:root{
  --bg:#f5f7fb; --card:#fff; --ink:#132033; --muted:#6a7588;
  --primary:#2563eb; --primary2:#1e40af; --accent:#f59e0b;
  --line:#dbe4f0; --soft:#eaf1ff; --good:#15803d; --bad:#dc2626;
  --shadow:0 18px 45px rgba(15,23,42,.10);
}
*{box-sizing:border-box}
body{margin:0;background:radial-gradient(circle at 10% 0%,#dbeafe,transparent 26%),var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"Noto Sans KR","Apple SD Gothic Neo",Arial,sans-serif;line-height:1.65}
button,input,select{font:inherit}
.app-shell{width:min(1180px,calc(100% - 28px));margin:0 auto;padding:28px 0 56px}
.hero{display:grid;grid-template-columns:1fr 300px;gap:24px;align-items:stretch;padding:34px;border-radius:32px;background:linear-gradient(135deg,#172554,#2563eb 72%,#60a5fa);color:white;box-shadow:var(--shadow);overflow:hidden;position:relative}
.hero:after{content:"";position:absolute;right:-70px;top:-70px;width:220px;height:220px;background:rgba(255,255,255,.13);border-radius:50%}
.eyebrow{margin:0 0 8px;color:#dbeafe;font-weight:900;letter-spacing:.04em}
.hero h1{margin:0;font-size:clamp(31px,5vw,52px);letter-spacing:-.05em;line-height:1.1}
.hero-desc{max-width:760px;color:#edf4ff}
.hero-actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:18px}
.primary-btn,.ghost-btn,.danger-btn{border:0;border-radius:16px;padding:13px 18px;font-weight:900;cursor:pointer;transition:.18s}
.primary-btn{background:var(--primary);color:white;box-shadow:0 10px 25px rgba(37,99,235,.26)}
.hero .primary-btn{background:white;color:#1e40af}
.ghost-btn{background:#fff;color:var(--primary2);border:1px solid var(--line)}
.danger-btn{background:#fee2e2;color:#991b1b;margin-top:14px}
.primary-btn:hover,.ghost-btn:hover,.danger-btn:hover{transform:translateY(-2px)}
.progress-card{background:rgba(255,255,255,.14);border:1px solid rgba(255,255,255,.24);border-radius:26px;padding:24px;backdrop-filter:blur(12px);display:flex;flex-direction:column;justify-content:center;position:relative;z-index:1}
.progress-card span,.progress-card small{color:#dbeafe}
.progress-card strong{font-size:46px;line-height:1.1}
.bar{height:11px;background:rgba(255,255,255,.25);border-radius:99px;overflow:hidden;margin:12px 0}
.bar i{display:block;height:100%;width:0;background:white;border-radius:99px;transition:.25s}
.tabs{display:flex;gap:10px;margin:22px 0;padding:10px;border:1px solid var(--line);border-radius:22px;background:rgba(255,255,255,.82);backdrop-filter:blur(12px);position:sticky;top:8px;z-index:20;box-shadow:0 10px 28px rgba(15,23,42,.05)}
.tab{flex:1;border:0;border-radius:15px;background:transparent;color:var(--muted);font-weight:900;padding:13px 10px;cursor:pointer;white-space:nowrap}
.tab.active{background:var(--primary);color:#fff}
.panel{display:none}.panel.active{display:block}
.section-title{margin:6px 0 18px}.section-title h2{font-size:32px;margin:0;letter-spacing:-.04em}.section-title p{margin:4px 0 0;color:var(--muted)}
.toolbar{display:flex;gap:10px;margin-bottom:16px}
.toolbar select,.toolbar input{border:1px solid var(--line);background:#fff;border-radius:16px;padding:13px 14px;outline:none}
.toolbar input{flex:1}
.grammar-grid{display:grid;grid-template-columns:310px 1fr;gap:18px}
.lesson-menu,.lesson-view,.test-card,.notice,.wrong-item,.source-card{background:var(--card);border:1px solid var(--line);box-shadow:0 12px 30px rgba(15,23,42,.06)}
.lesson-menu{border-radius:24px;padding:12px;max-height:700px;overflow:auto}
.lesson-button{width:100%;text-align:left;border:0;border-radius:17px;background:#f8fafc;padding:13px;margin-bottom:8px;cursor:pointer}
