:root {
    --theme-bg: #f8fafc;
    --theme-text: #1e293b;
    --theme-card-bg: #ffffff;
    --theme-card-border: #e2e8f0;
    --theme-muted: #94a3b8;
    --theme-link: #6366f1;
    --theme-input-bg: #ffffff;
    --theme-input-border: #e2e8f0;
    --theme-table-stripe: #f1f5f9;
    --theme-primary: #6366f1;
    --theme-primary-light: #818cf8;
    --theme-primary-dark: #4f46e5;
    --theme-success: #10b981;
    --theme-warning: #f59e0b;
    --theme-danger: #ef4444;
    --theme-info: #3b82f6;
    --success-light: rgba(16, 185, 129, 0.15);
    --warning-light: rgba(245, 158, 11, 0.15);
    --info-light: rgba(59, 130, 246, 0.15);
    --danger-light: rgba(239, 68, 68, 0.15);
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --gray-900: #0f172a;
}

body.theme-dark {
    --theme-bg: #0f172a;
    --theme-text: #e2e8f0;
    --theme-card-bg: #1e293b;
    --theme-card-border: #334155;
    --theme-muted: #94a3b8;
    --theme-link: #818cf8;
    --theme-input-bg: #1e293b;
    --theme-input-border: #475569;
    --theme-table-stripe: #1e293b;
    --theme-primary: #818cf8;
    --theme-primary-light: #a5b4fc;
    --theme-primary-dark: #6366f1;
    --theme-success: #34d399;
    --theme-warning: #fbbf24;
    --theme-danger: #f87171;
    --theme-info: #60a5fa;
    --success-light: rgba(52, 211, 153, 0.2);
    --warning-light: rgba(251, 191, 36, 0.2);
    --info-light: rgba(96, 165, 250, 0.2);
    --danger-light: rgba(248, 113, 113, 0.2);
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --bg-primary: #1e293b;
    --bg-secondary: #0f172a;
    --bg-tertiary: #1e293b;
    --gray-50: #0f172a;
    --gray-100: #111827;
    --gray-200: #1f2937;
    --gray-300: #374151;
    --gray-400: #4b5563;
    --gray-500: #6b7280;
    --gray-600: #9ca3af;
    --gray-700: #cbd5e1;
    --gray-800: #e2e8f0;
    --gray-900: #f1f5f9;
}

body {
    background-color: var(--theme-bg);
    color: var(--theme-text);
}

a {
    color: var(--theme-link);
}

.text-muted {
    color: var(--theme-muted) !important;
}

.card:not(.bg-primary):not(.bg-success):not(.bg-info):not(.bg-warning):not(.bg-danger):not(.bg-secondary) {
    background-color: var(--theme-card-bg);
    border-color: var(--theme-card-border);
    color: var(--theme-text);
}

.auth-card,
.exam-card,
.quick-action,
.login-card {
    background-color: var(--theme-card-bg);
    border-color: var(--theme-card-border);
    color: var(--theme-text);
}

.auth-footer {
    background-color: var(--theme-table-stripe);
    border-top-color: var(--theme-card-border);
}

.list-group-item:not(.active) {
    background-color: var(--theme-card-bg);
    border-color: var(--theme-card-border);
    color: var(--theme-text);
}

.table {
    color: var(--theme-text);
}

.table td,
.table th {
    border-color: var(--theme-card-border);
}

.table-striped > tbody > tr:nth-of-type(odd) {
    background-color: var(--theme-table-stripe);
}

.form-control,
.form-select,
.input-group-text {
    background-color: var(--theme-input-bg);
    color: var(--theme-text);
    border-color: var(--theme-input-border);
}

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

.bg-light {
    background-color: var(--theme-card-bg) !important;
}

label,
.form-label,
.form-check-label {
    color: var(--theme-text);
}

small,
.small,
.text-secondary {
    color: var(--theme-muted);
}

.form-floating input {
    background-color: var(--theme-input-bg);
    color: var(--theme-text);
    border-color: var(--theme-input-border);
}

