:root {
  --purple: #7F77DD; --purple-light: #EEEDFE; --purple-dark: #3C3489;
  --teal: #1D9E75; --teal-light: #E1F5EE; --teal-dark: #085041;
  --coral: #D85A30; --coral-light: #FAECE7; --coral-dark: #712B13;
  --amber: #BA7517; --amber-light: #FAEEDA; --amber-dark: #633806;
  --blue: #378ADD; --blue-light: #E6F1FB; --blue-dark: #185FA5;
  --green: #639922; --green-light: #EAF3DE; --green-dark: #3B6D11;
  --pink: #D4537E; --pink-light: #FBEAF0; --pink-dark: #993556;
  --gray: #888780; --surface: #f8f7f4; --white: #fff;
  --text: #1a1a18; --text2: #5a5955; --text3: #9a9895;
  --border: rgba(0,0,0,0.08); --radius: 10px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; font-family: system-ui, -apple-system, sans-serif; background: var(--surface); color: var(--text); font-size: 16px; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
input { font-family: inherit; }

/* LAYOUT */
.page { display: none; min-height: 100vh; flex-direction: column; }
.page.active { display: flex; }

/* LOGIN */
.login-wrap { flex: 1; display: flex; align-items: center; justify-content: center; padding: 24px; }
.login-box { background: var(--white); border: 0.5px solid var(--border); border-radius: 16px; padding: 36px 32px; width: 100%; max-width: 380px; }
.login-avatar { font-size: 48px; text-align: center; margin-bottom: 8px; }
.login-title { font-size: 22px; font-weight: 600; text-align: center; margin-bottom: 4px; }
.login-sub { font-size: 14px; color: var(--text2); text-align: center; margin-bottom: 28px; }
.field { margin-bottom: 14px; }
.field label { font-size: 13px; font-weight: 500; color: var(--text2); display: block; margin-bottom: 5px; }
.field input { width: 100%; padding: 10px 13px; border: 0.5px solid var(--border); border-radius: var(--radius); font-size: 15px; outline: none; transition: border-color .15s; }
.field input:focus { border-color: var(--purple); }
.btn-primary { width: 100%; background: var(--purple); color: #fff; border: none; border-radius: var(--radius); padding: 12px; font-size: 15px; font-weight: 600; margin-top: 8px; transition: opacity .15s; }
.btn-primary:hover { opacity: .88; }
.login-error { color: var(--coral-dark); font-size: 13px; text-align: center; margin-top: 10px; min-height: 18px; }

/* TOP NAV */
.topnav { background: var(--white); border-bottom: 0.5px solid var(--border); padding: 0 20px; display: flex; align-items: center; height: 56px; gap: 12px; }
.topnav-logo { font-size: 16px; font-weight: 700; color: var(--purple-dark); display: flex; align-items: center; gap: 6px; flex: 1; }
.topnav-logo span { font-size: 20px; }
.badge-pts { background: var(--amber-light); color: var(--amber-dark); border-radius: 20px; padding: 4px 11px; font-size: 13px; font-weight: 600; }
.badge-stars { background: var(--purple-light); color: var(--purple-dark); border-radius: 20px; padding: 4px 11px; font-size: 13px; font-weight: 600; }
.badge-racha { background: var(--coral-light); color: var(--coral-dark); border-radius: 20px; padding: 4px 11px; font-size: 13px; font-weight: 600; }
.btn-logout { background: none; border: 0.5px solid var(--border); border-radius: var(--radius); padding: 6px 12px; font-size: 13px; color: var(--text2); }
.btn-logout:hover { background: var(--surface); }

/* CONTENT */
.content { flex: 1; padding: 24px 20px; max-width: 720px; margin: 0 auto; width: 100%; }

