:root {
  --ink: #15233c;
  --muted: #667085;
  --paper: #f6f8fb;
  --surface: #ffffff;
  --line: #dbe2ea;
  --blue: #1268f3;
  --blue-dark: #0b4fbe;
  --cyan: #11b7b0;
  --coral: #ff6b4a;
  --yellow: #ffcf4a;
  --green: #1f9d6c;
  --danger: #d64141;
  --shadow: 0 18px 45px rgba(30, 52, 85, .09);
}

* { box-sizing: border-box; }
html { font-size: 16px; }
body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background:
    radial-gradient(circle at 90% 5%, rgba(17,183,176,.13), transparent 26rem),
    var(--paper);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}
button, input, textarea { font: inherit; }
button { color: inherit; }
button:disabled { cursor: default; opacity: .52; transform: none !important; }

.app-shell { min-height: 100vh; display: grid; grid-template-columns: 250px minmax(0, 1fr); }
.sidebar {
  min-height: 100vh;
  position: sticky;
  top: 0;
  align-self: start;
  padding: 28px 20px;
  color: white;
  background: #101d33;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.sidebar::after {
  content: "ă â ê ô ơ ư đ";
  position: absolute;
  right: -20px;
  bottom: 145px;
  width: 170px;
  color: rgba(255,255,255,.055);
  font: 800 2.7rem/1.25 Georgia, serif;
  letter-spacing: .1em;
  transform: rotate(-7deg);
  pointer-events: none;
}
.brand { display: flex; align-items: center; gap: 12px; margin-bottom: 42px; position: relative; z-index: 1; }
.brand-mark {
  width: 45px; height: 45px; display: grid; place-items: center;
  border-radius: 14px; color: #10203a; background: var(--yellow);
  font: 900 1.35rem/1 Georgia, serif; transform: rotate(-5deg);
}
.brand strong, .brand span { display: block; }
.brand strong { font-size: 1.02rem; }
.brand span { margin-top: 3px; color: #9db0cc; font-size: .78rem; }
.nav-list { display: grid; gap: 8px; position: relative; z-index: 1; }
.nav-item {
  width: 100%; min-height: 48px; border: 0; border-radius: 12px; padding: 0 14px;
  color: #b7c5d8; background: transparent; cursor: pointer;
  display: flex; align-items: center; justify-content: space-between; font-weight: 700;
  transition: .18s ease;
}
.nav-item:hover { background: rgba(255,255,255,.07); color: white; }
.nav-item.active { color: #0f1c30; background: white; box-shadow: 0 8px 24px rgba(0,0,0,.14); }
.nav-item small {
  min-width: 24px; height: 24px; padding: 0 6px; display: grid; place-items: center;
  border-radius: 12px; color: inherit; background: rgba(255,255,255,.08); font-size: .72rem;
}
.nav-item.active small { background: #edf3ff; color: var(--blue); }
.sidebar-note { margin-top: auto; padding: 18px; border: 1px solid rgba(255,255,255,.12); border-radius: 16px; background: rgba(255,255,255,.045); position: relative; z-index: 1; }
.sidebar-note strong { display: block; margin-top: 6px; }
.sidebar-note p { margin: 6px 0 0; color: #9db0cc; font-size: .8rem; line-height: 1.5; }
.help-button { width: 100%; margin-top: 13px; padding: 9px 11px; border: 1px solid rgba(255,255,255,.18); border-radius: 10px; color: white; background: rgba(255,255,255,.08); cursor: pointer; font-weight: 750; }

.main-area { min-width: 0; padding: 28px clamp(22px, 4vw, 64px) 64px; }
.topbar { display: flex; align-items: center; justify-content: space-between; gap: 24px; margin: 0 auto 28px; max-width: 1180px; }
.topbar h1 { margin: 5px 0 0; font-size: clamp(1.65rem, 3vw, 2.25rem); line-height: 1.1; letter-spacing: -.04em; }
.eyebrow { color: var(--blue); font-size: .72rem; font-weight: 850; letter-spacing: .11em; text-transform: uppercase; }
.streak-pill { padding: 10px 14px; border: 1px solid var(--line); border-radius: 999px; background: rgba(255,255,255,.82); color: #475467; font-size: .82rem; white-space: nowrap; }
.pulse { display: inline-block; width: 8px; height: 8px; margin-right: 7px; border-radius: 50%; background: var(--green); box-shadow: 0 0 0 4px rgba(31,157,108,.12); }
.mobile-menu { display: none; border: 1px solid var(--line); border-radius: 10px; background: white; padding: 9px 12px; font-weight: 750; }
.view { max-width: 1180px; margin: 0 auto; }

