/* ===== CSS Variables ===== */
:root {
  --color-bg: #0a0a0f;
  --color-surface: #12121a;
  --color-surface-elevated: #1a1a24;
  --color-surface-hover: #22222e;
  --color-border: #2a2a3a;
  --color-text: #ffffff;
  --color-text-secondary: #a0a0b0;
  --color-text-muted: #6a6a7a;
  --color-primary: #6366f1;
  --color-primary-hover: #818cf8;
  --color-primary-glow: rgba(99, 102, 241, 0.3);
  --color-success: #10b981;
  --color-success-bg: rgba(16, 185, 129, 0.1);
  --color-error: #ef4444;
  --color-error-bg: rgba(239, 68, 68, 0.1);
  --color-warning: #f59e0b;
  --color-telegram: #0088cc;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 20px var(--color-primary-glow);
  --transition-fast: 0.15s ease;
  --transition: 0.25s ease;
  --sidebar-width: 260px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; -webkit-font-smoothing: antialiased; }
body { font-family: 'Inter', -apple-system, sans-serif; background: var(--color-bg); color: var(--color-text); min-height: 100vh; line-height: 1.5; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }
input, textarea, select { font-family: inherit; font-size: inherit; }
a { color: inherit; text-decoration: none; }
.screen { min-height: 100vh; }
.screen[hidden] { display: none !important; }

/* Auth Screen */
.auth-screen { display: flex; align-items: center; justify-content: center; background: linear-gradient(135deg, var(--color-bg) 0%, #1a1a2e 100%); padding: 20px; }
.auth-container { max-width: 400px; width: 100%; text-align: center; animation: fadeIn 0.5s ease; }
.auth-logo { width: 100px; height: 100px; background: linear-gradient(135deg, var(--color-primary) 0%, #8b5cf6 100%); border-radius: var(--radius-xl); display: flex; align-items: center; justify-content: center; margin: 0 auto 24px; box-shadow: var(--shadow-glow); }
.auth-logo i { font-size: 48px; color: white; }
.auth-title { font-size: 2.5rem; font-weight: 700; margin-bottom: 8px; background: linear-gradient(135deg, #fff 0%, #a0a0b0 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.auth-subtitle { color: var(--color-text-secondary); font-size: 1.1rem; margin-bottom: 32px; }
.auth-features { display: flex; justify-content: center; gap: 24px; margin-bottom: 40px; flex-wrap: wrap; }
.auth-feature { display: flex; align-items: center; gap: 8px; color: var(--color-text-secondary); font-size: 0.9rem; }
.auth-feature i { color: var(--color-primary); }
.auth-btn { display: flex; align-items: center; justify-content: center; gap: 12px; width: 100%; padding: 16px 24px; border-radius: var(--radius-lg); font-size: 1rem; font-weight: 600; transition: all var(--transition); margin-bottom: 12px; }
.auth-btn:first-of-type { background: var(--color-telegram); color: white; }
.auth-btn:first-of-type:hover { background: #0099dd; transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0, 136, 204, 0.3); }
.auth-btn--secondary { background: var(--color-surface-elevated); color: var(--color-text); border: 1px solid var(--color-border); }
.auth-btn--secondary:hover { background: var(--color-surface-hover); border-color: var(--color-primary); }
.auth-hint { color: var(--color-text-muted); font-size: 0.85rem; margin-top: 24px; }

