:root{
  --primary:#4F46E5;
  --primary-hover:#4338ca;

  --bg:#0b1020;
  --bg-soft: rgba(255,255,255,.06);
  --card: rgba(255,255,255,.08);

  --text:#E5E7EB;
  --text-2:#A1A1AA;

  --border: rgba(255,255,255,.10);
  --border-2: rgba(255,255,255,.14);

  --radius: 18px;
  --shadow-soft: 0 10px 30px rgba(0,0,0,.25);
}

*{ box-sizing:border-box; }
html,body{ height:100%; }

body{
  margin:0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial, "Apple Color Emoji","Segoe UI Emoji";
  background:
    radial-gradient(900px 500px at 10% 10%, rgba(79,70,229,.35), transparent 60%),
    radial-gradient(900px 500px at 90% 30%, rgba(16,185,129,.18), transparent 55%),
    radial-gradient(900px 500px at 40% 90%, rgba(236,72,153,.14), transparent 55%),
    var(--bg);
  color:var(--text);
}

/* ===== Topbar ===== */
.topbar{
  position:sticky;
  top:0;
  z-index:10;
  display:flex;
  align-items:center;
  justify-content:space-between;
  padding:14px 18px;
  border-bottom:1px solid var(--border);
  background: rgba(10, 15, 30, .55);
  backdrop-filter: blur(14px);
}

.brand{ display:flex; align-items:center; gap:12px; }
.logo{
  width:40px; height:40px;
  border-radius: 14px;
  display:grid; place-items:center;
  font-weight:800;
  background: linear-gradient(135deg, rgba(79,70,229,.95), rgba(99,102,241,.55));
  box-shadow: 0 10px 25px rgba(79,70,229,.25);
}

.brand-title{ font-weight:800; letter-spacing:.2px; }
.brand-title span{ color:#c7d2fe; }
.brand-subtitle{
  margin-top:2px;
  font-size:.86rem;
  color:var(--text-2);
}

.topbar-actions{ display:flex; align-items:center; gap:10px; }

.chip{
  border:1px solid var(--border);
  background: rgba(255,255,255,.06);
  color:var(--text);
  padding:10px 12px;
  border-radius: 999px;
  cursor:pointer;
  display:flex; gap:8px; align-items:center;
  transition: .2s;
}
.chip:hover{
  transform: translateY(-1px);
  border-color: var(--border-2);
  background: rgba(255,255,255,.09);
}

.avatar{
  width:42px; height:42px;
  border-radius: 14px;
  border:1px solid var(--border);
  background: rgba(255,255,255,.06);
  color:var(--text);
  cursor:pointer;
  transition:.2s;
}
.avatar:hover{
  border-color: var(--border-2);
  background: rgba(255,255,255,.09);
  transform: translateY(-1px);
}

/* ===== Layout (Resizable Grid) ===== */
.app-container{
  max-width: 1400px;
  margin: 0 auto;
  padding: 18px;

  display:grid;
  gap: 12px;

  /* 3 колонки + 2 ресайзера */
  grid-template-columns: 1fr 10px 1fr 10px 1fr;

  height: calc(100vh - 72px); /* высота минус topbar */
  min-height: 0;
}

/* ===== Panels ===== */
.panel{
  border-radius: var(--radius);
  background: linear-gradient(180deg, var(--card), rgba(255,255,255,.05));
  border: 1px solid var(--border);
  box-shadow: var(--shadow-soft);
  overflow:hidden;
  display:flex;
  flex-direction:column;

  /* важно для скролла внутри */
  min-height: 0;
}

.panel-header{
  display:flex;
  align-items:center;
  gap:10px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
  background: rgba(255,255,255,.04);
  font-weight:700;
}

.panel-body{
  padding: 14px 16px;
  flex:1;

  /* ✅ отдельный скролл */
  overflow:auto;
  min-height: 0;
}

/* ===== Material textarea ===== */
.material-input{
  width:100%;
  height:100%;
  border: 1px solid transparent;
  background: rgba(0,0,0,.15);
  color: var(--text);
  border-radius: 14px;
  padding: 14px;
  resize:none;
  outline:none;
  line-height:1.6;
  font-size: .98rem;
  transition: .2s;
}
.material-input::placeholder{ color: rgba(229,231,235,.45); }
.material-input:focus{
  border-color: rgba(79,70,229,.55);
  box-shadow: 0 0 0 4px rgba(79,70,229,.18);
  background: rgba(0,0,0,.20);
}

.action-bar{
  padding: 12px 16px;
  border-top:1px solid var(--border);
  display:flex;
  justify-content:flex-end;
  background: rgba(255,255,255,.03);
}

.btn-primary{
  border: none;
  cursor:pointer;
  background: linear-gradient(135deg, var(--primary), #6366f1);
  color:white;
  padding: 11px 14px;
  border-radius: 14px;
  font-weight:700;
  display:flex;
  align-items:center;
  gap:10px;
  box-shadow: 0 14px 30px rgba(79,70,229,.25);
  transition:.2s;
}
.btn-primary:hover{ transform: translateY(-1px); filter: brightness(1.03); }
.btn-primary:active{ transform: translateY(0px); }

