:root {
  /* ===== BRAND COLORS — змінюй тут ===== */
  --primary:        #c66dff;
  --primary-glow:   rgba(198, 109, 255, 0.45);
  --accent:         #ff6b81;
  --accent-2:       #c66dff;
  --accent-3:       #ff9f6b;
  --success:        #4ade80;
  --warning:        #fbbf24;
  --error:          #f87171;

  /* ===== BACKGROUNDS ===== */
  --bg:             #0a0612;
  --bg-2:           #0d0918;
  --surface:        rgba(255,255,255,0.03);
  --surface-2:      rgba(255,255,255,0.05);
  --surface-3:      rgba(255,255,255,0.08);

  /* ===== BORDERS ===== */
  --border:         rgba(255,255,255,0.08);
  --border-hover:   rgba(255,255,255,0.18);

  /* ===== TEXT ===== */
  --text:           #ffffff;
  --text-muted:     #9999b0;
  --text-dim:       rgba(255,255,255,0.45);

  /* ===== CONSOLE ===== */
  --console-bg:     #0d0f14;
  --console-border: rgba(198,109,255,0.2);
  --console-text:   #e2e8f0;
  --console-muted:  #64748b;

  /* ===== MISC ===== */
  --radius:         20px;
  --radius-sm:      12px;
  --radius-xs:      8px;
  --font:           'Inter', 'Roboto', -apple-system, BlinkMacSystemFont, sans-serif;
  --mono:           'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
  --transition:     0.3s cubic-bezier(0.2, 0.8, 0.2, 1);
}

/* ===== RESET ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; height: 100%; }

body {
  font-family: var(--font);
  background-color: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  min-height: 100%;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 800px 600px at 80% 10%, rgba(255,107,129,0.12), transparent 60%),
    radial-gradient(ellipse 700px 500px at 10% 50%, rgba(198,109,255,0.10), transparent 60%),
    radial-gradient(ellipse 600px 400px at 90% 90%, rgba(255,159,107,0.08), transparent 60%);
  pointer-events: none;
  z-index: -1;
}

a { color: var(--accent); text-decoration: none; }
*:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: var(--radius-xs); }

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.15); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: rgba(255,255,255,0.25); }

/* ===== LOADER ===== */
#app-loader {
  position: fixed; inset: 0;
  background: var(--bg);
  z-index: 1000;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  gap: 16px;
  font-size: 13px;
  color: var(--text-muted);
}

.loader-logo {
  font-size: 28px; font-weight: 900;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, #fff, var(--accent));
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 8px;
}

.spinner {
  width: 36px; height: 36px;
  border: 2.5px solid rgba(255,255,255,0.08);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ===== SCREEN SYSTEM ===== */
.screen { display: none; min-height: 100vh; }
.screen.active { display: flex; }

/* ===== LOGIN SCREEN ===== */
#screen-login {
  align-items: center;
  justify-content: center;
  padding: 24px;
  flex-direction: column;
}

.login-card {
  width: 100%;
  max-width: 420px;
  background: linear-gradient(180deg, rgba(255,255,255,0.05) 0%, rgba(255,255,255,0.02) 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px 36px;
  position: relative;
  overflow: hidden;
}

.login-card::before {
  content: '';
  position: absolute; top: -40%; left: 50%;
  transform: translateX(-50%);
  width: 200px; height: 200px;
  background: radial-gradient(circle, var(--primary-glow), transparent 70%);
  filter: blur(30px);
  pointer-events: none;
}

.login-logo {
  text-align: center;
  margin-bottom: 8px;
}
.login-logo-text {
  font-size: 32px; font-weight: 900;
  letter-spacing: -0.04em;
  background: linear-gradient(135deg, #fff, var(--accent));
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.login-subtitle {
  text-align: center;
  color: var(--text-muted);
  font-size: 13px;
  margin-bottom: 32px;
}

.form-group { margin-bottom: 16px; }
.form-label {
  display: block;
  font-size: 12px; font-weight: 600;
  letter-spacing: 0.5px;
  color: var(--text-muted);
  margin-bottom: 8px;
  text-transform: uppercase;
}
.form-input {
  width: 100%;
  padding: 12px 16px;
  background: rgba(255,255,255,0.05);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 14px;
  font-family: var(--font);
  transition: border-color var(--transition), background var(--transition);
}
.form-input:focus {
  outline: none;
  border-color: var(--accent);
  background: rgba(255,255,255,0.08);
}
.form-input::placeholder { color: var(--text-dim); }

.login-error {
  color: var(--error);
  font-size: 13px;
  text-align: center;
  margin-top: 12px;
  min-height: 20px;
}

.login-hint {
  margin-top: 20px;
  padding: 12px;
  background: rgba(198,109,255,0.08);
  border: 1px solid rgba(198,109,255,0.2);
  border-radius: var(--radius-xs);
  font-size: 12px;
  color: var(--text-muted);
  text-align: center;
}
.login-hint code {
  color: var(--primary);
  font-family: var(--mono);
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  border: none; cursor: pointer;
  font-family: var(--font);
  font-size: 13px; font-weight: 600;
  border-radius: 100px;
  transition: all var(--transition);
  line-height: 1;
}
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
  box-shadow: 0 6px 18px rgba(255,107,129,0.25);
}
.btn-primary:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(255,107,129,0.4);
}