/* Main Layout */
.main-screen { display: flex; min-height: 100vh; }
.sidebar { width: var(--sidebar-width); background: var(--color-surface); border-right: 1px solid var(--color-border); display: flex; flex-direction: column; position: fixed; height: 100vh; z-index: 100; transition: transform var(--transition); }
.sidebar-header { padding: 20px; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--color-border); }
.logo { display: flex; align-items: center; gap: 12px; font-size: 1.25rem; font-weight: 700; }
.logo i { color: var(--color-primary); font-size: 1.5rem; }
.sidebar-toggle { display: none; color: var(--color-text-secondary); padding: 8px; border-radius: var(--radius-sm); }
.sidebar-nav { flex: 1; padding: 16px 12px; display: flex; flex-direction: column; gap: 4px; }
.nav-item { display: flex; align-items: center; gap: 12px; padding: 12px 16px; border-radius: var(--radius-md); color: var(--color-text-secondary); font-weight: 500; transition: all var(--transition-fast); width: 100%; text-align: left; }
.nav-item:hover { background: var(--color-surface-hover); color: var(--color-text); }
.nav-item.active { background: var(--color-primary); color: white; }
.nav-item i { width: 20px; text-align: center; }
.sidebar-footer { padding: 16px; border-top: 1px solid var(--color-border); }
.user-card { display: flex; align-items: center; gap: 12px; padding: 12px; background: var(--color-surface-elevated); border-radius: var(--radius-md); }
.user-avatar { width: 40px; height: 40px; background: linear-gradient(135deg, var(--color-primary) 0%, #8b5cf6 100%); border-radius: var(--radius-full); display: flex; align-items: center; justify-content: center; font-weight: 600; }
.user-info { display: flex; flex-direction: column; }
.user-name { font-weight: 600; font-size: 0.9rem; }
.user-status { font-size: 0.75rem; color: var(--color-text-muted); }

/* Main Content */
.main-content { flex: 1; margin-left: var(--sidebar-width); padding: 32px; max-width: 1200px; }
.view { animation: fadeIn 0.3s ease; }
.view[hidden] { display: none !important; }
.view-header { margin-bottom: 32px; }
.view-header h1 { font-size: 2rem; font-weight: 700; margin-bottom: 8px; }
.view-subtitle { color: var(--color-text-secondary); font-size: 1rem; }

/* Quick Actions */
.quick-actions { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; margin-bottom: 40px; }
.action-card { display: flex; align-items: center; gap: 20px; padding: 24px; background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-lg); transition: all var(--transition); text-align: left; }
.action-card:hover { border-color: var(--color-primary); transform: translateY(-4px); box-shadow: var(--shadow-md); }
.action-card--primary { background: linear-gradient(135deg, var(--color-primary) 0%, #8b5cf6 100%); border: none; }
.action-card--primary:hover { box-shadow: var(--shadow-glow); }
.action-icon { width: 56px; height: 56px; background: rgba(255, 255, 255, 0.1); border-radius: var(--radius-md); display: flex; align-items: center; justify-content: center; font-size: 1.5rem; }
.action-info h3 { font-size: 1.1rem; font-weight: 600; margin-bottom: 4px; }
.action-info p { font-size: 0.9rem; color: var(--color-text-secondary); }
.action-card--primary .action-info p { color: rgba(255, 255, 255, 0.8); }

/* Stats */
.stats-overview { margin-bottom: 40px; }
.stats-overview h2 { font-size: 1.25rem; margin-bottom: 20px; }
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 16px; }
.stat-card { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: 20px; text-align: center; }
.stat-icon { width: 48px; height: 48px; background: var(--color-primary-glow); border-radius: var(--radius-md); display: flex; align-items: center; justify-content: center; margin: 0 auto 12px; font-size: 1.25rem; color: var(--color-primary); }
.stat-value { font-size: 1.75rem; font-weight: 700; margin-bottom: 4px; }
.stat-label { font-size: 0.85rem; color: var(--color-text-muted); }

