:root {
  --primary: #5b5bd6;
  --accent: #8a8aff;
  --bg: #f2f1fb;
  --card: #ffffff;
  --text: #111111;
  --muted: #737373;
  --border: #ececec;
  --sidebar-bg: #ffffff;
}

[data-theme="dark"] {
  --primary: #8a8aff;
  --accent: #a5a5ff;
  --bg: #121420;
  --card: #1a1d28;
  --text: #e7e7f2;
  --muted: #9aa0b4;
  --border: #2a2f3f;
  --sidebar-bg: #141722;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: "Inter", "Segoe UI", system-ui, -apple-system, sans-serif;
  color: var(--text);
  background: var(--bg);
  font-size: 16px;
  letter-spacing: -0.01em;
  -webkit-font-smoothing: antialiased;
}

.app { display: flex; min-height: 100vh; }

/* Sidebar */
.sidebar {
  width: 230px;
  background: var(--sidebar-bg);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  padding: 24px 14px;
  position: fixed;
  top: 0; left: 0; bottom: 0;
  transition: transform 0.3s ease;
  z-index: 100;
  overflow-y: auto;
}

.brand {
  display: flex; align-items: center; gap: 10px;
  padding: 0 10px 28px;
}
.brand .logo {
  width: 32px; height: 32px;
  background: var(--primary);
  border-radius: 9px;
  display: flex; align-items: center; justify-content: center;
  font-weight: 500; color: #fff; font-size: 16px;
  letter-spacing: -1px;
}
.brand h1 { font-size: 19px; font-weight: 600; letter-spacing: -0.5px; }

.nav { flex: 1; display: flex; flex-direction: column; gap: 2px; }
.nav-label {
  font-size: 12px; font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.1em; color: var(--muted);
  padding: 18px 12px 8px;
}
.nav a {
  display: flex; align-items: center; gap: 12px;
  padding: 11px 12px;
  border-radius: 10px;
  color: var(--muted);
  text-decoration: none;
  font-size: 15px;
  font-weight: 500;
  transition: color 0.2s, background 0.2s;
}
.nav a:hover { color: var(--text); background: #f5f5f5; }
.nav a.active { color: var(--primary); background: #f0f0ff; font-weight: 600; }
.nav .icon { width: 18px; text-align: center; display: flex; align-items: center; justify-content: center; }

.sidebar-footer { padding: 10px 4px 0; }
.btn-logout {
  width: 100%;
  padding: 12px;
  border: none;
  background: transparent;
  color: var(--muted);
  border-radius: 10px;
  cursor: pointer;
  font-size: 15px;
  font-weight: 500;
  text-align: left;
  padding-left: 12px;
}
.btn-logout:hover { color: #ef4444; background: #fef2f2; }

/* Main */
.main { flex: 1; margin-left: 230px; display: flex; flex-direction: column; }

.topbar {
  display: flex; align-items: center; gap: 14px;
  padding: 20px 32px;
  border-bottom: 1px solid var(--border);
  background: rgba(250, 250, 250, 0.8);
  backdrop-filter: blur(8px);
  position: sticky; top: 0; z-index: 50;
}
.hamburger { display: none; font-size: 22px; background: none; border: none; cursor: pointer; color: var(--text); }
.page-title { font-size: 19px; font-weight: 600; letter-spacing: -0.4px; flex: 1; }
.topbar-right { display: flex; align-items: center; gap: 14px; }
.level-badge {
  font-size: 13px; font-weight: 500;
  color: var(--primary);
  background: #f0f0ff;
  padding: 6px 14px; border-radius: 20px;
}
.avatar {
  width: 34px; height: 34px; border-radius: 50%;
  background: linear-gradient(135deg, #d4d4d8, #a1a1aa);
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-weight: 500; font-size: 14px;
}

.content { padding: 32px; width: 100%; }

/* Placeholder */
.placeholder { padding: 80px 24px; }
.placeholder {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 80px 24px;
  text-align: center;
  color: var(--muted);
}
.placeholder h3 { color: var(--text); font-size: 22px; letter-spacing: -0.5px; margin-bottom: 10px; }
.placeholder p { max-width: 420px; margin: 0 auto; font-size: 15px; line-height: 1.7; color: var(--muted); }

/* Dashboard — glassy theme */
.dash {
  position: relative;
  margin: -32px;
  padding: 36px 32px 48px;
  min-height: calc(100vh - 70px);
  overflow: hidden;
  background: var(--bg);
}
.dash-inner { position: relative; z-index: 1; }

.glass {
  background: rgba(255, 255, 255, 0.55);
  -webkit-backdrop-filter: blur(18px);
  backdrop-filter: blur(18px);
  border: 1px solid rgba(255, 255, 255, 0.7);
  box-shadow: 0 8px 32px rgba(91, 91, 214, 0.12);
  border-radius: 18px;
}

.dash-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 26px 28px;
  margin-bottom: 22px;
}
.dash-title { font-size: 26px; font-weight: 800; letter-spacing: -1px; color: var(--text); }
.dash-sub { font-size: 14px; color: var(--muted); margin-top: 6px; }
.dash-head .level-badge { padding: 8px 16px; }

