/* ================= Phrasal Verbs - Shared Stylesheet ================= */
/* Used by all phrasal verb article pages */

/* ================= Base / Theme ================= */
:root {
  --text:#212529; --bg:#fff; --muted:#f8f9fa; --border:#e9ecef;
  --accent:#fd7e14; --accent-2:#e87312; --header-bg:#212529; --header-fg:#f8f9fa;
  --ok:#16a34a; --ok-soft:#dcfce7; --bad:#dc2626; --bad-soft:#fee2e2;
  --myth-color: #6c757d; --myth-soft: #e9ecef;
}
*{box-sizing:border-box;margin:0;padding:0}
html{height:100%}
body{font-family:'Inter',system-ui,-apple-system,'Segoe UI',Roboto,sans-serif;background:var(--bg);color:var(--text);line-height:1.7;scroll-behavior:smooth;min-height:100%;display:flex;flex-direction:column;word-wrap:break-word;overflow-wrap:break-word;max-width:100vw;overflow-x:hidden}
.container{max-width:100%;width:100%;margin:auto;padding:24px;background:#fff;flex:1 0 auto}
@media(min-width:1128px){.container{max-width:1080px}}
@media(max-width:480px){.container{padding:16px}}
img,svg,video,iframe,embed,object{max-width:100%;height:auto}
p,h1,h2,h3,h4,h5,h6,li,td,th{max-width:100%;overflow-wrap:break-word;word-wrap:break-word}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}

/* ================= Header / Footer ================= */
.site-header,.site-footer{background:var(--header-bg);color:var(--header-fg);padding:14px 24px}
.site-header{display:flex;justify-content:space-between;align-items:center;position:sticky;top:0;z-index:100;gap:12px}
.logo{font-weight:700;font-size:1.15rem;color:#fff;text-decoration:none;white-space:nowrap;flex-shrink:0}
.hamburger{background:none;border:1px solid rgba(255,255,255,0.4);color:#fff;border-radius:8px;padding:8px 12px;font-size:0.9rem;cursor:pointer;line-height:1;transition:background 0.2s;display:inline-flex;align-items:center;gap:6px;flex-shrink:0}
.hamburger:hover,.hamburger[aria-expanded="true"]{background:rgba(255,255,255,0.15)}
.article-nav{display:none;position:absolute;top:100%;right:12px;left:12px;flex-direction:column;gap:0;background:var(--header-bg);padding:8px 0;border-radius:8px;box-shadow:0 10px 25px rgba(0,0,0,0.35);min-width:200px;max-width:calc(100vw - 24px);z-index:101}
@media(min-width:400px){.article-nav{left:auto;right:16px;max-width:280px}}
.article-nav.open{display:flex}
.article-nav a{display:flex;align-items:center;gap:10px;padding:12px 18px;color:#f8f9fa;white-space:nowrap;text-decoration:none;transition:background 0.2s}
.article-nav a:hover{background:rgba(255,255,255,0.1);text-decoration:none}
.article-nav a + a{border-top:1px solid rgba(255,255,255,0.1)}
.article-nav .nav-icon{font-size:1.1rem;width:24px;text-align:center}
.article-nav .nav-label{font-size:0.95rem}
.site-footer{text-align:center;margin-top:auto;padding:40px;flex-shrink:0}
.breadcrumbs{margin-bottom:8px;font-size:0.85rem;color:#6c757d}
.breadcrumbs a{color:var(--accent)}

/* ================= Typography ================= */
h1{font-size:clamp(2rem,5vw,2.6rem);margin-bottom:8px;color:var(--text);line-height:1.2}
.byline{font-size:clamp(1rem,3vw,1.2rem);font-style:italic;color:#4a5568;margin-bottom:24px}
h2{font-size:clamp(1.5rem,4vw,2rem);color:var(--text);margin:48px 0 16px;border-bottom:2px solid var(--border);padding-bottom:8px}
h3{font-size:clamp(1.2rem,3vw,1.5rem);color:var(--text);margin-top:32px;margin-bottom:12px}
h4{font-size:clamp(1rem,2.5vw,1.2rem);font-weight:bold;color:var(--accent-2);margin-bottom:10px}
p{margin-bottom:16px;word-wrap:break-word}
ul{margin-left:24px;margin-bottom:24px;list-style-type:'🔸';padding-left:1em}
li{margin-bottom:12px;padding-left:0.5em}
.article-meta{display:flex;align-items:center;gap:12px;color:#6c757d;margin-bottom:32px;font-size:0.95rem}
.author-emoji{font-size:32px;line-height:1}
.intro{font-size:1.1rem;line-height:1.8;background:var(--muted);padding:20px;border-radius:12px;border-left:4px solid var(--accent);margin:24px 0}
.btn{background:var(--accent);color:#fff;border:none;padding:10px 14px;border-radius:10px;font-weight:700;cursor:pointer;transition:background-color 0.2s ease}
.btn:hover{background-color:var(--accent-2)}