/* MENU */
.welcome { margin-bottom: 24px; }
.welcome h1 { font-size: 24px; font-weight: 700; margin-bottom: 4px; }
.welcome p { font-size: 15px; color: var(--text2); }
.topic-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 12px; }
.topic-card { background: var(--white); border: 0.5px solid var(--border); border-radius: 14px; padding: 18px 14px; cursor: pointer; transition: border-color .15s, transform .1s; text-align: left; }
.topic-card:hover { border-color: var(--purple); transform: translateY(-2px); }
.topic-icon { font-size: 30px; margin-bottom: 10px; }
.topic-name { font-size: 14px; font-weight: 600; margin-bottom: 3px; }
.topic-desc { font-size: 12px; color: var(--text2); }
.topic-pct { display: inline-block; margin-top: 8px; font-size: 11px; font-weight: 600; padding: 2px 8px; border-radius: 20px; background: var(--green-light); color: var(--green-dark); }

/* EJERCICIOS */
.ex-header { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; }
.btn-back { background: none; border: 0.5px solid var(--border); border-radius: var(--radius); padding: 7px 14px; font-size: 13px; color: var(--text2); }
.btn-back:hover { background: var(--surface); }
.ex-label { font-weight: 600; font-size: 15px; flex: 1; }
.ex-counter { font-size: 13px; color: var(--text3); }
.progress-track { height: 6px; background: #e8e7e3; border-radius: 3px; margin-bottom: 20px; }
.progress-fill { height: 6px; border-radius: 3px; background: var(--purple); transition: width .4s; }
.question-card { background: var(--white); border: 0.5px solid var(--border); border-radius: 14px; padding: 28px 24px; margin-bottom: 16px; }
.question-text { font-size: 20px; font-weight: 600; line-height: 1.4; margin-bottom: 8px; }
.question-hint { font-size: 13px; color: var(--text3); }
.options-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-bottom: 14px; }
.opt { background: var(--white); border: 0.5px solid var(--border); border-radius: var(--radius); padding: 15px; font-size: 18px; font-weight: 600; color: var(--text); transition: all .15s; }
.opt:hover:not(:disabled) { border-color: var(--purple); background: var(--purple-light); color: var(--purple-dark); }
.opt.correct { background: var(--green-light); border-color: var(--teal); color: var(--teal-dark); }
.opt.wrong { background: var(--coral-light); border-color: var(--coral); color: var(--coral-dark); }
.opt:disabled { cursor: default; }
.feedback { border-radius: var(--radius); padding: 13px 16px; font-size: 14px; margin-bottom: 14px; display: none; }
.feedback.show { display: block; }
.feedback.correct { background: var(--green-light); color: var(--teal-dark); border: 0.5px solid var(--teal); }
.feedback.wrong { background: var(--coral-light); color: var(--coral-dark); border: 0.5px solid var(--coral); }
.btn-next { width: 100%; background: var(--purple); color: #fff; border: none; border-radius: var(--radius); padding: 14px; font-size: 15px; font-weight: 600; display: none; }
.btn-next.show { display: block; }
.btn-next:hover { opacity: .88; }

/* RESULTADOS */
.results-card { background: var(--white); border: 0.5px solid var(--border); border-radius: 14px; padding: 32px 24px; text-align: center; margin-bottom: 16px; }
.results-emoji { font-size: 52px; margin-bottom: 12px; }
.results-score { font-size: 44px; font-weight: 700; margin-bottom: 4px; }
.results-msg { font-size: 15px; color: var(--text2); margin-bottom: 16px; }
.results-stars { font-size: 30px; letter-spacing: 4px; margin-bottom: 16px; }
.results-earned { font-size: 14px; font-weight: 600; background: var(--purple-light); color: var(--purple-dark); display: inline-block; padding: 8px 18px; border-radius: 20px; }
.stat-row { display: flex; gap: 10px; margin-bottom: 16px; }
.stat-box { flex: 1; background: var(--white); border: 0.5px solid var(--border); border-radius: var(--radius); padding: 14px; text-align: center; }
.stat-val { font-size: 22px; font-weight: 700; }
.stat-lbl { font-size: 12px; color: var(--text3); margin-top: 2px; }
.action-row { display: flex; gap: 10px; }
.btn-sec { flex: 1; background: var(--white); border: 0.5px solid var(--border); border-radius: var(--radius); padding: 12px; font-size: 14px; font-weight: 500; color: var(--text); }
.btn-sec:hover { background: var(--surface); }
.btn-pri { flex: 1; background: var(--purple); color: #fff; border: none; border-radius: var(--radius); padding: 12px; font-size: 14px; font-weight: 600; }
.btn-pri:hover { opacity: .88; }

