/* CSS Variables */
:root {
  /* Colors */
  --color-primary: #000000;
  --color-secondary: #FFFFFF;
  --color-gray-100: #F5F5F5;
  --color-gray-200: #E5E5E5;
  --color-gray-300: #C0C0C0;
  --color-gray-400: #808080;
  --color-gray-500: #4A4A4A;
  --color-gray-600: #1A1A1A;
  
  /* Typography */
  --font-family-kr: 'Noto Sans KR', system-ui, sans-serif;
  --font-family-en: 'Inter', system-ui, sans-serif;
  
  /* Spacing */
  --spacing-xs: 8px;
  --spacing-s: 16px;
  --spacing-m: 24px;
  --spacing-l: 32px;
  --spacing-xl: 48px;
  --spacing-xxl: 64px;
  --spacing-xxxl: 96px;
  
  /* Border Radius */
  --radius-s: 4px;
  --radius-m: 8px;
  --radius-l: 12px;
  --radius-xl: 16px;
  
  /* Shadows */
  --shadow-s: 0 2px 8px rgba(0, 0, 0, 0.1);
  --shadow-m: 0 4px 16px rgba(0, 0, 0, 0.15);
  --shadow-l: 0 8px 32px rgba(0, 0, 0, 0.2);
  
  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family-kr);
  line-height: 1.6;
  color: var(--color-primary);
  background-color: var(--color-secondary);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-l);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: var(--spacing-m);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: var(--spacing-m);
  color: var(--color-gray-600);
}

/* Buttons */
.btn {
  display: inline-block;
  padding: var(--spacing-s) var(--spacing-l);
  border-radius: var(--radius-m);
  text-decoration: none;
  font-weight: 600;
  transition: all var(--transition-normal);
  border: none;
  cursor: pointer;
  font-size: 1rem;
}

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

.btn--primary:hover {
  background-color: var(--color-gray-600);
  transform: translateY(-2px);
  box-shadow: var(--shadow-m);
}

.btn--secondary {
  background-color: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn--secondary:hover {
  background-color: var(--color-primary);
  color: var(--color-secondary);
  transform: translateY(-2px);
}

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  z-index: 1000;
  border-bottom: 1px solid var(--color-gray-200);
}

.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-s) 0;
}

.nav__logo-link {
  text-decoration: none;
  color: inherit;
  transition: opacity var(--transition-fast);
}

.nav__logo-link:hover {
  opacity: 0.8;
}

.nav__logo h1 {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-primary);
  margin: 0;
}

.nav__menu {
  display: flex;
  list-style: none;
  gap: var(--spacing-xl);
}

.nav__link {
  text-decoration: none;
  color: var(--color-gray-600);
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav__link:hover {
  color: var(--color-primary);
}

.nav__toggle {
  display: none;
  flex-direction: column;
  cursor: pointer;
  gap: 4px;
}

.nav__toggle span {
  width: 25px;
  height: 3px;
  background-color: var(--color-primary);
  transition: all var(--transition-fast);
}

/* Hero Section */
.hero {
  position: relative;
  height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero__video-container {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
}

.hero__video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero__overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.4);
  z-index: 2;
}

.hero__content {
  position: relative;
  z-index: 3;
  text-align: center;
  color: var(--color-secondary);
}

.hero__title {
  font-size: 3.5rem;
  font-weight: 700;
  margin-bottom: var(--spacing-l);
  line-height: 1.1;
}

.hero__description {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-xl);
  color: var(--color-gray-200);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero__buttons {
  display: flex;
  gap: var(--spacing-m);
  justify-content: center;
  flex-wrap: wrap;
}

/* Section Styles */
.section {
  padding: var(--spacing-xxxl) 0;
}

.section__header {
  text-align: center;
  margin-bottom: var(--spacing-xxl);
}

.section__title {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-m);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  gap: var(--spacing-m);
  justify-content: center;
}

.section__icon {
  width: 2.5rem;
  height: 2.5rem;
  color: var(--color-primary);
  flex-shrink: 0;
}

.section__icon svg {
  width: 100%;
  height: 100%;
}

.section__subtitle {
  font-size: 1.125rem;
  color: var(--color-gray-500);
  max-width: 600px;
  margin: 0 auto;
}

/* About Section */
.about__content {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xxl);
}

