:root{
  --bg: #f9fbff;          /* blanc bleuté */
  --text: #0f172a;        /* texte anthracite */
  --panel: #ffffff;       /* cartes */
  --muted: #475569;       /* gris lisible */
  --accent: #007BFF;      /* bleu principal */
  --ok: #16a34a;          /* vert check */
  --ko: #dc2626;          /* rouge erreur */
  --ring: rgba(0,123,255,0.3);
}

/* Base */
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  color:var(--text);
  background:var(--bg);
  font-size: 20px;
}
.wrap{max-width:1000px; margin:0 auto; padding:20px}
.header{margin-bottom:16px}
.header h1{margin:0 0 6px 0; font-size:34px}
.header p{margin:0; color:var(--muted); font-size:20px;}

.footer{margin-top:24px; color:var(--muted); font-size:16px}
.back{display:inline-block; margin-bottom:12px; text-decoration:none; color:var(--accent); font-weight:500; font-size:20px}
.back:hover{text-decoration:underline}

/* Image viewer */
.viewer{background:var(--panel); padding:10px; border-radius:14px; border:1px solid #e5e7eb}
.img-stage{position:relative; display:flex; align-items:center; justify-content:center; min-height:45vh; background:#fff; border-radius:12px; overflow:hidden}
.img-stage img{max-width:100%; max-height:60vh; display:block}
.pager{text-align:center; margin-top:12px; font-weight:600; color:var(--muted); font-size:20px}

/* Form A→J en tableau 2 colonnes */
.kv {
  display: grid;
  grid-template-columns: 1fr 1fr; /* ✅ 2 colonnes */
  gap: 20px;
  margin-top: 30px;
  justify-content: center;
}

.kv > div {
  display: flex;
  align-items: center;
  gap: 12px;
  background: var(--panel);
  border: 1px solid #e5e7eb;
  border-radius: 14px;
  padding: 14px 18px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.05);
}

/* Lettre pastille bien visible */
label {
  flex: 0 0 50px;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
  font-size: 26px;
  border-radius: 12px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.15);
  margin: 0;
}

/* Champs numériques très visibles */
input[type=text], input[type=number]{
  flex: 1;
  font-size:24px;
  text-align:center;
  padding:18px 0;
  border-radius:10px;
  border:2px solid #cbd5e1;
  background:#fff;
  outline:none;
  transition:all 0.2s ease;
  box-shadow:0 2px 6px rgba(0,0,0,0.05);
}
input[type=text]:focus, input[type=number]:focus{
  border-color: var(--accent);
  box-shadow:0 0 0 4px var(--ring);
}
.input-valid{
  border-color: var(--ok)!important;
  background:#e6fbe9!important;
  color:#065f46;
  font-weight:700;
}
.input-invalid{
  border-color: var(--ko)!important;
  background:#fee2e2!important;
  color:#7f1d1d;
  font-weight:700;
}
input::placeholder{color:#94a3b8; font-size:16px;}

/* Toolbar */
.toolbar{display:flex; justify-content:center; gap:20px; margin-top:20px;}
.btn{
  min-width:200px;
  padding:16px 24px;
  border-radius:12px;
  background:var(--accent);
  color:#fff;
  border:none;
  cursor:pointer;
  font-weight:600;
  font-size:20px;
}
.btn.secondary{background:#475569}
.btn:focus{outline:3px solid var(--ring); outline-offset:2px}
.btn:hover{background:#0056b3}

/* Indices */
.hint-icon{display:none;}
.hint-btn{
  margin-left: auto;
  padding:8px 14px;
  background:var(--accent);
  color:#fff;
  border:none;
  border-radius:8px;
  cursor:pointer;
  font-size:16px;
  font-weight:600;
}
.hint-btn:hover{background:#0056b3;}
.hint-bubble{
  margin-top:8px;
  padding:10px 14px;
  background:#007BFF;
  color:#fff;
  border-radius:8px;
  font-size:18px;
  display:block;
}
.hint-bubble[hidden]{display:none}

/* Chronomètre */
.chrono-wrap{ display:flex; justify-content:flex-end; margin:16px 0; }
#chrono1-time, #chrono2-time{
  font-variant-numeric: tabular-nums;
  font-weight:800;
  font-size:28px;
  padding:12px 20px;
  border:2px solid var(--accent);
  border-radius:12px;
  background:#fff;
  min-width:120px;
  text-align:center;
}

/* Navigation boutons centrés */
.pager-controls-bottom {
  display: flex;
  justify-content: center;
  gap: 40px;
  margin: 30px 0;
}
.nav-btn-bottom {
  min-width:220px;
  padding:18px 32px;
  font-size:22px;
  font-weight:bold;
  border-radius:12px;
  border:2px solid #1e3a8a;
  background:#fff;
  color:#1e3a8a;
  cursor:pointer;
  box-shadow:0 0 10px rgba(30,58,138,0.3),0 0 20px rgba(30,58,138,0.15) inset;
  transition:all .25s ease;
}
.nav-btn-bottom:hover{
  background:#1e3a8a;
  color:#fff;
  transform:translateY(-2px);
}

/* Mobile */
@media (max-width: 680px){
  body{font-size:18px;}
  .img-stage{ min-height:35vh; }
  .img-stage img{ max-height:50vh; }
  .kv{grid-template-columns: 1fr;} /* ✅ repasse en colonne unique */
  input[type=text], input[type=number]{font-size:22px;}
  .nav-btn-bottom{min-width:150px; font-size:18px;}
}

/* Floating help button */
.btn-aide {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background: var(--accent);
  color: white;
  border: none;
  padding: 14px 20px;
  font-size: 18px;
  border-radius: 8px;
  cursor: pointer;
  box-shadow: 0 2px 6px rgba(0,0,0,0.2);
  font-weight:600;
}
.btn-aide:hover { background:#0056b3; }

/* Login */
.login-container {
  width: 90%;
  max-width: 500px;
  padding: 50px 40px;
  background: var(--panel);
  border-radius: 20px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.2);
  text-align: center;
  margin: auto;
}
.login-container h1 {
  margin-bottom: 30px;
  font-size: 32px;
  font-weight: 800;
  color: var(--accent);
}
.login-container input {
  width: 100%;
  padding: 20px;
  border: 2px solid #cbd5e1;
  border-radius: 12px;
  margin-bottom: 24px;
  font-size: 22px;
  text-align: center;
  font-weight: 600;
}
.login-container button {
  width: 100%;
  padding: 22px;
  border-radius: 12px;
  background: var(--accent);
  color: white;
  font-weight: 700;
  font-size: 26px;
  border: none;
  cursor: pointer;
  transition: transform 0.2s ease, background 0.3s ease;
}
.login-container button:hover {
  background:#0056b3;
  transform: translateY(-3px);
}
.error { color: var(--ko); margin-bottom: 16px; font-weight: 600; font-size:18px; }

/* Cards accueil */
.grid{display:grid; gap:16px; grid-template-columns: repeat(auto-fit, minmax(260px,1fr))}
.card{background:var(--panel); border:1px solid #e5e7eb; border-radius:14px; padding:16px; box-shadow:0 6px 24px rgba(2,8,23,0.06)}
.card h2{margin:0 0 8px 0}
.card p{margin:0 0 12px 0; color:var(--muted)}
.card-btn{display:inline-flex; align-items:center; gap:8px; padding:10px 14px; border-radius:10px; background:var(--accent); color:#fff; text-decoration:none; border:none; cursor:pointer}
.card-btn:focus{outline:3px solid var(--ring); outline-offset:2px}