/* ==========================================================================
   BSZ1 JEGYZET - PREMIUM DESIGN SYSTEM & DARK MODE CONTRAST ENGINE
   ========================================================================== */

:root {
    --bsz-bg: #f8fafc;
    --bsz-sidebar-bg: #ffffff;
    --bsz-sidebar-border: #e2e8f0;
    --bsz-card-bg: #ffffff;
    --bsz-card-border: #e2e8f0;
    --bsz-card-shadow: 0 4px 20px -2px rgba(15, 23, 42, 0.05);
    
    --bsz-text-main: #0f172a;
    --bsz-text-muted: #475569;
    --bsz-text-subtle: #64748b;
    
    --bsz-primary: #4f46e5;
    --bsz-primary-light: #eef2ff;
    --bsz-primary-border: #c7d2fe;
    
    --bsz-accent-def-bg: #f5f3ff;
    --bsz-accent-def-border: #ddd6fe;
    --bsz-accent-def-text: #5b21b6;
    
    --bsz-accent-note-bg: #eef2ff;
    --bsz-accent-note-border: #c7d2fe;
    --bsz-accent-note-text: #3730a3;
    
    --bsz-accent-proof-bg: #f8fafc;
    --bsz-accent-proof-border: #e2e8f0;
    --bsz-accent-proof-tag: #e11d48;
}

html.dark {
    --bsz-bg: #0b0f19;
    --bsz-sidebar-bg: #0f172a;
    --bsz-sidebar-border: rgba(255, 255, 255, 0.08);
    --bsz-card-bg: #131b2e;
    --bsz-card-border: rgba(255, 255, 255, 0.08);
    --bsz-card-shadow: 0 10px 30px -5px rgba(0, 0, 0, 0.5);
    
    --bsz-text-main: #f8fafc;
    --bsz-text-muted: #cbd5e1;
    --bsz-text-subtle: #94a3b8;
    
    --bsz-primary: #818cf8;
    --bsz-primary-light: rgba(99, 102, 241, 0.15);
    --bsz-primary-border: rgba(99, 102, 241, 0.4);
    
    --bsz-accent-def-bg: rgba(124, 58, 237, 0.15);
    --bsz-accent-def-border: rgba(139, 92, 246, 0.4);
    --bsz-accent-def-text: #c4b5fd;
    
    --bsz-accent-note-bg: rgba(79, 70, 229, 0.15);
    --bsz-accent-note-border: rgba(99, 102, 241, 0.4);
    --bsz-accent-note-text: #a5b4fc;
    
    --bsz-accent-proof-bg: #0d1322;
    --bsz-accent-proof-border: rgba(255, 255, 255, 0.08);
    --bsz-accent-proof-tag: #fb7185;
}

/* Base Body Styles */
body {
    background-color: var(--bsz-bg) !important;
    color: var(--bsz-text-main) !important;
    font-family: 'Inter', system-ui, -apple-system, sans-serif !important;
    transition: background-color 0.25s ease, color 0.25s ease;
    min-height: 100vh;
}

/* --- TAILWIND UTILITY OVERRIDES FOR DARK MODE --- */
html.dark .bg-white {
    background-color: var(--bsz-sidebar-bg) !important;
}
html.dark .bg-slate-50 {
    background-color: var(--bsz-bg) !important;
}
html.dark .bg-slate-100 {
    background-color: rgba(255, 255, 255, 0.06) !important;
}
html.dark .border-slate-100,
html.dark .border-slate-200,
html.dark .border-slate-300 {
    border-color: var(--bsz-card-border) !important;
}
html.dark .border-indigo-100 {
    border-color: var(--bsz-card-border) !important;
}

html.dark .text-slate-900,
html.dark .text-slate-800 {
    color: #f8fafc !important;
}
html.dark .text-slate-700,
html.dark .text-slate-600 {
    color: #cbd5e1 !important;
}
html.dark .text-slate-500,
html.dark .text-slate-400 {
    color: #94a3b8 !important;
}
html.dark .text-indigo-900,
html.dark .text-indigo-800 {
    color: #a5b4fc !important;
}
html.dark .text-indigo-700,
html.dark .text-indigo-600 {
    color: #818cf8 !important;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: rgba(148, 163, 184, 0.3);
    border-radius: 9999px;
}
html.dark ::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.15);
}
::-webkit-scrollbar-thumb:hover {
    background: rgba(99, 102, 241, 0.6);
}

