px rgba(227, 227, 227, 0.1);
}

html.light .phone-screen {
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15),
    0 0 20px rgba(26, 26, 26, 0.05);
}

/* 데스크톱에서만 hover */
@media (hover: hover) {
  .feature-card:hover .phone-screen {
    transform: scale(1.05);
  }
}

/* 모바일 터치 */
.phone-screen:active {
  transform: scale(1.02);
  opacity: 0.95;
}

/* ===== FEATURES SECTION ===== */
.features-section {
  padding: 120px 20px;
}

.section-header {
  text-align: center;
  margin-bottom: 80px;
}

.section-title {
  font-size: 48px;
  font-weight: 700;
  letter-spacing: -2px;
  margin-bottom: 16px;
}

.section-description {
  font-size: 18px;
  max-width: 600px;
  margin: 0 auto;
}

html.dark .section-description {
  color: var(--muted-dark);
}

html.light .section-description {
  color: var(--muted-light);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 60px;
}

.feature-card {
  text-align: center;
  padding: 40px 20px;
  border-radius: 20px;
  transition: all 0.3s ease;
  animation: fadeIn 0.6s ease-out;
}

/* 데스크톱에서만 hover */
@media (hover: hover) {
  .feature-card:hover {
    transform: translateY(-8px);
  }
}



.feature-card:hover {
  transform: translateY(-8px);
}

.feature-image {
  margin-bottom: 32px;
  display: flex;
  justify-content: center;
}

.feature-card:hover .phone-screen {
  transform: scale(1.05);
}

.feature-title {
  font-size: 24px;
  font-weight: 600;
  margin-bottom: 16px;
}

.feature-text {
  font-size: 16px;
  line-height: 1.7;
}

html.dark .feature-text {
  color: var(--muted-dark);
}

html.light .feature-text {
  color: var(--muted-light);
}

/* ===== HOW IT WORKS ===== */
.how-section {
  padding: 120px 20px;
}



.steps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 60px;
}

.step-card {
  text-align: center;
  padding: 40px 20px;
}

.step-number {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  font-size: 36px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 24px;
  border: 1px solid;
}

html.dark .step-number {
  background: linear-gradient(135deg, #505050 0%, #3a3a3a 100%);
  border-color: #505050;
  color: var(--fg-dark);
}

html.light .step-number {
  background: linear-gradient(135deg, #e8e8e8 0%, #d0d0d0 100%);
  border-color: #d0d0d0;
  color: var(--fg-light);
}

.step-title {
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 16px;
}

.step-text {
  font-size: 16px;
  line-height: 1.7;
}

html.dark .step-text {
  color: var(--muted-dark);
}

html.light .step-text {
  color: var(--muted-light);
}

/* ===== DOWNLOAD SECTION ===== */
.download-section {
  padding: 120px 20px;
  text-align: center;
}

.download-title {
  font-size: 48px;
  font-weight: 700;
  margin-bottom: 16px;
}

.download-text {
  font-size: 18px;
  margin-bottom: 40px;
}

html.dark .download-text {
  color: var(--muted-dark);
}

html.light .download-text {
  color: var(--muted-light);
}

.download-buttons {
  display: flex;
  gap: 30px;
  justify-content: center;
  flex-wrap: wrap;
}

/* Store buttons */
.store-button {
  display: inline-block;
  line-height: 0;
  transition: transform 0.3s ease;
}

/* 데스크톱에서만 hover */
@media (hover: hover) {
  .store-button:hover {
    transform: translateY(-4px);
  }
}

/* 모바일 터치 */
.store-button:active {
  transform: translateY(-2px);
  opacity: 0.8;
}

.store-button-disabled {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}

.store-badge {
  height: 60px;
  width: auto;
}

@media (max-width: 768px) {
  .store-badge {
    height: 50px;
  }
}

/* ===== FOOTER ===== */
.footer {
  padding: 60px 20px;
  text-align: center;
  border-top: 1px solid;
}

html.dark .footer {
  background: #202020;
  border-color: #202020;
}

html.light .footer {
  background: #e3e3e3;
  border-color: #e0e0e0;
}

.footer-copy {
  margin-bottom: 20px;
  font-size: 14px;
}

html.dark .footer-copy {
  color: #808080;
}

html.light .footer-copy {
  color: #999999;
}

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

.footer-links a {
  text-decoration: none;
  font-size: 14px;
  transition: color 0.3s;
}

html.dark .footer-links a {
  color: var(--muted-dark);
}

html.dark .footer-links a:hover {
  color: var(--fg-dark);
}

html.light .footer-links a {
  color: var(--muted-light);
}

html.light .footer-links a:hover {
  color: var(--fg-light);
}

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

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }

  to {
    opacity: 1;
  }
}

@keyframes float {

  0%,
  100% {
    transform: translateY(0px);
  }

  50% {
    transform: translateY(-15px);
  }
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .header-right {
    gap: 16px;
    /* 간격 줄이기 */
  }

  .header-nav {
    display: flex;
    gap: 16px;
    /* 간격 줄이기 */
    font-size: 14px;
    /* 폰트 작게 */
  }

  .logo-icon {
    height: 32px;
  }

  .hero-icon {
    height: 80px;
  }

  .hero-section .container {
    grid-template-columns: 1fr;
    gap: 60px;
  }

  .hero-title-main {
    font-size: 64px;
  }

  .hero-subtitle {
    font-size: 28px;
  }

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

  .hero-image {
    order: 2;
  }

  .iphone-frame {
    width: 260px;
  }

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

  .features-grid,
  .steps-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .download-buttons {
    gap: 16px;
    flex-direction: row;
    flex-wrap: nowrap;
  }

  .store-badge {
    height: 44px;
  }
}

/* 작은 화면 (iPhone SE 등) */
@media (max-width: 400px) {
  .download-buttons {
    gap: 12px;
  }

  .store-badge {
    height: 40px;
    /* 더 작게 */
  }
}