/* style.css */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --cream:      #F8F4EE;
  --cream-dark: #EFE9DE;
  --ink:        #1C2035;
  --red:        #C0392B;
  --red-light:  #E8574A;
  --gold:       #C9954A;
  --gold-light: #E8B96A;
  --sage:       #4A6741;
  --sky:        #2E6B9E;
  --surface:    #FFFFFF;
  --border:     #E0D8CC;
  --text:       #2A2520;
  --text-mid:   #5C5248;
  --text-muted: #9A9088;
  --radius:     12px;
  --radius-lg:  20px;
  --sidebar-w:  248px;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'DM Sans', sans-serif;
  background-color: var(--cream);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}

/* ── Nav ── */
nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(248,244,238,0.90);
  backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
}

.nav-inner {
  max-width: 1320px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between; height: 60px; gap: 16px;
}

.nav-brand { display: flex; align-items: center; gap: 10px; text-decoration: none; flex-shrink: 0; }

.nav-logo {
  width: 34px; height: 34px; background: var(--red); border-radius: 9px;
  display: flex; align-items: center; justify-content: center;
  font-family: 'Noto Serif SC', serif; font-size: 16px; color: white; font-weight: 700;
}

.nav-title-zh {
  font-family: 'Noto Serif SC', serif; font-size: 13px; font-weight: 600;
  color: var(--red); letter-spacing: 0.03em;
}

.breadcrumb {
  display: flex; align-items: center; gap: 8px;
  font-size: 13px; color: var(--text-muted); min-width: 0;
}

.breadcrumb a { color: var(--text-muted); text-decoration: none; white-space: nowrap; }
.breadcrumb a:hover { color: var(--red); }
.breadcrumb-current { color: var(--text); font-weight: 500; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

.btn-nav {
  display: flex; align-items: center; gap: 6px;
  padding: 7px 14px; border-radius: 8px; font-size: 13px; font-weight: 500;
  font-family: 'DM Sans', sans-serif; cursor: pointer; text-decoration: none;
  transition: all 0.2s; border: 1.5px solid var(--border); background: var(--surface); color: var(--text-mid);
}

.btn-nav:hover { border-color: var(--red); color: var(--red); background: rgba(192,57,43,0.06); }

/* ── Layout & Sidebar ── */
.page-layout {
  max-width: 1320px; margin: 0 auto;
  display: grid; grid-template-columns: var(--sidebar-w) 1fr;
  min-height: calc(100vh - 60px);
}

.sidebar {
  border-right: 1px solid var(--border); padding: 28px 0;
  position: sticky; top: 60px; height: calc(100vh - 60px); overflow-y: auto;
}

.sidebar-inner { padding: 0 18px; }

.sidebar-topic-header {
  background: linear-gradient(135deg, var(--red) 0%, #a02818 100%);
  border-radius: 14px; padding: 18px; margin-bottom: 22px; text-align: center;
}

.sidebar-topic-number { font-size: 10px; font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase; color: rgba(255,255,255,0.55); margin-bottom: 5px; }
.sidebar-char { font-family: 'Noto Serif SC', serif; font-size: 40px; font-weight: 700; color: white; line-height: 1; margin-bottom: 4px; }
.sidebar-pinyin { font-size: 12px; color: rgba(255,255,255,0.70); margin-bottom: 2px; }
.sidebar-title { font-size: 11.5px; font-weight: 600; color: rgba(255,255,255,0.88); }

.sidebar-section-label {
  font-size: 10px; font-weight: 600; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--text-muted); padding: 0 12px; margin-bottom: 8px;
}

.sidebar-nav { list-style: none; margin-bottom: 24px; }
.sidebar-nav li a {
  display: flex; align-items: center; gap: 10px;
  padding: 9px 12px; border-radius: 9px;
  font-size: 13.5px; font-weight: 500; color: var(--text-mid); text-decoration: none;
  transition: all 0.18s; cursor: pointer;
}
.sidebar-nav li a:hover, .sidebar-nav li a.active { background: rgba(192,57,43,0.09); color: var(--red); }
.sidebar-nav li a .nav-icon { font-size: 15px; width: 20px; text-align: center; }
.sidebar-divider { height: 1px; background: var(--border); margin: 4px 0 18px; }
.sidebar::-webkit-scrollbar { width: 4px; }
.sidebar::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }

/* ── Main Content & Sections ── */
.main-content { padding: 40px 48px 80px; min-width: 0; }
.content-section { margin-bottom: 56px; scroll-margin-top: 80px; animation: fadeUp 0.5s ease both; }
.content-section:nth-child(1) { animation-delay: 0.05s; }
.content-section:nth-child(2) { animation-delay: 0.12s; }
.content-section:nth-child(3) { animation-delay: 0.18s; }
.content-section:nth-child(4) { animation-delay: 0.24s; }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

.section-header-line { display: flex; align-items: center; gap: 14px; margin-bottom: 26px; }
.section-icon { width: 42px; height: 42px; border-radius: 11px; display: flex; align-items: center; justify-content: center; font-size: 20px; flex-shrink: 0; }
.icon-vocab   { background: rgba(201,149,74,0.15); }
.icon-grammar { background: rgba(46,107,158,0.12); }
.icon-reading { background: rgba(74,103,65,0.12); }
.icon-audio   { background: rgba(192,57,43,0.10); }

.section-label { font-size: 11px; font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 2px; }
.section-heading { font-family: 'Cormorant Garamond', serif; font-size: 26px; font-weight: 700; color: var(--ink); line-height: 1.15; }

/* ── Vocabulary ── */
.vocab-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 12px; }
.vocab-card {
  background: var(--surface); border: 1.5px solid var(--border); border-radius: var(--radius);
  padding: 16px 18px; display: flex; align-items: center; gap: 14px;
  transition: all 0.2s; position: relative; overflow: hidden;
}
.vocab-card:hover { border-color: var(--gold); box-shadow: 0 4px 16px rgba(201,149,74,0.15); transform: translateY(-2px); }
.vocab-hanzi { font-family: 'Noto Serif SC', serif; font-size: 34px; font-weight: 700; color: var(--ink); line-height: 1; flex-shrink: 0; width: 50px; text-align: center; }
.vocab-details { min-width: 0; flex: 1; }
.vocab-pinyin  { font-size: 13px; color: var(--gold); font-weight: 600; letter-spacing: 0.02em; margin-bottom: 2px; }
.vocab-english { font-size: 14px; font-weight: 500; color: var(--text); margin-bottom: 2px; }
.vocab-type    { font-size: 11px; color: var(--text-muted); font-style: italic; }

.speak-btn, .example-speak {
  width: 30px; height: 30px; border-radius: 50%; background: var(--cream);
  border: none; cursor: pointer; display: flex; align-items: center; justify-content: center;
  color: var(--text-muted); transition: all 0.18s; flex-shrink: 0;
}
.speak-btn:hover, .example-speak:hover { background: var(--gold); color: white; transform: scale(1.1); }
.speak-btn.speaking, .example-speak.speaking { background: var(--red); color: white; animation: pulse 0.8s ease-in-out infinite; }
@keyframes pulse { 0%,100% { transform: scale(1); } 50% { transform: scale(1.12); } }

.tip-box {
  background: rgba(201,149,74,0.08); border: 1.5px solid rgba(201,149,74,0.30);
  border-radius: var(--radius); padding: 14px 16px;
  display: flex; gap: 10px; align-items: flex-start; margin-top: 16px;
}
.tip-box-icon { font-size: 17px; flex-shrink: 0; line-height: 1.4; }
.tip-box-text { font-size: 13.5px; color: var(--text-mid); line-height: 1.65; }
.tip-box-text strong { color: var(--gold); }