.about__main {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-xxl);
  align-items: start;
}

.about__intro {
  margin-bottom: var(--spacing-xl);
}

.about__description {
  font-size: 1.125rem;
  line-height: 1.7;
  color: var(--color-gray-600);
  margin-bottom: var(--spacing-l);
}

.about__philosophy {
  background-color: var(--color-gray-100);
  padding: var(--spacing-xl);
  border-radius: var(--radius-l);
  border-left: 4px solid var(--color-primary);
}

.philosophy__title {
  color: var(--color-primary);
  margin-bottom: var(--spacing-l);
  font-size: 1.5rem;
  font-weight: 600;
}

.philosophy__list {
  list-style: none;
  margin: 0;
}

.philosophy__list li {
  position: relative;
  margin-bottom: var(--spacing-m);
  padding-left: var(--spacing-l);
  font-size: 1.125rem;
  line-height: 1.6;
  color: var(--color-gray-600);
}

.philosophy__list li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: bold;
  font-size: 1.25rem;
}

.about__features {
  margin-top: var(--spacing-xxl);
  background: linear-gradient(135deg, var(--color-gray-100) 0%, var(--color-secondary) 100%);
  padding: var(--spacing-xxl);
  border-radius: var(--radius-xl);
  position: relative;
  overflow: hidden;
}

.about__features::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(0,0,0,0.03) 0%, transparent 70%);
  animation: float 20s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0px) rotate(0deg); }
  50% { transform: translateY(-20px) rotate(180deg); }
}

.features__title {
  text-align: center;
  color: var(--color-primary);
  margin-bottom: var(--spacing-xxl);
  font-size: 2.5rem;
  font-weight: 700;
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  gap: var(--spacing-m);
  justify-content: center;
}

.features__title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-gray-400));
  border-radius: 2px;
}

.features__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-xl);
  position: relative;
  z-index: 2;
}

.feature__card {
  background: var(--color-secondary);
  padding: var(--spacing-xxl);
  border-radius: var(--radius-xl);
  border: 2px solid var(--color-gray-200);
  text-align: center;
  transition: all var(--transition-slow);
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.feature__card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 100%;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-gray-600) 100%);
  opacity: 0;
  transition: opacity var(--transition-normal);
  z-index: 1;
}

.feature__card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-gray-400));
  transform: scaleX(0);
  transition: transform var(--transition-normal);
  z-index: 3;
}

.feature__card:hover {
  transform: translateY(-12px) scale(1.02);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
  border-color: var(--color-primary);
}

.feature__card:hover::before {
  opacity: 0.05;
}

.feature__card:hover::after {
  transform: scaleX(1);
}

.feature__icon {
  width: 4rem;
  height: 4rem;
  margin-bottom: var(--spacing-l);
  display: block;
  position: relative;
  z-index: 2;
  transition: transform var(--transition-normal);
  color: var(--color-primary);
}

.feature__icon svg {
  width: 100%;
  height: 100%;
}

.feature__card:hover .feature__icon {
  transform: scale(1.1) rotate(5deg);
}

.feature__card h4 {
  color: var(--color-primary);
  margin-bottom: var(--spacing-m);
  font-size: 1.5rem;
  font-weight: 700;
  position: relative;
  z-index: 2;
  transition: color var(--transition-normal);
}

.feature__card:hover h4 {
  color: var(--color-primary);
}

.feature__card p {
  color: var(--color-gray-600);
  margin: 0;
  line-height: 1.7;
  font-size: 1.1rem;
  position: relative;
  z-index: 2;
  transition: color var(--transition-normal);
}

.feature__card:hover p {
  color: var(--color-gray-700);
}

/* 카드별 개별 애니메이션 */
.feature__card:nth-child(1) {
  animation: slideInUp 0.6s ease-out 0.1s both;
}

.feature__card:nth-child(2) {
  animation: slideInUp 0.6s ease-out 0.2s both;
}

.feature__card:nth-child(3) {
  animation: slideInUp 0.6s ease-out 0.3s both;
}

.feature__card:nth-child(4) {
  animation: slideInUp 0.6s ease-out 0.4s both;
}

@keyframes slideInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Products Section */
.products__container {
  position: relative;
}

.product__main {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-xxl);
  align-items: stretch;
}

