/* ============================================================
   과학아 놀자! - 공통 스타일 (playhanja style.css 참고, 과학 테마)
   ============================================================ */
:root {
  --color-bg: #f2fbf7;
  --color-primary: #0d9488;
  --color-primary-dark: #0b7c73;
  --color-secondary: #0284c7;
  --color-accent: #f59e0b;
  --color-purple: #7c3aed;
  --color-text: #22332f;
  --color-text-soft: #6b7f7a;
  --color-card: #ffffff;
  --color-border: #d9efe7;
  --shadow-soft: 0 8px 24px rgba(13, 148, 136, 0.12);
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 10px;
  --font-main: 'Gowun Dodum', 'Noto Sans KR', sans-serif;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; font-family: var(--font-main); background: var(--color-bg); color: var(--color-text); scroll-behavior: smooth; }
body {
  background-image:
    radial-gradient(circle at 10% 10%, #d9f7ec 0%, transparent 40%),
    radial-gradient(circle at 90% 20%, #e0f2fe 0%, transparent 40%),
    radial-gradient(circle at 50% 90%, #fef3c7 0%, transparent 45%);
  min-height: 100vh;
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; margin: 0; padding: 0; }
button { font-family: inherit; cursor: pointer; }
img { max-width: 100%; display: block; }
.container { max-width: 1180px; margin: 0 auto; padding: 0 20px; }
.muted { color: var(--color-text-soft); }

/* Header */
.site-header { position: sticky; top: 0; z-index: 100; background: rgba(242,251,247,.92); backdrop-filter: blur(6px); border-bottom: 3px solid var(--color-border); }
.site-header .nav-wrap { display: flex; align-items: center; justify-content: space-between; padding: 14px 20px; max-width: 1180px; margin: 0 auto; gap: 12px; }
.logo { display: flex; align-items: center; gap: 8px; font-size: 1.35rem; font-weight: 800; color: var(--color-primary-dark); white-space: nowrap; }
.logo .logo-char { font-size: 1.7rem; background: linear-gradient(135deg, #99f6e4, #38bdf8); border-radius: 50%; width: 46px; height: 46px; display: flex; align-items: center; justify-content: center; box-shadow: var(--shadow-soft); }
.main-nav ul { margin: 0; padding: 0; }
.main-nav .nav-desktop { display: flex; gap: 6px; align-items: center; }
.main-nav .nav-mobile { display: none; }
.main-nav a, .nav-group-btn { padding: 10px 16px; border-radius: 999px; font-weight: 700; color: var(--color-text-soft); font-size: .98rem; background: none; border: none; white-space: nowrap; }
.main-nav a:hover, .main-nav a.active, .nav-group-btn:hover, .nav-group-btn.active { background: var(--color-primary); color: #fff; }
.nav-group { position: relative; }
.nav-dropdown { display: none; position: absolute; top: calc(100% + 8px); left: 0; background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius-md); box-shadow: var(--shadow-soft); min-width: 280px; padding: 8px; z-index: 200; }
.nav-group.open .nav-dropdown { display: block; }
.nav-dropdown a { display: flex; gap: 10px; padding: 10px 12px; border-radius: 12px; }
.nav-dropdown a:hover, .nav-dropdown a.current { background: #f0fdfa; }
.nd-icon { font-size: 1.3rem; }
.nd-body strong { display: block; font-size: .95rem; }
.nd-body small { color: var(--color-text-soft); font-size: .8rem; }
.nav-toggle { display: none; background: none; border: none; font-size: 1.6rem; color: var(--color-primary-dark); }
.auth-box { margin-left: 8px; flex-shrink: 0; }
.auth-login-btn { background: var(--color-primary); color: #fff; padding: 8px 16px; border-radius: 999px; font-weight: 700; font-size: .9rem; }
.auth-user { font-weight: 800; color: var(--color-primary-dark); }
.family-nav-wrap { position: relative; }
.family-btn { background: #fff; border: 1px solid var(--color-border); border-radius: 999px; padding: 8px 14px; font-weight: 700; font-size: .85rem; color: var(--color-text-soft); }
.family-dropdown { display: none; position: absolute; right: 0; top: 110%; background: #fff; border: 1px solid var(--color-border); border-radius: 12px; box-shadow: var(--shadow-soft); min-width: 200px; padding: 6px; z-index: 300; }
.family-dropdown.show { display: block; }
.family-dropdown a { display: flex; gap: 8px; padding: 8px 10px; border-radius: 8px; font-size: .9rem; }
.family-dropdown a:hover { background: #f0fdfa; }