.lesson-button strong{display:block;color:var(--ink)}
.lesson-button span{font-size:13px;color:var(--muted)}
.lesson-button.active{background:var(--soft);outline:2px solid #bfdbfe}
.lesson-view{border-radius:28px;padding:28px;min-height:560px}
.badge-row{display:flex;gap:8px;flex-wrap:wrap}
.badge{display:inline-flex;padding:6px 10px;border-radius:999px;background:var(--soft);color:var(--primary2);font-size:13px;font-weight:900}
.lesson-view h3{font-size:34px;line-height:1.18;margin:14px 0}
.info{background:#f8fafc;border:1px solid var(--line);border-radius:20px;padding:17px;margin:12px 0}
.info strong{display:block;margin-bottom:6px}
.pattern{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;background:#111827;color:white;border-radius:16px;padding:14px;overflow:auto}
.practice{display:grid;gap:9px;margin-top:10px}
.practice-row{display:grid;grid-template-columns:1fr auto;gap:10px;align-items:center;background:white;border:1px solid var(--line);border-radius:15px;padding:12px}
.answer-chip{display:none;background:#dcfce7;color:#166534;border-radius:999px;padding:5px 10px;font-weight:900}
.show-answers .answer-chip{display:inline-flex}
.word-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}
.word-card{min-height:172px;background:#fff;border:1px solid var(--line);border-radius:24px;padding:18px;cursor:pointer;box-shadow:0 12px 30px rgba(15,23,42,.06);transition:.18s;position:relative;overflow:hidden}
.word-card:hover{transform:translateY(-4px);box-shadow:var(--shadow)}
.word-card .cat{display:inline-flex;font-size:12px;font-weight:900;padding:5px 9px;border-radius:999px;background:#fef3c7;color:#92400e}
.word-card h3{font-size:28px;margin:12px 0 3px}
.word-card p{margin:0;color:var(--muted)}
.word-card.flipped{background:#172554;color:white}
.word-card.flipped p{color:#dbeafe}.word-card.flipped .cat{background:rgba(255,255,255,.16);color:#fff}
.test-card{max-width:760px;margin:auto;border-radius:30px;padding:30px}
.test-top{display:flex;justify-content:space-between;color:var(--muted);font-weight:900}
.test-card h3{font-size:28px}
.answer-area{display:grid;gap:10px}.answer-area input{width:100%;border:1px solid var(--line);border-radius:16px;padding:14px}
.option{border:1px solid var(--line);border-radius:16px;padding:15px;text-align:left;background:#fff;cursor:pointer;font-weight:800}
.option.selected{outline:3px solid #bfdbfe}.option.correct{border-color:#86efac;background:#f0fdf4}.option.wrong{border-color:#fecaca;background:#fef2f2}
.feedback{min-height:30px;font-weight:900}.feedback.good{color:var(--good)}.feedback.bad{color:var(--bad)}
.test-actions{display:flex;gap:10px;margin-top:14px}
.wrong-list{display:grid;gap:12px}.wrong-item{border-radius:20px;padding:16px}.wrong-item strong{display:block}
.source-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.source-card{border-radius:24px;padding:24px}.source-card strong{font-size:38px;display:block;color:var(--primary2)}.source-card span{color:var(--muted)}
.notice{border-radius:24px;padding:20px;margin-top:16px}
@media(max-width:900px){.hero,.grammar-grid{grid-template-columns:1fr}.word-grid,.source-grid{grid-template-columns:repeat(2,1fr)}.tabs{overflow:auto}.tab{min-width:100px}}
@media(max-width:560px){.app-shell{width:min(100% - 16px,1180px);padding-top:14px}.hero{padding:24px;border-radius:24px}.toolbar{flex-direction:column}.word-grid,.source-grid{grid-template-columns:1fr}.lesson-view{padding:20px}.test-actions{flex-direction:column}}

