/* ===========================
   S-FAN Landing Page Styles
   =========================== */

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

:root {
  --navy: #1a3c8f;
  --navy-dark: #122b6e;
  --navy-light: #2a52b0;
  --white: #ffffff;
  --gray-dark: #333333;
  --gray-mid: #666666;
  --gray-light: #f5f6fa;
  --border: #e0e4ef;
  --shadow: 0 4px 20px rgba(26,60,143,0.10);
  --shadow-hover: 0 8px 32px rgba(26,60,143,0.18);
  --radius: 12px;
  --transition: 0.3s ease;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Noto Sans KR', 'Apple SD Gothic Neo', sans-serif;
  color: var(--gray-dark);
  background: var(--white);
  line-height: 1.7;
  font-size: 16px;
}

img { max-width: 100%; height: auto; display: block; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---- Buttons ---- */
.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 50px;
  font-weight: 700;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all var(--transition);
  border: 2px solid transparent;
}

.btn-outline {
  border-color: var(--navy);
  color: var(--navy);
  background: transparent;
}
.btn-outline:hover {
  background: var(--navy);
  color: var(--white);
}

.btn-primary {
  background: var(--navy);
  color: var(--white);
  border-color: var(--navy);
}
.btn-primary:hover {
  background: var(--navy-dark);
  border-color: var(--navy-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.btn-white {
  background: var(--white);
  color: var(--navy);
  border-color: var(--white);
}
.btn-white:hover {
  background: transparent;
  color: var(--white);
}

.btn-sm {
  padding: 8px 18px;
  font-size: 0.85rem;
}

/* ---- Animations ---- */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}
.delay-1 { transition-delay: 0.15s; }
.delay-2 { transition-delay: 0.30s; }
.delay-3 { transition-delay: 0.45s; }

/* ---- Section Common ---- */
.section { padding: 80px 0; }
.section-title {
  font-size: 2rem;
  font-weight: 900;
  color: var(--navy);
  text-align: center;
  margin-bottom: 12px;
}
.section-sub {
  text-align: center;
  font-size: 1.05rem;
  color: var(--gray-mid);
  margin-bottom: 8px;
}
.section-desc {
  text-align: center;
  color: var(--gray-mid);
  margin-bottom: 48px;
}

/* ===========================
   HEADER
   =========================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--white);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 2px 12px rgba(0,0,0,0.06);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.logo-img { height: 36px; width: auto; }
.main-nav { display: flex; gap: 32px; }
.main-nav a {
  font-weight: 500;
  color: var(--gray-dark);
  font-size: 0.95rem;
  transition: color var(--transition);
}
.main-nav a:hover { color: var(--navy); }
.nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--navy);
}

/* ===========================
   HERO
   =========================== */
.hero {
  background: linear-gradient(135deg, #f0f4ff 0%, #ffffff 60%);
  padding: 80px 0 60px;
  overflow: hidden;
}
.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}
.hero-sub {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--navy);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 12px;
}
.hero-title {
  font-size: 3.2rem;
  font-weight: 900;
  color: var(--navy);
  line-height: 1.15;
  margin-bottom: 16px;
}
.hero-desc-line {
  font-size: 1.1rem;
  color: var(--gray-mid);
  margin-bottom: 8px;
}
.hero-desc {
  font-size: 1.05rem;
  color: var(--gray-dark);
  font-weight: 500;
  margin-bottom: 32px;
}
.hero-image img {
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  width: 100%;
  max-height: 420px;
  object-fit: contain;
}

/* ===========================
   CATEGORY NAV BAR
   =========================== */
.cat-nav {
  background: #1a1a2e;
  padding: 0;
  overflow-x: auto;
}
.cat-nav-inner {
  display: flex;
  gap: 0;
  white-space: nowrap;
}
.cat-nav a {
  display: inline-block;
  padding: 14px 24px;
  color: #ccd6f6;
  font-size: 0.9rem;
  font-weight: 500;
  transition: all var(--transition);
  border-right: 1px solid rgba(255,255,255,0.1);
}
.cat-nav a:hover {
  background: var(--navy);
  color: var(--white);
}

/* ===========================
   PRODUCT GRID
   =========================== */
.product-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-top: 48px;
}
.product-card {
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition);
  display: flex;
  flex-direction: column;
}
.product-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
}
.product-img-wrap {
  position: relative;
  background: #f8f9ff;
  height: 220px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.product-img-wrap img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  padding: 16px;
}
.product-img-placeholder {
  background: linear-gradient(135deg, #e8edf8, #f0f4ff);
}
.placeholder-icon {
  font-size: 4rem;
  opacity: 0.5;
}
.product-badge {
  position: absolute;
  bottom: 10px;
  left: 10px;
  background: var(--navy);
  color: var(--white);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 20px;
}
.product-badge.new { background: #e63946; }
.product-badge.eco { background: #2d6a4f; }
.product-info {
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.product-info h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--navy);
}
.product-info p {
  font-size: 0.88rem;
  color: var(--gray-mid);
  flex: 1;
}
.product-info .btn { align-self: flex-start; margin-top: 8px; }

