:root {
  --primary-color: #005bac;
  --secondary-color: #4facfe;
  --text-color: #333;
  --bg-color: #f5f7fa;
  --white: #ffffff;
  --spacing-unit: 1rem;
}

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

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

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

/* Header */
.header {
  background-color: var(--white);
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
  padding: 1.2rem 0;
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary-color);
}

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

.nav a {
  text-decoration: none;
  color: #666;
  font-weight: 500;
  transition: color 0.2s;
}

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

/* Hero Section */
.hero {
  background: linear-gradient(135deg, #005bac 0%, #0082c8 100%);
  color: var(--white);
  padding: 6rem 0;
  text-align: center;
}

.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
  font-weight: 700;
}

.hero p {
  font-size: 1.1rem;
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto;
}

/* Applications Section */
.applications {
  padding: 4rem 0;
}

.applications h2 {
  text-align: center;
  margin-bottom: 3rem;
  font-size: 2rem;
  color: #222;
}

.app-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}

.app-card {
  background-color: var(--white);
  border: none;
  border-radius: 12px;
  padding: 2.5rem 1.5rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 4px 6px rgba(0,0,0,0.05);
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
}

.app-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

.app-card .icon {
  font-size: 3rem;
  margin-bottom: 1.5rem;
}

.app-card h3 {
  font-size: 1.25rem;
  margin-bottom: 1rem;
  color: var(--primary-color);
}

.app-card p {
  color: #666;
  font-size: 0.95rem;
  line-height: 1.5;
}

/* Footer */
.footer {
  background-color: #f0f2f5;
  color: #666;
  padding: 2rem 0;
  text-align: center;
  margin-top: auto;
  font-size: 0.9rem;
}

/* Modal */
.modal-overlay {
  display: none;
  position: fixed;
  z-index: 2000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0,0,0,0.5);
  align-items: center;
  justify-content: center;
}

.modal-content {
  background-color: var(--white);
  padding: 2.5rem;
  border-radius: 12px;
  width: 90%;
  max-width: 500px;
  position: relative;
  box-shadow: 0 5px 30px rgba(0,0,0,0.3);
  animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
  from { transform: translateY(-20px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

.close-btn {
  position: absolute;
  top: 1rem;
  right: 1.5rem;
  font-size: 1.5rem;
  font-weight: bold;
  color: #aaa;
  cursor: pointer;
  transition: color 0.2s;
}

.close-btn:hover {
  color: #333;
}

.modal-content h2 {
  margin-bottom: 1.5rem;
  color: var(--primary-color);
  border-bottom: 2px solid #f0f0f0;
  padding-bottom: 0.5rem;
}

/* Forms */
.form-group {
  margin-bottom: 1rem;
  text-align: left;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
}

.form-group input, .form-group textarea {
  width: 100%;
  padding: 0.8rem;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 1rem;
}

.submit-btn, .btn-primary {
  width: 100%;
  padding: 1rem;
  background-color: var(--primary-color);
  color: white;
  border: none;
  border-radius: 4px;
  font-size: 1rem;
  cursor: pointer;
  transition: background-color 0.2s;
}

.submit-btn:hover, .btn-primary:hover {
  background-color: #004a8c;
}

/* Login Page Styles */
.login-page {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

.login-container {
  width: 100%;
  max-width: 400px;
  padding: 1rem;
}

.login-card {
  background: var(--white);
  padding: 2.5rem;
  border-radius: 16px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.1);
  text-align: center;
}

.login-header h1 {
  font-size: 1.2rem;
  color: #666;
  margin-bottom: 0.5rem;
}

.login-header h2 {
  font-size: 1.8rem;
  color: var(--primary-color);
  margin-bottom: 1rem;
}

.login-header p {
  font-size: 0.9rem;
  color: #888;
  margin-bottom: 2rem;
}

.login-footer {
  margin-top: 1.5rem;
  font-size: 0.9rem;
}

.login-footer a {
  color: var(--primary-color);
  text-decoration: none;
  font-weight: bold;
}