.hero {
  min-height: 320px; padding: clamp(28px, 5vw, 58px); border-radius: 28px;
  color: white; background:
    linear-gradient(115deg, rgba(11,79,190,.96), rgba(18,104,243,.90)),
    linear-gradient(30deg, #12213c, #1268f3);
  box-shadow: var(--shadow); position: relative; overflow: hidden;
  display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(260px, .65fr); gap: 30px; align-items: end;
}
.hero::before { content: "TÊN TÔI LÀ NAM"; position: absolute; right: -22px; top: 28px; color: rgba(255,255,255,.07); font: 900 clamp(3.4rem, 8vw, 7.7rem)/.85 Georgia, serif; width: 520px; text-align: right; }
.hero-content { position: relative; z-index: 1; }
.hero-kicker { display: inline-flex; align-items: center; gap: 7px; color: #dfe9ff; font-size: .8rem; font-weight: 750; }
.hero-kicker::before { content: ""; width: 22px; height: 3px; border-radius: 2px; background: var(--yellow); }
.hero h2 { margin: 18px 0 10px; max-width: 690px; font-size: clamp(2.2rem, 5vw, 4.4rem); line-height: .98; letter-spacing: -.055em; }
.hero p { margin: 0 0 26px; max-width: 540px; color: #dce7fb; font-size: 1rem; line-height: 1.65; }
.primary-button, .secondary-button, .ghost-button, .audio-button, .option-button, .chip-button {
  border: 0; border-radius: 12px; cursor: pointer; font-weight: 800; transition: .16s ease;
}
.primary-button { padding: 13px 19px; background: var(--yellow); color: #17243a; box-shadow: 0 7px 18px rgba(0,0,0,.13); }
.primary-button:hover { transform: translateY(-1px); background: #ffd968; }
.secondary-button { padding: 12px 17px; background: var(--blue); color: white; }
.secondary-button:hover { background: var(--blue-dark); }
.ghost-button { padding: 11px 15px; border: 1px solid var(--line); background: white; color: #334155; }
.ghost-button:hover { border-color: #a8b7ca; background: #f8fafc; }
.hero-meter { position: relative; z-index: 1; padding: 22px; border: 1px solid rgba(255,255,255,.18); border-radius: 20px; background: rgba(255,255,255,.1); backdrop-filter: blur(8px); }
.hero-meter-top { display: flex; justify-content: space-between; align-items: baseline; }
.hero-meter-top strong { font-size: 2rem; }
.hero-meter-top span { color: #dce7fb; font-size: .8rem; }
.meter-track { height: 8px; margin: 14px 0 10px; border-radius: 99px; background: rgba(255,255,255,.18); overflow: hidden; }
.meter-fill { height: 100%; width: 0; background: var(--yellow); border-radius: inherit; transition: width .35s ease; }
.hero-meter small { color: #dce7fb; line-height: 1.45; }

