:root {
    --industrial-bg: #000000; /* 검은색 */
    --industrial-surface: #31363F; /* 어두운 회색 */
    --industrial-primary-accent: #00ADB5; /* 청록색/시안 */
    --industrial-secondary-accent: #00ADB5; /* 청록색/시안 */
    --industrial-text: #FFFFFF; /* 흰색 */
    --industrial-border: #4F545B;
}

body {
    font-family: 'Segoe UI', 'Roboto', sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--industrial-bg);
    color: var(--industrial-text);
    padding-top: 60px; /* Navbar height */
}

.navbar {
    background-color: var(--industrial-surface) !important;
    border-bottom: 2px solid var(--industrial-primary-accent);
}

.navbar-brand {
    font-weight: bold;
    font-size: 1.4rem;
    color: var(--industrial-primary-accent) !important;
}
.navbar-toggler-icon {
    filter: invert(1) sepia(1) saturate(5) hue-rotate(180deg); /* To make it visible on dark bg */
}


/* 사이드바 - Bootstrap Offcanvas 사용 */
.custom-sidebar.offcanvas {
    background-color: var(--industrial-surface);
    color: var(--industrial-text);
    border-right: 1px solid var(--industrial-border);
    width: 280px;
}
.custom-sidebar .offcanvas-header {
    border-bottom: 1px solid var(--industrial-border);
}
.custom-sidebar .offcanvas-title {
    color: var(--industrial-primary-accent);
}
.custom-sidebar .list-unstyled a,
.custom-sidebar .list-unstyled li {
    color: var(--industrial-text);
    padding: 10px 15px;
    border-radius: 4px;
    transition: background-color 0.3s, color 0.3s;
    text-decoration: none; /* 링크 밑줄 제거 */
    display: block; /* 클릭 영역 확장 */
}
.custom-sidebar .list-unstyled a:hover,
.custom-sidebar .list-unstyled li:hover {
    background-color: var(--industrial-primary-accent);
    color: var(--industrial-bg);
}
.custom-sidebar .list-unstyled .active-item { /* 현재 선택된 항목 스타일 */
    background-color: var(--industrial-primary-accent);
    color: var(--industrial-bg);
    font-weight: bold;
}


.custom-main-content {
    padding: 20px;
    transition: margin-left .3s;
}

/* PC 화면에서 사이드바가 항상 보이도록 처리 */
@media (min-width: 992px) {
    .custom-sidebar.offcanvas-start {
        transform: none;
        visibility: visible !important;
        height: calc(100vh - 60px); /* Navbar height */
        position: fixed;
        top: 60px; /* Navbar height */
        left: 0;
    }
    .custom-main-content {
        margin-left: 280px; /* Sidebar width */
    }
    .navbar-toggler {
        display: none; /* PC에서는 토글 버튼 숨김 */
    }
}


.custom-card {
    background: var(--industrial-surface);
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    margin-bottom: 30px;
    border: 1px solid var(--industrial-border);
}

.custom-upload-area {
    border: 3px dashed var(--industrial-primary-accent);
    border-radius: 8px;
    padding: 40px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background-color: rgba(255, 211, 105, 0.05); /* 은은한 액센트 배경 */
}

.custom-upload-area:hover,
.custom-upload-area.active {
    border-color: var(--industrial-secondary-accent);
    background: rgba(0, 173, 181, 0.1);
}
.custom-upload-area .fas {
    color: var(--industrial-primary-accent);
    transition: color 0.3s;
}
.custom-upload-area:hover .fas,
.custom-upload-area.active .fas {
    color: var(--industrial-secondary-accent);
}


.custom-btn-upload {
    background: var(--industrial-primary-accent);
    color: var(--industrial-bg);
    border: none;
    padding: 12px 24px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1em;
    font-weight: bold;
    transition: background-color 0.3s, transform 0.2s;
    text-transform: uppercase;
}

.custom-btn-upload:hover {
    background: var(--industrial-secondary-accent);
    color: var(--industrial-text);
    transform: translateY(-2px);
}

.table {
    border-color: var(--industrial-border);
}
.table th, .table td {
    color: var(--industrial-text);
    border-color: var(--industrial-border);
}
.table thead th {
    background-color: var(--industrial-bg); /* 테이블 헤더 배경색 */
    color: var(--industrial-primary-accent);
    border-bottom: 2px solid var(--industrial-primary-accent);
}
.table tbody tr:nth-child(odd) td { /* 홀수 행 배경색 살짝 다르게 */
    background-color: rgba(255,255,255,0.02);
}

.custom-card h3, .custom-card h4, .custom-card h5 {
    color: var(--industrial-primary-accent);
    margin-bottom: 20px;
    text-transform: uppercase;
    letter-spacing: 1px;
}
.custom-card p {
    color: var(--industrial-text);
}

footer {
    background-color: var(--industrial-surface);
    color: var(--industrial-text);
    padding: 20px 0;
    text-align: center;
    font-size: 0.9em;
    border-top: 2px solid var(--industrial-primary-accent);
    margin-top: 40px;
}