/* LOGROS */
.logros-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: 10px; margin-top: 16px; }
.logro-card { background: var(--white); border: 0.5px solid var(--border); border-radius: 12px; padding: 14px 12px; text-align: center; }
.logro-icon { font-size: 28px; margin-bottom: 6px; }
.logro-name { font-size: 12px; font-weight: 600; margin-bottom: 3px; }
.logro-desc { font-size: 11px; color: var(--text3); }
.logro-card.locked { opacity: .35; filter: grayscale(1); }

/* PANEL PADRES */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: 10px; margin-bottom: 20px; }
.stat-card { background: var(--white); border: 0.5px solid var(--border); border-radius: 12px; padding: 16px; }
.stat-card .val { font-size: 26px; font-weight: 700; }
.stat-card .lbl { font-size: 12px; color: var(--text3); margin-top: 3px; }
.section-title { font-size: 15px; font-weight: 700; color: var(--text); margin-bottom: 12px; }
.tema-row { display: flex; align-items: center; gap: 10px; padding: 10px 0; border-bottom: 0.5px solid var(--border); }
.tema-row:last-child { border-bottom: none; }
.tema-name { font-size: 13px; color: var(--text2); width: 130px; flex-shrink: 0; }
.tema-track { flex: 1; height: 8px; background: #e8e7e3; border-radius: 4px; overflow: hidden; }
.tema-fill { height: 8px; border-radius: 4px; background: var(--purple); }
.tema-pct { font-size: 12px; color: var(--text3); width: 36px; text-align: right; }
.history-list { background: var(--white); border: 0.5px solid var(--border); border-radius: 12px; overflow: hidden; margin-bottom: 20px; }
.history-item { display: flex; align-items: center; padding: 11px 16px; border-bottom: 0.5px solid var(--border); gap: 10px; }
.history-item:last-child { border-bottom: none; }
.history-topic { font-size: 13px; color: var(--text); flex: 1; }
.history-badge { font-size: 11px; font-weight: 600; padding: 3px 10px; border-radius: 20px; }
.history-date { font-size: 12px; color: var(--text3); }
.empty { padding: 32px; text-align: center; color: var(--text3); font-size: 14px; }
.semana-bars { display: flex; align-items: flex-end; gap: 6px; height: 80px; margin-bottom: 4px; }
.semana-bar { flex: 1; border-radius: 4px 4px 0 0; background: var(--purple-light); min-height: 4px; transition: height .4s; }
.semana-bar.hoy { background: var(--purple); }
.semana-labels { display: flex; gap: 6px; }
.semana-label { flex: 1; text-align: center; font-size: 10px; color: var(--text3); }

/* TABS */
.tabs { display: flex; gap: 4px; margin-bottom: 20px; background: var(--surface); border-radius: var(--radius); padding: 3px; }
.tab { flex: 1; padding: 8px; border: none; border-radius: 7px; font-size: 13px; font-weight: 500; color: var(--text2); background: none; cursor: pointer; }
.tab.active { background: var(--white); color: var(--purple-dark); box-shadow: 0 1px 3px rgba(0,0,0,.1); }

@media (max-width: 480px) {
  .topic-grid { grid-template-columns: 1fr 1fr; }
  .options-grid { grid-template-columns: 1fr 1fr; }
  .content { padding: 16px; }
  .topnav { padding: 0 12px; gap: 6px; }
}