/* --- SIDEBAR STYLING --- */
#sidebar {
    background-color: var(--bsz-sidebar-bg) !important;
    border-color: var(--bsz-sidebar-border) !important;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), background-color 0.25s ease, border-color 0.25s ease !important;
}

#sidebar .border-b,
#sidebar .border-slate-100,
#sidebar .border-slate-200 {
    border-color: var(--bsz-sidebar-border) !important;
}

/* Navigation Items */
.nav-item {
    display: flex !important;
    flex-direction: column !important;
    width: 100% !important;
    text-align: left !important;
    padding: 0.85rem 1rem !important;
    border-radius: 0.85rem !important;
    border: 1.5px solid transparent !important;
    margin-bottom: 0.45rem !important;
    background-color: transparent !important;
    color: var(--bsz-text-muted) !important;
    text-decoration: none !important;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1) !important;
    position: relative;
    overflow: hidden;
}

.nav-item .theorem-num {
    color: var(--bsz-text-subtle) !important;
    font-size: 0.72rem !important;
    font-weight: 700 !important;
    letter-spacing: 0.05em !important;
    text-transform: uppercase !important;
    margin-bottom: 0.15rem !important;
    transition: color 0.2s ease !important;
}

.nav-item span.font-bold {
    color: var(--bsz-text-main) !important;
    font-size: 0.88rem !important;
    line-height: 1.35 !important;
    font-weight: 600 !important;
    transition: color 0.2s ease !important;
}

/* Light Mode Hover */
.nav-item:hover {
    background-color: rgba(99, 102, 241, 0.08) !important;
    border-color: rgba(99, 102, 241, 0.25) !important;
    transform: translateX(3px);
}
.nav-item:hover .theorem-num {
    color: #4f46e5 !important;
}
.nav-item:hover span.font-bold {
    color: #312e81 !important;
}

/* Light Mode Active */
.nav-item.active {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.12), rgba(168, 85, 247, 0.1)) !important;
    border-color: #6366f1 !important;
    box-shadow: 0 4px 14px rgba(99, 102, 241, 0.15) !important;
    transform: translateX(4px);
}
.nav-item.active .theorem-num {
    color: #4f46e5 !important;
    font-weight: 800 !important;
}
.nav-item.active span.font-bold {
    color: #1e1b4b !important;
    font-weight: 700 !important;
}

/* --- DARK MODE NAVIGATION HOVER FIX (CRITICAL) --- */
html.dark .nav-item {
    color: #cbd5e1 !important;
    background-color: transparent !important;
}
html.dark .nav-item .theorem-num {
    color: #94a3b8 !important;
}
html.dark .nav-item span.font-bold {
    color: #e2e8f0 !important;
}

/* Dark Mode Hover - NEVER WHITE BACKGROUND! */
html.dark .nav-item:hover {
    background-color: rgba(99, 102, 241, 0.22) !important;
    border-color: rgba(99, 102, 241, 0.5) !important;
    transform: translateX(3px);
}
html.dark .nav-item:hover .theorem-num {
    color: #a5b4fc !important;
}
html.dark .nav-item:hover span.font-bold {
    color: #ffffff !important;
}

/* Dark Mode Active */
html.dark .nav-item.active {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.32), rgba(168, 85, 247, 0.25)) !important;
    border-color: #818cf8 !important;
    box-shadow: 0 0 20px rgba(99, 102, 241, 0.3) !important;
    transform: translateX(4px);
}
html.dark .nav-item.active .theorem-num {
    color: #c7d2fe !important;
    font-weight: 800 !important;
}
html.dark .nav-item.active span.font-bold {
    color: #ffffff !important;
    font-weight: 700 !important;
}

/* --- CONTENT CONTAINERS & CARDS --- */
main {
    background-color: transparent !important;
}

/* Math Display Blocks */
.math-display {
    background-color: var(--bsz-card-bg) !important;
    border-left: 4px solid var(--bsz-primary) !important;
    border-top: 1px solid var(--bsz-card-border) !important;
    border-right: 1px solid var(--bsz-card-border) !important;
    border-bottom: 1px solid var(--bsz-card-border) !important;
    padding: 1.25rem 1.5rem !important;
    margin: 1.5rem 0 !important;
    border-radius: 0 1rem 1rem 0 !important;
    box-shadow: var(--bsz-card-shadow) !important;
    color: var(--bsz-text-main) !important;
    overflow-x: auto !important;
}

