:root {
    --bg-color: #0d0d10;
    --card-bg: #16161a;
    --text-primary: #fffffe;
    --text-secondary: #94a1b2;
    --accent: #7f5af0; /* Iris purple */
    --accent-glow: rgba(127, 90, 240, 0.3);
    --gold: #ffaa00; /* Amber for theology vibe */
    --border: #232328;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: 'Inter', 'Noto Serif KR', sans-serif;
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

.background-glow {
    position: fixed;
    top: -20%;
    left: -20%;
    width: 140%;
    height: 140%;
    background: radial-gradient(circle at 50% 50%, rgba(127, 90, 240, 0.05) 0%, transparent 60%);
    z-index: -1;
    pointer-events: none;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Header */
header {
    padding: 1.5rem 0;
    border-bottom: 1px solid var(--border);
    background: rgba(13, 13, 16, 0.8);
    backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.logo {
    font-family: 'Cinzel', serif;
    font-size: 1.5rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-primary);
}

.logo i {
    color: var(--accent);
}

nav a {
    color: var(--text-secondary);
    text-decoration: none;
    margin-left: 2rem;
    font-weight: 500;
    transition: color 0.3s;
}

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

/* Hero */
.hero {
    text-align: center;
    padding: 6rem 0 4rem;
}

.hero h1 {
    font-size: 3rem;
    font-family: 'Cinzel', serif;
    margin-bottom: 1rem;
    background: linear-gradient(to right, #fffffe, #94a1b2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 3rem;
}

.search-bar {
    max-width: 600px;
    margin: 0 auto;
    position: relative;
}

.search-bar i {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
}

.search-bar input {
    width: 100%;
    padding: 1rem 1rem 1rem 3rem;
    border-radius: 50px;
    border: 1px solid var(--border);
    background: var(--card-bg);
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.3s ease;
}

.search-bar input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 4px var(--accent-glow);
}

/* Controls */
.controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--border);
    padding-bottom: 1rem;
}

.filter-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 0.5rem 1rem;
    cursor: pointer;
    border-radius: 20px;
    font-family: inherit;
    transition: all 0.2s;
}

.filter-btn:hover, .filter-btn.active {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

/* Grid */
.book-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    padding-bottom: 4rem;
}

.book-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
    transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    flex-direction: column;
}

.book-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent);
    box-shadow: 0 10px 20px -10px rgba(0, 0, 0, 0.5);
}

.book-meta {
    font-size: 0.8rem;
    color: var(--gold);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.book-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    line-height: 1.4;
    font-family: 'Noto Serif KR', serif;
}

.book-author {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

.book-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: var(--text-primary);
    background: rgba(127, 90, 240, 0.1);
    padding: 0.8rem 1.2rem;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: background 0.2s;
    justify-content: center;
}

.book-link:hover {
    background: var(--accent);
    color: #fff;
}

footer {
    border-top: 1px solid var(--border);
    padding: 2rem 0;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
}