/* ================= Table ================= */
.table-scroll-hint{font-size:0.85rem;color:#6c757d;margin:8px 0;font-style:italic}
@media(min-width:768px){.table-scroll-hint{display:none}}
.table-wrap{position:relative;border:1px solid var(--border);border-radius:12px;background:#fff;margin:24px 0;max-width:100%;overflow:hidden}
.table-scroll{position:relative;overflow-x:auto;-webkit-overflow-scrolling:touch;max-width:100%}
table.data-table{width:100%;border-collapse:collapse}
table.data-table th,table.data-table td{padding:12px 15px;border:1px solid var(--border);text-align:left;vertical-align:top}
table.data-table thead th{background:var(--muted);font-weight:600}
table.data-table tbody tr:nth-child(even){background:#f8f9fa}

/* ================= Best Practice / What Not To Do / Myth Cards ================= */
.best-practice-card{background:var(--ok-soft);border-left:4px solid var(--ok);padding:16px;border-radius:8px;margin:16px 0}
.best-practice-card h5{color:var(--ok);margin-top:0}
.what-not-to-do-card{background:var(--bad-soft);border-left:4px solid var(--bad);padding:16px;border-radius:8px;margin:16px 0}
.what-not-to-do-card h5{color:var(--bad);margin-top:0}
.myth-card{background:var(--myth-soft);border-left:4px solid var(--myth-color);padding:16px;border-radius:8px;margin:16px 0}
.myth-card h5{color:var(--myth-color);margin-top:0}

/* ================= Example Box ================= */
.example-box{background:#fff3cd;border:2px solid #ffeaa7;border-radius:12px;padding:20px;margin:20px 0}
.example-box h4{color:#8b4513;margin-bottom:15px}

/* ================= Interactive Box ================= */
.interactive-box{background:#f8f9fa;border:1px solid var(--border);border-radius:12px;padding:24px;margin:24px 0}

/* ================= Concept Cards ================= */
.concept-cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:20px;margin:30px 0}
.concept-card{background:linear-gradient(135deg,#fff,var(--muted));border:2px solid var(--accent);border-radius:12px;padding:20px;transition:all .3s ease;cursor:pointer}
.concept-card:hover{transform:translateY(-5px);box-shadow:0 8px 25px rgba(253,126,20,0.15)}
.concept-card .icon{font-size:2rem;display:block;margin-bottom:10px}
.concept-card h4{color:var(--accent);margin-bottom:15px;font-size:1.3rem}
.concept-card .description{color:#495057;line-height:1.6}

/* ================= Related Cards ================= */
.related-cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:16px;margin:25px 0}
.related-card{display:flex;gap:12px;align-items:flex-start;background:#fff;border:1px solid var(--border);border-radius:12px;padding:14px;transition:transform .2s ease,box-shadow .2s ease}
.related-card:hover{transform:translateY(-4px);box-shadow:0 8px 22px rgba(0,0,0,0.06)}
.related-card .thumb{width:54px;height:54px;flex-shrink:0;border-radius:10px;background:#fff7ed;display:flex;align-items:center;justify-content:center;font-size:1.4rem;border:1px solid #ffd8a8}
.related-card .content{flex:1}
.related-card .title{display:inline-block;font-weight:700;color:var(--text)}
.related-card .desc{color:#495057;font-size:0.95rem;margin-top:4px}

/* ================= Glossary Chips ================= */
.glossary-cloud{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px;justify-content:center}
.glossary-chip{position:relative;display:inline-flex;align-items:center;gap:4px;padding:6px 12px;border-radius:999px;background:#fff7ed;border:1px solid #ffd8a8;color:#d9480f;font-weight:600;font-size:0.85rem;cursor:default;box-shadow:none}
.glossary-chip .icon{font-size:0.9rem}