.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-bottom: 28px;
}
.stat-card {
  background: rgba(255, 255, 255, 0.55);
  -webkit-backdrop-filter: blur(18px);
  backdrop-filter: blur(18px);
  border: 1px solid rgba(255, 255, 255, 0.7);
  box-shadow: 0 8px 32px rgba(91, 91, 214, 0.12);
  border-radius: 18px;
  padding: 26px 28px;
  position: relative;
  overflow: hidden;
}
.stat-card::after {
  content: "";
  position: absolute; top: 0; right: 0;
  width: 120px; height: 120px;
  background: radial-gradient(circle at top right, rgba(138, 138, 255, 0.25), transparent 70%);
  border-radius: 50%;
}
.stat-icon { font-size: 26px; margin-bottom: 14px; }
.stat-card .num {
  font-size: 38px; font-weight: 800; letter-spacing: -2px;
  background: linear-gradient(135deg, #5b5bd6, #e056a0);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.stat-card .label { font-size: 15px; color: var(--muted); margin-top: 8px; }

.dash-section { margin-top: 6px; }
.dash-actions { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.dash-action {
  display: flex; flex-direction: column; align-items: flex-start; gap: 4px;
  padding: 22px; text-align: left; cursor: pointer; font-family: inherit;
  color: var(--text);
  background: rgba(255, 255, 255, 0.55);
  -webkit-backdrop-filter: blur(18px); backdrop-filter: blur(18px);
  border: 1px solid rgba(255, 255, 255, 0.7);
  border-radius: 18px;
  box-shadow: 0 8px 32px rgba(91, 91, 214, 0.10);
  transition: transform 0.2s, box-shadow 0.2s;
}
.dash-action:hover { transform: translateY(-3px); box-shadow: 0 12px 40px rgba(91, 91, 214, 0.18); }
.dash-action-icon { font-size: 24px; margin-bottom: 10px; }
.dash-action-name { font-size: 16px; font-weight: 700; }
.dash-action-sub { font-size: 13px; color: var(--muted); }
.dashboard-title { font-size: 15px; font-weight: 600; margin-bottom: 14px; }

.overlay { display: none; position: fixed; inset: 0; background: rgba(0, 0, 0, 0.35); z-index: 90; }

/* Modal detail popup */
.modal-overlay { position: fixed; inset: 0; background: rgba(0, 0, 0, 0.45); z-index: 300; display: flex; align-items: center; justify-content: center; padding: 16px; opacity: 0; transition: opacity 0.2s; }
.modal-overlay.show { opacity: 1; }
.modal-pop { background: var(--card); border: 1px solid var(--border); border-radius: 16px; max-width: 600px; width: 100%; max-height: 85vh; overflow-y: auto; padding: 24px; position: relative; transform: translateY(10px); transition: transform 0.2s; }
.modal-overlay.show .modal-pop { transform: translateY(0); }
.modal-close { position: absolute; top: 12px; right: 12px; background: none; border: none; font-size: 18px; cursor: pointer; color: var(--muted); line-height: 1; }
.modal-close:hover { color: var(--primary); }
.modal-title { font-size: 20px; font-weight: 800; margin: 0 0 4px; }
.modal-sub { font-size: 14px; color: var(--muted); margin-bottom: 10px; }
.modal-bn { color: var(--primary); font-weight: 700; }
.modal-neg { font-size: 14px; margin-bottom: 14px; padding: 8px 12px; background: rgba(220, 38, 38, 0.08); border: 1px solid rgba(220, 38, 38, 0.2); border-radius: 10px; display: inline-block; }
.modal-link { border: none; background: none; color: var(--primary); font-weight: 700; font-size: 15px; cursor: pointer; padding: 2px 0; text-decoration: underline; text-underline-offset: 3px; }
.modal-link:hover { opacity: 0.8; }
[data-theme="dark"] .modal-pop { background: #1a1d28; }

/* Vocabulary */
.vocab-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}
.vocab-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  flex: 1;
}
.test-btn {
  padding: 11px 20px;
  border: none;
  background: var(--primary);
  color: #fff;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
  font-family: inherit;
  white-space: nowrap;
}
.test-btn:hover { background: var(--accent); }
.test-btn.voice { background: #16a34a; }
.test-btn.voice:hover { background: #22c55e; }
.head-actions { display: flex; gap: 10px; flex-wrap: wrap; }