/* ── Grammar ── */
.grammar-block { background: var(--surface); border: 1.5px solid var(--border); border-radius: var(--radius-lg); padding: 26px 28px; margin-bottom: 16px; }
.grammar-point-title { font-family: 'Cormorant Garamond', serif; font-size: 20px; font-weight: 700; color: var(--sky); margin-bottom: 10px; }
.grammar-explanation { font-size: 14.5px; color: var(--text-mid); line-height: 1.75; margin-bottom: 16px; }
.grammar-structure-box { background: rgba(46,107,158,0.07); border: 1px solid rgba(46,107,158,0.20); border-radius: 8px; padding: 12px 16px; margin-bottom: 16px; }
.grammar-structure-label { font-size: 10px; font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase; color: var(--sky); margin-bottom: 6px; }
.grammar-structure-formula { font-family: 'Cormorant Garamond', serif; font-size: 18px; font-weight: 600; color: var(--ink); }
.grammar-examples-label { font-size: 11px; font-weight: 600; letter-spacing: 0.10em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 10px; }
.grammar-example { display: flex; align-items: flex-start; gap: 14px; padding: 11px 0; border-bottom: 1px solid var(--cream-dark); }
.grammar-example:last-child { border-bottom: none; }
.example-num { font-size: 11px; font-weight: 700; color: var(--text-muted); width: 18px; flex-shrink: 0; padding-top: 2px; }
.example-content { flex: 1; }
.example-zh { font-family: 'Noto Serif SC', serif; font-size: 18px; font-weight: 600; color: var(--ink); margin-bottom: 2px; line-height: 1.4; }
.example-py { font-size: 13px; color: var(--gold); margin-bottom: 2px; letter-spacing: 0.02em; }
.example-en { font-size: 13px; color: var(--text-muted); font-style: italic; }

/* ── Reading & Toggles ── */
.reading-subsection { margin-bottom: 28px; }
.reading-sub-label { display: flex; align-items: center; gap: 10px; font-family: 'Cormorant Garamond', serif; font-size: 20px; font-weight: 700; color: var(--ink); margin-bottom: 14px; }
.reading-sub-label .sub-tag { font-family: 'DM Sans', sans-serif; font-size: 10px; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; padding: 3px 10px; border-radius: 100px; }
.tag-presentational { background: rgba(74,103,65,0.12); color: var(--sage); }
.tag-conversational { background: rgba(201,149,74,0.15); color: var(--gold); }
.reading-passage { background: var(--surface); border: 1.5px solid var(--border); border-radius: var(--radius-lg); overflow: hidden; }
.reading-header { padding: 18px 26px; display: flex; align-items: center; justify-content: space-between; }
.reading-header-present { background: linear-gradient(135deg, var(--sage) 0%, #3a5630 100%); }
.reading-header-conv { background: linear-gradient(135deg, #8B6914 0%, var(--gold) 100%); }
.reading-title-zh { font-family: 'Noto Serif SC', serif; font-size: 17px; font-weight: 700; color: white; }
.reading-title-en { font-size: 12px; color: rgba(255,255,255,0.65); margin-top: 2px; }
.reading-level-badge { background: rgba(255,255,255,0.18); border-radius: 100px; padding: 4px 12px; font-size: 11px; font-weight: 600; color: white; letter-spacing: 0.06em; }
.reading-body { padding: 24px 26px; }
.reading-toggle-bar { display: flex; gap: 8px; margin-bottom: 18px; padding-bottom: 18px; border-bottom: 1px solid var(--cream-dark); flex-wrap: wrap; }

.toggle-btn { padding: 5px 14px; border-radius: 100px; font-size: 12px; font-weight: 600; font-family: 'DM Sans', sans-serif; cursor: pointer; border: 1.5px solid var(--border); background: transparent; color: var(--text-muted); transition: all 0.18s; }
.toggle-btn.sage-active { background: var(--sage); border-color: var(--sage); color: white; }
.toggle-btn.gold-active { background: #8B6914; border-color: #8B6914; color: white; }
.toggle-btn:hover:not(.sage-active):not(.gold-active) { border-color: var(--sage); color: var(--sage); }

.reading-layer { display: none; }
.reading-layer.visible { display: block; }
.reading-text { font-family: 'Noto Serif SC', serif; font-size: 20px; color: var(--ink); line-height: 2.15; margin-bottom: 0; letter-spacing: 0.03em; }
.reading-text-pinyin { font-size: 14px; color: var(--text-mid); line-height: 2.1; letter-spacing: 0.01em; }
.reading-text-translation { font-size: 14px; color: var(--text-muted); line-height: 1.8; font-style: italic; border-left: 3px solid var(--cream-dark); padding-left: 16px; }

