:root {
    --bg-main: #f8fafc;
    --bg-panel: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --success: #10b981;
    --danger: #ef4444;
    --border: #e2e8f0;
    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05);
    --glass: rgba(255, 255, 255, 0.8);
    --card-bg: #ffffff;
    --font-family-main: 'Poppins', sans-serif;
}

[data-theme="dark"] {
    --bg-main: #0f172a;
    --bg-panel: #1e293b;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --accent: #60a5fa;
    --accent-hover: #3b82f6;
    --border: #334155;
    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.5);
    --glass: rgba(30, 41, 59, 0.8);
    --card-bg: #1e293b;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: var(--font-family-main); background: var(--bg-main); color: var(--text-main); transition: 0.3s ease; overflow-x: hidden; width: 100%; min-height: 100vh; }

/* TOASTS */
#toast-container { position: fixed; top: 20px; right: 20px; z-index: 9999; display: flex; flex-direction: column; gap: 10px; }
.toast { background: var(--bg-panel); color: var(--text-main); padding: 15px 25px; border-radius: 8px; box-shadow: var(--shadow); border-left: 4px solid var(--accent); font-weight: 600; animation: slideInRight 0.3s ease forwards; display: flex; align-items: center; gap: 10px; }
.toast.success { border-left-color: var(--success); }
.toast.error { border-left-color: var(--danger); }
@keyframes slideInRight { from { transform: translateX(100%); opacity: 0; } to { transform: translateX(0); opacity: 1; } }
@keyframes fadeOut { to { opacity: 0; transform: translateY(-10px); } }

/* LAYOUT */
#app-container { 
    display: flex; 
    min-height: 100vh; 
    position: relative;
    background: var(--bg-main);
}

/* Nowoczesne paski przewijania (Globalne) */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: rgba(0,0,0,0.1);
    border-radius: 10px;
}
[data-theme="dark"] ::-webkit-scrollbar-thumb {
    background: rgba(255,255,255,0.1);
}
::-webkit-scrollbar-thumb:hover {
    background: var(--accent);
}

.sidebar { 
    width: var(--sidebar-width); 
    background: var(--bg-panel); 
    padding: 50px 0;
    display: flex; 
    flex-direction: column; 
    position: fixed; 
    top: 0;
    left: 0;
    height: var(--sidebar-height, 100vh); 
    z-index: 2000; 
    transition: all 0.6s cubic-bezier(0.16, 1, 0.3, 1); 
    overflow-y: auto; 
    overflow-x: hidden !important; /* Całkowite wyeliminowanie poziomego paska */
    box-shadow: 15px 0 45px rgba(0,0,0,0.06);
    border-right: 1px solid var(--border);
    border-radius: 0 var(--sidebar-radius) var(--sidebar-radius) 0;
    
    /* Ukrycie paska przewijania dla Sidebar - zachowując funkcję przewijania */
    -ms-overflow-style: none; /* IE and Edge */
    scrollbar-width: none; /* Firefox */
}

.sidebar::-webkit-scrollbar {
    display: none; /* Chrome, Safari, Opera */
}

.sidebar.collapsed { 
    transform: translateX(-100%); 
    box-shadow: none; 
}

.sidebar-toggle {
    position: fixed;
    top: 40px;
    left: calc(var(--sidebar-width) - 27px); 
    width: 54px;
    height: 54px;
    background: var(--accent);
    border: 4px solid var(--bg-main);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: white;
    z-index: 2100;
    transition: all 0.6s cubic-bezier(0.16, 1, 0.3, 1);
    box-shadow: 0 8px 25px rgba(59, 130, 246, 0.3);
}

.sidebar-toggle:hover {
    background: var(--accent-hover);
    transform: scale(1.1);
    box-shadow: 0 12px 30px rgba(59, 130, 246, 0.4);
}