/* ===== Chat layout ===== */
.panel--chat .panel-body{
  display:flex;
  flex-direction:column;
}

.chat-container{
  flex: 1;
  min-height: 0;

  display:flex;
  flex-direction:column;
  gap:12px;

  overflow:auto;        /* ✅ скролл истории */
  padding-right: 2px;
}

.message{
  max-width: 88%;
  padding: 12px 14px;
  border-radius: 16px;
  line-height: 1.5;
  font-size: .95rem;
  border: 1px solid var(--border);
  background: rgba(255,255,255,.06);
  animation: fadeIn .2s ease;
}

.msg-ai{
  align-self:flex-start;
  background: rgba(255,255,255,.06);
}

.msg-user{
  align-self:flex-end;
  background: rgba(79,70,229,.25);
  border-color: rgba(79,70,229,.35);
}

.chat-input-area{
  margin-top: 12px;
  display:flex;
  gap:10px;
  padding-top: 12px;
  border-top: 1px solid var(--border);
}

.chat-input{
  flex:1;
  padding: 12px 14px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,.18);
  color: var(--text);
  outline:none;
  transition:.2s;
}
.chat-input:focus{
  border-color: rgba(79,70,229,.55);
  box-shadow: 0 0 0 4px rgba(79,70,229,.18);
}

.btn-icon{
  width: 46px;
  height: 46px;
  border-radius: 14px;
  border:1px solid rgba(79,70,229,.35);
  background: rgba(79,70,229,.25);
  color:white;
  cursor:pointer;
  display:grid;
  place-items:center;
  transition:.2s;
}
.btn-icon:hover{ transform: translateY(-1px); background: rgba(79,70,229,.32); }
.btn-icon:active{ transform: translateY(0px); }

/* ===== Result hint ===== */
.hint{
  color: rgba(229,231,235,.55);
  text-align:center;
  margin-top: 40px;
  padding: 14px;
  border: 1px dashed rgba(255,255,255,.14);
  border-radius: 14px;
  background: rgba(0,0,0,.10);
}

/* ===== Resizer ===== */
.resizer{
  width: 10px;
  cursor: col-resize;
  border-radius: 999px;
  background: rgba(255,255,255,.06);
  border: 1px solid rgba(255,255,255,.08);
  position: relative;
}
.resizer:hover{ background: rgba(255,255,255,.10); }
.resizer::after{
  content:"";
  position:absolute;
  inset: 25% 3px;
  border-radius: 999px;
  background: rgba(255,255,255,.14);
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar{ width: 8px; }
::-webkit-scrollbar-thumb{ background: rgba(255,255,255,.14); border-radius: 999px; }
::-webkit-scrollbar-thumb:hover{ background: rgba(255,255,255,.22); }

/* ===== Responsive ===== */
@media (max-width: 1200px){
  .app-container{
    grid-template-columns: 1fr;
    height: auto;
  }
  .resizer{ display:none; }
}

/* Animation */
@keyframes fadeIn{
  from{ opacity:0; transform: translateY(6px); }
  to{ opacity:1; transform: translateY(0); }
}

/* ===== RESULT (Test styles) ===== */
#resultContainer h3{
  margin: 0 0 12px 0;
  font-size: 1.05rem;
  font-weight: 800;
  display:flex;
  align-items:center;
  gap:10px;
}

#resultContainer h3 i{
  color: var(--primary);
}

.test-card{
  border: 1px solid var(--border);
  background: rgba(255,255,255,.06);
  border-radius: 16px;
  padding: 14px;
  box-shadow: 0 12px 28px rgba(0,0,0,.18);
  margin-bottom: 12px;
}

.question-title{
  font-weight: 700;
  margin-bottom: 10px;
  font-size: .98rem;
  color: var(--text);
}

.options-wrapper{
  display:flex;
  flex-direction:column;
  gap: 8px;
}

.option-btn{
  width: 100%;
  text-align: left;
  padding: 11px 12px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,.12);
  color: var(--text);
  cursor: pointer;
  transition: .18s;
}

.option-btn:hover{
  background: rgba(255,255,255,.08);
  border-color: var(--border-2);
  transform: translateY(-1px);
}

.option-btn:disabled{
  cursor: default;
  opacity: .95;
  transform: none;
}

.option-btn.correct{
  background: rgba(16,185,129,.18);
  border-color: rgba(16,185,129,.45);
}

.option-btn.wrong{
  background: rgba(239,68,68,.18);
  border-color: rgba(239,68,68,.45);
}

.explanation{
  margin-top: 10px;
  padding: 10px 12px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,.10);
  color: rgba(229,231,235,.85);
  font-size: .92rem;
  line-height: 1.55;
}