:root {
    /* Dark Mode Variables */
    --bg-dark: #0f172a;
    --card-bg: #1e293b;
    --text-main: #f1f5f9;
    --text-dim: #94a3b8;
    --border: #334155;
    --web-color: #38bdf8;
    --pwn-color: #f87171;
    --rev-color: #fbbf24;
    --crypto-color: #4ade80;
}

body.light-mode {
    --bg-dark: #f1f5f9;
    --card-bg: #ffffff;
    --text-main: #1e293b;
    --text-dim: #64748b;
    --border: #e2e8f0;
}

body {
    background-color: var(--bg-dark);
    color: var(--text-main);
    font-family: 'Pretendard', sans-serif;
    margin: 0;
    transition: all 0.3s ease;
}

header {
    text-align: center;
    padding: 2rem;
    background: linear-gradient(180deg, rgba(30,41,59,0.5) 0%, transparent 100%);
}

.header-top {
    display: flex;
    justify-content: flex-end;
    max-width: 1100px;
    margin: 0 auto;
}

.theme-btn {
    background: var(--card-bg);
    color: var(--text-main);
    border: 1px solid var(--border);
    padding: 8px 15px;
    border-radius: 8px;
    cursor: pointer;
}

.search-wrapper { margin-top: 20px; }
#dashboard-search {
    width: 80%;
    max-width: 400px;
    padding: 10px 15px;
    border-radius: 20px;
    border: 1px solid var(--border);
    background: var(--card-bg);
    color: var(--text-main);
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 20px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(450px, 1fr));
    gap: 25px;
}

.category-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px;
    transition: transform 0.3s ease;
}

.category-card:hover { transform: translateY(-5px); }

.web h2 { color: var(--web-color); border-bottom: 2px solid var(--web-color); }
.pwn h2 { color: var(--pwn-color); border-bottom: 2px solid var(--pwn-color); }
.rev h2 { color: var(--rev-color); border-bottom: 2px solid var(--rev-color); }
.crypto h2 { color: var(--crypto-color); border-bottom: 2px solid var(--crypto-color); }

details { margin: 10px 0; background: rgba(0,0,0,0.1); border-radius: 5px; }
summary { padding: 10px; cursor: pointer; font-weight: bold; }
ul { padding-left: 25px; }
li { margin: 5px 0; color: var(--text-dim); }
a { color: var(--text-main); text-decoration: none; }
a:hover { text-decoration: underline; }

.hidden { display: none; }
footer { text-align: center; padding: 40px; color: var(--text-dim); }
/* --- Error Page Styles --- */

.error-container {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    text-align: center;
    padding: 20px;
}

.error-content {
    background: var(--card-bg);
    padding: 3rem;
    border-radius: 20px;
    border: 1px solid var(--border);
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.error-code {
    font-size: 6rem;
    margin: 0;
    background: linear-gradient(45deg, var(--web-color), var(--pwn-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 800;
}

.error-message {
    font-size: 2rem;
    font-weight: bold;
    margin-bottom: 1rem;
    color: var(--text-main);
}

.error-desc {
    color: var(--text-dim);
    margin-bottom: 2rem;
}

.back-home {
    display: inline-block;
    background: var(--border);
    color: var(--text-main);
    padding: 12px 25px;
    border-radius: 10px;
    text-decoration: none;
    transition: all 0.3s ease;
    font-weight: 600;
}

.back-home:hover {
    background: var(--web-color);
    color: #000;
    transform: scale(1.05);
    text-decoration: none;
}