.section-head { display: flex; align-items: end; justify-content: space-between; gap: 16px; margin: 34px 0 16px; }
.section-head h2, .section-head h3 { margin: 0; letter-spacing: -.025em; }
.section-head p { margin: 6px 0 0; color: var(--muted); font-size: .9rem; }
.mode-grid { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 12px; }
.mode-card { min-height: 220px; padding: 20px; border: 1px solid var(--line); border-radius: 18px; background: var(--surface); cursor: pointer; text-align: left; box-shadow: 0 8px 22px rgba(30,52,85,.045); transition: .18s ease; }
.mode-card:hover { transform: translateY(-3px); border-color: #a9c3f9; box-shadow: 0 15px 34px rgba(30,52,85,.09); }
.mode-card .mode-no { color: var(--blue); font: 800 .72rem/1 Georgia, serif; }
.mode-card h3 { margin: 20px 0 5px; font-size: 1.08rem; }
.mode-card p { margin: 0; color: var(--muted); font-size: .8rem; line-height: 1.45; }
.mode-progress { display: flex; align-items: baseline; justify-content: space-between; gap: 8px; margin-top: 18px; }
.mode-progress strong { color: var(--ink); font-size: .83rem; }
.mode-progress span { color: var(--muted); font-size: .7rem; }
.mode-meter { height: 5px; margin: 9px 0; overflow: hidden; border-radius: 99px; background: #e8edf5; }
.mode-meter i { display: block; height: 100%; border-radius: inherit; background: var(--blue); }
.mode-next { min-height: 34px; color: #60718a; font-size: .72rem; line-height: 1.45; }
.review-mode.has-review, .review-summary.has-review { border-color: #f3c475; background: #fffaf0; }
.review-mode.has-review .mode-progress strong { color: #a35b00; }

.progress-board { margin-top: 26px; padding: clamp(18px, 3vw, 28px); border: 1px solid var(--line); border-radius: 20px; background: rgba(255,255,255,.72); box-shadow: 0 8px 22px rgba(30,52,85,.035); }
.progress-board-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; margin-bottom: 18px; }
.progress-board-head h2 { margin: 0; font-size: 1.15rem; }
.progress-board-head p { margin: 5px 0 0; color: var(--muted); font-size: .83rem; line-height: 1.45; }
.progress-board-head > span { flex: 0 0 auto; padding: 7px 10px; border-radius: 99px; color: var(--blue-dark); background: #eaf1ff; font-size: .76rem; font-weight: 800; }
.task-groups { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.task-group { padding: 15px; border: 1px solid #e2e8f0; border-radius: 14px; background: white; }
.task-group-title { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: 10px; }
.task-group-title h3 { margin: 0; font-size: .92rem; }
.task-group-title span { color: var(--blue-dark); font-size: .75rem; font-weight: 850; }
.task-list { display: grid; gap: 5px; }
.task-row { display: grid; grid-template-columns: 16px minmax(0, 1fr) auto; align-items: center; gap: 7px; width: 100%; padding: 6px 0; border: 0; background: transparent; color: var(--ink); cursor: pointer; text-align: left; font: inherit; }
.task-row:hover span { color: var(--blue); text-decoration: underline; text-underline-offset: 3px; }
.task-row i { font-style: normal; font-weight: 900; text-align: center; }
.task-row span { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: .77rem; }
.task-row b { color: var(--muted); font-size: .68rem; font-weight: 700; white-space: nowrap; }
.task-row.done i, .task-row.done b { color: var(--green); }
.task-row.active i, .task-row.active b { color: var(--blue); }
.task-row.pending { color: #60718a; }
.task-row.locked { color: #98a2b3; cursor: not-allowed; }
.task-row.locked i, .task-row.locked b { color: #98a2b3; }
.task-row:disabled:hover span { color: inherit; text-decoration: none; }
.review-summary { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-top: 12px; padding: 14px 15px; border: 1px solid #dce5ef; border-radius: 14px; background: #f8fbff; }
.review-summary strong, .review-summary span { display: block; }
.review-summary strong { font-size: .82rem; }
.review-summary span { margin-top: 3px; color: var(--muted); font-size: .74rem; }
.review-preview { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 6px; }
.review-preview button { max-width: 185px; overflow: hidden; border: 0; border-radius: 8px; background: rgba(255,255,255,.8); color: #a35b00; cursor: pointer; font-size: .7rem; line-height: 1.45; text-align: left; text-overflow: ellipsis; white-space: nowrap; }
.local-progress-note { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-top: 14px; padding: 15px; border: 1px solid #dce5ef; border-radius: 14px; background: white; }
.local-progress-note strong, .local-progress-note span { display: block; }
.local-progress-note strong { font-size: .84rem; }
.local-progress-note span { max-width: 720px; margin-top: 4px; color: var(--muted); font-size: .76rem; line-height: 1.5; }