/* Voice Test */
.voice-prompt {
  font-size: 28px; font-weight: 700; letter-spacing: -0.5px;
  background: #f0f0ff; color: var(--primary);
  border-radius: 14px; padding: 24px;
  text-align: center; margin: 18px 0 8px;
}
.sound-hint {
  border: 1px solid var(--border); background: var(--card);
  border-radius: 999px; padding: 8px 16px;
  font-size: 14px; font-weight: 600; color: var(--text);
  cursor: pointer; font-family: inherit;
}
.sound-hint:hover { border-color: var(--primary); color: var(--primary); }
.mic-btn {
  display: block; margin: 22px auto 8px;
  width: 84px; height: 84px;
  border: none; border-radius: 50%;
  background: var(--primary); color: #fff;
  font-size: 34px; cursor: pointer;
  transition: transform 0.2s, background 0.2s;
}
.mic-btn:hover { background: var(--accent); transform: scale(1.05); }
.mic-btn:disabled { background: #c7c7f0; cursor: default; transform: none; }
.voice-input {
  display: block; width: 100%; max-width: 320px; margin: 14px auto;
  padding: 14px 16px; border: 1px solid var(--border); border-radius: 12px;
  font-size: 16px; font-family: inherit; text-align: center;
}
.voice-input:focus { outline: none; border-color: var(--primary); }
.type-link {
  border: none; background: none; color: var(--muted);
  font-size: 13px; cursor: pointer; text-decoration: underline;
  font-family: inherit; padding: 4px;
}
.type-link:hover { color: var(--primary); }
.type-area { margin-top: 14px; }
.engine-row {
  display: flex; align-items: center; justify-content: center;
  gap: 10px; margin-top: 14px;
  font-size: 13px; color: var(--muted);
}
.engine-row select {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 8px; padding: 6px 10px;
  font-size: 13px; font-family: inherit; color: var(--text);
}
.engine-row select:focus { outline: none; border-color: var(--primary); }
.warm-note {
  margin-top: 8px; text-align: center;
  font-size: 12px; color: var(--muted);
}
.stop-btn {
  display: none; margin: 18px auto 6px;
  border: 1px solid var(--border); background: var(--card);
  border-radius: 999px; padding: 10px 22px;
  font-size: 14px; font-weight: 600; color: var(--text);
  cursor: pointer; font-family: inherit;
}
.stop-btn:hover { border-color: var(--accent); color: var(--accent); }
.voice-banner {
  background: #fffbeb; border: 1px solid #f59e0b;
  color: #92400e; border-radius: 12px;
  padding: 12px 16px; font-size: 14px; line-height: 1.6;
  margin-top: 14px;
}
.voice-heard { margin-top: 16px; }
.voice-result {
  border-radius: 12px; padding: 16px;
  font-size: 16px; line-height: 1.7;
}
.voice-result.correct { background: #f0fdf4; border: 1px solid #22c55e; color: #15803d; }
.voice-result.wrong { background: #fef2f2; border: 1px solid #ef4444; color: #b91c1c; }
.voice-answer { margin-top: 4px; font-size: 14px; }
.vtab {
  padding: 10px 18px;
  border: 1px solid var(--border);
  background: var(--card);
  border-radius: 999px;
  font-size: 14px;
  font-weight: 500;
  color: var(--muted);
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}
.vtab:hover { color: var(--text); border-color: #d6d6d6; }
.vtab.active {
  color: var(--primary);
  border-color: var(--primary);
  background: #f0f0ff;
  font-weight: 500;
}

.cefr-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
.cefr-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px;
  text-align: left;
  font-family: inherit;
  cursor: pointer;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.cefr-card:hover { border-color: var(--primary); box-shadow: 0 4px 14px rgba(91, 91, 214, 0.12); }
.cefr-card .cefr-badge {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  font-size: 12px;
  font-weight: 500;
  padding: 4px 12px;
  border-radius: 8px;
  margin-bottom: 12px;
}
.cefr-card h4 { font-size: 16px; font-weight: 600; margin-bottom: 6px; }
.cefr-card p { font-size: 14px; line-height: 1.6; color: var(--muted); }
.cefr-count {
  display: inline-block; margin-top: 12px;
  font-size: 13px; font-weight: 500; color: var(--primary);
  background: #f0f0ff; padding: 4px 10px; border-radius: 6px;
}

.level-head { display: flex; align-items: center; gap: 12px; margin-bottom: 18px; }
.level-back { border: none; background: none; color: var(--muted); font-size: 15px; font-weight: 500; cursor: pointer; padding: 0; }
.level-back:hover { color: var(--primary); }

/* Word list */
.word-list-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.word-item {
  text-align: left;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 24px;
  cursor: pointer;
  transition: border-color 0.2s, box-shadow 0.2s;
  font-family: inherit;
}
.word-item:hover { border-color: var(--primary); box-shadow: 0 4px 14px rgba(91, 91, 214, 0.12); }
.witem-main { display: flex; align-items: center; justify-content: space-between; gap: 8px; margin-bottom: 6px; }
.witem-word { font-size: 20px; font-weight: 600; letter-spacing: -0.4px; }
.witem-pos { font-size: 12px; color: var(--muted); background: #f5f5f5; padding: 2px 8px; border-radius: 6px; }
.witem-meaning { display: block; font-size: 15px; color: var(--muted); }
.witem-cefr {
  display: inline-block; margin-top: 12px;
  font-size: 12px; font-weight: 500; color: var(--primary);
  background: #f0f0ff; padding: 2px 8px; border-radius: 6px;
}

/* Word detail */
.back-btn {
  border: none; background: none; color: var(--muted);
  font-size: 15px; font-weight: 500; cursor: pointer;
  padding: 0 0 16px;
}
.back-btn:hover { color: var(--primary); }

.word-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 32px;
}
.word-head { margin-bottom: 22px; }
.word-title-row { display: flex; align-items: center; gap: 14px; }
.word-title { font-size: 34px; font-weight: 700; letter-spacing: -2px; }
.audio-btn {
  width: 40px; height: 40px;
  border: 1px solid var(--border);
  background: #f0f0ff; color: var(--primary);
  border-radius: 50%;
  font-size: 16px; cursor: pointer;
  transition: background 0.2s;
}
.audio-btn:hover { background: var(--primary); color: #fff; }
.word-meta { display: flex; align-items: center; gap: 10px; margin-top: 12px; flex-wrap: wrap; }
.ipa { font-size: 17px; color: var(--muted); }
.pos-badge { font-size: 13px; font-weight: 500; color: var(--text); background: #f5f5f5; padding: 3px 10px; border-radius: 6px; }