.product__card {
  background: var(--color-secondary);
  border-radius: var(--radius-xl);
  border: 2px solid var(--color-gray-200);
  overflow: hidden;
  transition: all var(--transition-slow);
  position: relative;
  display: flex;
  flex-direction: column;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
}

.product__card--featured {
  background: linear-gradient(135deg, var(--color-secondary) 0%, var(--color-gray-100) 100%);
  border-color: var(--color-primary);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.12);
}

.product__card--featured::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-gray-400));
}

.product__card:hover {
  transform: translateY(-12px);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
  border-color: var(--color-primary);
}

.product__header {
  padding: var(--spacing-xxl) var(--spacing-xxl) var(--spacing-l);
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-l);
}

.product__icon {
  width: 4rem;
  height: 4rem;
  flex-shrink: 0;
  transition: transform var(--transition-normal);
  color: var(--color-primary);
}

.product__icon svg {
  width: 100%;
  height: 100%;
}

.product__card:hover .product__icon {
  transform: scale(1.1) rotate(5deg);
}

.product__title-group {
  flex: 1;
}

.product__name {
  color: var(--color-primary);
  margin-bottom: var(--spacing-xs);
  font-size: 1.75rem;
  font-weight: 700;
  line-height: 1.2;
}

.product__tagline {
  color: var(--color-gray-500);
  font-size: 1rem;
  font-weight: 500;
  margin: 0;
  line-height: 1.4;
}

.product__content {
  padding: 0 var(--spacing-xxl) var(--spacing-l);
  flex: 1;
}

.product__description {
  color: var(--color-gray-600);
  font-size: 1.125rem;
  line-height: 1.6;
  margin-bottom: var(--spacing-l);
}

.product__features {
  list-style: none;
  margin: 0;
  padding: 0;
}

.product__features li {
  position: relative;
  padding-left: var(--spacing-l);
  margin-bottom: var(--spacing-s);
  color: var(--color-gray-600);
  line-height: 1.6;
  font-size: 1rem;
}

.product__features li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: bold;
  font-size: 1.1rem;
}

.product__cta {
  padding: var(--spacing-l) var(--spacing-xxl) var(--spacing-xxl);
  margin-top: auto;
}

.product__cta .btn {
  width: 100%;
  text-align: center;
  justify-content: center;
}

/* 카드별 개별 애니메이션 */
.product__card--featured {
  animation: slideInLeft 0.8s ease-out 0.2s both;
}

.product__card--secondary {
  animation: slideInRight 0.8s ease-out 0.4s both;
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* Demo Section */
.demo__content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-xxl);
  align-items: center;
}

.demo__text h3 {
  color: var(--color-primary);
  margin-bottom: var(--spacing-s);
}

.demo__preview {
  background-color: var(--color-gray-100);
  border-radius: var(--radius-l);
  padding: var(--spacing-xxl);
  text-align: center;
  border: 2px solid var(--color-gray-200);
  overflow: hidden;
}

.demo__video-container {
  position: relative;
  width: 100%;
  height: 0;
  padding-bottom: 56.25%; /* 16:9 aspect ratio */
  background-color: var(--color-gray-200);
  border-radius: var(--radius-m);
  overflow: hidden;
}

.demo__video {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: var(--radius-m);
}

/* Contact Section */
.contact__content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-xxl);
}

.contact__info h3 {
  color: var(--color-primary);
  margin-bottom: var(--spacing-l);
}

.contact__item {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-m);
  margin-bottom: var(--spacing-l);
}

.contact__icon {
  width: 1.5rem;
  height: 1.5rem;
  margin-top: 4px;
  color: var(--color-primary);
  flex-shrink: 0;
}

.contact__icon svg {
  width: 100%;
  height: 100%;
}

.contact__item h4 {
  color: var(--color-primary);
  margin-bottom: var(--spacing-xs);
}

.contact__item p {
  color: var(--color-gray-600);
  margin: 0;
}

.contact__form {
  display: grid;
  gap: var(--spacing-m);
}

.form__group input,
.form__group textarea {
  width: 100%;
  padding: var(--spacing-s);
  border: 2px solid var(--color-gray-200);
  border-radius: var(--radius-m);
  font-family: inherit;
  font-size: 1rem;
  transition: border-color var(--transition-fast);
}

.form__group input:focus,
.form__group textarea:focus {
  outline: none;
  border-color: var(--color-primary);
}