#sidebar.collapsed + .sidebar-toggle {
    left: 20px !important;
}

.content { 
    flex: 1; 
    padding: 40px; 
    margin-left: var(--content-margin);
    max-width: var(--app-max-width, 1400px); 
    margin-right: auto;
    width: auto;
    transition: all 0.6s cubic-bezier(0.16, 1, 0.3, 1);
    min-width: 0;
}

.content.expanded {
    margin-left: 0;
    max-width: 100% !important;
}

.logo { font-size: 28px; font-weight: 800; letter-spacing: -1px; margin-bottom: 5px; }
.logo span { color: var(--accent); }
.premium-badge { font-size: 10px; font-weight: 800; color: var(--accent); letter-spacing: 2px; margin-bottom: 40px; }

.nav-links { list-style: none; flex: 1; }
.nav-links li { margin-bottom: 10px; }
.nav-links button { width: 100%; text-align: left; padding: var(--sidebar-btn-padding); border: none; background: transparent; color: var(--text-muted); font-size: var(--sidebar-btn-font-size); font-weight: 600; border-radius: 12px; cursor: pointer; transition: 0.2s; display: flex; align-items: center; gap: 15px; font-family: var(--font-family-main); white-space: nowrap; overflow: hidden; text-overflow: ellipsis;}
.nav-links button:hover, .nav-links button.active { background: var(--accent); color: white; transform: translateX(5px); }

/* SIDEBAR RE-ENABLED */

/* TYPOGRAPHY & UTILS */
h2 { font-size: 32px; font-weight: 700; margin-bottom: 10px; letter-spacing: -0.5px; }
.subtitle { color: var(--text-muted); font-size: 16px; margin-bottom: 40px; }
.fade-in { animation: fadeIn 0.4s ease; }
.slide-in { animation: slideInUp 0.5s cubic-bezier(0.16, 1, 0.3, 1); }
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes slideInUp { from { transform: translateY(20px); opacity: 0; } to { transform: translateY(0); opacity: 1; } }

/* BUTTONS */
.btn { padding: 12px 24px; border-radius: 12px; font-weight: 600; cursor: pointer; border: none; transition: 0.2s; font-family: var(--font-family-main); display: inline-flex; align-items: center; gap: 8px; justify-content: center; }
.btn.primary { background: var(--accent); color: white; }
.btn.primary:hover { background: var(--accent-hover); transform: translateY(-2px); }
.btn.secondary { background: var(--bg-panel); color: var(--text-main); border: 1px solid var(--border); }
.btn.secondary:hover { border-color: var(--text-muted); }
.btn.danger { background: var(--danger); color: white; }
.btn.massive { font-size: 18px; padding: 18px 36px; width: 100%; border-radius: 16px; }
.btn.sm { padding: 6px 12px; font-size: 14px; }
.shadow-hover:hover { box-shadow: 0 10px 20px -10px var(--accent); }
.danger-text { color: var(--danger) !important; }

/* DASHBOARD STATS */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(var(--main-menu-grid-size, 250px), 1fr)); gap: 20px; margin-bottom: 40px; }
.stat-card { background: var(--bg-panel); padding: 30px; border-radius: 20px; text-align: center; box-shadow: var(--shadow); border: 1px solid var(--border); position: relative; overflow: hidden; }
.stat-card::before { content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 4px; }
.stat-card.mastered::before { background: var(--success); }
.stat-card.review::before { background: var(--accent); }
.stat-card.total::before { background: var(--text-muted); }
.stat-card .icon-wrap { width: 50px; height: 50px; background: var(--bg-main); border-radius: 50%; display: flex; align-items: center; justify-content: center; margin: 0 auto 15px; font-size: 20px; color: var(--text-muted); }
.stat-card h4 { color: var(--text-muted); font-weight: 600; font-size: 14px; text-transform: uppercase; letter-spacing: 1px; }
.stat-card h3 { font-size: 48px; font-weight: 800; margin-top: 10px; }
.quick-actions { display: flex; gap: 15px; flex-wrap: wrap; }