.lesson-list { display: grid; gap: 18px; }
.lesson-card { padding: 26px; border: 1px solid var(--line); border-radius: 22px; background: white; display: grid; grid-template-columns: 82px 1fr auto; gap: 22px; align-items: center; box-shadow: 0 10px 30px rgba(30,52,85,.045); }
.lesson-number { width: 82px; aspect-ratio: 1; border-radius: 20px; background: #edf3ff; color: var(--blue); display: grid; place-items: center; font: 900 2rem/1 Georgia, serif; }
.lesson-card:nth-child(2) .lesson-number { background: #e6fbf8; color: #078a84; }
.lesson-card h2 { margin: 0 0 8px; font-size: 1.35rem; }
.lesson-card p { margin: 0 0 12px; color: var(--muted); line-height: 1.55; }
.tag-row { display: flex; flex-wrap: wrap; gap: 7px; }
.mini-tag { padding: 5px 8px; border-radius: 7px; background: #f2f4f7; color: #475467; font-size: .72rem; font-weight: 700; }
.lesson-actions { display: grid; gap: 8px; min-width: 130px; }

.training-shell { display: grid; grid-template-columns: 210px minmax(0, 1fr); gap: 22px; align-items: start; }
.guided-banner, .free-mode-banner { margin-bottom: 14px; padding: 16px 18px; border-radius: 16px; }
.guided-banner { border: 1px solid #b9d0f7; background: #eef5ff; }
.guided-banner span, .guided-banner strong, .guided-banner small, .free-mode-banner strong, .free-mode-banner span { display: block; }
.guided-banner span { color: var(--blue); font-size: .74rem; font-weight: 850; }
.guided-banner strong { margin-top: 5px; font-size: 1rem; }
.guided-banner small { margin-top: 5px; color: var(--muted); line-height: 1.45; }
.guided-meter { height: 6px; margin-top: 13px; overflow: hidden; border-radius: 99px; background: #d7e4f8; }
.guided-meter i { display: block; height: 100%; border-radius: inherit; background: var(--blue); }
.free-mode-banner { display: flex; align-items: center; gap: 10px; border: 1px solid #b9e3d2; background: #eefaf5; }
.free-mode-banner strong { color: #147252; font-size: .86rem; }
.free-mode-banner span { color: #527064; font-size: .78rem; }
.lesson-rail { padding: 12px; border: 1px solid var(--line); border-radius: 18px; background: white; position: sticky; top: 24px; }
.rail-title { padding: 8px 10px 12px; color: var(--muted); font-size: .75rem; font-weight: 800; letter-spacing: .08em; }
.rail-button { width: 100%; padding: 13px 12px; border: 0; border-radius: 11px; background: transparent; text-align: left; cursor: pointer; }
.rail-button strong, .rail-button span { display: block; }
.rail-button strong { font-size: .9rem; }
.rail-button span { margin-top: 3px; color: var(--muted); font-size: .72rem; }
.rail-button.active { color: var(--blue-dark); background: #edf3ff; }
.train-panel { min-width: 0; }
.tab-bar { padding: 6px; margin-bottom: 16px; border: 1px solid var(--line); border-radius: 15px; background: white; display: flex; gap: 5px; overflow-x: auto; }
.tab-button { flex: 1; min-width: 92px; padding: 10px 14px; border: 0; border-radius: 10px; background: transparent; color: #667085; font-weight: 800; cursor: pointer; }
.tab-button.active { color: white; background: var(--ink); }
.content-card { padding: clamp(20px, 4vw, 34px); border: 1px solid var(--line); border-radius: 22px; background: white; box-shadow: var(--shadow); }
.card-topline { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-bottom: 22px; }
.source-badge { display: inline-flex; align-items: center; gap: 6px; padding: 6px 9px; border-radius: 8px; color: #075e59; background: #e7f8f6; font-size: .72rem; font-weight: 850; }
.source-badge.ai { color: #91450c; background: #fff1df; }
.page-ref { color: var(--muted); font-size: .76rem; }
.content-title { margin: 0 0 7px; font-size: clamp(1.35rem, 3vw, 1.8rem); }
.content-subtitle { margin: 0 0 24px; color: var(--muted); line-height: 1.55; }