/* ===========================
   AIR CIRCULATION
   =========================== */
.air-principle {
  background: linear-gradient(135deg, #e8f4fd 0%, #fce4f0 100%);
}
.air-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}
.air-diagrams {
  display: flex;
  gap: 24px;
}
.air-diagram-card {
  flex: 1;
}
.air-season {
  background: var(--white);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  box-shadow: var(--shadow);
}
.air-season.summer { border-top: 4px solid #f4a261; }
.air-season.winter { border-top: 4px solid #4895ef; }
.air-icon { font-size: 2.5rem; margin-bottom: 8px; }
.air-season h4 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--navy);
}
.air-arrows { margin: 12px 0; }
.arrow-down, .arrow-up {
  font-size: 0.85rem;
  font-weight: 600;
  padding: 4px 0;
}
.arrow-down { color: #f4a261; }
.arrow-up { color: #4895ef; }
.air-season p { font-size: 0.82rem; color: var(--gray-mid); margin-top: 8px; }

.air-text h2 {
  font-size: 1.7rem;
  font-weight: 900;
  color: var(--navy);
  line-height: 1.4;
  margin-bottom: 20px;
}
.air-text p {
  color: var(--gray-mid);
  margin-bottom: 20px;
  line-height: 1.8;
}
.air-benefits { display: flex; flex-direction: column; gap: 10px; }
.air-benefits li {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--gray-dark);
}

/* ===========================
   SHOPPING
   =========================== */
.shopping { background: var(--gray-light); }
.shop-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
  margin-top: 40px;
}
.shop-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  border-radius: 50px;
  font-weight: 700;
  font-size: 0.95rem;
  min-width: 160px;
  transition: all var(--transition);
  border: 2px solid transparent;
}
.shop-btn:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); }
.shop-btn.naver { background: #03c75a; color: #fff; }
.shop-btn.auction { background: #e5002b; color: #fff; }
.shop-btn.gmarket { background: #ff6600; color: #fff; }
.shop-btn.st11 { background: #ff0000; color: #fff; }
.shop-btn.coupang { background: #c00; color: #fff; }
.shop-btn.kakao { background: #fee500; color: #3c1e1e; }

/* ===========================
   SPECS
   =========================== */
.specs { background: var(--white); }
.spec-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 48px;
}
.spec-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: box-shadow var(--transition), transform var(--transition);
}
.spec-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-4px);
}
.spec-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 6px;
}
.spec-model {
  font-size: 1.1rem;
  font-weight: 900;
  color: var(--navy);
}
.spec-tag {
  background: #e8edf8;
  color: var(--navy);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 20px;
}
.spec-tag.eco-tag { background: #d8f3dc; color: #2d6a4f; }
.spec-subtitle {
  font-size: 0.85rem;
  color: var(--gray-mid);
  margin-bottom: 16px;
}
.spec-table { width: 100%; border-collapse: collapse; }
.spec-table tr { border-bottom: 1px solid var(--border); }
.spec-table tr:last-child { border-bottom: none; }
.spec-table th {
  text-align: left;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--gray-mid);
  padding: 7px 0;
  width: 40%;
}
.spec-table td {
  font-size: 0.85rem;
  color: var(--gray-dark);
  padding: 7px 0;
}

/* ===========================
   FEATURES
   =========================== */
.features { background: var(--gray-light); }
.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
  margin-top: 48px;
}
.feature-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  transition: transform var(--transition), box-shadow var(--transition);
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}
.feature-icon { font-size: 2.5rem; margin-bottom: 16px; }
.feature-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 10px;
}
.feature-card p { color: var(--gray-mid); font-size: 0.92rem; line-height: 1.7; }

/* ===========================
   CTA BANNER
   =========================== */
.cta-banner {
  background: url('images/hero-fan.webp') center/cover no-repeat;
  position: relative;
}
.cta-overlay {
  background: linear-gradient(135deg, rgba(26,60,143,0.88) 0%, rgba(18,43,110,0.92) 100%);
  padding: 100px 0;
}
.cta-inner { text-align: center; }
.cta-inner h2 {
  font-size: 2.2rem;
  font-weight: 900;
  color: var(--white);
  line-height: 1.4;
  margin-bottom: 20px;
}
.cta-inner p {
  font-size: 1.05rem;
  color: rgba(255,255,255,0.85);
  margin-bottom: 10px;
}
.cta-sub { font-size: 0.95rem !important; margin-bottom: 36px !important; }
.cta-inner .btn { font-size: 1rem; padding: 14px 36px; }