.word-meanings { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 24px; }
.meaning-box { background: #fafafa; border: 1px solid var(--border); border-radius: 12px; padding: 16px; }
.m-label { font-size: 12px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); }
.m-text { font-size: 17px; margin-top: 6px; line-height: 1.5; }

.wsec { margin-bottom: 20px; }
.wsec-title { font-size: 13px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); margin-bottom: 10px; }
.wsec-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; }

.chip {
  display: inline-block;
  font-size: 13px; font-weight: 500;
  background: #f5f5f5; color: var(--text);
  padding: 6px 13px; border-radius: 999px;
  margin: 0 6px 6px 0;
  font-family: inherit;
}
.chip.say { border: 1px solid var(--border); cursor: pointer; transition: all 0.2s; }
.chip.say:hover { background: #f0f0ff; color: var(--primary); border-color: var(--primary); }

.word-list { list-style: none; }
.word-list li { position: relative; padding-left: 16px; font-size: 15px; line-height: 1.7; color: var(--text); }
.word-list li::before { content: "•"; position: absolute; left: 2px; color: var(--primary); }

.media-box {
  background: #fafafa; border: 1px dashed var(--border);
  border-radius: 12px; padding: 24px 16px;
  text-align: center; font-size: 14px; color: var(--muted);
}
.media-box.video { color: var(--primary); }

.action-row { display: flex; flex-wrap: wrap; gap: 10px; margin: 22px 0; }
.action-btn {
  padding: 12px 20px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--card);
  font-size: 15px; font-weight: 500; cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}
.action-btn:hover { border-color: var(--primary); color: var(--primary); }

.ai-box, .mini-box {
  border: 1px solid var(--border); border-radius: 12px;
  padding: 18px; margin-top: 14px;
  background: #fafaff;
}
.ai-tag {
  display: inline-block; font-size: 12px; font-weight: 500; text-transform: uppercase;
  letter-spacing: 0.06em; color: var(--primary); margin-bottom: 8px;
}
.ai-box p, .mini-box p { font-size: 15px; line-height: 1.7; }
.mini-btn {
  margin-top: 10px; border: none; background: var(--primary); color: #fff;
  padding: 10px 18px; border-radius: 8px; font-size: 14px; font-weight: 500; cursor: pointer;
  font-family: inherit;
}
.mini-answer { color: var(--primary); font-weight: 500; margin-top: 10px; }

.flash-card {
  margin-top: 14px; border: 1px solid var(--border); border-radius: 14px;
  padding: 40px 24px; text-align: center; cursor: pointer; background: #fafaff;
  transition: box-shadow 0.2s;
}
.flash-card:hover { box-shadow: 0 4px 14px rgba(91, 91, 214, 0.15); }
.flash-text { font-size: 26px; font-weight: 700; letter-spacing: -1px; margin-bottom: 16px; }

/* Vocab Test */
.test-top { display: flex; align-items: center; justify-content: space-between; margin-bottom: 10px; }
.test-progress { font-size: 14px; font-weight: 600; color: var(--muted); }
.test-question { font-size: 38px; font-weight: 700; letter-spacing: -1.5px; margin-bottom: 6px; }
.test-hint { font-size: 15px; color: var(--muted); margin-bottom: 26px; }
.test-options { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.test-opt {
  text-align: left;
  padding: 18px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: #fafafa;
  font-size: 16px;
  font-weight: 500;
  color: var(--text);
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}
.test-opt:hover { border-color: var(--primary); background: #f0f0ff; }
.test-opt.correct { border-color: #22c55e; background: #f0fdf4; color: #15803d; }
.test-opt.wrong { border-color: #ef4444; background: #fef2f2; color: #b91c1c; }
.test-opt:disabled { cursor: default; }

.test-result { text-align: center; padding: 48px 32px; }
.result-score { font-size: 64px; font-weight: 700; letter-spacing: -2px; color: var(--primary); }
.result-pct { font-size: 22px; font-weight: 600; color: var(--text); margin-top: 4px; }
.result-msg { font-size: 15px; color: var(--muted); margin: 14px 0 28px; }
.result-learned { margin-bottom: 22px; }
.learned-num { font-size: 26px; font-weight: 700; margin-top: 6px; }
.learned-num span { font-size: 15px; font-weight: 500; color: var(--muted); }
.result-bar {
  height: 10px; border-radius: 999px; background: #f0f0f0;
  overflow: hidden; max-width: 400px; margin: 0 auto 28px;
}
.result-bar-fill {
  height: 100%; border-radius: 999px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  transition: width 0.8s ease;
}

