*, *::before, *::after { box-sizing: border-box; }
html { font-size: 18px; }
body {
  margin: 0; min-height: 100vh; display: flex; flex-direction: column;
  background: var(--color-bg); color: var(--color-text);
  font-family: var(--font-body); line-height: 1.5;
}
a { color: var(--color-secondary); }
:focus-visible { outline: 4px solid var(--color-secondary); outline-offset: 3px; }

.site-header {
  display: flex; align-items: center; justify-content: space-between; gap: var(--space-3);
  padding: var(--space-3) var(--space-4); background: var(--color-surface);
  border-bottom: 3px solid var(--color-border);
}
.brand { display: flex; align-items: center; gap: var(--space-2); font-weight: 800; font-size: 1.3rem; color: var(--color-text); text-decoration: none; }
.brand .mascot { font-size: 1.8rem; }
.site-nav { display: flex; align-items: center; gap: var(--space-3); }
.site-nav form { margin: 0; }

main { flex: 1; width: 100%; max-width: 960px; margin: 0 auto; padding: var(--space-4); }
.site-footer { text-align: center; color: var(--color-muted); padding: var(--space-4); font-size: .85rem; }

.card {
  background: var(--color-surface); border: 3px solid var(--color-border);
  border-radius: var(--radius-lg); box-shadow: var(--shadow-card); padding: var(--space-4);
}
.hero { text-align: center; padding: var(--space-5) var(--space-4); }
.hero .mascot-big { font-size: clamp(4rem, 18vw, 7rem); display: inline-block; animation: bob 3s ease-in-out infinite; }
.hero h1 { font-size: clamp(1.8rem, 6vw, 2.8rem); margin: var(--space-3) 0 var(--space-2); }
.hero p { color: var(--color-muted); font-size: 1.1rem; margin: 0 auto var(--space-4); max-width: 34ch; }
.letters { display: flex; flex-wrap: wrap; gap: var(--space-2); justify-content: center; margin-top: var(--space-4); }
.letters span { width: 44px; height: 44px; display: grid; place-items: center; border-radius: var(--radius-sm); font-weight: 800; color: #fff; }
.letters span:nth-child(4n+1) { background: var(--color-primary); }
.letters span:nth-child(4n+2) { background: var(--color-secondary); }
.letters span:nth-child(4n+3) { background: var(--color-success); }
.letters span:nth-child(4n+4) { background: var(--color-warning); color: var(--color-text); }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: var(--space-2);
  min-height: var(--touch-target); padding: 0 var(--space-4); border: 0; cursor: pointer;
  border-radius: var(--radius-md); font: inherit; font-weight: 800; text-decoration: none;
  background: var(--color-primary); color: #fff; box-shadow: 0 5px 0 var(--color-primary-dark);
  transition: transform .1s ease, box-shadow .1s ease;
}
.btn:active { transform: translateY(4px); box-shadow: 0 1px 0 var(--color-primary-dark); }
.btn-ghost { background: transparent; color: var(--color-text); box-shadow: none; border: 3px solid var(--color-border); }
.btn-block { width: 100%; }

.form-card { max-width: 440px; margin: var(--space-4) auto; }
.form-card h1 { margin-top: 0; }
.field { margin-bottom: var(--space-3); }
.field label { display: block; font-weight: 800; margin-bottom: var(--space-1); }
.field input {
  width: 100%; min-height: var(--touch-target); padding: 0 var(--space-3);
  border: 3px solid var(--color-border); border-radius: var(--radius-md); font: inherit;
  background: var(--color-surface); color: var(--color-text);
}
.field input:focus { border-color: var(--color-secondary); outline: none; }
.field .error { color: var(--color-danger); font-size: .9rem; }

.flashes { list-style: none; padding: 0; margin: 0 0 var(--space-3); }
.flash { padding: var(--space-3); border-radius: var(--radius-md); margin-bottom: var(--space-2); font-weight: 700; }
.flash-info { background: #e7f0ff; } .flash-danger { background: #ffe3ea; } .flash-success { background: #dcf7ec; }