.speak-btn{
  position:absolute;
  right:14px;
  top:14px;
  width:42px;
  height:42px;
  border:0;
  border-radius:999px;
  background:#eaf1ff;
  color:#1e40af;
  font-size:19px;
  font-weight:900;
  cursor:pointer;
  display:inline-flex;
  align-items:center;
  justify-content:center;
  box-shadow:0 8px 18px rgba(37,99,235,.16);
}
.speak-btn:hover{
  transform:scale(1.06);
  background:#dbeafe;
}
.word-card.flipped .speak-btn{
  background:rgba(255,255,255,.18);
  color:#fff;
}
.sound-tip{
  display:inline-flex;
  align-items:center;
  gap:6px;
  margin:0 0 12px;
  padding:8px 12px;
  border-radius:999px;
  background:#eff6ff;
  color:#1e40af;
  font-size:13px;
  font-weight:900;
}


/* ===== Premium mobile layout override ===== */
body{
  background:
    radial-gradient(circle at 16% -8%, rgba(96,165,250,.35), transparent 34%),
    linear-gradient(180deg,#f8fbff 0%,#eef4ff 42%,#f7f9fd 100%);
}
.app-shell{
  width:min(1120px,calc(100% - 24px));
}
.hero{
  grid-template-columns:1fr 260px;
  padding:30px;
  border-radius:30px;
  background:
    radial-gradient(circle at 90% 0%, rgba(255,255,255,.20), transparent 28%),
    linear-gradient(135deg,#10204c 0%,#2457dc 56%,#4f8df7 100%);
}
.hero h1{
  max-width:760px;
}
.progress-card{
  min-height:190px;
}
.tabs{
  gap:8px;
  padding:8px;
  border-radius:20px;
}
.tab{
  flex:1 0 auto;
}
.panel{
  animation:fadeUp .22s ease;
}
@keyframes fadeUp{
  from{opacity:.65;transform:translateY(6px)}
  to{opacity:1;transform:translateY(0)}
}
.word-grid{
  align-items:stretch;
}
.sound-tip{
  grid-column:1/-1;
  width:max-content;
  max-width:100%;
}
.lesson-view,
.test-card{
  background:
    linear-gradient(180deg,#fff 0%,#fbfdff 100%);
}
.lesson-button{
  transition:.18s;
}
.lesson-button:hover{
  transform:translateX(2px);
}