/* ================= Quick Nav ================= */
.quick-nav{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;margin:24px 0}
.quick-nav a{display:inline-flex;align-items:center;gap:4px;padding:6px 12px;background:var(--muted);border:1px solid var(--border);border-radius:999px;font-size:0.8rem;font-weight:600;color:var(--text);transition:all 0.2s;white-space:nowrap}
.quick-nav a:hover{background:var(--accent);color:#fff;border-color:var(--accent);text-decoration:none}
@media(max-width:480px){
  .quick-nav{gap:6px}
  .quick-nav a{padding:5px 8px;font-size:0.75rem;gap:3px}
}

/* ================= Hero Section ================= */
.hero-section{text-align:center;margin-bottom:16px;overflow:hidden}
.hero-word{font-size:clamp(2rem,8vw,4rem);font-weight:800;color:var(--accent);margin-bottom:4px;text-align:center;word-wrap:break-word;overflow-wrap:break-word;max-width:100%}
.hero-phonetic{font-size:1.1rem;color:#6c757d;margin-bottom:8px;font-family:monospace}
.hero-type{display:inline-flex;align-items:center;gap:6px;background:var(--muted);color:var(--text);padding:6px 14px;border-radius:8px;font-size:0.85rem;font-weight:500;margin-bottom:8px;border:1px solid var(--border)}
.hero-type-label{font-weight:600;color:var(--accent)}
.hero-type-info{display:inline-flex;align-items:center;justify-content:center;width:18px;height:18px;background:var(--accent);color:#fff;border-radius:50%;font-size:0.7rem;cursor:help;position:relative}
.hero-type-info:hover::after{content:attr(data-tooltip);position:absolute;bottom:130%;left:50%;transform:translateX(-50%);background:#333;color:#fff;padding:8px 12px;border-radius:6px;font-size:0.8rem;white-space:nowrap;z-index:10;font-weight:400}
.hero-type-info:hover::before{content:'';position:absolute;bottom:100%;left:50%;transform:translateX(-50%);border:6px solid transparent;border-top-color:#333}
.speak-btn{background:var(--muted);color:var(--accent);border:none;padding:6px 14px;border-radius:999px;cursor:pointer;font-size:0.9rem;font-weight:600;transition:all 0.2s;display:inline-flex;align-items:center;gap:6px;margin-top:8px}
.speak-btn:hover{background:var(--accent);color:#fff}
.speak-btn.speaking{background:var(--bad);color:#fff}

/* ================= Share Buttons ================= */
.share-section{margin:32px 0;padding:20px;background:var(--muted);border-radius:12px;text-align:center}
.share-section h4{margin-bottom:12px;color:var(--text);font-size:1rem}
.share-buttons{display:flex;justify-content:center;gap:10px;flex-wrap:wrap}
.share-btn{display:inline-flex;align-items:center;gap:6px;padding:8px 14px;border-radius:999px;border:none;cursor:pointer;font-size:0.85rem;font-weight:600;transition:all 0.2s;text-decoration:none}
.share-btn:hover{transform:translateY(-2px);box-shadow:0 4px 12px rgba(0,0,0,0.15)}
.share-btn.twitter{background:#1DA1F2;color:#fff}
.share-btn.facebook{background:#4267B2;color:#fff}
.share-btn.linkedin{background:#0077B5;color:#fff}
.share-btn.whatsapp{background:#25D366;color:#fff}
.share-btn.copy{background:var(--accent);color:#fff}
.share-btn.copy.copied{background:var(--ok)}
@media(max-width:400px){
  .share-btn{padding:6px 10px;font-size:0.8rem}
  .share-btn span.share-label{display:none}
}

/* ================= Story TTS Button ================= */
.story-speak-btn{background:var(--muted);border:1px solid var(--border);padding:4px 10px;border-radius:999px;cursor:pointer;font-size:0.8rem;margin-left:8px;vertical-align:middle;transition:all 0.2s}
.story-speak-btn:hover{background:var(--accent);color:#fff;border-color:var(--accent)}
.story-speak-btn.speaking{background:var(--bad);color:#fff;border-color:var(--bad)}