/* Dialogue */
.dialogue-line { display: flex; gap: 12px; margin-bottom: 10px; align-items: flex-start; }
.dialogue-speaker { font-size: 11px; font-weight: 700; letter-spacing: 0.05em; text-transform: uppercase; padding: 3px 9px; border-radius: 100px; flex-shrink: 0; margin-top: 2px; white-space: nowrap; }
.speaker-a { background: rgba(192,57,43,0.10); color: var(--red); }
.speaker-b { background: rgba(46,107,158,0.10); color: var(--sky); }
.dialogue-text { flex: 1; }
.d-zh { font-family: 'Noto Serif SC', serif; font-size: 18px; color: var(--ink); line-height: 1.5; margin-bottom: 1px; }
.d-py { font-size: 12px; color: var(--gold); margin-bottom: 1px; }
.d-en { font-size: 12px; color: var(--text-muted); font-style: italic; }

.reading-body[data-view="hanzi"] .d-py, .reading-body[data-view="hanzi"] .d-en { display: none; }
.reading-body[data-view="pinyin"] .d-zh, .reading-body[data-view="pinyin"] .d-en { display: none; }
.reading-body[data-view="translation"] .d-zh, .reading-body[data-view="translation"] .d-py { display: none; }
.reading-text-pinyin, .reading-text-translation { display: none; }

.comprehension-section { margin-top: 22px; padding-top: 22px; border-top: 1px solid var(--cream-dark); }
.comprehension-label { font-size: 11px; font-weight: 600; letter-spacing: 0.10em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 12px; }
.question-item { display: flex; gap: 12px; margin-bottom: 10px; align-items: flex-start; }
.question-num { width: 24px; height: 24px; background: var(--cream-dark); border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 11px; font-weight: 700; color: var(--text-mid); flex-shrink: 0; }
.question-text { font-size: 14px; color: var(--text); line-height: 1.6; padding-top: 2px; }
.question-zh { font-family: 'Noto Serif SC', serif; font-size: 15px; display: block; margin-bottom: 1px; }
.question-en { font-size: 13px; color: var(--text-muted); }

/* ── Audio / TTS ── */
.tts-notice { background: rgba(192,57,43,0.06); border: 1.5px solid rgba(192,57,43,0.18); border-radius: var(--radius); padding: 12px 16px; margin-bottom: 20px; display: flex; align-items: flex-start; gap: 10px; font-size: 13px; color: var(--text-mid); line-height: 1.6; }
.tts-notice strong { color: var(--red); }
.audio-tracks-list { display: flex; flex-direction: column; gap: 14px; }
.audio-track { background: var(--surface); border: 1.5px solid var(--border); border-radius: var(--radius); padding: 18px 20px; transition: all 0.2s; }
.audio-track:hover { border-color: rgba(192,57,43,0.30); box-shadow: 0 4px 16px rgba(192,57,43,0.08); }
.audio-track-header { display: flex; align-items: center; gap: 14px; margin-bottom: 14px; }
.track-icon { width: 42px; height: 42px; border-radius: 11px; display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.track-icon-red { background: linear-gradient(135deg, var(--red) 0%, #a02818 100%); box-shadow: 0 3px 10px rgba(192,57,43,0.25); }
.track-icon-gold { background: linear-gradient(135deg, #8B6914 0%, var(--gold) 100%); box-shadow: 0 3px 10px rgba(201,149,74,0.25); }
.track-icon-sky { background: linear-gradient(135deg, var(--sky) 0%, #1c4e77 100%); box-shadow: 0 3px 10px rgba(46,107,158,0.25); }
.track-info { flex: 1; min-width: 0; }
.track-title { font-size: 15px; font-weight: 600; color: var(--ink); margin-bottom: 3px; }
.track-subtitle { font-size: 12px; color: var(--text-muted); }

