:root {
    --primary-color: #00529b;
    --secondary-color: #6c757d;
    --background-color: #f4f7f6;
    --text-color: #333;
    --card-background-color: #fff;
    --card-border-color: #e0e0e0;
    --font-family: 'Roboto', 'Noto Sans KR', sans-serif;
    --hero-overlay-color: rgba(0, 0, 0, 0.5);
    --shadow-color: 0px 10px 20px rgba(0, 0, 0, 0.1);
}

body {
    font-family: var(--font-family);
    margin: 0;
    background-color: var(--background-color);
    color: var(--text-color);
}

header {
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    z-index: 1000;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 1.5rem;
}

nav a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s;
}

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

.hero {
    position: relative;
    background: url('https://images.unsplash.com/photo-1521791136064-7986c2920216?q=80&w=2070&auto=format&fit=crop') no-repeat center center/cover;
    color: white;
    text-align: center;
    padding: 8rem 1rem;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--hero-overlay-color);
    z-index: 1;
}

.hero h1, .hero .search-bar {
    position: relative;
    z-index: 2;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 2rem;
    font-weight: 700;
}

.search-bar {
    display: flex;
    justify-content: center;
    max-width: 600px;
    margin: 0 auto;
    box-shadow: var(--shadow-color);
}

.search-bar input {
    width: 100%;
    padding: 1rem;
    border: none;
    border-radius: 8px 0 0 8px;
    font-size: 1rem;
}

.search-bar button {
    padding: 1rem 2rem;
    border: none;
    background-color: var(--primary-color);
    color: white;
    border-radius: 0 8px 8px 0;
    cursor: pointer;
    font-size: 1rem;
    transition: background-color 0.3s;
}

.search-bar button:hover {
    background-color: #003d73;
}

main {
    padding: 4rem 2rem;
}

.placeholder-section {
    padding: 4rem 2rem;
    text-align: center;
    background-color: #fff;
    margin: 2rem 0;
    border-radius: 8px;
    box-shadow: var(--shadow-color);
}

footer {
    text-align: center;
    padding: 2rem 1rem;
    background-color: #222;
    color: #aaa;
}