/* ================= Meaning Section ================= */
.meaning-section{margin-bottom:32px}
.meaning-header{display:flex;align-items:center;gap:12px;margin-bottom:12px}
.meaning-number{display:inline-flex;align-items:center;justify-content:center;width:40px;height:40px;background:var(--accent);color:#fff;border-radius:50%;font-size:1.2rem;font-weight:700;flex-shrink:0}
.meaning-title{font-size:1.3rem;font-weight:700;color:var(--text)}
.meaning-def{margin-bottom:16px}
.example-sentence{background:#fff;border-left:4px solid var(--accent);padding:12px 16px;border-radius:0 8px 8px 0;margin-bottom:12px}
.example-sentence .sentence{font-style:italic;color:#495057;margin-bottom:6px}
.example-sentence .context{font-size:0.9rem;color:#6c757d}
.word-chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}
.word-chip{display:inline-flex;align-items:center;gap:4px;padding:4px 10px;border-radius:999px;font-size:0.85rem;font-weight:600}
.word-chip.synonym{background:var(--ok-soft);color:var(--ok)}
.word-chip.antonym{background:var(--bad-soft);color:var(--bad)}

/* ================= SVG Interactive ================= */
.svg-container{text-align:center;margin:24px 0}
.svg-container svg{max-width:100%;height:auto}
.interactive-element{cursor:pointer;transition:all 0.3s}
.interactive-element:hover{transform:scale(1.05);filter:drop-shadow(0 0 8px rgba(253,126,20,0.6))}

/* ================= Accordion ================= */
.accordion{display:grid;gap:8px}
.accordion-header{width:100%;text-align:left;background:var(--muted);border:1px solid var(--border);padding:16px 20px;border-radius:8px;cursor:pointer;font-size:1.1rem;font-weight:bold;display:flex;align-items:center}
.accordion-header .accordion-title{margin-right:auto;padding-right:1rem}
.accordion-header::after{content:'+';color:#6c757d}
.accordion-header[aria-expanded="true"]{background:#e9ecef;border-bottom-left-radius:0;border-bottom-right-radius:0}
.accordion-header[aria-expanded="true"]::after{content:'−'}
.accordion-content{padding:20px;display:none;border:1px solid var(--border);border-top:none;border-radius:0 0 8px 8px}

/* ================= Quiz ================= */
.quiz-container{padding:16px;border:2px solid var(--border);border-radius:12px;background:#fff}
.quiz-navigation{display:flex;justify-content:center;align-items:center;gap:8px;margin-bottom:12px;padding-bottom:10px;border-bottom:1px solid var(--border);flex-wrap:nowrap}
.quiz-navigation .btn{padding:5px 10px;font-size:0.8rem;white-space:nowrap;min-width:auto}
.quiz-navigation span{font-size:0.85rem;white-space:nowrap}
.quiz-navigation .btn:disabled{opacity:0.5;cursor:not-allowed}
.quiz-body{display:none}
.quiz-body.active{display:block}
.quiz-options{display:grid;gap:10px}
.quiz-option label{display:flex;align-items:center;gap:10px;padding:12px;border:2px solid var(--border);border-radius:8px;cursor:pointer;background:#f8f9fa}
.quiz-option input[type="radio"]{flex-shrink:0}
.quiz-option .explanation{display:none;margin-top:10px;padding:12px;border-radius:6px;border-left:4px solid #a0aec0;font-size:0.95rem;line-height:1.5}
.quiz-option.selected.correct label{background:var(--ok-soft);border-color:var(--ok)}
.quiz-option.selected.wrong label{background:var(--bad-soft);border-color:var(--bad)}
.quiz-option.correct .explanation{border-left-color:var(--ok);background:#f0fff4}
.quiz-option.wrong .explanation{border-left-color:var(--bad);background:#fff5f5}
@media(max-width:400px){
  .quiz-navigation .btn{padding:4px 8px;font-size:0.75rem}
  .quiz-navigation span{font-size:0.8rem}
  .quiz-navigation{gap:6px}
}

/* ================= Story Section ================= */
.story-intro{background:linear-gradient(135deg,rgba(253,126,20,0.06),#fff);border-left:4px solid var(--accent);padding:16px;border-radius:10px;margin:20px 0;color:#495057}
.story-intro .highlight{color:var(--accent-2);font-weight:700}
.story-toggle{color:var(--accent-2);font-weight:700;cursor:pointer;text-decoration:none;display:inline-block;margin-top:6px}

/* ================= Chart Container ================= */
.chart-container{background:#fff;border:1px solid var(--border);border-radius:12px;padding:16px;margin:24px 0}
.chart-title{font-size:1.1rem;font-weight:700;color:var(--accent-2);text-align:center;margin-bottom:12px}