@keyframes bob { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-10px); } }
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation: none !important; transition: none !important; } }
:root[data-motion="reduced"] *, :root[data-motion="reduced"] *::before { animation: none !important; transition: none !important; }

@media (max-width: 600px) {
  html { font-size: 17px; }
  main { padding: var(--space-3); }
  .site-header { padding: var(--space-2) var(--space-3); flex-wrap: wrap; }
  .brand { font-size: 1.1rem; }
  .site-nav { flex-wrap: wrap; gap: var(--space-1) var(--space-2); }
  .site-nav .btn-ghost { min-height: 44px; padding: 0 var(--space-3); }
}

/* ---- Phase 01: student ---- */
.muted { color: var(--color-muted); } .center { text-align: center; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.nav-link { color: var(--color-text); font-weight: 800; text-decoration: none; padding: var(--space-2); white-space: nowrap; }
input[type="date"], select {
  width: 100%; min-height: var(--touch-target); padding: 0 var(--space-3); font: inherit;
  border: 3px solid var(--color-border); border-radius: var(--radius-md);
  background: var(--color-surface); color: var(--color-text);
}
fieldset.avatars { border: 0; padding: 0; margin: 0 0 var(--space-3); }
fieldset.avatars legend { font-weight: 800; margin-bottom: var(--space-2); padding: 0; }
.avatars { display: flex; flex-wrap: wrap; gap: var(--space-2); }
.avatars legend { width: 100%; }
.avatar-option { cursor: pointer; text-align: center; }
.avatar-face {
  display: grid; place-items: center; width: 64px; height: 64px; font-size: 2.2rem;
  border-radius: var(--radius-md); border: 3px solid var(--color-border); background: var(--color-surface);
  transition: transform .1s ease;
}
.avatar-name { display: block; font-size: .8rem; color: var(--color-muted); }
.avatar-option input:checked + .avatar-face { border-color: var(--color-primary); background: #fff0ea; transform: scale(1.08); }
.avatar-option input:focus-visible + .avatar-face { outline: 4px solid var(--color-secondary); outline-offset: 2px; }

.home-hello { display: flex; align-items: center; gap: var(--space-4); margin-bottom: var(--space-4); }
.home-hello h1 { margin: 0; font-size: clamp(1.5rem, 5vw, 2.2rem); }
.home-hello p { margin: 0; }
.avatar-big { font-size: 4rem; }
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-3); margin-bottom: var(--space-4); }
.stat {
  background: var(--color-surface); border: 3px solid var(--color-border); border-radius: var(--radius-md);
  padding: var(--space-3); text-align: center; display: flex; flex-direction: column; align-items: center;
}
.stat strong { font-size: 1.6rem; line-height: 1.1; }
.stat span:last-child { font-size: .8rem; color: var(--color-muted); }
.stat-icon { font-size: 1.6rem; }
.continue h2 { margin-top: 0; }
.lesson-tile { display: flex; align-items: center; gap: var(--space-3); padding: var(--space-3); border-radius: var(--radius-md); background: #fff0ea; }
.lesson-tile-disabled { opacity: .85; }
.letter-big { font-size: 2.4rem; font-weight: 800; color: var(--color-primary); min-width: 90px; text-align: center; }
@media (max-width: 600px) {
  .stats { grid-template-columns: repeat(2, 1fr); }
  .home-hello { flex-direction: column; text-align: center; }
}

/* ---- Phase 02: shared bits (progress bar, clickable lesson tile) ---- */
a.lesson-tile { color: var(--color-text); text-decoration: none; min-height: var(--touch-target); }
a.lesson-tile:hover { background: var(--color-warning); background: color-mix(in srgb, var(--color-warning) 25%, var(--color-surface)); }
.progress-caption { margin: var(--space-3) 0 var(--space-1); font-size: .9rem; }
.progress { height: 14px; border-radius: 999px; background: var(--color-border); overflow: hidden; }
.progress > span { display: block; height: 100%; border-radius: 999px; background: var(--color-success); transition: width .4s ease; }
.btn-small { min-height: 44px; padding: 0 var(--space-3); font-size: .9rem; }