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

:root {
    --bg-color: #1a1a2e;
    --primary-color: #16213e;
    --secondary-color: #0f3460;
    --accent-color: #e94560;
    --text-color: #dcdcdc;
    --header-color: #ffffff;
    --gold-color: #ffd700;
}

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

h1, h2 {
    font-family: 'KoPub Batang', serif;
    color: var(--header-color);
    font-weight: 600;
}

a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: var(--gold-color);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* --- Layout & Structure --- */
header {
    background-color: var(--primary-color);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.5);
}

header h1 a {
    font-size: 1.5rem;
    color: var(--header-color);
    font-weight: bold;
    z-index: 1001; /* Make sure title is above nav on mobile */
}

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

main {
    padding: 2rem;
    max-width: 900px;
    margin: 0 auto;
}

section {
    background-color: var(--primary-color);
    padding: 2.5rem;
    margin-bottom: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
    border: 1px solid var(--secondary-color);
}

section h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--gold-color);
    border-bottom: 2px solid var(--secondary-color);
    padding-bottom: 0.5rem;
}

footer {
    text-align: center;
    padding: 2rem;
    margin-top: 2rem;
    background-color: var(--primary-color);
    color: var(--text-color);
    font-size: 0.9rem;
}

.footer-links {
    margin-bottom: 1rem;
}

.footer-links a {
    margin: 0 1rem;
    color: var(--text-color);
}

/* --- Hero Section --- */
#hero {
    background: linear-gradient(rgba(22, 33, 62, 0.8), rgba(26, 26, 46, 0.9)), url('https://images.unsplash.com/photo-1534270804882-6b5025b4ea15?q=80&w=2070&auto=format&fit=crop') center/cover no-repeat;
    text-align: center;
    padding: 5rem 2rem;
    border-radius: 12px;
}

.hero-text h2 {
    font-size: 2.8rem;
    margin-bottom: 1rem;
    color: var(--header-color);
}

.hero-text p {
    font-size: 1.2rem;
    color: var(--text-color);
}

/* --- Saju Calculator --- */
saju-calculator {
    display: block;
    margin-top: 2rem;
    padding: 2rem;
    background-color: var(--secondary-color);
    border-radius: 8px;
}

/* --- Hamburger Menu --- */
.nav-toggle {
    display: none; /* Hidden by default on desktop */
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    z-index: 1001;
}

.nav-toggle .hamburger {
    display: block;
    width: 25px;
    height: 3px;
    background-color: var(--header-color);
    position: relative;
    transition: transform 0.3s ease;
}

.nav-toggle .hamburger::before,
.nav-toggle .hamburger::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 3px;
    background-color: var(--header-color);
    left: 0;
    transition: transform 0.3s ease, top 0.3s ease;
}

.nav-toggle .hamburger::before {
    top: -8px;
}

.nav-toggle .hamburger::after {
    top: 8px;
}

/* --- Responsive Design --- */
@media (max-width: 768px) {
    header {
        padding: 1rem;
    }

    .nav-toggle {
        display: block; /* Show hamburger on mobile */
    }

    /* Transform hamburger to 'X' when active */
    .nav-toggle.active .hamburger {
        transform: rotate(45deg);
    }
    .nav-toggle.active .hamburger::before {
        top: 0;
        transform: rotate(90deg);
    }
    .nav-toggle.active .hamburger::after {
        top: 0;
        transform: rotate(90deg);
    } 
    
    header nav {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        background-color: var(--primary-color);
        transform: translateX(-100%);
        transition: transform 0.3s ease-in-out;
        padding-top: 5rem;
    }

    header nav.active {
        transform: translateX(0);
    }

    header nav ul {
        flex-direction: column;
        align-items: center;
        gap: 2rem;
    }

    main {
        padding: 1.5rem 1rem;
    }

    section {
        padding: 2rem 1.5rem;
    }

    h1, header h1 a { font-size: 1.4rem; }
    h2, section h2 { font-size: 1.8rem; }
    .hero-text h2 { font-size: 2rem; }
    .hero-text p { font-size: 1.1rem; }
}