/* ================= Language Carousel ================= */
.lang-carousel{position:relative;margin:24px 0}
.lang-carousel-track{display:flex;overflow:hidden;border-radius:12px}
.lang-carousel-slide{min-width:100%;display:none;animation:fadeIn 0.3s}
.lang-carousel-slide.active{display:flex;gap:16px;justify-content:center;flex-wrap:wrap}
.lang-carousel-nav{display:flex;justify-content:center;align-items:center;gap:16px;margin-top:16px}
.lang-carousel-btn{background:var(--muted);border:1px solid var(--border);width:40px;height:40px;border-radius:50%;cursor:pointer;font-size:1.2rem;display:flex;align-items:center;justify-content:center;transition:all 0.2s}
.lang-carousel-btn:hover{background:var(--accent);color:#fff;border-color:var(--accent)}
.lang-carousel-btn:disabled{opacity:0.4;cursor:not-allowed}
.lang-carousel-dots{display:flex;gap:8px}
.lang-carousel-dot{width:10px;height:10px;border-radius:50%;background:var(--border);border:none;cursor:pointer;transition:all 0.2s}
.lang-carousel-dot.active{background:var(--accent);transform:scale(1.2)}
.lang-carousel-counter{font-size:0.9rem;color:#6c757d;font-weight:600}

/* Language Cards (inside carousel) */
.language-card{background:#fff;border:1px solid var(--border);border-radius:12px;padding:16px;width:100%;max-width:320px;flex-shrink:0}
.language-card .lang-header{display:flex;align-items:center;gap:12px;margin-bottom:12px}
.language-card .lang-flag{font-size:2rem}
.language-card .lang-name{font-weight:700;color:var(--text)}
.language-card .translation{font-size:1.05rem;color:#495057;margin-bottom:6px}
.language-card .romanization{font-size:0.9rem;color:#6c757d;font-style:italic;margin-bottom:8px}
.lang-speak-btn{background:var(--muted);border:none;padding:6px 12px;border-radius:999px;cursor:pointer;font-size:0.9rem;display:inline-flex;align-items:center;gap:6px;margin-top:8px}
.lang-speak-btn:hover{background:var(--accent);color:#fff}

@media(min-width:768px){
  .lang-carousel-slide.active{flex-wrap:nowrap}
  .language-card{max-width:calc(50% - 8px)}
}
@media(max-width:480px){
  .language-card{padding:14px}
  .language-card .translation{font-size:1rem}
}

/* ================= Pop Culture Carousel ================= */
.pop-culture-carousel{position:relative;margin:24px 0}
.pop-culture-track{display:flex;overflow:hidden;border-radius:12px}
.pop-culture-slide{min-width:100%;display:none;animation:fadeIn 0.3s}
.pop-culture-slide.active{display:flex;gap:16px;justify-content:center;flex-wrap:wrap}
.pop-culture-card{background:linear-gradient(135deg,#fff,var(--muted));border:2px solid var(--border);border-radius:12px;padding:16px;width:100%;max-width:320px;flex-shrink:0;transition:all 0.3s ease}
.pop-culture-card:hover{transform:translateY(-4px);box-shadow:0 8px 20px rgba(253,126,20,0.12);border-color:var(--accent)}
.pop-culture-card .card-emoji{font-size:2.2rem;margin-bottom:8px;display:block}
.pop-culture-card .card-type{display:inline-block;background:var(--accent);color:#fff;padding:3px 10px;border-radius:999px;font-size:0.75rem;font-weight:600;margin-bottom:8px}
.pop-culture-card .card-source{font-weight:700;color:var(--text);font-size:0.95rem;margin-bottom:6px}
.pop-culture-card .card-quote{font-style:italic;color:#495057;font-size:0.95rem;line-height:1.5;margin-bottom:8px;min-height:48px}
.pop-culture-card .card-context{font-size:0.85rem;color:#6c757d;border-top:1px solid var(--border);padding-top:8px}
.pop-culture-nav{display:flex;justify-content:center;align-items:center;gap:16px;margin-top:16px}
.pop-culture-btn{background:var(--muted);border:1px solid var(--border);width:40px;height:40px;border-radius:50%;cursor:pointer;font-size:1.2rem;display:flex;align-items:center;justify-content:center;transition:all 0.2s}
.pop-culture-btn:hover{background:var(--accent);color:#fff;border-color:var(--accent)}
.pop-culture-btn:disabled{opacity:0.4;cursor:not-allowed}
.pop-culture-dots{display:flex;gap:8px}
.pop-culture-dot{width:10px;height:10px;border-radius:50%;background:var(--border);border:none;cursor:pointer;transition:all 0.2s}
.pop-culture-dot.active{background:var(--accent);transform:scale(1.2)}
.pop-culture-counter{font-size:0.9rem;color:#6c757d;font-weight:600}
@media(min-width:768px){
  .pop-culture-slide.active{flex-wrap:nowrap}
  .pop-culture-card{max-width:calc(50% - 8px)}
}
@media(max-width:480px){
  .pop-culture-card{padding:14px}
  .pop-culture-card .card-quote{font-size:0.9rem;min-height:0}
}