/* Topics */
.topics-preview { margin-bottom: 40px; }
.section-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px; }
.section-header h2 { font-size: 1.25rem; }
.btn-link { color: var(--color-primary); font-size: 0.9rem; font-weight: 500; display: flex; align-items: center; gap: 8px; }
.btn-link:hover { color: var(--color-primary-hover); }
.topics-grid, .topics-full-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 16px; }
.topic-card { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: 20px; transition: all var(--transition); cursor: pointer; }
.topic-card:hover { border-color: var(--color-primary); transform: translateY(-2px); }
.topic-number { width: 36px; height: 36px; background: var(--color-primary-glow); border-radius: var(--radius-sm); display: flex; align-items: center; justify-content: center; font-weight: 700; color: var(--color-primary); margin-bottom: 12px; }
.topic-title { font-weight: 600; font-size: 0.95rem; margin-bottom: 8px; line-height: 1.3; }
.topic-stats { display: flex; align-items: center; gap: 8px; font-size: 0.8rem; color: var(--color-text-muted); }
.topic-progress { flex: 1; height: 4px; background: var(--color-border); border-radius: var(--radius-full); overflow: hidden; }
.topic-progress-fill { height: 100%; background: var(--color-success); border-radius: var(--radius-full); }

/* Training */
.training-container { max-width: 800px; margin: 0 auto; }
.training-header { display: flex; align-items: center; gap: 20px; margin-bottom: 32px; padding: 16px 20px; background: var(--color-surface); border-radius: var(--radius-lg); border: 1px solid var(--color-border); }
.training-progress { flex: 1; }
.progress-text { font-size: 0.9rem; color: var(--color-text-secondary); margin-bottom: 8px; display: block; }
.progress-bar { height: 8px; background: var(--color-border); border-radius: var(--radius-full); overflow: hidden; }
.progress-fill { height: 100%; background: linear-gradient(90deg, var(--color-primary) 0%, #8b5cf6 100%); border-radius: var(--radius-full); transition: width var(--transition); }
.training-timer { display: flex; align-items: center; gap: 8px; font-size: 1.1rem; font-weight: 600; color: var(--color-text-secondary); }
.training-timer i { color: var(--color-primary); }
.btn-icon { width: 40px; height: 40px; border-radius: var(--radius-sm); display: flex; align-items: center; justify-content: center; color: var(--color-text-secondary); transition: all var(--transition-fast); }
.btn-icon:hover { background: var(--color-error-bg); color: var(--color-error); }

/* Task Card */
.task-card { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-xl); padding: 32px; margin-bottom: 24px; }
.task-topic { margin-bottom: 16px; }
.topic-badge { display: inline-block; padding: 6px 12px; background: var(--color-primary-glow); color: var(--color-primary); border-radius: var(--radius-full); font-size: 0.85rem; font-weight: 600; }
.task-title { font-size: 1.5rem; font-weight: 700; margin-bottom: 20px; }
.task-body { margin-bottom: 24px; }
.task-body p { font-size: 1.1rem; line-height: 1.7; color: var(--color-text-secondary); }
.task-image { margin-top: 20px; border-radius: var(--radius-md); overflow: hidden; }
.task-image img { max-width: 100%; height: auto; }
.task-answer { margin-top: 24px; }
.task-answer label { display: block; font-weight: 600; margin-bottom: 12px; color: var(--color-text-secondary); }
.answer-input { width: 100%; padding: 16px 20px; background: var(--color-surface-elevated); border: 2px solid var(--color-border); border-radius: var(--radius-md); color: var(--color-text); font-size: 1.1rem; transition: border-color var(--transition-fast); }
.answer-input:focus { outline: none; border-color: var(--color-primary); }
.answer-input.correct { border-color: var(--color-success); background: var(--color-success-bg); }
.answer-input.incorrect { border-color: var(--color-error); background: var(--color-error-bg); }
.answer-hint { margin-top: 8px; font-size: 0.9rem; color: var(--color-text-muted); }
.task-solution { margin-top: 24px; padding: 20px; background: var(--color-surface-elevated); border-radius: var(--radius-md); border-left: 4px solid var(--color-primary); }
.task-solution h4 { display: flex; align-items: center; gap: 8px; color: var(--color-primary); margin-bottom: 12px; }
.task-solution p { color: var(--color-text-secondary); line-height: 1.6; }