.btn-ghost {
  background: rgba(255,255,255,0.05);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-ghost:hover:not(:disabled) {
  background: rgba(255,255,255,0.09);
  border-color: var(--border-hover);
}

.btn-success {
  background: linear-gradient(135deg, #22c55e, #16a34a);
  color: #fff;
  box-shadow: 0 6px 18px rgba(34,197,94,0.25);
}

.btn-full { width: 100%; }

/* ===== DASHBOARD SCREEN ===== */
#screen-dashboard {
  flex-direction: column;
}

/* ===== TOP NAV ===== */
.topnav {
  display: flex; align-items: center;
  padding: 14px 28px;
  background: rgba(10,6,18,0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  gap: 16px;
  position: sticky; top: 0; z-index: 100;
}
.topnav-logo {
  font-size: 20px; font-weight: 900;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, #fff, var(--accent));
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
  flex-shrink: 0;
}
.topnav-spacer { flex: 1; }
.topnav-user {
  display: flex; align-items: center; gap: 10px;
  font-size: 13px; color: var(--text-muted);
}
.user-avatar {
  width: 32px; height: 32px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  display: flex; align-items: center; justify-content: center;
  font-size: 13px; font-weight: 700; color: #fff;
  flex-shrink: 0;
}
.topnav-score {
  display: flex; align-items: center; gap: 6px;
  padding: 6px 14px;
  background: rgba(198,109,255,0.1);
  border: 1px solid rgba(198,109,255,0.2);
  border-radius: 100px;
  font-size: 13px; font-weight: 700;
  color: var(--primary);
}

/* ===== DASHBOARD BODY ===== */
.dashboard-body {
  flex: 1;
  padding: 36px 28px 60px;
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

.dashboard-hero {
  margin-bottom: 40px;
  padding: 32px 36px;
  background: linear-gradient(135deg, #0d0918 0%, #1a0f2e 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  position: relative; overflow: hidden;
}
.dashboard-hero::before {
  content: '';
  position: absolute; top: -20%; right: -10%;
  width: 60%; height: 140%;
  background: radial-gradient(circle at 60% 50%, rgba(255,107,129,0.15), transparent 50%),
              radial-gradient(circle at 90% 40%, rgba(198,109,255,0.12), transparent 50%);
  filter: blur(40px);
  pointer-events: none;
}
.dashboard-hero-content { position: relative; z-index: 1; }
.dashboard-hero h1 {
  font-size: clamp(22px, 4vw, 36px);
  font-weight: 800; letter-spacing: -0.03em; line-height: 1.1;
}
.dashboard-hero h1 em {
  font-style: normal;
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.dashboard-hero p {
  color: var(--text-muted); font-size: 14px; margin-top: 10px;
  max-width: 480px;
}
.progress-bar-wrap {
  margin-top: 20px;
  display: flex; align-items: center; gap: 14px;
}
.progress-bar-bg {
  flex: 1; height: 6px; border-radius: 3px;
  background: rgba(255,255,255,0.08);
}
.progress-bar-fill {
  height: 100%; border-radius: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  transition: width 0.6s cubic-bezier(0.2, 0.8, 0.2, 1);
}
.progress-label {
  font-size: 12px; color: var(--text-muted); white-space: nowrap;
}

/* ===== LESSON GRID ===== */
.lessons-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}

.lesson-card {
  background: linear-gradient(180deg, rgba(255,255,255,0.04) 0%, rgba(255,255,255,0.015) 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  cursor: pointer;
  transition: all var(--transition);
  position: relative; overflow: hidden;
}
.lesson-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-hover);
}
.lesson-card::before {
  content: '';
  position: absolute; bottom: -40%; left: 50%;
  transform: translateX(-50%);
  width: 60%; height: 60%;
  background: var(--primary-glow);
  border-radius: 50%;
  filter: blur(50px);
  opacity: 0;
  transition: opacity 0.4s;
  pointer-events: none;
}
.lesson-card:hover::before { opacity: 1; }
.lesson-card.completed { border-color: rgba(74,222,128,0.3); }
.lesson-card.locked { opacity: 0.5; cursor: not-allowed; }
.lesson-card.locked:hover { transform: none; }
.lesson-card-top {
  display: flex; align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}
.lesson-num {
  width: 36px; height: 36px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  display: flex; align-items: center; justify-content: center;
  font-size: 13px; font-weight: 800; color: #fff;
  box-shadow: 0 4px 12px rgba(255,107,129,0.3);
}
.lesson-status-icon { font-size: 18px; }
.lesson-card h3 {
  font-size: 16px; font-weight: 700;
  letter-spacing: -0.01em; margin-bottom: 6px;
}
.lesson-card p {
  font-size: 12px; color: var(--text-muted); line-height: 1.5;
}
.lesson-card-footer {
  display: flex; align-items: center; justify-content: space-between;
  margin-top: 16px;
}
.lesson-points {
  font-size: 12px; color: var(--primary); font-weight: 600;
}
.lesson-badge {
  font-size: 10px; font-weight: 700; letter-spacing: 1px;
  text-transform: uppercase; color: var(--accent);
  padding: 3px 8px;
  background: rgba(255,107,129,0.1);
  border: 1px solid rgba(255,107,129,0.2);
  border-radius: 100px;
}

/* ===== LESSON SCREEN ===== */
#screen-lesson {
  flex-direction: column;
}

.lesson-layout {
  flex: 1; display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: calc(100vh - 60px);
  overflow: hidden;
}

