:root[data-theme="light"] {
  --primary: #6366f1;
  --primary-hover: #4f46e5;
  --secondary: #ec4899;
  --background: #f8fafc;
  --surface: #ffffff;
  --text-main: #1e293b;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --radius: 12px;
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1);
}

:root[data-theme="dark"] {
  --primary: #818cf8;
  --primary-hover: #6366f1;
  --secondary: #f472b6;
  --background: #0f172a;
  --surface: #1e293b;
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --border: #334155;
  --radius: 12px;
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.3);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  transition: background-color 0.3s, color 0.3s, border-color 0.3s;
}

body {
  font-family: 'Noto Sans KR', sans-serif;
  background-color: var(--background);
  color: var(--text-main);
  line-height: 1.6;
}

header {
  background-color: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

nav {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0.75rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
}

.nav-controls {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-muted);
  font-weight: 500;
  cursor: pointer;
}

.nav-links a:hover, .nav-links a.active {
  color: var(--primary);
}

main {
  max-width: 1200px;
  margin: 2rem auto;
  padding: 0 2rem;
  min-height: 70vh;
}

/* Views Management */
.view {
  display: none;
}
.view.active {
  display: block;
}

.hero {
  text-align: center;
  padding: 6rem 0;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  margin-bottom: 1.5rem;
  background: linear-gradient(to right, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  font-size: 1.25rem;
  color: var(--text-muted);
  max-width: 700px;
  margin: 0 auto 2.5rem;
}

.section {
  padding: 4rem 0;
}

.card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 2.5rem;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  max-width: 600px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: 1.5rem;
}

label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
  color: var(--text-main);
}

input, select {
  width: 100%;
  padding: 0.75rem 1rem;
  background-color: var(--background);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-main);
  font-family: inherit;
}

input:focus {
  outline: none;
  border-color: var(--primary);
  ring: 2px var(--primary);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
  font-family: inherit;
}

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

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
}

.btn-outline {
  background-color: transparent;
  border: 1px solid var(--border);
  color: var(--text-main);
}

.lang-toggle {
  display: flex;
  background-color: var(--background);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 2px;
  gap: 2px;
}

.lang-btn {
  padding: 4px 12px;
  border-radius: 18px;
  border: none;
  background: none;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.2s;
}

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

.lang-btn:hover:not(.active) {
  background-color: var(--border);
}

.icon-btn {
  padding: 0.5rem;
  font-size: 1.25rem;
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.icon-btn:hover {
  background-color: var(--border);
  color: var(--primary);
}

/* Grid for recommendations */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 2rem;
}

.product-card {
  background: var(--surface);
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
}

.product-image {
  width: 100%;
  aspect-ratio: 1;
  background-color: var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
}

.product-info {
  padding: 1.25rem;
}

footer {
  text-align: center;
  padding: 4rem 2rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
  margin-top: 4rem;
}

/* Utils */
.flex { display: flex; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: 0.5rem; }
.mt-4 { margin-top: 1rem; }
.text-center { text-align: center; }
.hidden { display: none; }