* { box-sizing: border-box; }
:root {
  --bg: #071019;
  --panel: #0d1b29;
  --panel-2: #112438;
  --border: rgba(255,255,255,.12);
  --text: #f3f8ff;
  --muted: #94a8bc;
  --cyan: #55d6be;
  --blue: #68a4ff;
  --gold: #f5c76b;
  --danger: #ff718b;
}
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: Inter, Arial, sans-serif;
  background:
    radial-gradient(circle at 12% 6%, rgba(85,214,190,.18), transparent 24rem),
    radial-gradient(circle at 88% 18%, rgba(104,164,255,.17), transparent 26rem),
    var(--bg);
}
button, input, textarea { font: inherit; }
button { cursor: pointer; }
.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 14px max(20px, calc((100vw - 1180px) / 2));
  background: rgba(7,16,25,.88);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(18px);
}
.back {
  color: var(--text);
  text-decoration: none;
  font-weight: 800;
}
.topbar-progress { width: min(390px, 48vw); color: var(--muted); font-size: 13px; font-weight: 700; }
.progress-track { height: 7px; margin-top: 7px; overflow: hidden; border-radius: 9px; background: rgba(255,255,255,.09); }
.progress-track span { display: block; width: 0; height: 100%; background: linear-gradient(90deg, var(--cyan), var(--blue)); transition: width .35s; }
.course-shell { width: min(1180px, 100%); margin: auto; padding: 54px 22px 80px; }
.hero {
  display: grid;
  grid-template-columns: 1.55fr .75fr;
  gap: 28px;
  align-items: end;
  padding: 52px;
  border: 1px solid var(--border);
  border-radius: 36px;
  background: linear-gradient(135deg, rgba(17,36,56,.96), rgba(9,24,35,.92));
  box-shadow: 0 30px 90px rgba(0,0,0,.35);
}
.eyebrow { margin: 0 0 12px; color: var(--cyan); font-size: 12px; font-weight: 900; letter-spacing: .16em; text-transform: uppercase; }
h1 { margin: 0; font-size: clamp(48px, 8vw, 88px); line-height: .93; letter-spacing: -.07em; }
h1 em { color: var(--cyan); font-style: normal; }
h2 { margin: 0; font-size: clamp(30px, 5vw, 48px); letter-spacing: -.045em; }
h3 { margin: 0 0 12px; }
.hero-copy, .muted { color: var(--muted); line-height: 1.75; }
.hero-copy { max-width: 700px; margin: 24px 0; font-size: 18px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.primary, .ghost, .filter, .tab, .icon-btn, .answer-btn, .complete-btn {
  border: 1px solid var(--border);
  border-radius: 14px;
  color: var(--text);
  font-weight: 800;
}
.primary, .complete-btn { padding: 14px 20px; border: 0; color: #03120f; background: linear-gradient(135deg, var(--cyan), #8de8d8); }
.ghost { padding: 14px 20px; background: rgba(255,255,255,.06); }
.level-card { padding: 28px; border: 1px solid var(--border); border-radius: 24px; background: rgba(255,255,255,.055); }
.level-card strong { display: block; margin: 16px 0; font-size: 23px; }
.level-card ul { margin: 0; padding-left: 20px; color: var(--muted); line-height: 1.9; }
.level-badge, .module-level, .tag { display: inline-flex; padding: 7px 11px; border-radius: 999px; background: rgba(85,214,190,.12); color: var(--cyan); font-size: 12px; font-weight: 900; }
.dashboard { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin: 22px 0 70px; }
.stat { padding: 22px; border: 1px solid var(--border); border-radius: 20px; background: rgba(255,255,255,.04); }
.stat strong { display: block; font-size: 34px; }
.stat span { color: var(--muted); font-size: 13px; font-weight: 800; }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 24px; margin-bottom: 24px; }
.level-filter, .lesson-tabs { display: flex; flex-wrap: wrap; gap: 8px; }
.filter, .tab { padding: 10px 13px; background: rgba(255,255,255,.04); color: var(--muted); }
.filter.active, .tab.active { color: #061310; border-color: transparent; background: var(--cyan); }
.module-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.module-card {
  position: relative;
  padding: 28px;
  border: 1px solid var(--border);
  border-radius: 26px;
  background: linear-gradient(145deg, rgba(17,36,56,.82), rgba(10,25,38,.82));
  transition: transform .2s, border-color .2s;
}
.module-card:hover { transform: translateY(-4px); border-color: rgba(85,214,190,.55); }
.module-card.completed { border-color: rgba(85,214,190,.48); }
.module-card h3 { margin: 18px 0 9px; font-size: 25px; }
.module-card p { color: var(--muted); line-height: 1.65; }
.module-meta { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-top: 24px; }
.module-open { padding: 11px 16px; border: 0; border-radius: 12px; color: #071019; background: var(--text); font-weight: 900; }
.module-open { display: inline-flex; text-decoration: none; }
.checkmark { color: var(--cyan); font-weight: 900; }
.lesson-panel, .phrase-lab { margin-top: 70px; padding: 34px; border: 1px solid var(--border); border-radius: 30px; background: rgba(13,27,41,.94); }
.lesson-shell { width: min(1050px, 100%); }
.lesson-shell .lesson-panel { margin-top: 0; }
.lesson-page h1 { font-size: clamp(42px, 7vw, 72px); }
