/* ---------- CSS VARIABLES & THEME ---------- */
:root {
    /* High-Contrast Industrial Palette */
    --bg-main: #09090b;       /* Deep obsidian black */
    --bg-panel: #131316;      /* Slightly elevated dark panel */
    --bg-elevated: #1e1e24;   /* For hover states and inputs */
    
    --text-primary: #f4f4f5;  /* Stark white */
    --text-secondary: #a1a1aa; /* Muted slate grey */
    
    /* Industrial Safety Accents */
    --accent-primary: #facc15; /* Safety Yellow */
    --accent-hover: #eab308;
    --accent-blue: #38bdf8;    /* Electric Blue for secondary highlights */
    
    --border-color: #27272a;
    --border-focus: #facc15;
    
    /* Status Colors */
    --warning: #ef4444;       /* Alert Red */
    --success: #22c55e;       /* Terminal Green */
    --info: #0ea5e9;          /* Cyan */

    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --transition-snappy: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --border-radius-sm: 4px;
    --border-radius-md: 6px;
    --border-radius-lg: 12px;
}

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

body {
    background-color: var(--bg-main);
    color: var(--text-primary);
    font-family: var(--font-family);
    font-size: 14px;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Custom Scrollbar for Industrial Feel */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-main);
}
::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: var(--border-radius-sm);
}
::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* ---------- TYPOGRAPHY & UTILITIES ---------- */
h1, h2, h3, h4 {
    font-weight: 600;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

.subtitle {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

.text-accent { color: var(--accent-primary); }
.text-warning { color: var(--warning); }
.text-success { color: var(--success); }
.text-info { color: var(--info); }

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

/* Sharp, dark acrylic panels */
.glass-panel {
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-md);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.4);
}

/* ---------- APP LAYOUT ---------- */
.app-layout {
    display: flex;
    height: 100vh;
    width: 100vw;
    overflow: hidden;
}

/* ---------- SIDEBAR ---------- */
.sidebar {
    width: 260px;
    background-color: var(--bg-panel);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
    z-index: 10;
}

.sidebar-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-icon {
    font-size: 1.5rem;
    color: var(--accent-primary);
    filter: drop-shadow(0 0 8px rgba(250, 204, 21, 0.4));
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: 0.05em;
}

.logo-highlight {
    color: var(--text-secondary);
    font-weight: 300;
}

.sidebar-nav {
    flex: 1;
    padding: 1.5rem 0;
    overflow-y: auto;
}

.nav-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.nav-item {
    padding: 0 1rem;
}

.nav-btn {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    background: transparent;
    border: none;
    border-radius: var(--border-radius-sm);
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    text-align: left;
    cursor: pointer;
    transition: all var(--transition-snappy);
}

.nav-btn i {
    font-size: 1rem;
    width: 20px;
    text-align: center;
    transition: color var(--transition-snappy);
}

.nav-btn:hover {
    background-color: var(--bg-elevated);
    color: var(--text-primary);
}

.nav-btn.active {
    background-color: rgba(250, 204, 21, 0.1);
    color: var(--accent-primary);
    position: relative;
}

.nav-btn.active::before {
    content: '';
    position: absolute;
    left: -1rem;
    top: 50%;
    transform: translateY(-50%);
    height: 60%;
    width: 4px;
    background-color: var(--accent-primary);
    border-radius: 0 4px 4px 0;
    box-shadow: 0 0 8px var(--accent-primary);
}

.nav-btn.active i {
    color: var(--accent-primary);
}

.sidebar-footer {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
    background-color: rgba(0, 0, 0, 0.2);
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.avatar {
    width: 36px;
    height: 36px;
    background-color: var(--bg-elevated);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
}

.user-info {
    display: flex;
    flex-direction: column;
}

.user-name {
    font-size: 0.875rem;
    font-weight: 600;
}

.user-role {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* ---------- MAIN CONTENT AREA ---------- */
.main-wrapper {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

/* ---------- TOPBAR ---------- */
.topbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background-color: var(--bg-main);
    border-bottom: 1px solid var(--border-color);
    height: 72px;
    gap: 1rem;
}

.topbar-left {
    display: flex;
    align-items: center;
    flex: 1;
    max-width: 400px;
}

.search-bar {
    position: relative;
    width: 100%;
}

.search-bar i {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    pointer-events: none;
}

.search-bar input {
    width: 100%;
    background-color: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 0.6rem 1rem 0.6rem 2.5rem;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.875rem;
    transition: all var(--transition-snappy);
}

.search-bar input:focus {
    outline: none;
    border-color: var(--accent-blue);
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.15);
}

.search-bar input::placeholder {
    color: var(--text-secondary);
}

.search-shortcut {
    position: absolute;
    right: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    background: var(--bg-main);
    border: 1px solid var(--border-color);
    padding: 0.1rem 0.4rem;
    border-radius: var(--border-radius-sm);
    font-size: 0.7rem;
    color: var(--text-secondary);
    pointer-events: none;
}

.mobile-menu-toggle {
    display: none;
}

.sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(2px);
    z-index: 5;
}

.topbar-actions {
    display: flex;
    gap: 1rem;
}

.icon-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    position: relative;
    transition: all var(--transition-snappy);
}

.icon-btn:hover {
    background-color: var(--bg-elevated);
    color: var(--text-primary);
    border-color: var(--text-secondary);
}