/* KNOWLEDGE BASE */
.category-nav { display: flex; gap: 10px; overflow-x: auto; padding-bottom: 15px; margin-bottom: 30px; }
.category-nav button { white-space: nowrap; border-radius: 20px; padding: 8px 16px; }
.category-section { margin-bottom: 50px; }
.category-header { display: flex; align-items: center; gap: 15px; margin-bottom: 20px; padding-bottom: 10px; border-bottom: 2px solid var(--border); }
.category-header i { font-size: 24px; color: var(--accent); }
.words-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 20px; }

/* WORD CARD */
.word-card { background: var(--card-bg); border: 2px solid var(--border); border-radius: var(--border-radius-override); padding: 25px; box-shadow: var(--shadow); transition: 0.3s; position: relative; }
.word-card:hover { transform: translateY(-5px); border-color: var(--accent); }
.word-card.mastered { border-color: var(--success); }
.word-card.review { border-left: 4px solid var(--accent); }
.word-header { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 15px; }
.word-en { font-size: var(--word-en-size); font-weight: 800; color: var(--word-en-color); display: flex; align-items: center; gap: 10px; }
.word-pl { font-size: var(--word-pl-size); color: var(--word-pl-color); font-weight: 600; margin-top: 5px; }
.play-btn { background: var(--bg-main); border: none; width: 35px; height: 35px; border-radius: 50%; color: var(--text-main); cursor: pointer; transition: 0.2s; display: flex; align-items: center; justify-content: center; }
.play-btn:hover { background: var(--accent); color: white; }
.play-btn i { font-size: var(--icon-size, 16px); }
.btn i { font-size: var(--icon-size, 16px); }
.ex-en i { font-size: var(--icon-size, 16px); }

.hover-actions { opacity: 0; transition: opacity 0.2s; display: flex; gap: 5px; }
.word-card:hover .hover-actions { opacity: 1; }
.examples-list { list-style: none; margin-top: 15px; border-top: 1px dashed var(--border); padding-top: 15px; }
.examples-list li { margin-bottom: 10px; font-size: 14px; line-height: 1.5; }
.ex-en { font-weight: 600; color: var(--text-main); display: block; }
.ex-pl { color: var(--text-muted); display: block; font-size: 13px; }
.card-actions { display: flex; justify-content: space-between; margin-top: 20px; }

/* TRAINING CONFIG */
.config-form { background: var(--bg-panel); padding: 40px; border-radius: 20px; border: 1px solid var(--border); box-shadow: var(--shadow); max-width: 800px; }
.form-group { margin-bottom: 30px; }
.form-group label { display: block; font-weight: 600; margin-bottom: 10px; color: var(--text-muted); }
.input-modern { width: 100%; padding: 15px; border-radius: 12px; border: 2px solid var(--border); background: var(--bg-main); color: var(--text-main); font-family: var(--font-family-main); font-size: 16px; transition: 0.2s; }
.input-modern:focus { outline: none; border-color: var(--accent); }
.checkbox-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 15px; }
.checkbox-card { display: flex; align-items: center; gap: 10px; padding: 15px; border: 2px solid var(--border); border-radius: 12px; cursor: pointer; transition: 0.2s; font-weight: 600; }
.checkbox-card:hover { border-color: var(--accent); }
.checkbox-card input:checked + span { color: var(--accent); }

/* 3D FLASHCARD TRAINING */
#view-active-training { display: flex; flex-direction: column; align-items: center; justify-content: center; min-height: 80vh; }
.progress-bar-wrap { width: 100%; max-width: 600px; height: 12px; background: var(--border); border-radius: 6px; margin-bottom: 20px; overflow: hidden; border: 1px solid var(--border); }
.progress-bar-fill { height: 100%; background: linear-gradient(90deg, var(--accent), var(--success)); width: 0%; transition: width 0.3s ease; }
.training-info { color: var(--text-muted); margin-bottom: 40px; font-weight: 600; text-align: center; }