/* Training Actions */
.training-actions { display: flex; gap: 12px; }
.btn { padding: 14px 24px; border-radius: var(--radius-md); font-weight: 600; font-size: 1rem; display: flex; align-items: center; gap: 8px; transition: all var(--transition-fast); }
.btn--secondary { background: var(--color-surface-elevated); color: var(--color-text); border: 1px solid var(--color-border); }
.btn--secondary:hover:not(:disabled) { background: var(--color-surface-hover); border-color: var(--color-primary); }
.btn--primary { background: var(--color-primary); color: white; flex: 1; justify-content: center; }
.btn--primary:hover:not(:disabled) { background: var(--color-primary-hover); transform: translateY(-2px); }
.btn--success { background: var(--color-success); color: white; flex: 1; justify-content: center; }
.btn--success:hover { filter: brightness(1.1); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

/* Monitoring */
.monitoring-tabs { display: flex; gap: 8px; margin-bottom: 24px; padding: 4px; background: var(--color-surface); border-radius: var(--radius-md); }
.tab-btn { flex: 1; padding: 12px; border-radius: var(--radius-sm); font-weight: 500; color: var(--color-text-secondary); transition: all var(--transition-fast); }
.tab-btn:hover { color: var(--color-text); }
.tab-btn.active { background: var(--color-primary); color: white; }
.tab-content[hidden] { display: none; }
.monitoring-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 16px; }
.monitoring-card { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: 20px; }
.monitoring-card-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 16px; }
.monitoring-card-title { font-weight: 600; }
.monitoring-card-badge { padding: 4px 10px; border-radius: var(--radius-full); font-size: 0.8rem; font-weight: 600; }
.monitoring-card-badge.success { background: var(--color-success-bg); color: var(--color-success); }
.monitoring-card-badge.warning { background: rgba(245, 158, 11, 0.1); color: var(--color-warning); }
.monitoring-card-badge.error { background: var(--color-error-bg); color: var(--color-error); }
.monitoring-stats { display: flex; gap: 16px; }
.monitoring-stat { text-align: center; }
.monitoring-stat-value { font-size: 1.25rem; font-weight: 700; }
.monitoring-stat-label { font-size: 0.75rem; color: var(--color-text-muted); }
.sessions-list { display: flex; flex-direction: column; gap: 12px; }
.session-item { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-md); padding: 16px; display: flex; justify-content: space-between; align-items: center; }
.session-info { display: flex; flex-direction: column; gap: 4px; }
.session-date { font-weight: 600; }
.session-details { font-size: 0.85rem; color: var(--color-text-muted); }
.session-score { font-size: 1.25rem; font-weight: 700; color: var(--color-primary); }

/* Stats Detailed */
.stats-detailed { display: grid; grid-template-columns: 300px 1fr; gap: 24px; }
.stats-card-large { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-xl); padding: 32px; text-align: center; }
.stats-card-large h3 { margin-bottom: 24px; }
.circular-progress { width: 150px; height: 150px; background: conic-gradient(var(--color-primary) 0deg, var(--color-border) 0deg); border-radius: 50%; display: flex; align-items: center; justify-content: center; margin: 0 auto 16px; position: relative; }
.circular-progress::before { content: ''; position: absolute; width: 120px; height: 120px; background: var(--color-surface); border-radius: 50%; }
.progress-value { position: relative; font-size: 1.5rem; font-weight: 700; }
.stats-breakdown { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-xl); padding: 24px; }
.stats-breakdown h3 { margin-bottom: 20px; }
.breakdown-list { display: flex; flex-direction: column; gap: 12px; }
.breakdown-item { display: flex; align-items: center; gap: 12px; padding: 12px; background: var(--color-surface-elevated); border-radius: var(--radius-md); }
.breakdown-number { width: 32px; height: 32px; background: var(--color-primary-glow); border-radius: var(--radius-sm); display: flex; align-items: center; justify-content: center; font-weight: 600; color: var(--color-primary); font-size: 0.85rem; }
.breakdown-info { flex: 1; }
.breakdown-title { font-weight: 500; font-size: 0.9rem; }
.breakdown-progress { height: 4px; background: var(--color-border); border-radius: var(--radius-full); margin-top: 6px; }
.breakdown-progress-fill { height: 100%; background: var(--color-success); border-radius: var(--radius-full); }
.breakdown-value { font-weight: 600; color: var(--color-text-secondary); }