.form-floating input:focus {
    background-color: var(--theme-input-bg);
}

.form-floating label {
    color: var(--theme-muted);
}

.form-floating input:focus + label,
.form-floating input:not(:placeholder-shown) + label {
    background: var(--theme-card-bg);
    color: var(--theme-link);
}

.form-icon,
.password-toggle {
    color: var(--theme-muted);
}

.form-control:focus,
.form-select:focus {
    box-shadow: 0 0 0 0.2rem rgba(99, 102, 241, 0.25);
}

.btn-outline-secondary,
.btn-outline-light {
    color: var(--theme-text);
    border-color: var(--theme-input-border);
}

.btn-outline-secondary:hover,
.btn-outline-light:hover {
    background-color: var(--theme-table-stripe);
    color: var(--theme-text);
}

.btn-primary {
    background-color: var(--theme-primary);
    border-color: var(--theme-primary);
}

.btn-primary:hover {
    background-color: var(--theme-primary-dark);
    border-color: var(--theme-primary-dark);
}

.btn-success {
    background-color: var(--theme-success);
    border-color: var(--theme-success);
}

.btn-warning {
    background-color: var(--theme-warning);
    border-color: var(--theme-warning);
    color: #1e293b;
}

.btn-danger {
    background-color: var(--theme-danger);
    border-color: var(--theme-danger);
}

.btn-info {
    background-color: var(--theme-info);
    border-color: var(--theme-info);
    color: #0f172a;
}

.theme-toggle-fab {
    position: fixed;
    top: 16px;
    right: 16px;
    z-index: 2000;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 1px solid var(--theme-card-border);
    background: linear-gradient(135deg, var(--theme-primary) 0%, var(--theme-primary-light) 100%);
    color: #ffffff;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    cursor: pointer;
    transition: all 0.3s ease;
    animation: float 3s ease-in-out infinite;
}

.theme-toggle-fab:hover {
    transform: scale(1.1) rotate(10deg);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.25);
}

@keyframes float {
    0% { transform: translateY(0px); }
    50% { transform: translateY(-5px); }
    100% { transform: translateY(0px); }
}

body.theme-dark .theme-toggle-fab {
    background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

body.theme-dark .theme-toggle-fab:hover {
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.4);
}

.theme-toggle-fab svg {
    width: 20px;
    height: 20px;
}

.theme-toggle-fab:focus-visible {
    outline: 2px solid var(--theme-link);
    outline-offset: 3px;
}

/* Enhanced dark mode styles */
body.theme-dark {
    /* Enhanced scrollbar for dark mode */
    scrollbar-color: #475569 #1e293b;
}

body.theme-dark ::-webkit-scrollbar {
    width: 12px;
}

body.theme-dark ::-webkit-scrollbar-track {
    background: #1e293b;
}

body.theme-dark ::-webkit-scrollbar-thumb {
    background-color: #475569;
    border-radius: 6px;
    border: 3px solid #1e293b;
}

/* Better contrast for buttons in dark mode */
body.theme-dark .btn-outline-secondary,
body.theme-dark .btn-outline-light {
    color: var(--text-primary);
    border-color: var(--theme-input-border);
    background-color: rgba(30, 41, 59, 0.5);
}

body.theme-dark .btn-outline-secondary:hover,
body.theme-dark .btn-outline-light:hover {
    background-color: var(--theme-input-bg);
    color: var(--theme-primary);
}

/* Improve contrast for disabled elements */
body.theme-dark .disabled,
body.theme-dark [disabled] {
    opacity: 0.6;
    color: var(--text-muted);
}

/* Better contrast for form controls */
body.theme-dark .form-control:disabled,
body.theme-dark .form-control[readonly] {
    background-color: #1e293b;
    color: var(--text-muted);
}

@media (max-width: 576px) {
    .theme-toggle-fab {
        top: 12px;
        right: 12px;
        width: 40px;
        height: 40px;
    }
}