.math-display p {
    color: var(--bsz-text-main) !important;
}

.math-display .underline,
.math-display p.font-bold {
    color: var(--bsz-primary) !important;
    text-decoration: none !important;
    font-weight: 700 !important;
    display: inline-block;
    margin-bottom: 0.5rem;
}

/* Proof Blocks */
.proof-block {
    background-color: var(--bsz-accent-proof-bg) !important;
    border: 1px solid var(--bsz-accent-proof-border) !important;
    padding: 1.25rem 1.5rem !important;
    margin: 1.25rem 0 !important;
    border-radius: 1rem !important;
    color: var(--bsz-text-muted) !important;
    line-height: 1.7 !important;
}

.proof-block p, 
.proof-block li, 
.proof-block div {
    color: var(--bsz-text-muted) !important;
}

.proof-block .text-rose-600,
.proof-block p.font-bold {
    color: var(--bsz-accent-proof-tag) !important;
    font-weight: 800 !important;
}

/* Note & Definition Highlight Boxes */
.bg-indigo-50,
.bg-purple-50,
.bg-blue-50 {
    background-color: var(--bsz-accent-note-bg) !important;
    border: 1px solid var(--bsz-accent-note-border) !important;
    border-radius: 1rem !important;
    color: var(--bsz-text-main) !important;
}

.bg-indigo-50 p,
.bg-indigo-50 li,
.bg-indigo-50 span,
.bg-purple-50 p,
.bg-purple-50 li,
.bg-blue-50 p {
    color: var(--bsz-text-main) !important;
}

/* MathJax Formulas in Dark Mode (Crystal Clear, No Halos) */
html.dark .mjx-chtml,
html.dark mjx-container,
html.dark .MathJax {
    color: #f1f5f9 !important;
    fill: #f1f5f9 !important;
    filter: none !important;
}

html.dark canvas {
    filter: brightness(1.1) contrast(1.1) !important;
}

/* Interactive Calculators & Inputs */
input[type="text"],
input[type="number"],
select {
    background-color: var(--bsz-card-bg) !important;
    border: 1.5px solid var(--bsz-card-border) !important;
    color: var(--bsz-text-main) !important;
    border-radius: 0.75rem !important;
    padding: 0.6rem 0.85rem !important;
    transition: all 0.2s ease !important;
}

input[type="text"]:focus,
input[type="number"]:focus,
select:focus {
    outline: none !important;
    border-color: var(--bsz-primary) !important;
    box-shadow: 0 0 0 3px var(--bsz-primary-light) !important;
}

/* Interactive Action Buttons */
button.bg-indigo-600,
.btn-primary {
    background: linear-gradient(135deg, #4f46e5, #7c3aed) !important;
    color: #ffffff !important;
    border: none !important;
    box-shadow: 0 4px 14px rgba(79, 70, 229, 0.3) !important;
    transition: all 0.2s ease !important;
}

button.bg-indigo-600:hover,
.btn-primary:hover {
    background: linear-gradient(135deg, #4338ca, #6d28d9) !important;
    box-shadow: 0 6px 20px rgba(79, 70, 229, 0.45) !important;
    transform: translateY(-1px);
}

button.bg-indigo-600:active,
.btn-primary:active {
    transform: scale(0.98);
}

/* Theme Toggle Button Modern Styling */
#theme-toggle,
.theme-toggle-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 38px;
    height: 38px;
    border-radius: 10px;
    background: var(--bsz-sidebar-border);
    border: 1px solid var(--bsz-card-border);
    color: var(--bsz-text-muted);
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

#theme-toggle:hover,
.theme-toggle-btn:hover {
    background: rgba(99, 102, 241, 0.15);
    color: var(--bsz-primary);
    transform: rotate(15deg);
}

html.dark #theme-toggle,
html.dark .theme-toggle-btn {
    background: rgba(255, 255, 255, 0.08) !important;
    border-color: rgba(255, 255, 255, 0.12) !important;
    color: #fbbf24 !important;
}

html.dark #theme-toggle:hover,
html.dark .theme-toggle-btn:hover {
    background: rgba(251, 191, 36, 0.15) !important;
    color: #fde047 !important;
    box-shadow: 0 0 12px rgba(251, 191, 36, 0.25) !important;
}

/* Mobile Header */
.md\:hidden.bg-white {
    background-color: var(--bsz-sidebar-bg) !important;
    border-color: var(--bsz-sidebar-border) !important;
}

/* Chat Widget Positioning Adjustment */
#vds-chat-widget {
    z-index: 999999 !important;
}