/* Hero */
.hero { padding: 48px 0 24px; }
.hero-grid { display: grid; grid-template-columns: 1.2fr .8fr; gap: 28px; align-items: center; }
.hero-badge { display: inline-block; background: #ccfbf1; color: #0f766e; font-weight: 800; padding: 6px 14px; border-radius: 999px; font-size: .9rem; }
.hero h1 { font-size: 2.4rem; line-height: 1.35; margin: 14px 0; }
.hero h1 span { color: var(--color-primary); }
.lead { color: var(--color-text-soft); line-height: 1.8; }
.hero-actions { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 18px; }
.hero-visual .hero-card { background: #fff; border-radius: var(--radius-lg); box-shadow: var(--shadow-soft); padding: 26px; text-align: center; }
.hero-visual .big-emoji { font-size: 4rem; }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 13px 24px; border-radius: 999px; font-weight: 800; border: 2px solid transparent; font-size: 1rem; transition: transform .15s ease, filter .15s ease, box-shadow .15s ease; box-shadow: var(--shadow-soft); }
.btn:hover { transform: translateY(-2px); }
.btn:focus-visible, .pill-link:focus-visible, .chip:focus-visible, .unit-chip:focus-visible, .mini-q:focus-visible, .level-card:focus-visible { outline: 3px solid var(--color-accent); outline-offset: 2px; }
.btn-primary { background: var(--color-primary); color: #fff; }
.btn-primary:hover { background: var(--color-primary-dark); filter: brightness(1.05); }
.btn-secondary { background: var(--color-accent); color: #fff; }
.btn-outline { background: #fff; border-color: var(--color-primary); color: var(--color-primary-dark); box-shadow: 0 2px 8px rgba(13,148,136,.08); }
.btn-outline:hover { background: #f0fdfa; }
.btn-sm { padding: 9px 16px; font-size: .9rem; min-height: 40px; }
.btn:disabled { opacity: .5; cursor: not-allowed; transform: none; }

/* 3차 보조 pill 링크 */
.hero-actions--main { margin-bottom: 4px; }
.hero-actions--sub { gap: 8px; margin-top: 10px; }
.pill-link { display: inline-flex; align-items: center; padding: 9px 16px; border-radius: 999px; background: #fff; border: 2px solid var(--color-border); font-weight: 700; font-size: .9rem; color: var(--color-text-soft); min-height: 40px; transition: transform .15s ease, border-color .15s ease; }
.pill-link:hover { border-color: var(--color-primary); color: var(--color-primary-dark); transform: translateY(-1px); }

/* 탐구 미션 카드 */
.hero-card--mission { border: 2px solid #fff; background: linear-gradient(180deg, #ffffff 0%, #f0fdfa 100%); position: relative; }
.mission-badge { display: inline-block; background: #0b3b36; color: #fff; font-weight: 800; font-size: .82rem; padding: 6px 14px; border-radius: 999px; margin-bottom: 10px; }
.mission-note { font-size: .82rem; color: var(--color-text-soft); background: #ecfdf5; border-radius: 10px; padding: 8px 12px; margin: 12px 0 0; }

/* 실험 추천 한 줄 카드 */
.exp-pick { display: flex; gap: 12px; align-items: center; background: #fff7ed; border: 2px solid #fed7aa; border-radius: 14px; padding: 14px 16px; box-shadow: var(--shadow-soft); transition: transform .15s ease; }
.exp-pick:hover { transform: translateY(-2px); }
.exp-pick-emoji { font-size: 1.8rem; }

/* 섹션 배경 변형 */
.section--soft { background: #ffffff; border-top: 1px solid var(--color-border); border-bottom: 1px solid var(--color-border); }
.section--tint { background: #fffdf4; border-top: 1px solid #fde68a55; border-bottom: 1px solid #fde68a55; }