.alphabet-grid { display: grid; grid-template-columns: repeat(6, 1fr); gap: 9px; }
.letter-button { min-height: 67px; border: 1px solid var(--line); border-radius: 12px; background: #fbfcfe; cursor: pointer; }
.letter-button:hover { color: var(--blue); border-color: #9bbcf9; background: #f2f6ff; }
.letter-button b { display: block; font-size: 1.25rem; }
.letter-button small { color: var(--muted); }
.alphabet-section + .alphabet-section { margin-top: 20px; }
.alphabet-section h3, .combination-section h3 { margin: 0 0 10px; font-size: 1rem; }
.combination-section { margin-top: 28px; padding: 20px; border: 1px solid #dce8fb; border-radius: 16px; background: #f7faff; }
.combination-section > div > p { margin: 0; color: var(--muted); font-size: .92rem; line-height: 1.5; }
.combination-group { margin-top: 18px; }
.combination-group h4 { margin: 0 0 9px; color: var(--blue); font-size: .93rem; }
.combination-grid { display: grid; grid-template-columns: repeat(6, 1fr); gap: 9px; }
.combination-button { min-height: 69px; border: 1px solid #cadcf7; border-radius: 12px; background: white; cursor: pointer; }
.combination-button:hover { color: var(--blue); border-color: #7caaf0; background: #eef5ff; }
.combination-button b { display: block; font-size: 1.05rem; }
.combination-button small { color: var(--muted); font-size: .76rem; }
.example-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin-top: 16px; }
.word-tile { padding: 15px; border: 1px solid var(--line); border-radius: 13px; background: white; display: flex; justify-content: space-between; align-items: center; gap: 10px; }
.word-tile strong, .word-tile span { display: block; }
.word-tile strong { font-size: 1.04rem; }
.word-tile span { margin-top: 3px; color: var(--muted); font-size: .78rem; }
.audio-button { flex: 0 0 auto; width: 36px; height: 36px; background: #edf3ff; color: var(--blue); }
.audio-button:hover { background: #dfeaff; }

.dialogue-stage { min-height: 285px; padding: clamp(24px, 5vw, 48px); border-radius: 20px; background: #f3f7ff; position: relative; overflow: hidden; }
.dialogue-stage::after { content: attr(data-speaker); position: absolute; right: 20px; bottom: -36px; color: rgba(18,104,243,.08); font: 900 9rem/1 Georgia, serif; }
.dialogue-line { position: relative; z-index: 1; max-width: 690px; }
.speaker { display: inline-grid; place-items: center; width: 34px; height: 34px; border-radius: 50%; color: white; background: var(--coral); font-weight: 900; }
.vietnamese-line { margin: 23px 0 10px; font-size: clamp(1.65rem, 4vw, 2.6rem); line-height: 1.25; font-weight: 800; }
.translation { color: #52627a; font-size: 1.03rem; line-height: 1.6; }
.hidden-text { filter: blur(7px); user-select: none; }
.control-row { display: flex; flex-wrap: wrap; gap: 9px; margin-top: 18px; }
.step-row { display: flex; justify-content: space-between; align-items: center; gap: 10px; margin-top: 18px; }
.step-count { color: var(--muted); font-size: .82rem; }

.vocab-list { display: grid; grid-template-columns: 1fr 1fr; gap: 9px; }
.vocab-group-title { grid-column: 1 / -1; margin: 14px 0 2px; color: var(--ink); font-size: .95rem; }
.vocab-row { padding: 13px 15px; border: 1px solid var(--line); border-radius: 11px; display: flex; align-items: center; justify-content: space-between; gap: 14px; }
.vocab-row strong { color: var(--blue-dark); }
.vocab-row span { margin-left: auto; color: #475467; }
.grammar-stack { display: grid; gap: 12px; }
.grammar-box { padding: 18px; border-left: 4px solid var(--cyan); border-radius: 5px 13px 13px 5px; background: #f5fbfb; }
.grammar-box h4 { margin: 0 0 8px; }
.grammar-box p { margin: 5px 0; color: #475467; line-height: 1.6; }
.pronoun-table { width: 100%; border-collapse: collapse; margin-top: 12px; }
.pronoun-table th, .pronoun-table td { padding: 12px 10px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
.pronoun-table th { color: var(--muted); font-size: .75rem; letter-spacing: .05em; }