.tts-play-row { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.tts-main-btn { display: flex; align-items: center; gap: 8px; padding: 9px 20px; border-radius: 100px; font-size: 14px; font-weight: 600; font-family: 'DM Sans', sans-serif; cursor: pointer; border: none; transition: all 0.2s; color: white; }
.tts-main-btn.btn-red { background: var(--red); box-shadow: 0 3px 12px rgba(192,57,43,0.30); }
.tts-main-btn.btn-gold { background: #8B6914; box-shadow: 0 3px 12px rgba(201,149,74,0.30); }
.tts-main-btn.btn-sky { background: var(--sky); box-shadow: 0 3px 12px rgba(46,107,158,0.25); }
.tts-main-btn:hover { filter: brightness(1.1); transform: translateY(-1px); }
.tts-main-btn.playing { filter: brightness(0.88); }
.tts-speed-label { font-size: 12px; color: var(--text-muted); margin-left: 6px; }
.tts-speed-select { padding: 6px 10px; border-radius: 8px; border: 1.5px solid var(--border); background: var(--surface); font-family: 'DM Sans', sans-serif; font-size: 13px; color: var(--text-mid); cursor: pointer; }

.audio-transcript { margin-top: 14px; padding-top: 14px; border-top: 1px solid var(--cream-dark); }
.transcript-toggle { display: flex; align-items: center; gap: 6px; font-size: 12px; font-weight: 600; color: var(--text-muted); cursor: pointer; background: none; border: none; font-family: 'DM Sans', sans-serif; padding: 0; transition: color 0.18s; user-select: none; }
.transcript-toggle:hover { color: var(--red); }
.transcript-chevron { transition: transform 0.2s; }
.transcript-toggle[aria-expanded="true"] .transcript-chevron { transform: rotate(180deg); }
.transcript-body { display: none; margin-top: 12px; }
.transcript-body.open { display: block; }
.transcript-line { margin-bottom: 10px; }
.t-zh { font-family: 'Noto Serif SC', serif; font-size: 16px; color: var(--ink); line-height: 1.5; }
.t-py { font-size: 12px; color: var(--gold); margin-top: 1px; }
.t-en { font-size: 13px; color: var(--text-muted); margin-top: 1px; font-style: italic; }
.t-speaker { display: inline-block; font-size: 10px; font-weight: 700; letter-spacing: 0.06em; padding: 2px 7px; border-radius: 100px; margin-right: 6px; text-transform: uppercase; }
.t-speaker-a { background: rgba(192,57,43,0.10); color: var(--red); }
.t-speaker-b { background: rgba(46,107,158,0.10); color: var(--sky); }

/* ── Practice Banners & Notes ── */
.practice-nav-banner { display: flex; align-items: center; gap: 18px; border-radius: var(--radius-lg); padding: 20px 24px; text-decoration: none; transition: all 0.22s; margin-top: 20px; border: 2px solid transparent; }
.practice-nav-reading { background: linear-gradient(135deg, rgba(74,103,65,0.08) 0%, rgba(74,103,65,0.03) 100%); border-color: rgba(74,103,65,0.25); }
.practice-nav-reading:hover { background: linear-gradient(135deg, rgba(74,103,65,0.14) 0%, rgba(74,103,65,0.07) 100%); border-color: var(--sage); box-shadow: 0 6px 24px rgba(74,103,65,0.15); transform: translateY(-2px); }
.practice-nav-listening { background: linear-gradient(135deg, rgba(192,57,43,0.07) 0%, rgba(192,57,43,0.03) 100%); border-color: rgba(192,57,43,0.22); }
.practice-nav-listening:hover { background: linear-gradient(135deg, rgba(192,57,43,0.13) 0%, rgba(192,57,43,0.06) 100%); border-color: var(--red); box-shadow: 0 6px 24px rgba(192,57,43,0.15); transform: translateY(-2px); }
.practice-nav-icon { font-size: 32px; flex-shrink: 0; line-height: 1; }
.practice-nav-text { flex: 1; }
.practice-nav-label { font-size: 10px; font-weight: 700; letter-spacing: 0.14em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 3px; }
.practice-nav-title { font-family: 'Cormorant Garamond', serif; font-size: 20px; font-weight: 700; color: var(--ink); margin-bottom: 3px; }
.practice-nav-reading .practice-nav-title { color: var(--sage); }
.practice-nav-listening .practice-nav-title { color: var(--red); }
.practice-nav-sub { font-size: 13px; color: var(--text-muted); line-height: 1.5; }
.practice-nav-arrow { width: 44px; height: 44px; border-radius: 50%; flex-shrink: 0; display: flex; align-items: center; justify-content: center; transition: all 0.2s; }
.practice-nav-reading .practice-nav-arrow { background: rgba(74,103,65,0.12); color: var(--sage); }
.practice-nav-listening .practice-nav-arrow { background: rgba(192,57,43,0.10); color: var(--red); }
.practice-nav-reading:hover .practice-nav-arrow { background: var(--sage); color: white; }
.practice-nav-listening:hover .practice-nav-arrow { background: var(--red); color: white; }

