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

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

body {
  font-family: "Noto Sans KR", -apple-system, BlinkMacSystemFont, "Segoe UI",
    Roboto, sans-serif;
  color: #1a1a1a;
  line-height: 1.6;
  overflow-x: hidden;
}

:root {
  --primary: #ef4034;
  --primary-solid: #ef4034;
  --dark: #1a1a1a;
  --light: #ffffff;
  --gray-light: #f8f9fa;
  --gray-medium: #6c757d;
  --gray-dark: #343a40;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  --shadow-hover: 0 15px 40px rgba(0, 0, 0, 0.15);
}

/* -------- UTILITIES -------- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

/* -------- HEADER -------- */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  z-index: 1000;
  transition: all 0.3s ease;
}

.header-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.5rem 1rem 0.1rem;
  max-width: 1200px;
  margin: 0 auto;
}

.logo {
  display: flex;
  align-items: center;
  text-decoration: none;
}

.logo img {
  height: 60px;
  width: auto;
}

.nav-desktop {
  display: none;
  gap: 2rem;
  align-items: center;
}

.nav-desktop a {
  font-weight: 500;
  color: var(--dark);
  text-decoration: none;
  transition: all 0.3s ease;
  position: relative;
}

.nav-desktop a:not(.lang-btn)::after {
  content: "";
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: width 0.3s ease;
}

.nav-desktop a:hover::after {
  width: 100%;
}

.nav-desktop a:hover {
  color: var(--primary-solid);
}

.lang-btn {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--primary-solid);
  text-decoration: none;
  border: 1px solid var(--primary-solid);
  padding: 0.4rem 0.9rem;
  border-radius: 50px;
  transition: all 0.3s ease;
}

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

/* Mobile Menu */
.mobile-menu-btn {
  display: flex;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.mobile-menu-btn span {
  width: 25px;
  height: 3px;
  background: var(--dark);
  border-radius: 3px;
  transition: all 0.3s ease;
}

.mobile-menu {
  position: fixed;
  top: 0;
  right: -100%;
  width: 280px;
  height: 100vh;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  padding: 2rem;
  transition: right 0.3s ease;
  border-left: 1px solid var(--glass-border);
}

.mobile-menu.active {
  right: 0;
}

.mobile-menu-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--dark);
}

.mobile-nav {
  margin-top: 3rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.mobile-nav a {
  font-weight: 500;
  color: var(--dark);
  text-decoration: none;
  padding: 0.75rem 0;
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
  transition: color 0.3s ease;
}

.mobile-nav a:hover {
  color: var(--primary-solid);
}

.lang-icon-mobile {
  position: absolute;
  bottom: 2rem;
  right: 1.5rem;
  width: 48px;
  height: 48px;
  background-color: #f0f0f0;
  color: var(--dark);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1001;
  transition: background-color 0.2s ease-out;
}
.lang-icon-mobile:hover {
  background-color: #e0e0e0;
}

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

.slide {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0;
  transition: opacity 1.2s ease-in-out;
}

.slide::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(45deg, rgba(0, 0, 0, 0.4), rgba(0, 0, 0, 0.2));
}

.slide.active {
  opacity: 1;
}

.hero-content {
  position: relative;
  z-index: 10;
  text-align: center;
  color: white;
  max-width: 800px;
  padding: 0 1rem;
}

.hero h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  animation: slideUp 1s ease-out;
}

.hero p {
  font-size: clamp(1rem, 2vw, 1.25rem);
  margin-bottom: 2.5rem;
  opacity: 0.9;
  line-height: 1.7;
  animation: slideUp 1s ease-out 0.3s both;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  animation: slideUp 1s ease-out 0.6s both;
}

.btn-app-store {
  background: rgba(30, 30, 30, 0.75);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(10px);
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.6rem 1.25rem;
  border-radius: 12px;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  width: 170px;
  justify-content: center;
}
.btn-app-store:hover {
  background: rgba(50, 50, 50, 0.9);
  transform: translateY(-2px);
}
.btn-app-store img {
  height: 24px;
}

