:root {
    --bg-light: #ffffff;
    --text-light: #333333;
    --bg-dark: #1a1a1a;
    --text-dark: #f0f0f0;
    --accent: #3498db;
    --accent-hover: #2980b9;
    --today-bg: #e74c3c;
    --today-text: #fff;
    --border-color: #ddd;
}

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

body {
    font-family: 'Apple SD Gothic Neo', 'Noto Sans KR', sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background-color: #f9f9f9;
}

/* Header & Nav */
.site-header {
    background: #fff;
    border-bottom: 1px solid var(--border-color);
    padding: 15px 0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.site-header h1 {
    font-size: 1.5rem;
    color: #333;
}

.site-header nav a {
    text-decoration: none;
    color: #666;
    margin-left: 20px;
    font-weight: 500;
    transition: color 0.3s;
}

.site-header nav a:hover, .site-header nav a.active {
    color: var(--accent);
}

/* Main Content Wrapper */
main {
    flex: 1;
    display: flex;
    flex-direction: column;
}

/* Intro Text Section */
.intro-text {
    background: #fdfdfd;
    padding: 40px 20px;
    border-bottom: 1px solid #eee;
    text-align: center;
}

.intro-text .content-wrapper {
    max-width: 800px;
    margin: 0 auto;
}

.intro-text h1 {
    font-size: 2rem;
    color: #2c3e50;
    margin-bottom: 20px;
}

.intro-text p {
    color: #555;
    line-height: 1.6;
    font-size: 1.1rem;
}

/* App Section (Calendar Tool) */
.app-section {
    position: relative;
    background: #fff;
    min-height: 600px; 
}

/* Search Bar */
.search-container {
    display: flex;
    justify-content: center;
    gap: 10px;
    padding: 20px 0;
    background: #fff;
}

.search-container input {
    width: 70px;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    text-align: center;
    font-size: 1rem;
}

.search-container button {
    padding: 10px 20px;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-weight: bold;
    font-size: 1rem;
}

.search-container button:hover {
    background: var(--accent-hover);
}

/* Calendar Container */
.container {
    display: flex;
    flex-wrap: wrap; 
    border-top: 1px solid #eee;
}

.split {
    flex: 1;
    min-width: 350px; 
    padding: 40px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.header {
    text-align: center;
    margin-bottom: 30px;
}

.header h2 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    opacity: 0.8;
}

.date-display {
    font-size: 2rem;
    font-weight: bold;
}

/* Calendar Grid */
.calendar-wrapper {
    width: 100%;
    max-width: 450px;
}

.weekdays {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    text-align: center;
    font-weight: bold;
    margin-bottom: 15px;
    opacity: 0.7;
}

.days-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 5px;
}

.day {
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1rem;
    transition: background 0.2s;
    position: relative;
}

.day:hover {
    opacity: 0.7;
}

.day.empty {
    cursor: default;
}

.day.today {
    background: var(--today-bg) !important;
    color: var(--today-text) !important;
    font-weight: bold;
}

.day.selected {
    box-shadow: 0 0 0 2px var(--accent);
}

/* Light Panel */
.left-panel {
    background-color: var(--bg-light);
    color: var(--text-light);
    border-right: 1px solid #eee;
}
.left-panel .day:hover:not(.empty) { background-color: #f0f0f0; }

/* Dark Panel */
.right-panel {
    background-color: var(--bg-dark);
    color: var(--text-dark);
}
.right-panel .day:hover:not(.empty) { background-color: #333; }


/* Info/Article Section */
.info-section {
    background: #fff;
    padding: 60px 20px;
    border-top: 1px solid #eee;
}

.info-section h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 40px;
    color: #333;
}

.info-content {
    max-width: 800px;
    margin: 0 auto;
    line-height: 1.8;
    color: #444;
}

.info-content h3 {
    font-size: 1.3rem;
    color: #2c3e50;
    margin-top: 40px;
    margin-bottom: 15px;
    border-left: 4px solid var(--accent);
    padding-left: 10px;
}

.info-content p {
    margin-bottom: 20px;
    text-align: justify;
}

/* Data Tables */
.info-table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 30px;
    font-size: 0.95rem;
}

.info-table th, .info-table td {
    padding: 12px 15px;
    border: 1px solid #ddd;
    text-align: left;
}

.info-table th {
    background-color: #f4f4f4;
    font-weight: bold;
    color: #333;
}

.info-table tr:nth-child(even) {
    background-color: #fafafa;
}

.info-table tr:hover {
    background-color: #f1f1f1;
}

/* Footer */
.site-footer {
    background: #f8f9fa;
    padding: 40px 20px;
    text-align: center;
    border-top: 1px solid #e9ecef;
    color: #6c757d;
}

.site-footer a {
    color: #6c757d;
    text-decoration: underline;
}

.site-footer a:hover {
    color: var(--accent);
}

/* Responsive Tweaks */
@media (max-width: 768px) {
    .search-container {
        flex-wrap: wrap;
    }
    
    .left-panel {
        border-right: none;
        border-bottom: 1px solid #eee;
    }

    .info-section {
        padding: 40px 20px;
    }
    
    .info-table {
        font-size: 0.85rem;
    }
    
    .info-table th, .info-table td {
        padding: 8px;
    }
}