:root {
    /* Core theme colors */
    --primary: #404040;
    --primary-dark: #303030;
    --primary-light: #505050;
    --primary-accent: #606060;
    --secondary: #808080;
    --secondary-dark: #707070;
    --secondary-light: #909090;
    
    /* Background colors */
    --bg-dark: #121212;
    --bg-medium: #1a1a1a;
    --bg-light: #222222;
    --card-bg: #1e1e1e;
    --hover-bg: rgba(80, 80, 80, 0.1);
    --active-bg: rgba(80, 80, 80, 0.2);
    
    /* Text colors */
    --text-main: #c0c0c0;
    --text-secondary: #a0a0a0;
    --text-muted: #808080;
    --text-bright: #e0e0e0;
    --text-dim: #707070;
    
    /* Border colors */
    --border-color: #333333;
    --border-accent: #4a4a4a;
    --divider: rgba(120, 120, 120, 0.15);
    
    /* Status colors (muted for sad feeling) */
    --success: #4d6d5a;
    --danger: #744a4a;
    --warning: #7d715a;
    --info: #506d77;
    
    /* Shadow effects */
    --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
    --box-shadow-light: 0 2px 4px rgba(0, 0, 0, 0.1);
    --box-shadow-heavy: 0 8px 16px rgba(0, 0, 0, 0.3);
    
    /* Other visual elements */
    --border-radius: 6px;
    --transition-speed: 0.25s;
}

/* Base styling */
body {
    background-color: var(--bg-dark);
    color: var(--text-main);
    font-family: 'Inter', 'Segoe UI', Roboto, Arial, sans-serif;
    line-height: 1.5;
    transition: background-color 0.3s ease;
}

/* Link styling */
a {
    color: var(--secondary-light);
    transition: all var(--transition-speed) ease;
    text-decoration: none;
}

a:hover {
    color: var(--text-bright);
    text-decoration: none;
}

/* Card styling */
.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    transition: all var(--transition-speed) ease;
}

.card:hover {
    box-shadow: var(--box-shadow-heavy);
}

.card-header {
    background-color: var(--primary-dark);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 1.25rem;
}

.card-body {
    padding: 1.5rem;
}

/* Button styling */
.btn-primary {
    background-color: var(--primary);
    border-color: var(--primary-dark);
    color: var(--text-bright);
}

.btn-primary:hover, .btn-primary:focus {
    background-color: var(--primary-dark);
    border-color: var(--primary-dark);
    color: var(--text-bright);
}

.btn-secondary {
    background-color: var(--secondary);
    border-color: var(--secondary-dark);
    color: var(--text-bright);
}

.btn-secondary:hover, .btn-secondary:focus {
    background-color: var(--secondary-dark);
    border-color: var(--secondary-dark);
    color: var(--text-bright);
}

/* Form controls */
.form-control {
    background-color: var(--bg-light);
    border: 1px solid var(--border-color);
    color: var(--text-main);
}

.form-control:focus {
    background-color: var(--bg-medium);
    border-color: var(--primary-accent);
    color: var(--text-bright);
    box-shadow: 0 0 0 0.25rem rgba(80, 80, 80, 0.25);
}

.form-control::placeholder {
    color: var(--text-muted);
}

.form-check-input {
    background-color: var(--bg-light);
    border: 1px solid var(--border-color);
}

.form-check-input:checked {
    background-color: var(--primary);
    border-color: var(--primary);
}

/* Alert styling */
.alert-primary {
    background-color: var(--primary-dark);
    border-color: var(--primary);
    color: var(--text-main);
}

.alert-success {
    background-color: var(--success);
    border-color: var(--success);
    color: var(--text-bright);
}

.alert-danger {
    background-color: var(--danger);
    border-color: var(--danger);
    color: var(--text-bright);
}

.alert-warning {
    background-color: var(--warning);
    border-color: var(--warning);
    color: var(--text-bright);
}

.alert-info {
    background-color: var(--info);
    border-color: var(--info);
    color: var(--text-bright);
}

/* Table styling */
.table {
    color: var(--text-main);
}

.table-dark {
    background-color: var(--bg-medium);
    color: var(--text-main);
}

.table thead th {
    border-bottom: 2px solid var(--border-color);
    color: var(--text-secondary);
}

.table tbody tr:hover {
    background-color: var(--hover-bg);
}

/* Nav styles */
.nav-tabs .nav-link {
    color: var(--text-secondary);
    border: none;
    border-bottom: 2px solid transparent;
}

.nav-tabs .nav-link.active {
    color: var(--text-bright);
    background-color: transparent;
    border-bottom: 2px solid var(--primary);
}

.nav-tabs .nav-link:hover {
    border-color: transparent;
    border-bottom: 2px solid var(--primary-light);
}

/* Custom styles for the sad, melancholic feeling */
.navbar {
    background-color: var(--bg-medium);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    border-bottom: 1px solid var(--border-color);
}

.btn {
    transition: all 0.3s ease;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.btn:hover {
    transform: translateY(1px);
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

/* Melancholic animations */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slowPulse {
    0% { opacity: 0.8; }
    50% { opacity: 1; }
    100% { opacity: 0.8; }
}

.fade-in {
    animation: fadeIn 1.5s ease-in;
}

.pulse-subtle {
    animation: slowPulse 4s infinite;
}

/* Placeholder image styling for sad theme */
.placeholder-img {
    filter: grayscale(100%) brightness(0.8) contrast(1.1);
    opacity: 0.7;
    transition: all 0.5s ease;
}

.placeholder-img:hover {
    filter: grayscale(90%) brightness(0.85);
    opacity: 0.8;
}

/* Alert with primary custom styling */
.alert-primary-custom {
    background-color: rgba(64, 64, 64, 0.2);
    border-left: 4px solid var(--primary);
    color: var(--text-main);
    padding: 1rem;
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-dark);
}

::-webkit-scrollbar-thumb {
    background: var(--primary-dark);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary);
}

/* Subtle text shadow for headers */
h1, h2, h3, h4, h5, h6 {
    color: var(--text-bright);
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
    font-weight: 400;
    letter-spacing: 0.5px;
}

/* Badge styling */
.badge {
    font-weight: normal;
    letter-spacing: 0.5px;
}

.badge-primary {
    background-color: var(--primary);
    color: var(--text-bright);
}

/* Progress bar - more subdued for sad theme */
.progress {
    background-color: var(--bg-light);
    height: 8px;
    border-radius: 4px;
    overflow: hidden;
}

.progress-bar {
    background-color: var(--primary);
    transition: width 1s ease;
}

/* Subtle box transitions */
.transition-box {
    transition: all 0.4s ease-in-out;
}

.transition-box:hover {
    transform: translateY(-2px);
    box-shadow: var(--box-shadow-heavy);
}