.photo-credit {
  position: absolute;
  bottom: 1.5rem;
  right: 1.5rem;
  color: white;
  font-size: 0.8rem;
  font-weight: 500;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.6);
  opacity: 0.8;
  z-index: 15;
}

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

/* -------- SECTIONS -------- */
.section {
  padding: 6rem 0;
  position: relative;
}

.section p {
  text-align: center;
  color: var(--gray-medium);
  max-width: 700px;
  margin: 0 auto;
  font-size: 1.1rem;
  line-height: 1.7;
  word-break: keep-all;
}

.section h2 {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  font-weight: 700;
  text-align: center;
  color: var(--dark);
  margin-bottom: 1rem;
}

.section-content-wrapper {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
}

/* -------- FEATURE SECTIONS -------- */
.feature-section:nth-of-type(even) {
  background: var(--gray-light);
}
.feature-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: 4rem;
}

.feature-grid.reverse .text-content {
  grid-area: text;
}
.feature-grid.reverse .media-content {
  grid-area: media;
}
.feature-grid.reverse {
  grid-template-areas: "media text";
}

.text-content {
  text-align: left;
  position: relative;
  padding-top: 2rem;
}

.text-content .section-label {
  position: absolute;
  top: 0;
  left: 0;
  background: var(--primary-solid);
  color: white;
  padding: 0.3rem 0.8rem;
  border-radius: 50px;
  font-size: 0.9rem;
  font-weight: 700;
}

.text-content h2 {
  font-size: clamp(2rem, 4vw, 2.8rem);
  line-height: 1.3;
  margin-top: 0.5rem;
  text-align: left;
  word-break: keep-all;
}

.text-content .section-description {
  text-align: left;
  font-size: 1.2rem;
  color: var(--gray-medium);
  word-break: keep-all;
}

.phone-mockup {
  position: relative;
  border: 10px solid var(--dark);
  border-radius: 40px;
  background: var(--dark);
  width: 60%;
  margin: 0 auto;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.45);
}

.phone-mockup img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 30px;
}

.phone-mockup::before {
  content: "";
  position: absolute;
  top: 10px;
  left: 50%;
  transform: translateX(-50%);
  width: 25%;
  height: 6px;
  background-color: #000;
  border-radius: 3px;
  z-index: 10;
}

/* -------- HISTORY / TIMELINE SECTION -------- */
.history-section {
  background-color: var(--gray-light);
}
.history-section .section-content-wrapper {
  margin-bottom: 2rem;
}
.timeline {
  position: relative;
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem 0;
}
.timeline::before {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 3px;
  height: 100%;
  background-color: #e0e0e0;
}
.timeline-item {
  position: relative;
  width: 45%;
  padding: 1rem;
  margin-bottom: 1rem;
}
.timeline-item:nth-child(odd) {
  left: 5%;
  padding-right: 3rem;
  text-align: right;
}
.timeline-item:nth-child(even) {
  left: 50%;
  padding-left: 3rem;
}
.timeline-dot {
  position: absolute;
  top: 1.25rem;
  width: 20px;
  height: 20px;
  background-color: white;
  border: 4px solid var(--primary-solid);
  border-radius: 50%;
  z-index: 5;
}
.timeline-item:nth-child(odd) .timeline-dot {
  right: -10px;
}
.timeline-item:nth-child(even) .timeline-dot {
  left: -10px;
}
.timeline-content {
  text-align: left;
}
.timeline-year {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-solid);
  margin-bottom: 0.5rem;
}
.timeline-details {
  list-style: none;
  padding: 0;
  margin: 0;
  display: inline-block;
  text-align: left;
}
.timeline-details li {
  font-size: 0.95rem;
  color: var(--gray-medium);
  margin-bottom: 0.3rem;
  padding-left: 1rem;
  position: relative;
}
.timeline-details li::before {
  content: "·";
  position: absolute;
  left: 0;
  font-weight: 700;
}