/* LEFT PANEL */
.lesson-left {
  overflow-y: auto;
  border-right: 1px solid var(--border);
  display: flex; flex-direction: column;
}

.lesson-tabs {
  display: flex;
  border-bottom: 1px solid var(--border);
  background: rgba(255,255,255,0.02);
  flex-shrink: 0;
}
.tab-btn {
  flex: 1; padding: 14px 12px;
  background: transparent; border: none;
  color: var(--text-muted); font-family: var(--font);
  font-size: 13px; font-weight: 600;
  cursor: pointer; transition: all var(--transition);
  border-bottom: 2px solid transparent;
  letter-spacing: 0.3px;
}
.tab-btn.active {
  color: var(--text);
  border-bottom-color: var(--accent);
}
.tab-btn:hover:not(.active) { color: var(--text); }

.tab-panel { display: none; padding: 28px; flex: 1; }
.tab-panel.active { display: block; }

/* Theory content styles */
.tab-panel h2 {
  font-size: 22px; font-weight: 800; letter-spacing: -0.02em;
  margin-bottom: 18px;
}
.tab-panel h3 {
  font-size: 16px; font-weight: 700; margin: 24px 0 10px;
  color: var(--text);
}
.tab-panel h4 {
  font-size: 14px; font-weight: 700; margin-bottom: 6px;
}
.tab-panel p {
  font-size: 14px; line-height: 1.7; color: rgba(255,255,255,0.85);
  margin-bottom: 12px;
}
.tab-panel ul, .tab-panel ol { padding-left: 20px; }
.tab-panel li {
  font-size: 14px; line-height: 1.7; color: rgba(255,255,255,0.8);
  margin-bottom: 4px;
}

.code-example {
  background: var(--console-bg);
  border: 1px solid var(--console-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin: 12px 0;
}
.code-label {
  padding: 8px 14px;
  font-size: 11px; font-weight: 600;
  color: var(--primary); letter-spacing: 0.5px;
  background: rgba(198,109,255,0.08);
  border-bottom: 1px solid rgba(198,109,255,0.1);
}
.code-example pre {
  padding: 14px;
  overflow-x: auto;
}
.code-example code {
  font-family: var(--mono);
  font-size: 13px; line-height: 1.6;
  color: var(--console-text);
  white-space: pre;
}

.example-table {
  width: 100%; border-collapse: collapse;
  font-size: 13px;
}
.example-table th {
  padding: 8px 12px; text-align: left;
  background: rgba(198,109,255,0.1);
  color: var(--primary); font-weight: 700;
  font-size: 12px; letter-spacing: 0.3px;
}
.example-table td {
  padding: 8px 12px;
  border-top: 1px solid rgba(255,255,255,0.04);
  color: rgba(255,255,255,0.85);
}
.example-table tr:hover td { background: rgba(255,255,255,0.02); }

/* same styles for theory-table */
.theory-table {
  width: 100%; border-collapse: collapse;
  font-size: 13px; margin: 12px 0;
}
.theory-table th {
  padding: 8px 12px; text-align: left;
  background: rgba(198,109,255,0.1);
  color: var(--primary); font-weight: 700;
  font-size: 12px; letter-spacing: 0.3px;
  border: 1px solid var(--border);
}
.theory-table td {
  padding: 8px 12px;
  border: 1px solid rgba(255,255,255,0.06);
  color: rgba(255,255,255,0.85);
}
.theory-table tr:hover td { background: rgba(255,255,255,0.02); }

/* scrollable wrapper for tables in theory */
.example-table-wrap, .theory-table-wrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.theory-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 12px; margin: 12px 0;
}
.theory-card {
  padding: 16px;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  min-width: 0;
  overflow: hidden;
}
.theory-card-icon { font-size: 24px; margin-bottom: 8px; }
.theory-card h4 { font-size: 13px; margin-bottom: 6px; }
.theory-card p { font-size: 12px; color: var(--text-muted); margin: 0; word-break: break-word; }
.theory-card pre { margin: 6px 0 0; overflow-x: auto; }
.theory-card code { font-size: 11px; white-space: pre-wrap; word-break: break-word; }

.operators-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 8px; margin: 12px 0;
}
.op-item {
  padding: 10px 12px;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--border);
  border-radius: var(--radius-xs);
  font-size: 13px; color: var(--text-muted);
}
.op-item code {
  font-family: var(--mono); color: var(--primary); font-size: 14px;
}

.tip-box {
  padding: 14px 16px;
  background: rgba(198,109,255,0.08);
  border: 1px solid rgba(198,109,255,0.2);
  border-radius: var(--radius-xs);
  font-size: 13px; line-height: 1.6;
  margin: 12px 0;
}
.warning-box {
  padding: 14px 16px;
  background: rgba(251,191,36,0.08);
  border: 1px solid rgba(251,191,36,0.25);
  border-radius: var(--radius-xs);
  font-size: 13px; line-height: 1.6;
  margin: 12px 0;
}
.theory-list { padding-left: 20px; }
.theory-list li { margin-bottom: 6px; font-size: 14px; line-height: 1.6; }

/* QUIZ */
.quiz-wrap { max-width: 600px; }
.quiz-progress {
  font-size: 12px; color: var(--text-muted); margin-bottom: 20px;
  display: flex; align-items: center; gap: 8px;
}
.quiz-progress-dots {
  display: flex; gap: 6px;
}
.quiz-dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: rgba(255,255,255,0.15);
  transition: background 0.3s;
}
.quiz-dot.done { background: var(--success); }
.quiz-dot.current { background: var(--accent); }

