/* Frixos_ai — dark theme, vanilla CSS (Master Doc §2.3)
   Φιλικό για παιδί 9 ετών: μεγάλη γραμματοσειρά, μεγάλα κουμπιά. */

:root {
  --bg: #14161c;
  --bg-soft: #1c1f28;
  --bg-card: #232735;
  --border: #323848;
  --text: #e8eaf0;
  --text-dim: #9aa1b5;
  --accent: #ffb454;        /* ζεστό πορτοκαλί — προσιτό, όχι "εταιρικό" */
  --accent-soft: #ffb45426;
  --child: #3d7bd9;         /* μπαλόνι παιδιού */
  --ai: #2a2f3f;            /* μπαλόνι AI */
  --ok: #58c48c;
  --warn: #e2635e;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  font-size: 17px;
}
.hidden { display: none !important; }
.accent { color: var(--accent); }
.muted { color: var(--text-dim); font-weight: normal; font-size: .8em; }

/* ---------------------------------------------------------------- topbar -- */
.topbar {
  display: flex; align-items: center; gap: 16px;
  padding: 10px 16px;
  background: var(--bg-soft);
  border-bottom: 1px solid var(--border);
}
.brand { font-size: 1.25rem; font-weight: 700; }
.tabs { display: flex; gap: 8px; flex: 1; }
.tab {
  background: none; border: 1px solid transparent; color: var(--text-dim);
  font-size: 1rem; padding: 8px 14px; border-radius: 10px;
  cursor: pointer; text-decoration: none;
}
.tab.active, .tab:hover {
  color: var(--text); background: var(--bg-card);
  border-color: var(--border);
}
.logout { color: var(--text-dim); text-decoration: none; font-size: 1.2rem; }

/* ---------------------------------------------------------------- layout -- */
.layout {
  display: flex;
  height: calc(100vh - 57px);
}
.sidebar {
  width: 320px; min-width: 250px;
  border-right: 1px solid var(--border);
  background: var(--bg-soft);
  overflow-y: auto;
  padding: 12px;
}
.chat-area {
  flex: 1;
  display: flex; flex-direction: column;
  min-width: 0;
}

/* -------------------------------------------------------------- τετράδιο -- */
.big-btn {
  width: 100%;
  background: var(--accent); color: #201500;
  border: none; border-radius: 12px;
  font-size: 1.05rem; font-weight: 700;
  padding: 12px; cursor: pointer;
}
.big-btn:hover { filter: brightness(1.08); }
.conv-list, .chapter-list { list-style: none; margin: 12px 0 0; padding: 0; }
.conv-item {
  display: flex; gap: 10px; align-items: baseline;
  padding: 10px 12px; margin-bottom: 6px;
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 10px; cursor: pointer;
}
.conv-item:hover, .conv-item.active { border-color: var(--accent); }
.conv-num {
  color: var(--accent); font-weight: 700; white-space: nowrap;
}
.conv-title {
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
  flex: 1;
}
.conv-mode { font-size: .75rem; color: var(--text-dim); }

/* ---------------------------------------------------------- περιεχόμενα -- */
.subject-bar { display: flex; gap: 8px; flex-wrap: wrap; }
.subject-chip {
  border: 1px solid var(--border); background: var(--bg-card);
  color: var(--text); border-radius: 999px; padding: 8px 16px;
  font-size: .95rem; cursor: pointer;
}
.subject-chip.active { border-color: var(--accent); color: var(--accent); }
.unit-header {
  margin: 14px 4px 6px; font-size: .85rem; color: var(--text-dim);
  text-transform: uppercase; letter-spacing: .04em;
}
.chapter-item {
  padding: 10px 12px; margin-bottom: 6px;
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 10px;
}
.chapter-name { margin-bottom: 8px; }
.chapter-name .num { color: var(--accent); font-weight: 700; }
.chapter-pages {
  font-size: .78rem; color: var(--text-dim); margin-left: 6px;
}
.mode-btns { display: flex; gap: 8px; }
.mode-btn {
  flex: 1; border: 1px solid var(--border); background: var(--bg-soft);
  color: var(--text); border-radius: 8px; padding: 7px 0;
  font-size: .9rem; cursor: pointer;
}
.mode-btn:hover { border-color: var(--accent); color: var(--accent); }

/* ------------------------------------------------------------------ chat -- */
.chat-title {
  padding: 12px 20px; border-bottom: 1px solid var(--border);
  color: var(--text-dim); font-size: .95rem;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.messages {
  flex: 1; overflow-y: auto; padding: 20px;
  display: flex; flex-direction: column; gap: 14px;
}
.msg {
  max-width: 75%; padding: 12px 16px; border-radius: 16px;
  line-height: 1.55; white-space: pre-wrap; word-wrap: break-word;
}
.msg.child {
  align-self: flex-end; background: var(--child); color: #fff;
  border-bottom-right-radius: 4px;
}
.msg.ai {
  align-self: flex-start; background: var(--ai);
  border: 1px solid var(--border); border-bottom-left-radius: 4px;
}
.msg.ai .speak-btn {
  display: inline-block; margin-top: 8px;
  background: none; border: 1px solid var(--border); color: var(--text-dim);
  border-radius: 8px; padding: 4px 10px; cursor: pointer; font-size: .9rem;
}
.msg.ai .speak-btn:hover { color: var(--accent); border-color: var(--accent); }
.msg.thinking { color: var(--text-dim); font-style: italic; }
.page-link {
  color: var(--accent); text-decoration: underline dotted; cursor: pointer;
}