/* Grammar */
.grammar-count { font-size: 13px; color: var(--muted); margin-bottom: 14px; }
.level-name { font-size: 15px; color: var(--muted); }
.word-list-grid.grammar-grid { grid-template-columns: repeat(2, 1fr); }
.g-intro {
  font-size: 16px; line-height: 1.7; color: var(--text);
  background: #f8f8ff; border-radius: 12px; padding: 16px 18px; margin: 16px 0;
}
.g-rules { list-style: none; padding: 0; margin: 0; }
.g-rules li {
  position: relative; padding: 8px 0 8px 28px;
  font-size: 15px; line-height: 1.6;
  border-bottom: 1px dashed var(--border);
}
.g-rules li::before { content: "✓"; position: absolute; left: 0; top: 8px; color: var(--primary); font-weight: 700; }
.g-example { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 14px 16px; margin-bottom: 10px; }
.g-en { font-size: 16px; font-weight: 600; margin: 0 0 4px; cursor: pointer; }
.g-en:hover { color: var(--primary); }
.g-bn { font-size: 14px; color: var(--muted); margin: 0; }
.trans-box { border-left: 3px solid var(--primary); background: var(--card); }
.trans-label { display: inline-block; font-size: 12px; font-weight: 700; letter-spacing: 0.4px; color: var(--primary); margin-bottom: 6px; }
.story-text {
  font-size: 17px;
  font-weight: 500;
  line-height: 2.1;
  letter-spacing: 0.03em;
  word-spacing: 0.12em;
  text-align: justify;
  color: var(--text);
  cursor: default;
  margin: 0;
}
.story-text:hover { color: var(--text); }
.g-hint { font-size: 12px; color: var(--muted); text-transform: none; letter-spacing: 0; }

/* Grammar: topics list */
.grammar-topics .grammar-hero { margin-bottom: 26px; }
.grammar-hero h3 { font-size: 34px; font-weight: 700; letter-spacing: -2px; margin: 0 0 10px; }
.grammar-hero p { font-size: 15px; color: var(--muted); line-height: 1.7; max-width: 640px; }
.topic-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.topic-card {
  position: relative;
  display: flex; flex-direction: column; justify-content: center; gap: 8px; text-align: left;
  padding: 32px 26px; border: 1px solid var(--border); border-radius: 16px;
  background: var(--card); cursor: pointer; transition: all 0.2s; font-family: inherit;
}
.topic-card:hover { border-color: var(--primary); box-shadow: 0 6px 18px rgba(91, 91, 214, 0.14); transform: translateY(-2px); }
.topic-name { font-size: 19px; font-weight: 700; color: var(--text); }
.topic-steps { font-size: 13px; color: var(--muted); }
.topic-ic {
  width: 46px; height: 46px; border-radius: 12px;
  background: color-mix(in srgb, var(--tcol) 12%, transparent);
  display: flex; align-items: center; justify-content: center;
  color: var(--tcol); margin-bottom: 4px;
}
.topic-ic svg { display: block; }
.topic-ic .ic-text { font-size: 16px; font-weight: 700; }

/* Course level tags */
.tag-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.tag-chip {
  padding: 6px 14px; border-radius: 20px; font-size: 14px; font-weight: 500;
  background: rgba(91, 91, 214, 0.1); color: var(--primary);
}
.sub-grid { grid-template-columns: repeat(2, 1fr); }
.modal-cards { grid-template-columns: repeat(3, 1fr); gap: 14px; }
.modal-cards .sub-card {
  padding: 18px 16px;
  background: var(--card);
  background-image: none;
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
  transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}
.modal-cards .sub-card:hover {
  border-color: var(--primary);
  box-shadow: 0 8px 20px rgba(91, 91, 214, 0.12);
  transform: translateY(-2px);
}
.modal-cards .sub-card::after { display: none; }
.modal-cards .sub-icon {
  width: 36px; height: 36px; margin-bottom: 10px;
  border-radius: 10px;
  background: rgba(91, 91, 214, 0.08);
  font-size: 18px;
}
.modal-cards .topic-name { font-size: 14px; font-weight: 600; letter-spacing: -0.01em; }
.modal-cards .sub-desc { font-size: 12px; line-height: 1.55; margin: 2px 0 8px; color: var(--muted); }
.modal-cards .sub-struct { font-size: 11.5px; font-weight: 600; color: var(--primary); opacity: 0.9; }
[data-theme="dark"] .modal-cards .sub-card { background: #1a1d28; background-image: none; box-shadow: none; }
[data-theme="dark"] .modal-cards .sub-icon { background: rgba(138, 138, 255, 0.1); }
.sub-card {
  border-left: none;
  padding: 28px 24px;
  background-color: #ffffff;
  background-image:
    linear-gradient(rgba(91, 91, 214, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(91, 91, 214, 0.05) 1px, transparent 1px);
  background-size: 18px 18px;
}
.sub-card::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(120px 90px at 100% 0%, rgba(91, 91, 214, 0.08), transparent 70%);
  pointer-events: none;
  border-radius: inherit;
}
.sub-card .topic-name, .sub-card .sub-icon, .sub-card .topic-steps, .sub-card .sub-desc { position: relative; z-index: 1; }
.sub-desc { font-size: 13px; color: var(--muted); line-height: 1.6; margin: 2px 0 8px; }
.sub-icon {
  width: 46px; height: 46px; border-radius: 50%;
  background: rgba(91, 91, 214, 0.1);
  display: flex; align-items: center; justify-content: center;
  color: var(--primary); margin-bottom: 12px;
}
.sub-icon svg { display: block; }
.sub-card .topic-name { font-size: 18px; }
.sub-struct {
  font-weight: 600; letter-spacing: 0.02em;
  color: var(--primary);
}
[data-theme="dark"] .sub-card {
  background-color: #1a1d28;
  background-image:
    linear-gradient(rgba(138, 138, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(138, 138, 255, 0.05) 1px, transparent 1px);
  background-size: 18px 18px;
}