.lesson-header { display: flex; align-items: start; justify-content: space-between; gap: 20px; }
.lesson-tabs { margin: 30px 0 24px; padding-bottom: 18px; border-bottom: 1px solid var(--border); }
.icon-btn { width: 44px; height: 44px; background: rgba(255,255,255,.06); font-size: 24px; }
.content-grid, .vocab-grid, .dialogue-grid, .practice-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.content-card, .vocab-card, .dialogue-card, .practice-card, .quiz-card, .phrase-row {
  padding: 22px;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: rgba(255,255,255,.045);
}
.content-card ul { padding-left: 19px; color: var(--muted); line-height: 1.8; }
.content-card strong, .vocab-card strong { color: var(--cyan); }
.vocab-card { min-height: 168px; }
.vocab-card p { margin: 10px 0; color: var(--muted); }
.vocab-example { font-style: italic; line-height: 1.55; }
.speaker { margin: 13px 0; padding: 13px 15px; border-left: 3px solid var(--blue); border-radius: 0 12px 12px 0; background: rgba(104,164,255,.08); line-height: 1.65; }
.speaker.alt { border-left-color: var(--cyan); background: rgba(85,214,190,.07); }
.practice-card textarea { width: 100%; min-height: 115px; padding: 13px; resize: vertical; border: 1px solid var(--border); border-radius: 12px; color: var(--text); background: rgba(0,0,0,.22); }
.model-toggle { margin-top: 12px; padding: 10px 13px; border: 1px solid var(--border); border-radius: 10px; color: var(--text); background: rgba(255,255,255,.07); font-weight: 800; }
.model-answer { margin-top: 12px; padding: 14px; border-radius: 12px; color: var(--muted); background: rgba(85,214,190,.08); line-height: 1.65; }
.quiz-card { max-width: 760px; }
.answer-list { display: grid; gap: 10px; margin: 18px 0; }
.answer-btn { padding: 13px; text-align: left; background: rgba(255,255,255,.05); }
.answer-btn:hover { border-color: var(--blue); }
.answer-btn.correct { color: #06130f; border-color: var(--cyan); background: var(--cyan); }
.answer-btn.wrong { border-color: var(--danger); background: rgba(255,113,139,.14); }
.quiz-feedback { min-height: 26px; color: var(--muted); line-height: 1.6; }
.complete-btn { margin-top: 20px; }
.lesson-navigation { display: grid; grid-template-columns: 1fr auto 1fr; gap: 12px; margin-top: 34px; padding-top: 24px; border-top: 1px solid var(--border); }
.lesson-nav-link { padding: 13px 16px; border: 1px solid var(--border); border-radius: 13px; color: var(--text); text-decoration: none; font-weight: 800; background: rgba(255,255,255,.05); }
.lesson-nav-link:last-child { text-align: right; }
.lesson-nav-link.hidden { display: block !important; visibility: hidden; pointer-events: none; }
.overview-link { color: var(--cyan); text-align: center; }
.inline-action { display: inline-flex; text-decoration: none; }
.phrase-lab { display: grid; grid-template-columns: .7fr 1.3fr; gap: 30px; }
.work-plan { margin: 0 0 70px; padding: 34px; border: 1px solid var(--border); border-radius: 30px; background: rgba(13,27,41,.94); }
.work-plan-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-top: 24px; }
.work-plan-grid article { padding: 18px; border: 1px solid var(--border); border-radius: 17px; background: rgba(255,255,255,.045); }
.work-plan-grid strong { display: block; margin-bottom: 8px; color: var(--cyan); }
.work-plan-grid span { color: var(--muted); line-height: 1.55; }
.workplace-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.workplace-card { padding: 20px; border: 1px solid var(--border); border-radius: 18px; background: rgba(255,255,255,.045); }
.workplace-card h3 { color: var(--cyan); }
.workplace-card p, .workplace-card li { color: var(--muted); line-height: 1.65; }
.workplace-card ul { padding-left: 18px; }
.phrase-list { display: grid; gap: 10px; }
.phrase-row { display: grid; grid-template-columns: 1fr auto 1.3fr; gap: 14px; align-items: center; }
.phrase-row .basic { color: var(--muted); }
.phrase-row .better { color: var(--cyan); font-weight: 800; }
.hidden { display: none !important; }
@media (max-width: 850px) {
  .hero, .phrase-lab { grid-template-columns: 1fr; padding: 28px; }
  .work-plan-grid { grid-template-columns: repeat(2, 1fr); }
  .workplace-grid { grid-template-columns: 1fr; }
  .dashboard { grid-template-columns: repeat(2, 1fr); }
  .section-heading { align-items: start; flex-direction: column; }
  .module-grid, .content-grid, .vocab-grid, .dialogue-grid, .practice-grid { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  .course-shell { padding: 28px 14px 60px; }
  .topbar { align-items: start; flex-direction: column; }
  .topbar-progress { width: 100%; }
  .lesson-panel { padding: 20px; }
  .lesson-navigation { grid-template-columns: 1fr; }
  .lesson-nav-link, .lesson-nav-link:last-child { text-align: center; }
  .phrase-row { grid-template-columns: 1fr; }
  .work-plan-grid { grid-template-columns: 1fr; }
  .phrase-row span:nth-child(2) { display: none; }
}