.badge {
    position: absolute;
    top: -2px;
    right: -2px;
    background-color: var(--warning);
    color: #fff;
    font-size: 0.65rem;
    font-weight: 700;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 2px solid var(--bg-main);
}

/* ---------- CONTENT SECTIONS (SPA) ---------- */
.content-container {
    flex: 1;
    padding: 2rem;
    overflow-y: auto;
    background: radial-gradient(circle at top right, rgba(26,26,32,1) 0%, var(--bg-main) 40%);
}

.view-section {
    display: none;
}

.view-section.active {
    display: block;
    animation: fadeIn 0.4s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.section-header {
    margin-bottom: 2rem;
}

/* ---------- DASHBOARD GRID ---------- */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
}

.stat-card {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    transition: transform var(--transition-snappy), border-color var(--transition-snappy);
    position: relative;
    overflow: hidden;
}

.stat-card::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background-color: var(--border-color);
    transition: background-color var(--transition-snappy);
}

.stat-card:hover {
    transform: translateY(-2px);
    border-color: var(--text-secondary);
}

.stat-card:nth-child(1):hover::after { background-color: var(--accent-primary); }
.stat-card:nth-child(2):hover::after { background-color: var(--warning); }
.stat-card:nth-child(3):hover::after { background-color: var(--success); }
.stat-card:nth-child(4):hover::after { background-color: var(--info); }

/* HTML의 .stat-icon-wrapper 클래스명과 매치시켜 스타일 깨짐 해결 */
.stat-icon-wrapper {
    width: 56px;
    height: 56px;
    border-radius: var(--border-radius-md);
    background: var(--bg-elevated);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    border: 1px solid var(--border-color);
    flex-shrink: 0;
}

.stat-details h3 {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.stat-value {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-top: 0.25rem;
    letter-spacing: -0.05em;
}

/* ---------- TABLES ---------- */
.table-container {
    overflow-x: auto;
    padding: 1rem;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
}

.data-table th {
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    padding: 1rem;
    border-bottom: 2px solid var(--border-color);
    white-space: nowrap;
}

.data-table td {
    padding: 1rem;
    font-size: 0.875rem;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-primary);
    vertical-align: middle;
}

.data-table tbody tr {
    transition: background-color var(--transition-snappy);
}

.data-table tbody tr:hover {
    background-color: rgba(255, 255, 255, 0.02);
}

/* Table specific styling classes (Applied by JS later) */
.status-badge {
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
    display: inline-block;
}

.status-active {
    background: rgba(34, 197, 94, 0.15);
    color: var(--success);
    border: 1px solid rgba(34, 197, 94, 0.3);
}

.status-pending {
    background: rgba(250, 204, 21, 0.15);
    color: var(--accent-primary);
    border: 1px solid rgba(250, 204, 21, 0.3);
}

/* ---------- FORMS & INPUTS ---------- */
.form-container {
    max-width: 800px;
    padding: 2rem;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.form-group label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
}

input[type="text"],
input[type="number"],
input[type="date"],
select,
textarea {
    background-color: var(--bg-elevated);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    padding: 0.75rem 1rem;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.875rem;
    transition: all var(--transition-snappy);
    width: 100%;
}

select {
    appearance: none;
    background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23a1a1aa' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 1rem center;
    background-size: 1em;
}

input:focus,
select:focus,
textarea:focus {
    outline: none;
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px rgba(250, 204, 21, 0.15);
}

textarea {
    resize: vertical;
    min-height: 100px;
}

.form-actions {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

/* ---------- BUTTONS ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.6rem 1.25rem;
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    transition: all var(--transition-snappy);
    font-family: inherit;
    border: none;
}

.btn-primary {
    background-color: var(--accent-primary);
    color: #000;
    box-shadow: 0 4px 12px rgba(250, 204, 21, 0.2);
}

.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: 0 6px 16px rgba(250, 204, 21, 0.3);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background-color: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--bg-elevated);
    border-color: var(--text-secondary);
}

/* Small Action Buttons in Tables */
.action-btn {
    width: 28px;
    height: 28px;
    border-radius: var(--border-radius-sm);
    background: transparent;
    border: 1px solid transparent;
    color: var(--text-secondary);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-snappy);
    margin-right: 0.25rem;
}

.action-btn:hover {
    background: var(--bg-elevated);
    border-color: var(--border-color);
    color: var(--accent-primary);
}

/* ---------- RESPONSIVE DESIGN ---------- */
@media (max-width: 1024px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: flex;
        margin-right: 0.75rem;
    }

    .topbar {
        padding: 0.75rem 1rem;
        height: auto;
    }

    .search-shortcut {
        display: none; /* 모바일에서 단축키 텍스트 숨김 */
    }

    .topbar-actions {
        gap: 0.5rem;
    }

    .sidebar {
        position: fixed;
        left: -260px;
        height: 100vh;
        transition: left 0.3s ease;
    }
    
    .sidebar.open {
        left: 0;
    }

    .sidebar-overlay.active {
        display: block;
    }

    .content-container {
        padding: 1rem;
    }

    .section-header {
        margin-bottom: 1.5rem;
    }
    
    .section-header.flex-between {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }

    .form-row {
        grid-template-columns: 1fr;
        gap: 0;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}
```