.chat-form {
  display: flex; gap: 10px; align-items: center;
  padding: 14px 20px; border-top: 1px solid var(--border);
  background: var(--bg-soft);
}
#chat-input {
  flex: 1; background: var(--bg-card); color: var(--text);
  border: 1px solid var(--border); border-radius: 12px;
  font-size: 1.05rem; padding: 12px 16px; outline: none;
}
#chat-input:focus { border-color: var(--accent); }
.icon-btn {
  background: var(--bg-card); color: var(--text);
  border: 1px solid var(--border); border-radius: 12px;
  font-size: 1.15rem; width: 48px; height: 48px; cursor: pointer;
}
.icon-btn:hover { border-color: var(--accent); }
.icon-btn.send { background: var(--accent); color: #201500; border: none; }
.icon-btn.mic-on { background: var(--warn); color: #fff; border: none; }

/* ----------------------------------------------------------------- modal -- */
.modal {
  position: fixed; inset: 0; background: #000a;
  display: flex; align-items: center; justify-content: center; z-index: 50;
}
.modal-box {
  position: relative; background: var(--bg-card);
  border: 1px solid var(--border); border-radius: 14px;
  padding: 18px; max-width: min(92vw, 720px); max-height: 92vh;
  display: flex; flex-direction: column;
}
.modal-title { margin-bottom: 10px; color: var(--text-dim); }
.modal-img-wrap { overflow: auto; max-height: 78vh; border-radius: 8px; }
.modal-img-wrap img {
  display: block; max-width: 100%; cursor: zoom-in;
}
.modal-img-wrap.zoomed img {
  max-width: none; width: 190%; cursor: zoom-out;
}
.modal-close {
  position: absolute; top: 10px; right: 10px;
  background: none; border: none; color: var(--text-dim);
  font-size: 1.1rem; cursor: pointer;
}
.modal-close:hover { color: var(--warn); }
.modal-missing { color: var(--text-dim); }

/* ----------------------------------------------------------------- login -- */
.login-body {
  display: flex; align-items: center; justify-content: center; height: 100vh;
}
.login-card {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 16px; padding: 40px 48px; text-align: center;
}
.login-card h1 { margin: 0 0 6px; }
.login-hint { color: var(--text-dim); margin: 0 0 20px; }
.login-card input {
  display: block; width: 240px; margin: 0 auto 14px;
  background: var(--bg-soft); color: var(--text);
  border: 1px solid var(--border); border-radius: 10px;
  font-size: 1.1rem; padding: 12px 40px 12px 14px;
  text-align: center; outline: none;
}
.login-card input:focus { border-color: var(--accent); }
.code-wrap { position: relative; width: 240px; margin: 0 auto; }
.code-wrap input { width: 100%; margin: 0 0 14px; }
.code-wrap .eye-btn {
  position: absolute; right: 8px; top: 10px;
  width: auto; margin: 0; padding: 2px;
  background: none; border: none; border-radius: 0;
  font-size: 1.1rem; font-weight: 400; line-height: 1;
  color: var(--text-dim); cursor: pointer; outline: none;
  -webkit-tap-highlight-color: transparent;
  -webkit-appearance: none; appearance: none;
}
.code-wrap .eye-btn:focus, .code-wrap .eye-btn:focus-visible { outline: none; box-shadow: none; }
.code-wrap .eye-btn.eye-on, .code-wrap .eye-btn:hover { color: var(--accent); }
.login-card button {
  background: var(--accent); color: #201500; border: none;
  border-radius: 10px; font-size: 1rem; font-weight: 700;
  padding: 10px 28px; cursor: pointer;
}
.login-error { color: var(--warn); margin-top: 14px; }

/* ---------------------------------------------------------------- parent -- */
.parent-main { padding: 24px; max-width: 1000px; margin: 0 auto; }
.stats-row { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 24px; }
.stat-card {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 12px; padding: 14px 20px; min-width: 150px;
}
.stat-card .value { font-size: 1.6rem; font-weight: 700; color: var(--accent); }
.stat-card .label { color: var(--text-dim); font-size: .85rem; }
.log-list { display: flex; flex-direction: column; gap: 10px; }
.log-entry {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 10px; padding: 12px 16px;
}
.log-entry summary { cursor: pointer; display: flex; gap: 12px; align-items: baseline; }
.log-q { flex: 1; }
.log-meta { color: var(--text-dim); font-size: .8rem; white-space: nowrap; }
.log-badge {
  font-size: .72rem; padding: 2px 8px; border-radius: 999px;
  border: 1px solid var(--border); white-space: nowrap;
}
.log-badge.refusal { color: var(--warn); border-color: var(--warn); }
.log-badge.llm { color: var(--ok); border-color: var(--ok); }
.log-answer {
  margin-top: 10px; padding-top: 10px; border-top: 1px solid var(--border);
  color: var(--text-dim); white-space: pre-wrap; line-height: 1.5;
}

/* ---------------------------------------------------------------- mobile -- */
@media (max-width: 760px) {
  .layout { flex-direction: column; }
  .sidebar {
    width: 100%; min-width: 0; max-height: 40vh;
    border-right: none; border-bottom: 1px solid var(--border);
  }
  .msg { max-width: 90%; }
}