/* ===========================
   PRODUCT DETAILS
   =========================== */
.product-details { background: var(--white); }
.detail-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  margin-bottom: 80px;
  padding-bottom: 80px;
  border-bottom: 1px solid var(--border);
}
.detail-row:last-child { border-bottom: none; margin-bottom: 0; padding-bottom: 0; }
.detail-row.reverse { direction: rtl; }
.detail-row.reverse > * { direction: ltr; }
.detail-img img {
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  width: 100%;
  object-fit: contain;
  max-height: 380px;
  background: #f8f9ff;
  padding: 16px;
}
.detail-badge {
  display: inline-block;
  background: var(--navy);
  color: var(--white);
  font-size: 0.8rem;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 20px;
  margin-bottom: 14px;
}
.detail-badge.new { background: #e63946; }
.detail-badge.dark { background: #1a1a2e; }
.detail-text h3 {
  font-size: 1.6rem;
  font-weight: 900;
  color: var(--navy);
  margin-bottom: 16px;
  line-height: 1.3;
}
.detail-text p {
  color: var(--gray-mid);
  margin-bottom: 20px;
  line-height: 1.8;
}
.detail-text ul {
  list-style: disc;
  padding-left: 20px;
  margin-bottom: 28px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.detail-text ul li {
  font-size: 0.92rem;
  color: var(--gray-dark);
}

/* ===========================
   SAFETY
   =========================== */
.safety { background: var(--gray-light); }
.safety-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 48px;
}
.safety-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 28px 20px;
  text-align: center;
  box-shadow: var(--shadow);
  transition: transform var(--transition);
}
.safety-card:hover { transform: translateY(-4px); }
.safety-icon { font-size: 2.5rem; margin-bottom: 14px; }
.safety-card h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 10px;
}
.safety-card p { font-size: 0.87rem; color: var(--gray-mid); line-height: 1.6; }

/* ===========================
   FOOTER
   =========================== */
.site-footer {
  background: #1a1a2e;
  color: rgba(255,255,255,0.75);
  padding-top: 48px;
}
.footer-inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 40px;
  align-items: start;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.footer-logo img { height: 36px; filter: brightness(0) invert(1); }
.footer-info p {
  font-size: 0.85rem;
  line-height: 1.9;
}
.footer-info a { color: #7aa2f7; }
.cert-badge {
  display: inline-block;
  border: 1px solid rgba(255,255,255,0.3);
  border-radius: 8px;
  padding: 8px 16px;
  font-size: 0.8rem;
  color: rgba(255,255,255,0.7);
}
.footer-bottom {
  padding: 20px 0;
  text-align: center;
}
.footer-bottom p { font-size: 0.82rem; color: rgba(255,255,255,0.45); }

/* ===========================
   BACK TO TOP
   =========================== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  background: var(--navy);
  color: var(--white);
  border: none;
  border-radius: 50%;
  font-size: 1.1rem;
  cursor: pointer;
  box-shadow: var(--shadow);
  opacity: 0;
  transform: translateY(20px);
  transition: all var(--transition);
  z-index: 999;
}
.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
}
.back-to-top:hover { background: var(--navy-dark); }

/* ===========================
   RESPONSIVE
   =========================== */
@media (max-width: 1024px) {
  .product-grid { grid-template-columns: repeat(2, 1fr); }
  .spec-grid { grid-template-columns: repeat(2, 1fr); }
  .safety-grid { grid-template-columns: repeat(2, 1fr); }
  .hero-title { font-size: 2.5rem; }
}

@media (max-width: 768px) {
  .main-nav { display: none; }
  .nav-toggle { display: block; }
  .main-nav.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--white);
    padding: 16px 24px;
    border-bottom: 1px solid var(--border);
    box-shadow: 0 8px 24px rgba(0,0,0,0.1);
    gap: 16px;
    z-index: 999;
  }
  .hero-inner { grid-template-columns: 1fr; text-align: center; }
  .hero-image { order: -1; }
  .hero-title { font-size: 2rem; }
  .air-inner { grid-template-columns: 1fr; }
  .air-diagrams { flex-direction: row; }
  .product-grid { grid-template-columns: 1fr; }
  .spec-grid { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: 1fr; }
  .safety-grid { grid-template-columns: 1fr 1fr; }
  .detail-row { grid-template-columns: 1fr; gap: 32px; }
  .detail-row.reverse { direction: ltr; }
  .footer-inner { grid-template-columns: 1fr; gap: 24px; }
  .section-title { font-size: 1.6rem; }
  .cta-inner h2 { font-size: 1.6rem; }
  .cat-nav-inner { gap: 0; }
  .cat-nav a { padding: 12px 16px; font-size: 0.82rem; }
}

@media (max-width: 480px) {
  .safety-grid { grid-template-columns: 1fr; }
  .shop-grid { flex-direction: column; align-items: center; }
  .shop-btn { width: 100%; max-width: 280px; }
  .hero-title { font-size: 1.8rem; }
  .back-to-top { bottom: 20px; right: 20px; }
}