.exercise-switch { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 18px; }
.sub-switch { padding-bottom: 16px; border-bottom: 1px solid var(--line); }
.chip-button { padding: 8px 12px; border: 1px solid var(--line); background: white; color: #526174; }
.chip-button.active { color: var(--blue); border-color: #a9c4fb; background: #eef4ff; }
.chip-button:disabled, .ghost-button:disabled { cursor: not-allowed; opacity: .48; }
.exercise-box { padding: 24px; border: 1px solid var(--line); border-radius: 17px; background: #fbfcfe; }
.listen-prompt { display: flex; align-items: center; gap: 14px; margin-bottom: 20px; }
.listen-disc { width: 58px; height: 58px; border-radius: 50%; color: white; background: var(--blue); border: 8px solid #dce8ff; cursor: pointer; font-weight: 900; }
.options { display: grid; gap: 9px; }
.option-button { padding: 13px 15px; border: 1px solid var(--line); background: white; text-align: left; }
.option-button:hover { border-color: #9fbaf0; }
.option-button.correct { border-color: #79c9a9; background: #eaf8f1; color: #126a49; }
.option-button.wrong { border-color: #f0a2a2; background: #fff0f0; color: #a92f2f; }
.answer-input { width: 100%; min-height: 48px; padding: 12px 14px; border: 1px solid #bdc8d7; border-radius: 11px; outline: none; background: white; }
textarea.answer-input { min-height: 95px; resize: vertical; }
.answer-input:focus { border-color: var(--blue); box-shadow: 0 0 0 3px rgba(18,104,243,.11); }
.input-actions { display: flex; flex-wrap: wrap; gap: 9px; margin-top: 12px; }
.feedback { margin-top: 15px; padding: 13px 15px; border-radius: 11px; line-height: 1.55; }
.feedback.good { color: #126a49; background: #eaf8f1; }
.feedback.bad { color: #9f2e2e; background: #fff0f0; }
.feedback.info { color: #174d9b; background: #eef4ff; }
.diff-token { display: inline-block; margin: 2px 4px 2px 0; padding: 2px 6px; border-radius: 5px; background: #ffe0e0; color: #a52d2d; }
.practice-head { display: flex; align-items: center; justify-content: space-between; color: var(--blue-dark); font-size: .82rem; }
.practice-head span { font-weight: 850; }
.practice-head strong { color: var(--muted); }
.exercise-instruction { margin: 12px 0; color: var(--muted); line-height: 1.55; }
.practice-prompt { margin: 18px 0; font-size: clamp(1.45rem, 3.5vw, 2.15rem); line-height: 1.35; font-weight: 850; }
.practice-foot { margin-top: 18px; display: flex; align-items: center; justify-content: space-between; gap: 12px; color: var(--muted); }
.inline-audio { margin: 0 0 15px; }
.mini-review { flex: 0 0 auto; padding: 6px 8px; border: 0; border-radius: 8px; color: var(--muted); background: #f2f4f7; cursor: pointer; font-size: .72rem; font-weight: 750; }
.match-board { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.match-column { display: grid; gap: 9px; }
.match-card { min-height: 50px; padding: 11px 14px; border: 1px solid var(--line); border-radius: 11px; background: white; cursor: pointer; font-weight: 750; }
.match-card:hover, .match-card.selected { border-color: #8fb2f6; background: #eef4ff; color: var(--blue-dark); }
.match-card.matched { visibility: hidden; pointer-events: none; }

.speak-sentence { margin: 18px 0; font-size: clamp(1.55rem, 4vw, 2.3rem); font-weight: 850; line-height: 1.3; }
.mic-button { min-width: 142px; padding: 13px 17px; border: 0; border-radius: 13px; color: white; background: var(--coral); cursor: pointer; font-weight: 850; }
.mic-button.listening { background: var(--danger); animation: listening 1.1s infinite; }
@keyframes listening { 50% { box-shadow: 0 0 0 9px rgba(214,65,65,.12); } }
.recording-panel { margin-top: 16px; padding-top: 15px; border-top: 1px solid var(--line); }
.recording-note { margin: 9px 0 0; color: var(--muted); font-size: .84rem; line-height: 1.5; }