/* -------- CONTACT / SOCIAL SECTION -------- */
.contact-section {
  background: var(--light);
}
.social-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  max-width: 800px;
  margin: 3rem auto 0;
}
.social-card {
  background-color: white;
  border: 1px solid #e9ecef;
  border-radius: 16px;
  padding: 1.5rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  text-decoration: none;
  color: var(--dark);
  transition: all 0.3s ease;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
}
.social-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.1);
  border-color: var(--primary-solid);
}
.social-icon {
  width: 48px;
  height: 48px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
}
.social-icon.instagram {
  background: #f0f0f0;
}
.social-icon.naver {
  background: #f0f0f0;
}
.social-icon img {
  width: 28px;
  height: 28px;
}
.social-content {
  flex-grow: 1;
}
.social-content h3 {
  font-weight: 700;
}
.social-content p {
  font-size: 0.9rem;
  color: var(--gray-medium);
  text-align: left;
  margin: 0;
}
.social-arrow {
  font-size: 1.5rem;
  color: var(--gray-medium);
  transition: transform 0.3s ease;
}
.social-card:hover .social-arrow {
  transform: translateX(5px);
  color: var(--primary-solid);
}

/* -------- FOOTER -------- */
footer {
  background: var(--dark);
  color: rgba(255, 255, 255, 0.8);
  padding: 3rem 0 2rem;
}

.footer-content {
  display: grid;
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-section h4 {
  color: white;
  font-weight: 600;
  margin-bottom: 1rem;
}

.footer-section a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer-section a:hover {
  color: var(--primary-solid);
}

.footer-section .footer-contact-link {
  color: white;
  font-weight: 500;
}
.footer-section .footer-contact-link:hover {
  text-decoration: underline;
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.5);
}

/* -------- ANIMATIONS -------- */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* -------- SCROLL INDICATORS -------- */
.scroll-indicator {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--primary);
  transform-origin: left;
  transform: scaleX(0);
  z-index: 9999;
}

/* -------- RESPONSIVE STYLES -------- */
@media (max-width: 992px) {
  .feature-grid {
    gap: 2rem;
  }
  .timeline {
    max-width: 100%;
  }
}

@media (max-width: 768px) {
  .container {
    padding: 0 1rem;
  }

  .nav-desktop {
    display: none;
  }

  .mobile-menu-btn {
    display: flex;
  }

  .mobile-br::after {
    content: "\A";
    white-space: pre;
  }

  .hero .slide:nth-child(1) {
    background-position: 30% center;
  }
  .hero .slide:nth-child(2) {
    background-position: 47% center;
  }
  .hero .slide:nth-child(3) {
    background-position: 30% center;
  }
  .hero .slide:nth-child(4) {
    background-position: 70% center;
  }

  .feature-grid,
  .feature-grid.reverse {
    grid-template-columns: 1fr;
    gap: 3rem;
    grid-template-areas:
      "text"
      "media";
  }

  .feature-grid .text-content {
    grid-area: text;
  }
  .feature-grid .media-content {
    grid-area: media;
  }

  .media-content img {
    width: 100%;
  }

  .text-content {
    text-align: center;
    padding-top: 0;
  }
  .text-content .section-label {
    position: static;
    display: inline-block;
    margin-bottom: 1.5rem;
  }

  .text-content h2 {
    text-align: center;
    line-height: 1.4;
  }

  .text-content .section-description {
    text-align: center;
  }

  .timeline::before {
    left: 8px;
  }
  .timeline-item,
  .timeline-item:nth-child(even) {
    left: 0;
    width: 100%;
    padding-left: 3rem;
    padding-right: 1rem;
    text-align: left;
  }
  .timeline-dot,
  .timeline-item:nth-child(odd) .timeline-dot,
  .timeline-item:nth-child(even) .timeline-dot {
    left: 0;
  }

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

  .footer-content {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 768px) {
  .nav-desktop {
    display: flex;
  }
  .mobile-menu-btn {
    display: none;
  }
  .social-grid {
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
  }
  .footer-content {
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
  }
}