.quiz-question {
  font-size: 16px; font-weight: 700;
  margin-bottom: 18px; line-height: 1.45;
}
.quiz-options { display: flex; flex-direction: column; gap: 10px; }
.quiz-option {
  padding: 14px 18px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer; text-align: left;
  color: var(--text); font-family: var(--font);
  font-size: 14px; line-height: 1.4;
  transition: all var(--transition);
}
.quiz-option:hover:not(:disabled) {
  background: rgba(255,255,255,0.07);
  border-color: var(--border-hover);
}
.quiz-option.correct {
  background: rgba(74,222,128,0.1);
  border-color: rgba(74,222,128,0.4);
  color: var(--success);
}
.quiz-option.wrong {
  background: rgba(248,113,113,0.1);
  border-color: rgba(248,113,113,0.4);
  color: var(--error);
}
.quiz-feedback {
  margin-top: 16px;
  padding: 12px 16px;
  border-radius: var(--radius-xs);
  font-size: 13px; font-weight: 600;
}
.quiz-feedback.correct {
  background: rgba(74,222,128,0.1);
  border: 1px solid rgba(74,222,128,0.3);
  color: var(--success);
}
.quiz-feedback.wrong {
  background: rgba(248,113,113,0.1);
  border: 1px solid rgba(248,113,113,0.3);
  color: var(--error);
}

.quiz-result {
  text-align: center; padding: 24px;
}
.quiz-result-score {
  font-size: 48px; font-weight: 900;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.quiz-result-label { font-size: 14px; color: var(--text-muted); margin: 8px 0 20px; }
.quiz-unlock-msg {
  padding: 12px 16px;
  background: rgba(74,222,128,0.1);
  border: 1px solid rgba(74,222,128,0.3);
  border-radius: var(--radius-xs);
  font-size: 13px; color: var(--success); margin-bottom: 16px;
}

/* RIGHT PANEL — SQL Console */
.lesson-right {
  display: flex; flex-direction: column;
  overflow: hidden;
  background: var(--console-bg);
}

.console-header {
  display: flex; align-items: center;
  padding: 12px 16px;
  border-bottom: 1px solid var(--console-border);
  gap: 10px; flex-shrink: 0;
}
.console-title {
  font-size: 12px; font-weight: 700;
  letter-spacing: 1.5px; text-transform: uppercase;
  color: var(--primary);
  flex: 1;
}
.console-dots { display: flex; gap: 6px; }
.console-dot {
  width: 10px; height: 10px; border-radius: 50%;
}
.console-dot:nth-child(1) { background: #ff5f57; }
.console-dot:nth-child(2) { background: #ffbd2e; }
.console-dot:nth-child(3) { background: #28c840; }

.practice-task {
  padding: 14px 16px;
  background: rgba(198,109,255,0.06);
  border-bottom: 1px solid var(--console-border);
  flex-shrink: 0;
}
.practice-task-label {
  font-size: 10px; font-weight: 700; letter-spacing: 1.5px;
  text-transform: uppercase; color: var(--primary); margin-bottom: 6px;
}
.practice-task-text {
  font-size: 13px; line-height: 1.55; color: rgba(255,255,255,0.85);
  white-space: pre-wrap;
}

.sql-editor-wrap {
  flex: 1; display: flex; flex-direction: column;
  min-height: 0;
  overflow: hidden;
}

.sql-textarea {
  flex: 1;
  width: 100%;
  min-height: 150px;
  max-height: 280px;
  padding: 16px;
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--console-border);
  color: var(--console-text);
  font-family: var(--mono);
  font-size: 13px; line-height: 1.6;
  resize: none;
  outline: none;
}
.sql-textarea::placeholder { color: var(--console-muted); }

.editor-toolbar {
  display: flex; align-items: center;
  padding: 10px 16px; gap: 8px;
  border-bottom: 1px solid var(--console-border);
  flex-shrink: 0;
  flex-wrap: wrap;
}

.hint-section {
  padding: 12px 16px;
  border-bottom: 1px solid var(--console-border);
  flex-shrink: 0;
}
.hint-status {
  font-size: 11px; color: var(--text-muted); margin-bottom: 6px;
}
.hint-text {
  font-size: 13px; line-height: 1.55;
  color: rgba(255,220,120,0.9);
  padding: 10px 12px;
  background: rgba(251,191,36,0.07);
  border: 1px solid rgba(251,191,36,0.15);
  border-radius: var(--radius-xs);
  display: none;
}
.hint-text.visible { display: block; }

.sql-output {
  flex: 1; overflow-y: auto; overflow-x: auto;
  padding: 16px;
  min-height: 120px;
}
.output-empty {
  display: flex; align-items: center; justify-content: center;
  height: 80px; color: var(--console-muted); font-size: 13px;
}
.output-table-wrap { overflow-x: auto; }
.output-table {
  width: 100%; border-collapse: collapse;
  font-size: 12px; font-family: var(--mono);
}
.output-table th {
  padding: 8px 12px; text-align: left;
  background: rgba(198,109,255,0.12);
  color: var(--primary); font-weight: 700;
  font-size: 11px; letter-spacing: 0.5px;
  border-bottom: 1px solid rgba(198,109,255,0.2);
  white-space: nowrap;
}
.output-table td {
  padding: 7px 12px;
  border-bottom: 1px solid rgba(255,255,255,0.04);
  color: var(--console-text);
  white-space: nowrap;
}
.output-table tr:hover td { background: rgba(255,255,255,0.03); }

