:root {
    --bg: #f8fafc;
    --card: #ffffff;
    --border: #e2e8f0;
    --border-strong: #cbd5e1;
    --text: #0f172a;
    --text-muted: #64748b;
    --text-light: #94a3b8;
    --primary: #4f46e5;
    --primary-hover: #4338ca;
    --primary-light: #eef2ff;
    --success: #059669;
    --success-bg: #ecfdf5;
    --danger: #dc2626;
    --danger-bg: #fef2f2;
    --warning-bg: #fffbeb;
    --warning-text: #b45309;
    --sidebar: #0f172a;
    --sidebar-text: #cbd5e1;
    --sidebar-active: #4f46e5;
    --shadow-sm: 0 1px 2px rgba(15,23,42,.04);
    --shadow: 0 1px 3px rgba(15,23,42,.06), 0 1px 2px rgba(15,23,42,.04);
    --shadow-lg: 0 10px 25px -5px rgba(15,23,42,.08), 0 4px 6px -4px rgba(15,23,42,.04);
    --radius: 8px;
    --radius-sm: 6px;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Pretendard", "Segoe UI", "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
    background: var(--bg);
    color: var(--text);
    font-size: 14px;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

/* === 레이아웃 === */
.layout {
    display: flex;
    min-height: 100vh;
}

/* === 사이드바 === */
.sidebar {
    width: 240px;
    background: var(--sidebar);
    color: var(--sidebar-text);
    padding: 24px 16px;
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
    position: sticky;
    top: 0;
    height: 100vh;
}
.sidebar .brand {
    color: white;
    font-size: 16px;
    font-weight: 600;
    padding: 8px 12px 24px;
    border-bottom: 1px solid rgba(255,255,255,.08);
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 10px;
}
.sidebar .brand-dot {
    width: 8px; height: 8px; border-radius: 50%;
    background: var(--primary);
    box-shadow: 0 0 12px var(--primary);
}
.sidebar nav { flex: 1; }
.sidebar nav a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 12px;
    margin-bottom: 2px;
    color: var(--sidebar-text);
    text-decoration: none;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
    transition: all .15s ease;
}
.sidebar nav a:hover {
    background: rgba(255,255,255,.06);
    color: white;
}
.sidebar nav a.active {
    background: var(--primary);
    color: white;
}
.sidebar nav a .icon {
    width: 16px; height: 16px;
    opacity: .8;
}
.sidebar nav a.active .icon { opacity: 1; }
.sidebar .user-info {
    padding: 12px;
    border-top: 1px solid rgba(255,255,255,.08);
    font-size: 12px;
    color: var(--text-light);
}
.sidebar .user-info strong { color: white; font-weight: 600; display: block; margin-bottom: 2px; }

/* === 메인 === */
main {
    flex: 1;
    padding: 32px 40px;
    max-width: 1200px;
}
.page-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 24px;
}
.page-head h1 {
    font-size: 22px;
    font-weight: 700;
    margin: 0;
    color: var(--text);
    letter-spacing: -.01em;
}
.page-head .subtitle {
    color: var(--text-muted);
    font-size: 13px;
    margin-top: 4px;
}

/* === 카드 === */
.card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    margin-bottom: 16px;
    box-shadow: var(--shadow-sm);
}
.card-section {
    border-top: 1px solid var(--border);
    padding-top: 20px;
    margin-top: 20px;
}
.card-section:first-child {
    border-top: 0;
    padding-top: 0;
    margin-top: 0;
}
.card-title {
    font-size: 13px;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: .04em;
    margin: 0 0 16px;
}

/* === 통계 박스 === */
.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
    margin-bottom: 24px;
}
.stat-box {
    background: var(--card);
    border: 1px solid var(--border);
    padding: 20px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    transition: all .15s ease;
}
.stat-box:hover { box-shadow: var(--shadow); transform: translateY(-1px); }
.stat-box .label {
    color: var(--text-muted);
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: .04em;
    margin-bottom: 8px;
}
.stat-box .num {
    font-size: 28px;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -.02em;
}
.stat-box .num-sub {
    color: var(--text-light);
    font-size: 13px;
    margin-left: 6px;
}