/* Sections & cards */
.section { padding: 34px 0; }
.section-head { text-align: center; margin-bottom: 22px; }
.eyebrow { display: inline-block; font-size: .8rem; letter-spacing: 2px; font-weight: 800; color: var(--color-primary); background: #ccfbf1; padding: 4px 12px; border-radius: 999px; }
.section-head h2 { font-size: 1.7rem; margin: 10px 0 8px; }
.section-head p { color: var(--color-text-soft); line-height: 1.7; }
.steps-grid, .feature-grid, .level-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 18px; }
.step-card, .feature-card { background: var(--color-card); border-radius: var(--radius-md); box-shadow: var(--shadow-soft); padding: 22px; border: 1px solid var(--color-border); transition: transform .18s ease, box-shadow .18s ease; }
.step-card:hover, .feature-card:hover { transform: translateY(-4px); box-shadow: 0 12px 28px rgba(13,148,136,.16); }
.step-card h3, .feature-card h3 { margin: 10px 0 8px; }
.step-card p, .feature-card p { color: var(--color-text-soft); font-size: .92rem; line-height: 1.7; }
.step-num { display: inline-flex; width: 30px; height: 30px; border-radius: 50%; background: var(--color-primary); color: #fff; font-weight: 800; align-items: center; justify-content: center; }
.step-icon, .feature-icon { font-size: 2rem; }
.level-card { text-align: center; background: #fff; border-radius: var(--radius-lg); box-shadow: var(--shadow-soft); padding: 26px 18px 22px; border: 2px solid transparent; border-top-width: 6px; display: block; transition: transform .18s ease, box-shadow .18s ease; }
.level-card:hover { transform: translateY(-4px); box-shadow: 0 12px 28px rgba(13,148,136,.16); }
.level-card--el { border-color: #16a34a; }
.level-card--mi { border-color: #2563eb; }
.level-card--hi { border-color: var(--color-purple); }
.level-card .level-emoji { font-size: 2.2rem; width: 60px; height: 60px; display: inline-flex; align-items: center; justify-content: center; border-radius: 18px; background: #f0fdfa; box-shadow: var(--shadow-soft); }
.level-card h3 { margin: 12px 0 4px; }
.level-card p { color: var(--color-text-soft); font-size: .9rem; line-height: 1.6; margin: 0 0 14px; }

/* 기능 바로가기 그리드 (math menu-grid 참고, 과학 테마) */
.menu-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 12px; margin: 16px 0 0; padding: 0; }
.menu-grid li { list-style: none; }
.menu-grid a { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 6px; min-height: 112px; padding: 16px 10px; background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius-md); box-shadow: var(--shadow-soft); text-align: center; transition: transform .15s ease, border-color .15s ease; }
.menu-grid a:hover { transform: translateY(-3px); border-color: var(--color-primary); }
.menu-grid .emoji { font-size: 1.7rem; line-height: 1; }
.menu-grid .label { font-weight: 800; font-size: .95rem; }
.menu-grid .sub { font-size: .78rem; color: var(--color-text-soft); }

/* Concept cards */
.concept-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); gap: 16px; }
.concept-card { background: #fff; border-radius: var(--radius-md); box-shadow: var(--shadow-soft); padding: 18px; border: 1px solid var(--color-border); border-top: 6px solid var(--color-primary); display: flex; flex-direction: column; gap: 8px; min-width: 0; overflow-wrap: break-word; word-break: keep-all; transition: transform .18s ease, box-shadow .18s ease; }
.concept-card:hover { transform: translateY(-4px); box-shadow: 0 12px 28px rgba(13,148,136,.16); }
.concept-card h3 { margin: 0; font-size: 1.15rem; }
.concept-card .formula-line { background: #f0fdfa; border-radius: 10px; padding: 8px 12px; font-weight: 800; color: var(--color-primary-dark); }
.tag { display: inline-block; font-size: .75rem; font-weight: 800; padding: 3px 10px; border-radius: 999px; background: #eef2ff; color: #4338ca; margin-right: 4px; }
.tag-row { display: flex; flex-wrap: wrap; gap: 4px; }
.card-actions { display: flex; gap: 8px; margin-top: 6px; }

/* Filters */
.filter-bar { display: flex; flex-wrap: wrap; gap: 8px; margin: 16px 0; }
.filter-bar select, .filter-bar input { padding: 10px 14px; border-radius: 999px; border: 2px solid var(--color-border); font-family: inherit; font-size: .92rem; background: #fff; }
.chip-row { display: flex; flex-wrap: wrap; gap: 8px; margin: 10px 0; }
.chip { padding: 8px 14px; border-radius: 999px; background: #fff; border: 2px solid var(--color-border); font-weight: 700; font-size: .88rem; }
.chip.active { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }

/* Detail boxes */
.detail-wrap { max-width: 820px; margin: 0 auto; }
.formula-hero { background: linear-gradient(135deg, #0d9488, #0284c7); color: #fff; border-radius: var(--radius-lg); padding: 26px; text-align: center; font-size: 1.4rem; font-weight: 800; margin: 18px 0; }
.info-box { background: #fff; border-radius: var(--radius-md); padding: 20px; margin: 14px 0; border: 1px solid var(--color-border); box-shadow: var(--shadow-soft); }
.info-box h3 { margin-top: 0; }
.tip-box { background: #fefce8; border: 2px dashed #eab308; border-radius: 12px; padding: 14px 16px; margin: 12px 0; line-height: 1.7; }
.warn-box { background: #fef2f2; border: 2px solid #fca5a5; border-radius: 12px; padding: 14px 16px; margin: 12px 0; line-height: 1.7; }
.life-box { background: #f0fdf4; border-radius: 12px; padding: 14px 16px; margin: 12px 0; line-height: 1.7; }
.check-box { background: #eff6ff; border-radius: 12px; padding: 16px; margin: 12px 0; }
.exp-box { background: #fff7ed; border-radius: 12px; padding: 16px; margin: 12px 0; }
.step-list { counter-reset: step; padding: 0; }
.step-list li { background: #f8fafc; border-radius: 10px; padding: 10px 14px; margin: 8px 0; line-height: 1.7; list-style: none; }

/* Quiz / practice */
.quiz-card, .practice-card { background: #fff; border-radius: var(--radius-lg); box-shadow: var(--shadow-soft); padding: 26px; border: 1px solid var(--color-border); max-width: 760px; margin: 0 auto; }
.opt-btn { display: block; width: 100%; text-align: left; background: #f8fafc; border: 2px solid var(--color-border); border-radius: 12px; padding: 12px 16px; margin: 8px 0; font-size: 1rem; font-weight: 700; }
.opt-btn:hover { border-color: var(--color-primary); }
.opt-btn.correct { background: #dcfce7; border-color: #16a34a; }
.opt-btn.wrong { background: #fee2e2; border-color: #dc2626; }
.opt-btn:disabled { cursor: default; }
.answer-input { width: 100%; padding: 12px 16px; border-radius: 12px; border: 2px solid var(--color-border); font-size: 1.05rem; font-family: inherit; }
.feedback { border-radius: 12px; padding: 14px 16px; margin: 12px 0; line-height: 1.7; }
.feedback.ok { background: #dcfce7; }
.feedback.no { background: #fee2e2; }
.detail-controls { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; margin: 18px 0; }
.progress-dots { text-align: center; color: var(--color-text-soft); font-weight: 800; margin-bottom: 10px; }

/* Stats */
.stat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 14px; }
.stat-card { background: #fff; border-radius: var(--radius-md); box-shadow: var(--shadow-soft); padding: 18px; text-align: center; border: 1px solid var(--color-border); }
.stat-card strong { font-size: 1.8rem; display: block; color: var(--color-primary-dark); }
.bar-row { display: flex; align-items: center; gap: 10px; margin: 8px 0; }
.bar-row .bar-label { width: 90px; font-size: .88rem; font-weight: 700; }
.bar-track { flex: 1; background: #e5e7eb; border-radius: 999px; height: 14px; overflow: hidden; }
.bar-fill { height: 100%; background: linear-gradient(90deg, #14b8a6, #38bdf8); border-radius: 999px; }
.dash-stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 14px; margin: 18px 0; }
.dash-stat { background: #fff; border-radius: var(--radius-md); padding: 18px; text-align: center; box-shadow: var(--shadow-soft); border: 1px solid var(--color-border); display: block; }
.ds-icon { font-size: 1.8rem; }
.ds-num { font-size: 1.4rem; font-weight: 800; display: block; }
.ds-label { color: var(--color-text-soft); font-size: .88rem; }
.ds-bar { display: block; background: #e5e7eb; border-radius: 999px; height: 8px; margin-top: 8px; overflow: hidden; }
.ds-bar span { display: block; height: 100%; background: var(--color-primary); }