/* Modal */
.modal { border: none; background: transparent; padding: 0; max-width: 500px; width: 90%; }
.modal::backdrop { background: rgba(0, 0, 0, 0.8); backdrop-filter: blur(4px); }
.modal-content { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-xl); overflow: hidden; }
.modal-header { display: flex; justify-content: space-between; align-items: center; padding: 20px 24px; border-bottom: 1px solid var(--color-border); }
.modal-header h2 { font-size: 1.25rem; }
.modal-close { color: var(--color-text-muted); }
.modal-close:hover { color: var(--color-text); }
.modal-body { padding: 24px; max-height: 60vh; overflow-y: auto; }
.modal-footer { display: flex; gap: 12px; padding: 20px 24px; border-top: 1px solid var(--color-border); }
.modal-footer .btn { flex: 1; justify-content: center; }

/* Results */
.results-summary { text-align: center; margin-bottom: 24px; }
.results-score { margin-bottom: 24px; }
.score-circle { width: 120px; height: 120px; background: linear-gradient(135deg, var(--color-primary) 0%, #8b5cf6 100%); border-radius: 50%; display: flex; flex-direction: column; align-items: center; justify-content: center; margin: 0 auto; box-shadow: var(--shadow-glow); }
.score-value { font-size: 2.5rem; font-weight: 700; }
.score-total { font-size: 1rem; opacity: 0.8; }
.score-label { color: var(--color-text-secondary); }
.results-stats { display: flex; justify-content: center; gap: 32px; }
.result-stat { text-align: center; }
.result-stat i { font-size: 1.25rem; color: var(--color-primary); margin-bottom: 8px; }
.result-stat span { display: block; font-size: 1.25rem; font-weight: 600; }
.result-stat label { font-size: 0.8rem; color: var(--color-text-muted); }
.results-details { display: flex; flex-direction: column; gap: 12px; }
.result-item { display: flex; align-items: center; gap: 12px; padding: 12px; background: var(--color-surface-elevated); border-radius: var(--radius-md); }
.result-item.correct { border-left: 3px solid var(--color-success); }
.result-item.incorrect { border-left: 3px solid var(--color-error); }
.result-item-number { width: 28px; height: 28px; border-radius: var(--radius-sm); display: flex; align-items: center; justify-content: center; font-weight: 600; font-size: 0.85rem; }
.result-item.correct .result-item-number { background: var(--color-success-bg); color: var(--color-success); }
.result-item.incorrect .result-item-number { background: var(--color-error-bg); color: var(--color-error); }
.result-item-info { flex: 1; }
.result-item-title { font-weight: 500; font-size: 0.9rem; margin-bottom: 2px; }
.result-item-answer { font-size: 0.8rem; color: var(--color-text-muted); }
.result-item-icon { font-size: 1.25rem; }
.result-item.correct .result-item-icon { color: var(--color-success); }
.result-item.incorrect .result-item-icon { color: var(--color-error); }

/* Animations */
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes slideIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }

/* Responsive */
@media (max-width: 768px) {
  .sidebar { transform: translateX(-100%); }
  .sidebar.open { transform: translateX(0); }
  .sidebar-toggle { display: block; }
  .main-content { margin-left: 0; padding: 20px; }
  .stats-detailed { grid-template-columns: 1fr; }
  .quick-actions { grid-template-columns: 1fr; }
  .training-header { flex-wrap: wrap; }
  .training-actions { flex-wrap: wrap; }
  .btn { flex: 1 1 100%; }
}

.placeholder { text-align: center; padding: 40px; color: var(--color-text-muted); }