.reading-passage { padding: clamp(20px, 4vw, 32px); border-radius: 15px; background: #f3f7ff; }
.reading-pair + .reading-pair { margin-top: 22px; }
.reading-vi { font: 750 1.2rem/1.55 Georgia, "Times New Roman", serif; }
.reading-zh { margin-top: 5px; color: #52627a; font-size: .96rem; line-height: 1.6; }
.hide-reading-chinese .reading-zh { display: none; }
.question-block { margin-top: 18px; padding-top: 18px; border-top: 1px solid var(--line); }
.question-block h4 { margin: 0 0 12px; }
.sound-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin-top: 16px; }
.sound-card { padding: 19px; border: 1px solid var(--line); border-radius: 13px; text-align: center; background: white; cursor: pointer; }
.sound-card strong { display: block; font-size: 1.5rem; }
.sound-card span { color: var(--muted); font-size: .75rem; }
.sound-card.selected { color: var(--blue-dark); border-color: #8fb2f6; background: #eef4ff; }

.review-list { display: grid; gap: 11px; }
.review-item { padding: 18px; border: 1px solid var(--line); border-radius: 15px; background: white; display: grid; grid-template-columns: 1fr auto; gap: 16px; align-items: center; }
.review-item h3 { margin: 0 0 5px; font-size: 1rem; }
.review-item p { margin: 0; color: var(--muted); font-size: .84rem; line-height: 1.45; }
.review-item.expanded { display: block; }
.review-item.expanded .options, .review-item.expanded .answer-input { margin-top: 14px; }
.review-context { margin: 14px 0; padding: 14px; border-radius: 11px; background: #f3f7ff; }
.review-context p + p { margin-top: 10px; }
.review-context strong { color: var(--ink); }
.empty-state { padding: 55px 24px; border: 1px dashed #b9c4d3; border-radius: 20px; background: rgba(255,255,255,.65); text-align: center; }
.empty-state .empty-mark { width: 58px; height: 58px; margin: 0 auto 14px; border-radius: 18px; color: var(--green); background: #e9f8f1; display: grid; place-items: center; font-weight: 900; }
.empty-state h2 { margin: 0 0 8px; }
.empty-state p { margin: 0; color: var(--muted); }
.toast { position: fixed; right: 22px; bottom: 22px; z-index: 10; max-width: 340px; padding: 12px 16px; border-radius: 12px; color: white; background: #17243a; box-shadow: 0 15px 40px rgba(0,0,0,.2); opacity: 0; transform: translateY(12px); pointer-events: none; transition: .2s ease; }
.toast.show { opacity: 1; transform: translateY(0); }

.onboarding-backdrop { position: fixed; z-index: 50; inset: 0; padding: 18px; background: rgba(10,24,45,.58); display: grid; place-items: center; }
.onboarding-card { width: min(610px, 100%); max-height: calc(100vh - 36px); overflow: auto; padding: clamp(22px, 4vw, 34px); border-radius: 24px; background: white; box-shadow: 0 28px 80px rgba(0,0,0,.28); }
.onboarding-top { display: flex; justify-content: space-between; align-items: center; }
.close-button { width: 36px; height: 36px; border: 0; border-radius: 10px; background: #f2f4f7; cursor: pointer; font-size: 1.35rem; }
.onboarding-card h2 { margin: 18px 0; font-size: clamp(1.55rem, 4vw, 2rem); }
.guide-steps { display: grid; gap: 12px; }
.guide-steps > div { display: grid; grid-template-columns: 34px 1fr; gap: 12px; align-items: start; }
.guide-steps b { width: 32px; height: 32px; border-radius: 10px; color: white; background: var(--blue); display: grid; place-items: center; }
.guide-steps p { margin: 0; }
.guide-steps strong, .guide-steps span { display: block; }
.guide-steps span { margin-top: 3px; color: var(--muted); font-size: .88rem; line-height: 1.5; }
.privacy-note { margin: 18px 0; padding: 11px 13px; border-radius: 10px; color: #475467; background: #f6f8fb; font-size: .82rem; line-height: 1.5; }
.onboarding-actions { display: flex; flex-wrap: wrap; gap: 9px; }
.survey-backdrop { position: fixed; z-index: 60; inset: 0; padding: 18px; background: rgba(10,24,45,.58); display: grid; place-items: center; }
.survey-card { position: relative; width: min(600px, 100%); max-height: calc(100vh - 36px); overflow: auto; padding: clamp(22px, 4vw, 34px); border-radius: 24px; background: white; box-shadow: 0 28px 80px rgba(0,0,0,.28); }
.survey-card h2 { margin: 8px 0 20px; }
.survey-close { position: absolute; top: 18px; right: 18px; }
.survey-card fieldset { margin: 0 0 18px; padding: 0; border: 0; }
.survey-card legend, .survey-comment { display: block; margin-bottom: 9px; font-weight: 800; }
.survey-options { display: flex; flex-wrap: wrap; gap: 8px; }
.survey-options input { position: absolute; opacity: 0; pointer-events: none; }
.survey-options span { display: block; padding: 9px 14px; border: 1px solid var(--line); border-radius: 10px; cursor: pointer; background: white; }
.survey-options input:checked + span { border-color: var(--blue); color: var(--blue-dark); background: #eef4ff; }
.rating-options span { min-width: 42px; text-align: center; }
.survey-comment textarea, .intent-block select { box-sizing: border-box; width: 100%; margin-top: 9px; padding: 11px 13px; border: 1px solid var(--line); border-radius: 10px; font: inherit; }
.intent-block { margin-top: 20px; padding-top: 20px; border-top: 1px solid var(--line); }
.survey-actions { display: flex; justify-content: flex-end; gap: 9px; margin-top: 22px; }