.output-error {
  padding: 12px 14px;
  background: rgba(248,113,113,0.1);
  border: 1px solid rgba(248,113,113,0.3);
  border-radius: var(--radius-xs);
  color: var(--error); font-family: var(--mono); font-size: 12px;
}
.output-success {
  padding: 12px 14px;
  background: rgba(74,222,128,0.1);
  border: 1px solid rgba(74,222,128,0.3);
  border-radius: var(--radius-xs);
  color: var(--success); font-size: 13px; font-weight: 600;
  margin-bottom: 12px;
}
.output-rows-info {
  font-size: 11px; color: var(--text-muted); margin-top: 8px;
}

/* ===== TOAST NOTIFICATION ===== */
.toast {
  position: fixed; bottom: 24px; right: 24px;
  padding: 14px 20px;
  background: linear-gradient(135deg, rgba(20,16,32,0.95), rgba(15,10,24,0.95));
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 13px; font-weight: 600;
  backdrop-filter: blur(20px);
  z-index: 500;
  transform: translateY(80px); opacity: 0;
  transition: all 0.4s cubic-bezier(0.2, 0.8, 0.2, 1);
  max-width: 320px;
}
.toast.show { transform: translateY(0); opacity: 1; }
.toast.success { border-color: rgba(74,222,128,0.4); color: var(--success); }
.toast.error   { border-color: rgba(248,113,113,0.4); color: var(--error); }
.toast.info    { border-color: rgba(198,109,255,0.4); color: var(--primary); }

/* ===== LESSON SCREEN — THREE TABS ===== */
.lesson-layout-tabs {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
}

.lesson-layout-tabs .lesson-tabs {
  flex-shrink: 0;
}

.lesson-layout-tabs .tab-panel {
  flex: 1;
  overflow-y: auto;
  padding: 0;
}

.lesson-layout-tabs .tab-panel.active {
  display: flex;
  flex-direction: column;
}

.tab-panel-inner {
  padding: 28px 48px;
  max-width: 960px;
  width: 100%;
  margin: 0 auto;
}

/* Practice panel fills the tab fully */
.practice-panel {
  display: flex;
  flex-direction: column;
  flex: 1;
  min-height: 0;
  background: var(--console-bg);
}

.practice-panel .sql-editor-wrap {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
}

/* ===== TIMER ===== */
.topnav-timer {
  display: flex; align-items: center;
  padding: 6px 12px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  border-radius: 100px;
  font-size: 12px; font-weight: 700;
  color: var(--text-muted);
  font-family: var(--mono);
  letter-spacing: 0.5px;
}
.topnav-timer.running { color: var(--accent-3); border-color: rgba(255,159,107,0.3); }
.topnav-timer.done { color: var(--success); border-color: rgba(74,222,128,0.3); }

/* ===== LESSON CARD — reset btn & time ===== */
.lesson-card-time {
  font-size: 11px; color: var(--text-muted);
  display: flex; align-items: center; gap: 4px;
}
.btn-lesson-reset {
  padding: 4px 10px;
  font-size: 11px; font-weight: 600;
  background: rgba(255,255,255,0.05);
  border: 1px solid var(--border);
  border-radius: 100px;
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--transition);
  flex-shrink: 0;
}
.btn-lesson-reset:hover {
  color: var(--accent);
  border-color: rgba(255,107,129,0.4);
  background: rgba(255,107,129,0.08);
}

/* ===== SQL HIGHLIGHT OVERLAY ===== */
.editor-highlight-wrap {
  position: relative;
  flex: 1;
  min-height: 150px;
  max-height: 280px;
  overflow: hidden;
}

#sql-highlight, #sandbox-highlight {
  position: absolute;
  inset: 0;
  padding: 16px;
  margin: 0;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.6;
  color: transparent;
  background: transparent;
  white-space: pre-wrap;
  word-wrap: break-word;
  overflow: hidden;
  pointer-events: none;
  border: none;
  border-bottom: 1px solid var(--console-border);
  z-index: 1;
}

#sql-highlight code, #sandbox-highlight code {
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.6;
  background: none;
  padding: 0;
}

.editor-highlight-wrap .sql-textarea {
  position: relative;
  z-index: 2;
  width: 100%;
  height: 100%;
  min-height: 150px;
  max-height: 280px;
  background: transparent;
  caret-color: #fff;
  color: var(--console-text);
  resize: none;
}

/* Syntax highlight token colors */
.hl-kw   { color: var(--primary); font-weight: 600; }
.hl-fn   { color: var(--accent-3); }
.hl-str  { color: var(--success); }
.hl-num  { color: var(--accent); }
.hl-cmt  { color: var(--console-muted); font-style: italic; }
.hl-op   { color: rgba(255,255,255,0.5); }

/* ===== SANDBOX ===== */
#screen-sandbox {
  flex-direction: column;
}

.sandbox-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 24px 28px;
  max-width: 1100px;
  width: 100%;
  margin: 0 auto;
  gap: 16px;
}