/* Today widgets */
.today-card { display: flex; gap: 18px; background: #fff; border-radius: var(--radius-lg); box-shadow: var(--shadow-soft); padding: 24px; border: 1px solid var(--color-border); align-items: flex-start; }
.today-emoji { font-size: 3rem; }
.mini-q { display: flex; gap: 12px; align-items: center; background: #fff; border: 1px solid var(--color-border); border-radius: 12px; padding: 12px 14px; margin: 8px 0; box-shadow: var(--shadow-soft); }
.mini-q-num { background: var(--color-primary); color: #fff; font-weight: 800; border-radius: 10px; padding: 6px 10px; }
.mini-q-body { flex: 1; }
.mini-q-body small { display: block; color: var(--color-text-soft); }
.tip-card { background: #fffbeb; border: 1px solid #fde68a; border-radius: 12px; padding: 14px 16px; margin: 8px 0; }
.unit-chip { display: inline-block; background: #fff; border: 1px solid var(--color-border); border-radius: 999px; padding: 8px 14px; margin: 4px; font-weight: 700; box-shadow: var(--shadow-soft); }
.unit-chip small { color: var(--color-text-soft); }
.recent-row { display: flex; justify-content: space-between; background: #fff; border: 1px solid var(--color-border); border-radius: 10px; padding: 10px 14px; margin: 6px 0; }
.counter { text-align: center; }
.counter strong { font-size: 2rem; color: var(--color-primary-dark); display: block; }
.counter-row { display: flex; gap: 26px; justify-content: center; margin-top: 16px; }

/* Auth */
.auth-card { background: #fff; border-radius: var(--radius-lg); box-shadow: var(--shadow-soft); padding: 30px; max-width: 560px; margin: 0 auto; border: 1px solid var(--color-border); }
.btn-google { display: flex; align-items: center; justify-content: center; gap: 10px; width: 100%; background: #fff; border: 2px solid var(--color-border); border-radius: 12px; padding: 12px; font-weight: 800; font-size: 1rem; }
.auth-msg { border-radius: 10px; padding: 12px 14px; margin: 12px 0; display: none; line-height: 1.7; }
.auth-msg.show { display: block; }
.auth-msg.ok { background: #dcfce7; }
.auth-msg.error { background: #fee2e2; }
.auth-msg.info { background: #e0f2fe; }
.auth-note { color: var(--color-text-soft); font-size: .9rem; line-height: 1.8; }
.dash-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 16px; }
.dash-card { background: #fff; border-radius: var(--radius-md); box-shadow: var(--shadow-soft); padding: 20px; border: 1px solid var(--color-border); }
.dash-score-row, .dash-hist-row { display: flex; justify-content: space-between; padding: 8px 0; border-bottom: 1px dashed var(--color-border); font-size: .92rem; }

/* Worksheet print */
@media print {
  .site-header, .no-print, .detail-controls, .filter-bar { display: none !important; }
  body { background: #fff; }
  .quiz-card, .info-box { box-shadow: none; border: 1px solid #999; break-inside: avoid; }
}
.sheet { background: #fff; border-radius: 8px; padding: 28px; box-shadow: var(--shadow-soft); border: 1px solid var(--color-border); }
.sheet h2 { border-bottom: 3px solid var(--color-primary); padding-bottom: 8px; }
.sheet .q { margin: 14px 0; line-height: 1.8; }

/* Footer */
.site-footer { background: #0b3b36; color: #d7efe9; margin-top: 40px; padding: 34px 0 18px; }
.foot-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 18px; }
.site-footer h4 { margin: 0 0 8px; color: #fff; }
.site-footer p { font-size: .9rem; line-height: 1.7; opacity: .9; }
.site-footer a { text-decoration: underline; }
.foot-bottom { text-align: center; margin-top: 18px; font-size: .85rem; opacity: .8; }

/* Responsive */
@media (max-width: 1024px) {
  .main-nav .nav-desktop { display: none; }
  .nav-toggle { display: block; }
  .main-nav .nav-mobile { display: none; flex-direction: column; position: absolute; top: 100%; left: 0; right: 0; background: #fff; border-bottom: 3px solid var(--color-border); padding: 12px 20px 20px; z-index: 150; max-height: 70vh; overflow-y: auto; }
  .main-nav.open .nav-mobile { display: flex; }
  .m-group-title { font-weight: 800; color: var(--color-primary-dark); display: block; margin: 10px 0 4px; }
  .m-sub a { display: block; padding: 8px 10px; border-radius: 8px; }
  .m-sub a.active { background: var(--color-primary); color: #fff; }
  .hero { padding: 32px 0 16px; }
  .hero-grid { grid-template-columns: 1fr; gap: 20px; }
  .hero h1 { font-size: 1.9rem; }
  .hero-actions--main .btn { flex: 1 1 140px; }
  .today-card { flex-direction: column; }
  .level-grid { grid-template-columns: 1fr; }
  .menu-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 560px) {
  .section { padding: 30px 0; }
  .hero-actions--main { flex-direction: column; align-items: stretch; }
  .hero-actions--main .btn { width: 100%; }
  .menu-grid { grid-template-columns: repeat(2, 1fr); }
  .counter-row { gap: 16px; }
}