@media (max-width: 1050px) {
  .mode-grid { grid-template-columns: repeat(3, 1fr); }
  .hero { grid-template-columns: 1fr; }
  .hero-meter { max-width: 420px; }
  .example-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 760px) {
  .app-shell { display: block; }
  .sidebar { display: none; position: fixed; z-index: 20; inset: 0 auto 0 0; width: min(82vw, 290px); }
  .sidebar.open { display: flex; }
  .main-area { padding: 18px 16px 44px; }
  .mobile-menu { display: block; }
  .topbar { align-items: flex-start; gap: 12px; }
  .topbar > div:nth-child(2) { flex: 1; }
  .streak-pill { display: none; }
  .hero { min-height: 0; padding: 28px 22px; border-radius: 21px; }
  .hero h2 { font-size: 2.35rem; }
  .hero::before { font-size: 4rem; }
  .mode-grid { grid-template-columns: repeat(2, 1fr); }
  .task-groups { grid-template-columns: 1fr; }
  .progress-board-head, .review-summary { align-items: flex-start; flex-direction: column; }
  .local-progress-note, .free-mode-banner { align-items: flex-start; flex-direction: column; }
  .review-preview { justify-content: flex-start; }
  .lesson-card { grid-template-columns: 62px 1fr; padding: 19px; gap: 14px; }
  .lesson-number { width: 62px; border-radius: 16px; }
  .lesson-actions { grid-column: 1 / -1; grid-template-columns: 1fr 1fr; }
  .training-shell { display: block; }
  .lesson-rail { position: static; display: flex; margin-bottom: 12px; overflow-x: auto; }
  .rail-title { display: none; }
  .rail-button { min-width: 150px; }
  .alphabet-grid { grid-template-columns: repeat(4, 1fr); }
  .combination-grid { grid-template-columns: repeat(4, 1fr); }
  .example-grid, .vocab-list { grid-template-columns: 1fr; }
  .vocab-row { flex-wrap: wrap; }
  .vocab-row span { flex: 1; min-width: 92px; }
  .match-board { gap: 8px; }
}

@media (max-width: 440px) {
  .mode-grid { grid-template-columns: 1fr; }
  .mode-card { min-height: 0; }
  .alphabet-grid { grid-template-columns: repeat(3, 1fr); }
  .combination-grid { grid-template-columns: repeat(3, 1fr); }
  .sound-grid { grid-template-columns: 1fr; }
  .card-topline, .step-row { align-items: flex-start; }
  .step-row { flex-wrap: wrap; }
  .vietnamese-line { font-size: 1.55rem; }
  .exercise-box { padding: 18px; }
  .practice-foot { align-items: flex-start; flex-direction: column; }
}