.sandbox-datasets {
  flex-shrink: 0;
}

.dataset-btns {
  display: flex; gap: 8px; flex-wrap: wrap;
}

.dataset-btn {
  padding: 8px 16px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  border-radius: 100px;
  color: var(--text-muted);
  font-family: var(--font);
  font-size: 13px; font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
}
.dataset-btn:hover {
  background: rgba(255,255,255,0.08);
  color: var(--text);
  border-color: var(--border-hover);
}
.dataset-btn.active {
  background: rgba(198,109,255,0.12);
  border-color: rgba(198,109,255,0.4);
  color: var(--primary);
}

.sandbox-editor {
  flex: 1;
  display: flex;
  flex-direction: column;
  background: var(--console-bg);
  border: 1px solid var(--console-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  min-height: 0;
}

.sandbox-editor .editor-highlight-wrap {
  min-height: 200px;
  max-height: 360px;
}

.sandbox-editor .sql-textarea {
  min-height: 200px;
  max-height: 360px;
}

.sandbox-editor .sql-output {
  flex: 1;
  min-height: 160px;
}

/* ===== MODAL ===== */
.modal-overlay {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.65);
  backdrop-filter: blur(8px);
  z-index: 900;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.modal-card {
  background: linear-gradient(180deg, #120d1e 0%, #0e0a18 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  width: 100%;
  max-width: 520px;
  max-height: 85vh;
  overflow-y: auto;
  padding: 28px;
  position: relative;
}

.modal-header {
  display: flex; align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}
.modal-title {
  font-size: 18px; font-weight: 800; letter-spacing: -0.02em;
}

.modal-section {
  margin-bottom: 24px;
}
.modal-section-title {
  font-size: 11px; font-weight: 700;
  letter-spacing: 1px; text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.admin-users-list {
  display: flex; flex-wrap: wrap; gap: 8px;
}
.admin-user-chip {
  padding: 5px 12px;
  background: rgba(198,109,255,0.1);
  border: 1px solid rgba(198,109,255,0.2);
  border-radius: 100px;
  font-size: 12px; color: var(--primary);
  font-family: var(--mono);
}

.admin-code-wrap {
  display: flex; align-items: center;
  gap: 10px;
  background: var(--console-bg);
  border: 1px solid var(--console-border);
  border-radius: var(--radius-xs);
  padding: 12px 14px;
}
.admin-code {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--success);
  flex: 1;
  word-break: break-all;
}

/* ===== TRAINER SCREEN ===== */
#screen-trainer {
  flex-direction: column;
}

.trainer-progress-wrap {
  display: flex; align-items: center; gap: 10px;
  flex: 1; max-width: 260px;
}
.trainer-progress-bar {
  flex: 1; height: 6px;
  background: rgba(255,255,255,0.08);
  border-radius: 99px; overflow: hidden;
}
.trainer-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  border-radius: 99px;
  transition: width 0.4s cubic-bezier(0.2, 0.8, 0.2, 1);
}
.trainer-progress-label {
  font-size: 12px; color: var(--text-muted); white-space: nowrap;
}

.trainer-body {
  flex: 1;
  padding: 24px 28px 48px;
  max-width: 900px;
  width: 100%;
  margin: 0 auto;
}

.trainer-topics-bar {
  display: flex; gap: 8px; flex-wrap: wrap;
  margin-bottom: 20px;
}
.trainer-topic-btn {
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 12px; font-family: var(--font); font-weight: 500;
  padding: 6px 14px;
  border-radius: 100px;
  cursor: pointer;
  transition: all var(--transition);
}
.trainer-topic-btn:hover { border-color: var(--border-hover); color: var(--text); }
.trainer-topic-btn.active {
  background: rgba(198,109,255,0.12);
  border-color: rgba(198,109,255,0.4);
  color: var(--primary);
}

.trainer-task-card {
  background: linear-gradient(180deg, rgba(255,255,255,0.04) 0%, rgba(255,255,255,0.015) 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 20px;
}
.trainer-task-header {
  padding: 14px 20px;
  background: rgba(255,255,255,0.03);
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center; gap: 10px;
}
.trainer-task-num {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
  font-size: 11px; font-weight: 700;
  padding: 3px 10px; border-radius: 100px;
}
.trainer-task-topic {
  font-size: 11px; color: var(--text-muted);
  background: rgba(255,255,255,0.06);
  border: 1px solid var(--border);
  padding: 3px 10px; border-radius: 100px;
  font-weight: 500;
}

.trainer-task-body { padding: 20px; }

.trainer-task-question {
  font-size: 15px; font-weight: 600; line-height: 1.5;
  margin-bottom: 16px; color: var(--text);
}

.trainer-table-preview {
  margin-bottom: 16px; overflow-x: auto;
}
.trainer-table-preview table {
  border-collapse: collapse;
  font-size: 12px; font-family: var(--mono);
  white-space: nowrap;
}
.trainer-table-preview caption {
  text-align: left; font-size: 11px;
  color: var(--text-muted); margin-bottom: 6px;
  font-weight: 600; letter-spacing: 0.5px; text-transform: uppercase;
}
.trainer-table-preview th {
  background: rgba(198,109,255,0.1);
  color: var(--primary); font-weight: 700;
  padding: 7px 12px; text-align: left;
  border: 1px solid var(--border);
  font-size: 12px;
}
.trainer-table-preview td {
  padding: 6px 12px;
  border: 1px solid var(--border);
  color: var(--text-muted);
}