.flashcard-scene { width: 100%; max-width: 600px; height: 400px; perspective: 1000px; margin-bottom: 40px; }
.flashcard-inner { width: 100%; height: 100%; position: relative; transition: transform 0.6s cubic-bezier(0.4, 0.2, 0.2, 1); transform-style: preserve-3d; cursor: pointer; }
.flashcard-inner.is-flipped { transform: rotateY(180deg); }

.flashcard-front, .flashcard-back { position: absolute; width: 100%; height: 100%; backface-visibility: hidden; border-radius: 24px; box-shadow: var(--shadow); display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 20px; text-align: center; border: 2px solid var(--border); background: var(--bg-panel); }
.flashcard-front { border: 4px solid var(--accent); }
.flashcard-back { transform: rotateY(180deg); border-color: var(--accent); }

.fc-pl { 
    font-size: 5.5rem !important; 
    font-weight: 800 !important; 
    color: var(--text-main) !important; 
    line-height: 1.1; 
    word-break: break-word; 
    max-width: 100%; 
    display: block;
    width: 100%;
}
.fc-hint { font-size: 15px; color: var(--text-muted); margin-top: 30px; font-weight: 500; }
.fc-en { font-size: 4rem; font-weight: 800; color: var(--accent); margin-bottom: 15px; }
.fc-ex { font-size: 18px; color: var(--text-main); font-style: italic; line-height: 1.5; margin-top: 20px; }

.eval-buttons { display: flex; gap: 20px; opacity: 0; pointer-events: none; transition: 0.3s; transform: translateY(20px); }
.eval-buttons.show { opacity: 1; pointer-events: auto; transform: translateY(0); }
.eval-buttons .btn { padding: 15px 40px; font-size: 18px; }

/* MODAL EDYCJI */
.modal-backdrop { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.6); backdrop-filter: blur(5px); z-index: 1000; display: flex; align-items: center; justify-content: center; }
.modal { background: var(--bg-panel); width: 90%; max-width: 600px; border-radius: 20px; padding: 40px; box-shadow: 0 25px 50px -12px rgba(0,0,0,0.5); border: 1px solid var(--border); max-height: 90vh; overflow-y: auto; }
.modal h3 { font-size: 24px; margin-bottom: 20px; }
.modal label { display: block; margin-bottom: 15px; font-weight: 600; color: var(--text-muted); }
.modal-actions { display: flex; justify-content: flex-end; gap: 10px; margin-top: 30px; border-top: 1px solid var(--border); padding-top: 20px; }
.dynamic-group { background: var(--bg-main); padding: 20px; border-radius: 12px; margin-top: 20px; }
.example-input-group { display: flex; gap: 10px; margin-bottom: 10px; }

/* SCROLLBAR */
.custom-scrollbar::-webkit-scrollbar { height: 8px; width: 8px; }
.custom-scrollbar::-webkit-scrollbar-track { background: var(--bg-main); border-radius: 4px; }
.custom-scrollbar::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
.custom-scrollbar::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* INIT LOADER */
#init-loader { position: fixed; top: 50%; left: 50%; transform: translate(-50%, -50%); background: var(--bg-panel); padding: 50px; border-radius: 24px; box-shadow: 0 25px 50px -12px rgba(0,0,0,0.5); z-index: 2000; text-align: center; border: 1px solid var(--border); width: 90%; max-width: 500px; }
#init-loader h2 { margin-bottom: 15px; }
#init-loader p { color: var(--text-muted); margin-bottom: 30px; }
.upload-area { border: 2px dashed var(--accent); padding: 40px; border-radius: 16px; background: var(--bg-main); transition: 0.3s; }
.upload-area:hover { background: rgba(59, 130, 246, 0.1); }

/* ANIMATIONS */
.pulse-anim {
    animation: pulse 1.5s infinite;
}

@keyframes pulse {
    0% { transform: scale(1); box-shadow: 0 0 0 0 rgba(239, 68, 68, 0.7); }
    70% { transform: scale(1.05); box-shadow: 0 0 0 15px rgba(239, 68, 68, 0); }
    100% { transform: scale(1); box-shadow: 0 0 0 0 rgba(239, 68, 68, 0); }
}