/* Grammar: step tabs */
.step-count { font-size: 13px; font-weight: 600; color: var(--muted); }
.step-tabs { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 20px; }
.step-tab {
  padding: 8px 14px; border: 1px solid var(--border); border-radius: 999px;
  background: #fafafa; font-size: 13px; font-weight: 500; color: var(--text);
  cursor: pointer; transition: all 0.2s; font-family: inherit;
}
.step-tab:hover { border-color: var(--primary); }
.step-tab.active { background: var(--primary); border-color: var(--primary); color: #fff; }

/* Grammar: visual diagram */
.g-visual { background: #f8f8ff; border: 1px solid var(--border); border-radius: 12px; padding: 18px; margin-top: 16px; overflow-x: auto; }
.g-visual-caption { font-size: 14px; font-weight: 600; color: var(--primary); margin: 0 0 12px; }
.g-table { width: 100%; border-collapse: collapse; background: #fff; border-radius: 10px; overflow: hidden; min-width: 420px; }
.g-table th, .g-table td { border: 1px solid var(--border); padding: 10px 12px; font-size: 14px; text-align: left; }
.g-table th { background: var(--primary); color: #fff; font-weight: 500; }
.g-table tr:nth-child(even) td { background: #fafafa; }
.g-table td.num { width: 36px; text-align: center; font-weight: 600; color: var(--muted); }

/* Grammar: grouped structure tables */
.struct-group { margin-bottom: 18px; }
.struct-group:last-child { margin-bottom: 0; }
.struct-title { font-size: 16px; font-weight: 700; color: var(--primary); margin-bottom: 2px; }
.struct-line {
  display: inline-block; margin-bottom: 8px; padding: 3px 10px;
  background: rgba(91, 91, 214, 0.1); border-radius: 6px;
  font-size: 13px; font-weight: 600; font-family: monospace; color: var(--primary);
}
[data-theme="dark"] .struct-line { background: rgba(129, 140, 248, 0.15); }

/* Grammar: practice */
.pract-item { border: 1px solid var(--border); border-radius: 12px; padding: 14px 16px; margin-bottom: 12px; background: var(--card); }
.pract-q { font-size: 15px; margin: 0 0 10px; line-height: 1.6; }
.pract-blank { color: var(--primary); font-weight: 700; border-bottom: 2px solid var(--primary); padding: 0 6px; }
.pract-row { display: flex; gap: 10px; }
.pract-in { flex: 1; }
.pract-fb { margin-top: 10px; font-size: 14px; }
.pract-fb-result { border-radius: 8px; padding: 8px 12px; font-weight: 500; }
.pract-fb-result.ok { background: #f0fdf4; color: #15803d; }
.pract-fb-result.no { background: #fef2f2; color: #b91c1c; }

/* Grammar: quiz + exam */
.step-quiz { margin-top: 8px; }
.quiz-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 8px; }
.step-q { font-size: 18px; font-weight: 600; margin: 8px 0 16px; line-height: 1.6; }
.quiz-fb { margin-top: 14px; font-size: 14px; font-weight: 500; padding: 10px 14px; border-radius: 8px; }
.quiz-fb.ok { background: #f0fdf4; color: #15803d; }
.quiz-fb.no { background: #fef2f2; color: #b91c1c; }
.quiz-explain { font-weight: 400; opacity: 0.85; }
.exam-timer { font-size: 14px; font-weight: 600; color: var(--primary); }
.exam-q { border: 1px solid var(--border); border-radius: 12px; padding: 14px 16px; margin-bottom: 12px; background: var(--card); }
.exam-options .test-opt { padding: 12px; }
.test-opt.selected { border-color: var(--primary); background: #f0f0ff; }
.exam-review { font-size: 14px; padding: 10px 12px; border-radius: 8px; margin-bottom: 8px; font-weight: 500; }
.exam-review.ok { background: #f0fdf4; color: #15803d; }
.exam-review.no { background: #fef2f2; color: #b91c1c; }

/* Settings */
.settings-page { max-width: 640px; }
.settings-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 24px;
  margin-bottom: 18px;
}
.settings-name { font-size: 16px; font-weight: 700; }
.settings-desc { font-size: 14px; color: var(--muted); margin-top: 4px; }
.theme-options { display: flex; gap: 14px; margin-top: 18px; }
.theme-opt {
  flex: 1;
  display: flex; flex-direction: column; align-items: center; gap: 10px;
  padding: 18px; border-radius: 14px; cursor: pointer; font-family: inherit;
  background: var(--card); border: 2px solid var(--border); color: var(--text);
  font-weight: 600; font-size: 15px; transition: all 0.2s;
}
.theme-opt:hover { border-color: var(--primary); }
.theme-opt.active { border-color: var(--primary); background: #f0f0ff; }
.theme-swatch { width: 100%; height: 64px; border-radius: 10px; border: 1px solid var(--border); }
.theme-swatch.light { background: linear-gradient(135deg, #f0f2ff, #fff0f6); }
.theme-swatch.dark { background: linear-gradient(135deg, #12141d, #2a2f3f); }