.trainer-editor-wrap { margin-bottom: 12px; }
textarea.trainer-sql-input {
  width: 100%; min-height: 90px;
  background: var(--console-bg);
  border: 1px solid var(--console-border);
  border-radius: var(--radius-sm);
  color: var(--console-text);
  font-family: var(--mono); font-size: 13px; line-height: 1.6;
  padding: 14px 16px; resize: vertical; outline: none;
  transition: border-color var(--transition);
  caret-color: var(--primary);
}
textarea.trainer-sql-input:focus { border-color: var(--primary); }
textarea.trainer-sql-input.ok  { border-color: var(--success); }
textarea.trainer-sql-input.err { border-color: var(--error); }

.trainer-toolbar {
  display: flex; gap: 8px; align-items: center; flex-wrap: wrap;
  margin-bottom: 12px;
}

.trainer-feedback {
  margin-top: 12px;
  border-radius: var(--radius-xs);
  padding: 14px 16px; font-size: 13px; line-height: 1.6;
  display: none;
}
.trainer-feedback.show { display: block; }
.trainer-feedback.success {
  background: rgba(74,222,128,0.08);
  border: 1px solid rgba(74,222,128,0.25);
  color: var(--success);
}
.trainer-feedback.error {
  background: rgba(248,113,113,0.07);
  border: 1px solid rgba(248,113,113,0.25);
  color: var(--error);
}
.trainer-feedback.hint-box {
  background: rgba(251,191,36,0.07);
  border: 1px solid rgba(251,191,36,0.25);
  color: var(--warning);
}
.trainer-feedback strong { display: block; margin-bottom: 6px; font-size: 14px; }
.trainer-feedback code {
  background: rgba(255,255,255,0.06);
  padding: 2px 6px; border-radius: 4px;
  font-family: var(--mono); font-size: 12px; color: #fff;
}

.trainer-result-wrap {
  margin-top: 12px; overflow-x: auto; display: none;
}
.trainer-result-wrap.show { display: block; }
.trainer-result-label {
  font-size: 11px; color: var(--text-muted); margin-bottom: 6px;
  text-transform: uppercase; letter-spacing: 0.5px;
}
.trainer-result-table {
  border-collapse: collapse; font-size: 12px; font-family: var(--mono); width: 100%;
}
.trainer-result-table th {
  background: rgba(198,109,255,0.12);
  color: var(--primary); font-weight: 700;
  padding: 7px 12px; text-align: left;
  border: 1px solid var(--border);
  font-size: 11px; letter-spacing: 0.5px;
}
.trainer-result-table td {
  padding: 6px 12px;
  border-bottom: 1px solid rgba(255,255,255,0.04);
  border-left: 1px solid var(--border);
  border-right: 1px solid var(--border);
  color: var(--console-text);
}
.trainer-result-table tr:nth-child(even) td { background: rgba(255,255,255,0.02); }

.trainer-nav-row {
  display: flex; gap: 10px; flex-wrap: wrap;
  margin-top: 14px; align-items: center;
}
.trainer-hint-used {
  font-size: 11px; color: var(--text-muted); margin-left: auto;
}

.trainer-done-screen {
  text-align: center; padding: 60px 24px; display: none;
}
.trainer-done-screen.show { display: block; }
.trainer-done-icon { font-size: 64px; margin-bottom: 16px; }
.trainer-done-title {
  font-size: 28px; font-weight: 800; letter-spacing: -0.02em; margin-bottom: 10px;
}
.trainer-done-sub {
  color: var(--text-muted); font-size: 15px; margin-bottom: 28px;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 880px) {
  .tab-panel-inner { padding: 20px 16px; }
  .sandbox-body { padding: 16px; }
}

@media (max-width: 768px) {
  /* Topnav */
  .topnav { padding: 10px 14px; gap: 8px; }
  #lesson-title-nav { max-width: 160px; font-size: 12px; }
  .topnav-timer { display: none; }
  .topnav-score { font-size: 12px; padding: 5px 10px; }
  .topnav-logo { font-size: 16px; }

  /* Hide user name but keep avatar */
  .topnav-user span { display: none; }

  /* Dashboard */
  .dashboard-body { padding: 16px 14px 40px; }
  .dashboard-hero { padding: 20px 18px; }
  .dashboard-hero h1 { font-size: 22px; }
  .lessons-grid { grid-template-columns: 1fr; gap: 10px; }

  /* Login */
  .login-card { padding: 28px 20px; }

  /* Lesson — stack vertically */
  .lesson-layout-tabs {
    flex-direction: column;
    overflow: auto;
  }
  .lesson-layout-tabs .tab-panel {
    min-height: 0;
    overflow: auto;
  }
  .lesson-layout-tabs .tab-panel.active {
    display: flex;
    flex-direction: column;
  }

  /* Practice panel on mobile */
  .practice-panel {
    min-height: 100svh;
  }
  .sql-editor-wrap {
    min-height: 0;
  }
  .editor-highlight-wrap {
    max-height: 200px;
    min-height: 140px;
  }
  .sql-textarea {
    min-height: 140px;
    max-height: 200px;
    font-size: 13px;
  }
  #sql-highlight {
    min-height: 140px;
    max-height: 200px;
  }
  .sql-output {
    min-height: 120px;
    max-height: 40vh;
  }

  /* Editor toolbar wraps on small screens */
  .editor-toolbar {
    flex-wrap: wrap;
    gap: 6px;
  }