@media(max-width:700px){
  body{
    background:linear-gradient(180deg,#eff6ff 0%,#f8fafc 44%,#ffffff 100%);
  }
  .app-shell{
    width:100%;
    padding:0 0 40px;
  }
  .hero{
    width:100%;
    grid-template-columns:1fr;
    gap:16px;
    padding:22px 18px 20px;
    border-radius:0 0 28px 28px;
    box-shadow:0 16px 36px rgba(37,99,235,.22);
  }
  .hero h1{
    font-size:30px;
    line-height:1.14;
    letter-spacing:-.04em;
  }
  .hero-desc{
    margin:10px 0 0;
    font-size:15px;
    line-height:1.55;
  }
  .eyebrow{
    font-size:12px;
  }
  .hero-actions{
    display:grid;
    grid-template-columns:1fr 1fr;
    gap:9px;
    margin-top:16px;
  }
  .hero-actions .primary-btn,
  .hero-actions .ghost-btn{
    width:100%;
    padding:12px 10px;
    border-radius:14px;
    font-size:14px;
  }
  .progress-card{
    min-height:auto;
    padding:17px;
    border-radius:22px;
  }
  .progress-card strong{
    font-size:34px;
  }
  .tabs{
    position:sticky;
    top:0;
    margin:12px 10px 18px;
    overflow-x:auto;
    justify-content:flex-start;
    scrollbar-width:none;
    border-radius:18px;
    box-shadow:0 10px 24px rgba(15,23,42,.08);
  }
  .tabs::-webkit-scrollbar{
    display:none;
  }
  .tab{
    min-width:96px;
    padding:11px 12px;
    border-radius:13px;
    font-size:13px;
  }
  main{
    padding:0 10px;
  }
  .section-title{
    margin:0 0 12px;
  }
  .section-title h2{
    font-size:23px;
  }
  .section-title p{
    font-size:14px;
    line-height:1.5;
  }
  .toolbar{
    gap:8px;
    margin-bottom:12px;
  }
  .toolbar select,
  .toolbar input{
    padding:12px;
    border-radius:14px;
    font-size:14px;
  }
  .grammar-grid{
    gap:12px;
  }
  .lesson-menu{
    display:flex;
    overflow-x:auto;
    gap:9px;
    padding:8px;
    border-radius:18px;
    max-height:none;
    scrollbar-width:none;
  }
  .lesson-menu::-webkit-scrollbar{
    display:none;
  }
  .lesson-button{
    min-width:210px;
    margin-bottom:0;
    padding:12px;
    border-radius:15px;
  }
  .lesson-button strong{
    font-size:14px;
    line-height:1.35;
  }
  .lesson-button span{
    font-size:12px;
  }
  .lesson-view{
    min-height:auto;
    padding:18px;
    border-radius:22px;
    box-shadow:0 12px 28px rgba(15,23,42,.07);
  }
  .badge{
    font-size:12px;
    padding:5px 9px;
  }
  .lesson-view h3{
    font-size:25px;
    margin:12px 0 8px;
  }
  .info{
    padding:14px;
    margin:10px 0;
    border-radius:16px;
  }
  .pattern{
    font-size:12px;
    padding:12px;
    border-radius:13px;
  }
  .practice-row{
    grid-template-columns:1fr;
    gap:6px;
    padding:11px;
    border-radius:13px;
  }
  .word-grid{
    grid-template-columns:1fr 1fr;
    gap:10px;
  }
  .sound-tip{
    width:100%;
    justify-content:center;
    border-radius:14px;
    font-size:12px;
  }
  .word-card{
    min-height:148px;
    border-radius:20px;
    padding:15px;
  }
  .word-card h3{
    font-size:22px;
    line-height:1.2;
    padding-right:34px;
  }
  .word-card p{
    font-size:13px;
    line-height:1.45;
  }
  .word-card .cat{
    font-size:11px;
    padding:4px 8px;
  }
  .speak-btn{
    width:36px;
    height:36px;
    right:11px;
    top:11px;
    font-size:16px;
  }
  .test-card{
    padding:19px;
    border-radius:22px;
  }
  .test-card h3{
    font-size:22px;
    line-height:1.35;
  }
  .answer-area input,
  .option{
    padding:13px;
    border-radius:14px;
    font-size:15px;
  }
  .test-actions{
    display:grid;
    grid-template-columns:1fr 1fr;
  }
  .wrong-item,
  .notice{
    border-radius:18px;
    padding:14px;
  }
}

@media(max-width:380px){
  .word-grid{
    grid-template-columns:1fr;
  }
  .hero-actions,
  .test-actions{
    grid-template-columns:1fr;
  }
  .hero h1{
    font-size:27px;
  }
}

.sound-tip{
  border:1px solid #bfdbfe;
  box-shadow:0 8px 18px rgba(37,99,235,.08);
}


@media(max-width:700px){
  
}

/* Wide hero thumbnail for mobile and desktop */
.thumbnail-showcase{
  position:relative;
  z-index:1;
  grid-column:1 / -1;
  display:flex;
  align-items:center;
  justify-content:center;
  padding:10px;
  border-radius:26px;
  background:rgba(255,255,255,.14);
  border:1px solid rgba(255,255,255,.24);
  backdrop-filter:blur(12px);
}
.thumbnail-showcase img{
  width:100%;
  max-width:980px;
  aspect-ratio:1200/560;
  object-fit:cover;
  border-radius:22px;
  box-shadow:0 18px 38px rgba(0,0,0,.24);
}
@media(max-width:700px){
  .thumbnail-showcase{
    padding:6px;
    border-radius:22px;
  }
  .thumbnail-showcase img{
    width:100%;
    max-width:none;
    border-radius:18px;
  }
}