/* Dark theme overrides */
[data-theme="dark"] .nav a:hover { background: rgba(255, 255, 255, 0.06); }
[data-theme="dark"] .nav a.active { background: rgba(138, 138, 255, 0.16); color: #a5a5ff; }
[data-theme="dark"] .topbar { background: rgba(20, 23, 34, 0.85); }
[data-theme="dark"] .level-badge { background: rgba(138, 138, 255, 0.16); color: #a5a5ff; }
[data-theme="dark"] .avatar { background: linear-gradient(135deg, #3a3f52, #232838); }
[data-theme="dark"] .vtab:hover { border-color: #3a3f52; color: var(--text); }
[data-theme="dark"] .vtab.active { background: rgba(138, 138, 255, 0.16); }
[data-theme="dark"] .step-tab { background: #1d202c; }
[data-theme="dark"] .step-tab.active { background: var(--primary); color: #fff; }
[data-theme="dark"] .ai-box, [data-theme="dark"] .mini-box { background: #1a1d28; }
[data-theme="dark"] .g-intro { background: #191c27; }
[data-theme="dark"] .g-visual { background: #191c27; }
[data-theme="dark"] .g-example { background: #1a1d28; }
[data-theme="dark"] .g-table td, [data-theme="dark"] .g-table th { border-color: #2a2f3f; }
[data-theme="dark"] .g-table tr:nth-child(even) td { background: #1d212d; }
[data-theme="dark"] .flash-card { background: #1a1d28; }
[data-theme="dark"] .test-opt { background: #1d212d; }
[data-theme="dark"] .test-opt:hover { border-color: var(--primary); background: rgba(138, 138, 255, 0.1); }
[data-theme="dark"] .test-opt.correct { background: rgba(34, 197, 94, 0.15); color: #4ade80; border-color: #22c55e; }
[data-theme="dark"] .test-opt.wrong { background: rgba(239, 68, 68, 0.15); color: #f87171; border-color: #ef4444; }
[data-theme="dark"] .test-opt.selected { background: rgba(138, 138, 255, 0.18); }
[data-theme="dark"] .pract-fb-result.ok { background: rgba(34, 197, 94, 0.15); color: #4ade80; }
[data-theme="dark"] .pract-fb-result.no { background: rgba(239, 68, 68, 0.15); color: #f87171; }
[data-theme="dark"] .quiz-fb.ok { background: rgba(34, 197, 94, 0.15); color: #4ade80; }
[data-theme="dark"] .quiz-fb.no { background: rgba(239, 68, 68, 0.15); color: #f87171; }
[data-theme="dark"] .exam-review.ok { background: rgba(34, 197, 94, 0.15); color: #4ade80; }
[data-theme="dark"] .exam-review.no { background: rgba(239, 68, 68, 0.15); color: #f87171; }
[data-theme="dark"] .pos-badge { background: #262b3a; color: #cdd0e4; }
[data-theme="dark"] .result-bar { background: #262b3a; }
[data-theme="dark"] .pract-item { background: #1a1d28; }
[data-theme="dark"] .exam-q { background: #1a1d28; }
[data-theme="dark"] .theme-opt.active { background: rgba(138, 138, 255, 0.16); }
[data-theme="dark"] .glass,
[data-theme="dark"] .stat-card,
[data-theme="dark"] .dash-action {
  background: rgba(30, 34, 48, 0.62);
  border-color: rgba(255, 255, 255, 0.08);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
}
[data-theme="dark"] .dash {
  background: var(--bg);
}
[data-theme="dark"] .band-stat { background: rgba(138, 138, 255, 0.1); }
[data-theme="dark"] .bt-top { background: #1a1d28; }
[data-theme="dark"] .band-card { background: #1a1d28; }
[data-theme="dark"] .ring-bg { stroke: #2a2f3f; }

/* A1 reading split layout: story left, questions right */
.a1-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  align-items: start;
}
.a1-col { min-width: 0; }
.a1-col .wsec:first-child { margin-top: 0; }

/* Audio buttons */
.listen-btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 8px 16px; border-radius: 10px; border: 1px solid var(--border);
  background: var(--card); color: var(--text); font-family: inherit;
  font-size: 14px; font-weight: 600; cursor: pointer; transition: all 0.2s;
  margin-bottom: 12px;
}
.listen-btn:hover { border-color: var(--primary); color: var(--primary); background: rgba(91, 91, 214, 0.08); }
.listen-btn.playing { border-color: var(--primary); color: var(--primary); background: rgba(91, 91, 214, 0.14); }
.listen-mini {
  border: 1px solid var(--border); background: rgba(91, 91, 214, 0.08);
  color: var(--primary); border-radius: 8px; padding: 2px 8px; margin-left: 8px;
  font-size: 13px; cursor: pointer; transition: all 0.2s; line-height: 1.6;
}
.listen-mini:hover { border-color: var(--primary); background: rgba(91, 91, 214, 0.16); }

/* Mock test header */
.bt-top {
  display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 8px;
  padding: 10px 14px; border: 1px solid var(--border); border-radius: 12px; margin-bottom: 18px;
  background: var(--card); font-size: 14px; font-weight: 600; color: var(--text);
}
.bt-timer { color: var(--primary); font-variant-numeric: tabular-nums; }
.bt-prog { color: var(--muted); }