.cultural-note { background: var(--ink); color: white; border-radius: var(--radius-lg); padding: 22px 26px; display: flex; gap: 18px; margin-top: 56px; }
.cultural-icon { font-size: 32px; flex-shrink: 0; line-height: 1; }
.cultural-label { font-size: 10px; font-weight: 600; letter-spacing: 0.14em; text-transform: uppercase; color: var(--gold-light); margin-bottom: 5px; }
.cultural-title { font-family: 'Cormorant Garamond', serif; font-size: 20px; font-weight: 700; color: white; margin-bottom: 7px; }
.cultural-body { font-size: 13.5px; color: rgba(255,255,255,0.75); line-height: 1.7; }

.next-topic-bar { background: var(--surface); border: 1.5px solid var(--border); border-radius: var(--radius-lg); padding: 18px 22px; display: flex; align-items: center; justify-content: space-between; margin-top: 22px; text-decoration: none; transition: all 0.2s; }
.next-topic-bar:hover { border-color: var(--red); box-shadow: 0 4px 20px rgba(192,57,43,0.10); transform: translateX(4px); }
.next-label { font-size: 11px; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.1em; margin-bottom: 4px; }
.next-title { font-size: 16px; font-weight: 600; color: var(--ink); display: flex; align-items: center; gap: 10px; }
.next-char { font-family: 'Noto Serif SC', serif; color: var(--red); }
.next-arrow { width: 38px; height: 38px; border-radius: 50%; background: var(--cream); display: flex; align-items: center; justify-content: center; color: var(--text-mid); transition: all 0.2s; }
.next-topic-bar:hover .next-arrow { background: var(--red); color: white; }

@media (max-width: 900px) {
  .page-layout { grid-template-columns: 1fr; }
  .sidebar { position: static; height: auto; border-right: none; border-bottom: 1px solid var(--border); padding: 14px 0; }
  .sidebar-inner { display: flex; gap: 14px; align-items: center; padding: 0 16px; overflow-x: auto; }
  .sidebar-topic-header { flex-shrink: 0; margin: 0; padding: 12px 16px; display: flex; gap: 10px; align-items: center; text-align: left; }
  .sidebar-char { font-size: 30px; margin: 0; }
  .sidebar-topic-number { display: none; }
  .sidebar-nav, .sidebar-divider, .sidebar-section-label { display: none; }
  .mobile-tabs { display: flex !important; gap: 8px; padding: 4px 0; white-space: nowrap; }
  .mobile-tab { white-space: nowrap; padding: 7px 14px; border-radius: 100px; font-size: 13px; font-weight: 500; font-family: 'DM Sans', sans-serif; text-decoration: none; background: var(--surface); border: 1.5px solid var(--border); color: var(--text-mid); cursor: pointer; transition: all 0.18s; display: flex; align-items: center; gap: 5px; }
  .mobile-tab.active, .mobile-tab:hover { background: var(--red); border-color: var(--red); color: white; }
  .main-content { padding: 24px 16px 60px; }
  .vocab-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 520px) {
  .vocab-grid { grid-template-columns: 1fr; }
  .practice-nav-banner { flex-wrap: wrap; gap: 12px; }
  .practice-nav-arrow { display: none; }
}
@media (min-width: 901px) { .mobile-tabs { display: none; } }