/* ================= Fill-in-the-Blank ================= */
.fill-item{margin-bottom:20px;padding-bottom:16px;border-bottom:1px solid var(--border)}
.fill-item:last-child{border-bottom:none;margin-bottom:0}
.fill-input{border:2px solid var(--border);border-radius:6px;padding:6px 12px;font-size:1rem;width:140px;text-align:center;transition:border-color 0.2s}
.fill-input:focus{outline:none;border-color:var(--accent)}
.fill-input.correct{border-color:var(--ok);background:var(--ok-soft)}
.fill-input.wrong{border-color:var(--bad);background:var(--bad-soft)}
.fill-check-btn{margin-left:12px;padding:6px 16px;font-size:0.9rem}
.fill-feedback{margin-left:12px;font-weight:600;font-size:0.95rem}
.fill-feedback.correct{color:var(--ok)}
.fill-feedback.wrong{color:var(--bad)}

/* ================= Image Frame ================= */
.img-frame{text-align:center;margin:12px 0}
.img-frame img{max-height:70vh;max-width:100%;width:auto;height:auto;object-fit:contain;display:block;margin:0 auto}
@media(max-width:768px){
  .img-frame img{width:100%;height:auto;max-height:70vh;object-fit:cover}
}

/* ================= Tabs ================= */
.tabs{display:flex;flex-wrap:wrap;gap:10px;border-bottom:1px solid var(--border);margin:16px 0 12px;justify-content:center}
.tab-button{background:none;border:none;padding:10px 15px;font-size:1rem;font-weight:600;cursor:pointer;border-bottom:3px solid transparent;transition:all .2s ease}
.tab-button.active{color:var(--accent);border-bottom-color:var(--accent)}
.tab-panel{display:none;animation:fadeIn .3s}
.tab-panel.active{display:block}
@keyframes fadeIn{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:translateY(0)}}

/* ================= Footer ================= */
.footer-links{font-size:0.9rem;color:#adb5bd;margin-top:12px}
.footer-links a{color:#adb5bd}
.footer-credits{font-size:0.85rem;color:#6c757d;margin-top:16px}
.footer-credits a{color:#adb5bd}

/* ================= Loading / Error States ================= */
.loading-text{text-align:center;padding:40px;color:#6c757d}
.error-text{color:#dc2626;text-align:center;padding:40px}

/* Skeleton loaders */
.skeleton{background:linear-gradient(90deg,var(--muted) 25%,#e2e5e9 50%,var(--muted) 75%);background-size:200% 100%;animation:shimmer 1.5s infinite;border-radius:8px}
@keyframes shimmer{0%{background-position:200% 0}100%{background-position:-200% 0}}
.skeleton-title{height:48px;width:60%;margin:20px auto}
.skeleton-text{height:20px;width:80%;margin:12px auto}
.skeleton-loader{padding:20px}

/* Lazy loading placeholders */
.lazy-placeholder{min-height:200px;position:relative}
.lazy-placeholder .skeleton-loader{opacity:0.6}
.lazy-loaded{animation:fadeInSection 0.3s ease-out}
@keyframes fadeInSection{from{opacity:0}to{opacity:1}}

/* Image caption */
.img-caption{font-size:0.85rem;color:#6c757d;text-align:center;margin-top:8px;margin-bottom:24px}

/* Keywords label */
.keywords-label{color:#6c757d;font-size:0.9rem;margin-bottom:8px}

/* Fill blank heading */
.fill-blank-heading{margin-top:32px}

/* ================= Responsive ================= */
@media(max-width:768px){
  .concept-cards{grid-template-columns:1fr}
  .related-cards{grid-template-columns:1fr}
  .language-grid{grid-template-columns:1fr}
}
@media(max-width:600px){
  h1{font-size:clamp(1.8rem,6vw,2.2rem)}
  .interactive-box,.example-box{padding:18px}
}
@media(max-width:480px){
  .container{padding:20px}
}