/* Mock test start button */
.mock-btn {
  display: inline-flex; align-items: center; gap: 8px; margin-top: 4px;
  padding: 12px 20px; border: none; border-radius: 12px; cursor: pointer;
  background: linear-gradient(135deg, #5b5bd6, #7c5bd6); color: #fff;
  font-family: inherit; font-size: 15px; font-weight: 700; transition: all 0.2s;
  box-shadow: 0 6px 18px rgba(91, 91, 214, 0.25);
}
.mock-btn:hover { transform: translateY(-2px); box-shadow: 0 8px 22px rgba(91, 91, 214, 0.35); }

/* Estimated IELTS band result card */
.band-card {
  margin-top: 18px; padding: 24px; border: 1px solid var(--border); border-radius: 18px;
  background: var(--card); animation: bandIn 0.45s ease;
}
@keyframes bandIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }
.band-badge {
  display: inline-block; padding: 5px 12px; border-radius: 20px; font-size: 11px; font-weight: 800;
  letter-spacing: 0.06em; background: rgba(91, 91, 214, 0.12); color: var(--primary);
}
.band-main { display: grid; grid-template-columns: auto 1fr; gap: 28px; align-items: center; margin-top: 18px; }
.band-ring { position: relative; width: 170px; height: 170px; justify-self: center; }
.band-ring svg { width: 100%; height: 100%; transform: rotate(-90deg); }
.ring-bg { fill: none; stroke: var(--border); stroke-width: 12; }
.ring-fg {
  fill: none; stroke: var(--band-color, #5b5bd6); stroke-width: 12; stroke-linecap: round;
  stroke-dasharray: 440; stroke-dashoffset: 440;
  transition: stroke-dashoffset 1.1s cubic-bezier(0.22, 1, 0.36, 1);
}
.band-ring-center {
  position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center;
}
.band-val { font-size: 46px; font-weight: 800; color: var(--text); letter-spacing: -1px; line-height: 1; }
.band-max { font-size: 13px; color: var(--muted); font-weight: 600; margin-top: 4px; }
.band-stats { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 12px; }
.band-stat {
  background: rgba(91, 91, 214, 0.06); border: 1px solid var(--border); border-radius: 12px;
  padding: 10px 14px; text-align: center;
}
.band-stat b { display: block; font-size: 20px; color: var(--text); font-variant-numeric: tabular-nums; }
.band-stat span { font-size: 11px; color: var(--muted); text-transform: uppercase; letter-spacing: 0.04em; font-weight: 700; }
.band-perf { margin-top: 18px; padding: 12px 16px; border-radius: 12px; font-size: 16px; font-weight: 800; color: #fff; text-align: center; letter-spacing: 0.02em; }
.band-next { margin-top: 12px; font-size: 14px; color: var(--text); font-weight: 600; }
.band-note { margin-top: 10px; font-size: 12px; color: var(--muted); }
.band-card .mini-btn { margin-top: 16px; }

@media (max-width: 640px) {
  .word-meanings { grid-template-columns: 1fr; }
  .topic-grid { grid-template-columns: 1fr; }
  .a1-split { grid-template-columns: 1fr; }
  .band-main { grid-template-columns: 1fr; gap: 16px; }
  .band-stats { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .sidebar { transform: translateX(-100%); width: 260px; }
  .sidebar.open { transform: translateX(0); box-shadow: 0 0 40px rgba(0,0,0,0.1); }
  .main { margin-left: 0; }
  .hamburger { display: block; }
  .overlay.show { display: block; }
  .content { padding: 20px; }
  .stats, .word-list-grid, .cefr-grid { grid-template-columns: 1fr; }
  .test-options { grid-template-columns: 1fr; }
  .topic-grid { grid-template-columns: repeat(2, 1fr); }
  .dash { margin: -20px; padding: 24px 20px 40px; }
  .dash-actions { grid-template-columns: repeat(2, 1fr); }
}

/* Bigger font sizes */
body { font-size: 17px; }
.content h1, .content h2, .content h3 { line-height: 1.35; }
.word-title { font-size: 26px; }
.word-meta { font-size: 14px; }
.pos-badge, .step-count { font-size: 14px; }
.grammar-hero p, .dash-sub, .dash-action-sub { font-size: 16px; }
.dashboard-title { font-size: 16px; }
.stat-card .label, .stat-card .num { font-size: 16px; }
.topic-name { font-size: 20px; }
.sub-card .topic-name { font-size: 20px; }
.topic-steps { font-size: 14px; }
.sub-struct { font-size: 14px; }
.g-intro, .g-bn, .pract-q, .quiz-fb, .exam-review, .pract-fb, .exam-timer { font-size: 16px; }
.g-en { font-size: 17px; }
.wsec-title { font-size: 14px; }
.g-table th, .g-table td { font-size: 15.5px; }
.struct-title { font-size: 18px; }
.struct-line { font-size: 14.5px; }
.step-q { font-size: 19px; }
.test-opt, .mini-btn, .voice-input, .settings-name, .settings-desc { font-size: 15.5px; }
.test-hint, .ai-box p, .mini-box p, .level-name, .cefr-card p, .grammar-count { font-size: 16px; }
.word-list li, .witem-meaning, .result-msg, .learned-num span, .placeholder p { font-size: 16px; }
.nav-label { font-size: 15px; }
.cefr-card h4 { font-size: 17px; }
.dash-action-name { font-size: 17px; }
.result-score { font-size: 34px; }
@media (max-width: 768px) {
  .content h1 { font-size: 22px; }
  .content h2 { font-size: 20px; }
}