.form__group textarea {
  resize: vertical;
  min-height: 120px;
}

/* Footer */
.footer {
  background-color: var(--color-gray-100);
  padding: var(--spacing-xxl) 0 var(--spacing-l);
  border-top: 1px solid var(--color-gray-200);
}

.footer__content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer__brand h3 {
  color: var(--color-primary);
  margin-bottom: var(--spacing-s);
}

.footer__brand p {
  color: var(--color-gray-600);
  margin: 0;
}

.footer__links h4,
.footer__social h4 {
  color: var(--color-primary);
  margin-bottom: var(--spacing-m);
}

.footer__links ul {
  list-style: none;
}

.footer__links li {
  margin-bottom: var(--spacing-s);
}

.footer__links a {
  color: var(--color-gray-600);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

.social__links {
  display: flex;
  gap: var(--spacing-m);
}

.social__links a {
  width: 1.5rem;
  height: 1.5rem;
  color: var(--color-gray-600);
  transition: color var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
}

.social__links a svg {
  width: 100%;
  height: 100%;
}

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

.footer__bottom {
  text-align: center;
  padding-top: var(--spacing-l);
  border-top: 1px solid var(--color-gray-200);
}

.footer__bottom p {
  color: var(--color-gray-500);
  margin: 0;
}

/* Responsive Design */
@media (max-width: 1024px) {
  .container {
    padding: 0 var(--spacing-m);
  }
  
  .hero__title {
    font-size: 3rem;
  }
  
  .about__main {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }
  
  .features__grid {
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-l);
  }
  
  .about__features {
    padding: var(--spacing-xl);
  }
  
  .features__title {
    font-size: 2rem;
  }
  
  .section__title {
    font-size: 2rem;
  }
  
  .section__icon {
    width: 2rem;
    height: 2rem;
  }
  
  .product__main {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }
  
  .demo__content {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }
  
  .demo__preview {
    padding: var(--spacing-l);
  }
  
  .contact__content {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }
}

@media (max-width: 768px) {
  .nav__menu {
    display: none;
  }
  
  .nav__toggle {
    display: flex;
  }
  
  .hero__title {
    font-size: 2.5rem;
  }
  
  .hero__description {
    font-size: 1.125rem;
  }
  
  .hero__buttons {
    flex-direction: column;
    align-items: center;
  }
  
  .section {
    padding: var(--spacing-xxl) 0;
  }
  
  .section__title {
    font-size: 2rem;
  }
  
  .products__grid {
    grid-template-columns: 1fr;
  }
  
  .footer__content {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .social__links {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--spacing-s);
  }
  
  .hero__title {
    font-size: 2rem;
  }
  
  .hero__description {
    font-size: 1rem;
  }
  
  .section__title {
    font-size: 1.75rem;
  }
  
  .btn {
    padding: var(--spacing-s) var(--spacing-m);
    font-size: 0.875rem;
  }
  
  .features__grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-m);
  }
  
  .about__features {
    padding: var(--spacing-l);
  }
  
  .features__title {
    font-size: 1.75rem;
  }
  
  .section__title {
    font-size: 1.75rem;
  }
  
  .section__icon {
    width: 1.75rem;
    height: 1.75rem;
  }
  
  .feature__card {
    padding: var(--spacing-l);
  }
  
  .feature__icon {
    width: 3rem;
    height: 3rem;
  }
  
  .product__header {
    padding: var(--spacing-l);
    flex-direction: column;
    text-align: center;
    gap: var(--spacing-m);
  }
  
  .product__content {
    padding: 0 var(--spacing-l) var(--spacing-m);
  }
  
  .product__cta {
    padding: var(--spacing-m) var(--spacing-l) var(--spacing-l);
  }
  
  .product__name {
    font-size: 1.5rem;
  }
  
  .product__icon {
    width: 3rem;
    height: 3rem;
  }
  
  .demo__preview {
    padding: var(--spacing-m);
  }
}

/* Smooth scrolling for anchor links */
html {
  scroll-padding-top: 80px;
}

/* Focus styles for accessibility */
.btn:focus,
.nav__link:focus,
input:focus,
textarea:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Loading animation for video */
.hero__video {
  opacity: 0;
  animation: fadeIn 1s ease-in-out forwards;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}