  /* Task description */
  .practice-task { padding: 10px 14px; }
  .practice-task-text { font-size: 13px; }

  /* Hint section */
  .hint-section { padding: 10px 14px; }

  /* Theory/quiz panel */
  .tab-panel-inner { padding: 16px 14px; }

  /* Sandbox */
  .sandbox-body { padding: 12px; gap: 12px; }
  .sandbox-editor { min-height: 0; }

  /* Theory tables — scrollable */
  .code-example pre { overflow-x: auto; }
  .example-table-wrap { overflow-x: auto; }
  .example-table { min-width: 340px; }
  .operators-grid { grid-template-columns: 1fr 1fr; }

  /* Trainer */
  .trainer-body { padding: 16px 14px; }
  .trainer-task-body { padding: 16px; }
  .trainer-topics-bar { gap: 6px; }
  .trainer-topic-btn { font-size: 11px; padding: 5px 10px; }
}

@media (max-width: 480px) {
  .topnav { padding: 8px 10px; gap: 6px; }
  .topnav-logo { font-size: 14px; }
  #lesson-title-nav { display: none; }
  /* Hide score on very small screens to save space */
  .topnav-score { display: none; }
  .user-avatar { width: 28px; height: 28px; font-size: 11px; }

  .dashboard-hero { padding: 16px 14px; }
  .dashboard-hero h1 { font-size: 18px; }
  .dashboard-body { padding: 12px 10px 32px; }

  .tab-btn { font-size: 11px; padding: 12px 6px; }
  .btn { font-size: 12px; }
  .sql-textarea { font-size: 12px; min-height: 140px; }
  #sql-highlight { min-height: 140px; }
  .editor-toolbar { gap: 4px; }
  .editor-toolbar .btn { padding: 8px 10px; font-size: 11px; }
  #attempts-info { display: none; }
  .modal-card { margin: 12px; padding: 20px 16px; }

  /* Theory grids — single column on phones */
  .theory-grid { grid-template-columns: 1fr; }
  .operators-grid { grid-template-columns: 1fr; }

  /* Trainer on phones */
  .trainer-body { padding: 12px 10px; }
  .trainer-topics-bar { gap: 4px; }
  .trainer-topic-btn { font-size: 11px; padding: 4px 9px; }
  .trainer-task-header { padding: 12px 14px; }
  .trainer-task-body { padding: 12px; }
  .trainer-sql-input { font-size: 12px; min-height: 80px; }
  .trainer-nav-row { flex-direction: column; gap: 8px; }
  .trainer-nav-row .btn { width: 100%; justify-content: center; }
  .trainer-done-screen { padding: 40px 16px; }
  .trainer-done-title { font-size: 22px; }
  .trainer-progress-label { display: none; }
}

/* ===== COURSE SELECT SCREEN ===== */
#screen-course-select {
  flex-direction: column;
  background: var(--bg);
}

.course-select-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 40px 24px 60px;
  max-width: 760px;
  margin: 0 auto;
  width: 100%;
}

.course-select-title {
  font-size: 28px;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 8px;
}

.course-select-subtitle {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 36px;
}

.course-cards {
  display: flex;
  flex-direction: column;
  gap: 16px;
  width: 100%;
}

.course-card {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 24px 28px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  cursor: pointer;
  transition: border-color 0.18s, transform 0.12s, box-shadow 0.18s;
  position: relative;
}

.course-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(108,99,255,0.12);
}

.course-card-active {
  border-color: var(--accent);
  background: rgba(108,99,255,0.06);
}

.course-card-icon {
  font-size: 40px;
  flex-shrink: 0;
  width: 60px;
  text-align: center;
}

.course-card-info {
  flex: 1;
  min-width: 0;
}

.course-card-title {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 4px;
}

.course-card-subtitle {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.course-card-meta {
  display: flex;
  gap: 6px;
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.course-card-progress-bar {
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  overflow: hidden;
}

.course-card-progress-fill {
  height: 100%;
  border-radius: 2px;
  transition: width 0.4s;
}

.course-card-arrow {
  font-size: 18px;
  color: var(--text-muted);
  flex-shrink: 0;
}

.course-card-active .course-card-arrow {
  color: var(--accent);
  font-size: 20px;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition-duration: 0.01ms !important;
    animation: none !important;
  }
}

/* ═══════════════════════════════════════════
   Доповнення адаптації (екрани цього застосунку)
   ═══════════════════════════════════════════ */
#screen-home {
  flex-direction: column;
}

/* компактні кнопки навігації */
.nav-btn { padding: 7px 14px; font-size: 12px; }

/* мобільна верстка */
@media (max-width: 640px) {
  .topnav { flex-wrap: wrap; gap: 8px; padding: 10px 12px; }
  .dashboard-hero-content h1 { font-size: 24px; }
  .lessons-grid { grid-template-columns: 1fr; }
  .editor-toolbar { flex-wrap: wrap; }
  .tab-panel { padding: 16px; }
}

/* махаюча рука у привітанні */
.wave {
  display: inline-block;
  animation: wave-hand 1.8s ease-in-out 2;
  transform-origin: 70% 70%;
}
@keyframes wave-hand {
  0%, 100% { transform: rotate(0deg); }
  20% { transform: rotate(-10deg); }
  40% { transform: rotate(16deg); }
  60% { transform: rotate(-8deg); }
  80% { transform: rotate(12deg); }
}