/* === 폼 === */
.form-row {
    display: grid;
    grid-template-columns: 140px 1fr;
    gap: 16px;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
}
.form-row:last-child { border-bottom: 0; }
.form-row label {
    font-size: 13px;
    font-weight: 600;
    color: var(--text);
}
.form-row label .req { color: var(--danger); margin-left: 2px; }
.form-row .hint {
    color: var(--text-muted);
    font-size: 12px;
    font-weight: 400;
    margin-top: 2px;
}
input[type=text], input[type=email], input[type=password], input:not([type]), select, textarea {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-family: inherit;
    background: white;
    color: var(--text);
    transition: all .15s ease;
}
input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79,70,229,.12);
}
.checkbox-group {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}
.checkbox-group label {
    display: flex;
    align-items: center;
    gap: 6px;
    font-weight: 500;
    color: var(--text);
    cursor: pointer;
}
input[type=checkbox] {
    width: 16px; height: 16px;
    accent-color: var(--primary);
    cursor: pointer;
}

/* === 버튼 === */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    border: 1px solid transparent;
    background: var(--primary);
    color: white;
    border-radius: var(--radius-sm);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    transition: all .15s ease;
    font-family: inherit;
}
.btn:hover { background: var(--primary-hover); }
.btn-secondary {
    background: white;
    color: var(--text);
    border-color: var(--border-strong);
}
.btn-secondary:hover {
    background: var(--bg);
    border-color: var(--text-muted);
}
.btn-danger {
    background: var(--danger);
    color: white;
}
.btn-danger:hover { background: #b91c1c; }
.btn-ghost {
    background: transparent;
    color: var(--text-muted);
    border-color: var(--border);
}
.btn-ghost:hover { background: var(--bg); color: var(--text); }
.btn-sm { padding: 5px 10px; font-size: 12px; }
.btn-lg { padding: 10px 20px; font-size: 14px; }
.actions {
    display: flex;
    justify-content: flex-end;
    gap: 8px;
    margin-top: 24px;
    padding-top: 20px;
    border-top: 1px solid var(--border);
}

/* === 알림 === */
.flash {
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    margin-bottom: 16px;
    font-size: 13px;
    border: 1px solid;
}
.flash-success { background: var(--success-bg); color: var(--success); border-color: #a7f3d0; }
.flash-error { background: var(--danger-bg); color: var(--danger); border-color: #fecaca; }
.flash-info { background: var(--primary-light); color: var(--primary); border-color: #c7d2fe; }
.flash pre {
    margin: 4px 0 0;
    font-family: 'SF Mono', Monaco, Consolas, monospace;
    font-size: 12px;
    white-space: pre-wrap;
    color: inherit;
}

/* === 테이블 === */
.table-wrap {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}
table { width: 100%; border-collapse: collapse; }
th {
    background: var(--bg);
    color: var(--text-muted);
    padding: 12px 16px;
    text-align: left;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: .04em;
    border-bottom: 1px solid var(--border);
}
td {
    padding: 14px 16px;
    border-bottom: 1px solid var(--border);
    font-size: 13px;
    color: var(--text);
    vertical-align: middle;
}
tbody tr:last-child td { border-bottom: 0; }
tbody tr:hover td { background: #fafbfc; }
td strong { font-weight: 600; }
.tag {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 11px;
    font-weight: 600;
    background: var(--bg);
    color: var(--text-muted);
    border: 1px solid var(--border);
}
.tag-success { background: var(--success-bg); color: var(--success); border-color: #a7f3d0; }
.tag-danger { background: var(--danger-bg); color: var(--danger); border-color: #fecaca; }
.tag-warning { background: var(--warning-bg); color: var(--warning-text); border-color: #fde68a; }

code {
    background: var(--bg);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'SF Mono', Monaco, Consolas, monospace;
    font-size: 12px;
    color: var(--text);
    border: 1px solid var(--border);
}

/* === 반응형 === */
@media (max-width: 768px) {
    .layout { flex-direction: column; }
    .sidebar {
        width: 100%;
        height: auto;
        position: static;
        padding: 12px;
        flex-direction: row;
        align-items: center;
        gap: 16px;
    }
    .sidebar .brand { border-bottom: 0; padding: 0; margin: 0; }
    .sidebar nav { display: flex; gap: 4px; flex: 1; overflow-x: auto; }
    .sidebar nav a { padding: 6px 10px; white-space: nowrap; }
    .sidebar .user-info { display: none; }
    main { padding: 20px 16px; }
    .form-row { grid-template-columns: 1fr; gap: 6px; padding: 12px 0; }
}