/* ═══════════════════════════════════════════════════════════════════════════
   Study Notes Chat v2.0 — Full stylesheet
   Mobile-first · Accordion · Converters · Study cards · Put Converting Value gate · Chat
   ═══════════════════════════════════════════════════════════════════════════ */

/* ── Root tokens ── */
#snc-outer {
  --green:    #2e7d32;
  --green-l:  #e8f5e9;
  --green-d:  #1b5e20;
  --amber:    #f57f17;
  --amber-l:  #fff8e1;
  --blue:     #1565c0;
  --blue-l:   #e3f2fd;
  --red:      #c62828;
  --paper:    #fafdf6;
  --border:   #c8e6c9;
  --text:     #1b1b1b;
  --muted:    #757575;
  --radius:   8px;
  --shadow:   0 2px 10px rgba(0,0,0,.10);

  font-family: 'Segoe UI', Arial, sans-serif;
  font-size: 14px;
  color: var(--text);
  max-width: 760px;
  margin: 0 auto;
  padding: 0 4px;
  box-sizing: border-box;
}
#snc-outer *, #snc-outer *::before, #snc-outer *::after { box-sizing: inherit; }

/* ── Floating close button ── */
#snc-float-close {
  display: none;
  position: fixed;
  bottom: 18px;
  right: 18px;
  z-index: 9999;
  background: var(--red);
  color: #fff;
  border: none;
  border-radius: 50px;
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 4px 14px rgba(0,0,0,.25);
  transition: background .2s;
}
#snc-float-close:hover { background: #b71c1c; }
#snc-float-close.snc-visible { display: block; }

/* ══════════════════════════════════════════════════════════════════════
   ACCORDION
   ══════════════════════════════════════════════════════════════════════ */
#snc-accordion {
  border: 2px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  background: #fff;
}

.snc-acc-item { border-bottom: 1px solid var(--border); }
.snc-acc-item:last-child { border-bottom: none; }

/* Accordion header button */
.snc-acc-head {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 13px 16px;
  background: var(--green-l);
  border: none;
  cursor: pointer;
  font-size: 14px;
  font-weight: 700;
  color: var(--green-d);
  text-align: left;
  transition: background .18s;
  gap: 8px;
}
.snc-acc-head:hover { background: #c8e6c9; }
.snc-acc-head.snc-open { background: var(--green); color: #fff; }

.snc-acc-head--chat { background: var(--blue-l); color: var(--blue); }
.snc-acc-head--chat:hover { background: #bbdefb; }
.snc-acc-head--chat.snc-open { background: var(--blue); color: #fff; }

.snc-acc-arrow { font-size: 18px; transition: transform .25s; flex-shrink: 0; }
.snc-acc-head.snc-open .snc-acc-arrow { transform: rotate(180deg); }

.snc-lock-badge { font-size: 12px; margin-left: 4px; opacity: .8; }

/* Accordion body */
.snc-acc-body {
  padding: 16px;
  background: #fff;
  border-top: 1px solid var(--border);
}

/* ══════════════════════════════════════════════════════════════════════
   UNIT CONVERTERS
   ══════════════════════════════════════════════════════════════════════ */
.snc-tool-card {
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
  margin-bottom: 12px;
}
.snc-tool-card:last-child { margin-bottom: 0; }

.snc-tool-title {
  font-weight: 700;
  color: var(--green-d);
  margin-bottom: 10px;
  font-size: 13px;
  letter-spacing: .02em;
}

.snc-conv-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: flex-end;
}
.snc-conv-col { flex: 1 1 100px; min-width: 90px; }
.snc-conv-col label {
  display: block;
  font-size: 11px;
  color: var(--muted);
  margin-bottom: 4px;
  font-weight: 600;
}
.snc-conv-col input[type="number"] {
  width: 100%;
  padding: 7px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 13px;
  background: #fff;
  color: var(--text);
  appearance: textfield;
}
.snc-conv-col input[type="number"]:focus {
  outline: none;
  border-color: var(--green);
  box-shadow: 0 0 0 2px rgba(46,125,50,.15);
}
.snc-conv-eq {
  font-size: 18px;
  color: var(--muted);
  padding-bottom: 8px;
  flex-shrink: 0;
}
.snc-formula-hint {
  margin: 8px 0 0;
  font-size: 11px;
  color: var(--muted);
  font-style: italic;
}

/* ══════════════════════════════════════════════════════════════════════
   STUDY CONTENT GRID (Maths / Physics / Chemistry / Biology)
   ══════════════════════════════════════════════════════════════════════ */
.snc-subject-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 12px;
}

.snc-formula-block {
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
}
.snc-formula-block h4 {
  margin: 0 0 8px;
  font-size: 13px;
  font-weight: 700;
  color: var(--green-d);
  border-bottom: 1px solid var(--border);
  padding-bottom: 6px;
}
.snc-formula-block ul {
  margin: 0;
  padding: 0 0 0 16px;
  list-style: disc;
}
.snc-formula-block li {
  font-size: 12.5px;
  line-height: 1.55;
  margin-bottom: 4px;
  color: #333;
}
.snc-formula-block li strong { color: var(--green-d); }

/* ══════════════════════════════════════════════════════════════════════
   PASSWORD GATE
   ══════════════════════════════════════════════════════════════════════ */
#snc-gate {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 24px 12px;
}
#snc-gate-inner {
  background: var(--blue-l);
  border: 1px solid #90caf9;
  border-radius: 10px;
  padding: 22px 24px;
  max-width: 420px;
  width: 100%;
  text-align: center;
}
#snc-gate-icon { font-size: 36px; margin-bottom: 6px; }
#snc-gate-title { font-weight: 700; font-size: 15px; margin: 0 0 4px; color: var(--blue); }
#snc-gate-hint { font-size: 12px; color: var(--muted); margin: 0 0 14px; min-height: 18px; }

#snc-gate-pw-row {
  display: flex;
  gap: 8px;
  margin-bottom: 8px;
}
#snc-gate-pw {
  flex: 1;
  padding: 9px 12px;
  border: 1px solid #90caf9;
  border-radius: 6px;
  font-size: 14px;
}
#snc-gate-pw:focus { outline: none; border-color: var(--blue); }
#snc-gate-btn {
  background: var(--blue);
  color: #fff;
  border: none;
  border-radius: 6px;
  padding: 9px 18px;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: background .2s;
}
#snc-gate-btn:hover { background: #0d47a1; }

#snc-gate-err {
  color: var(--red);
  font-size: 12px;
  font-weight: 600;
  margin: 0;
  min-height: 18px;
}

/* ── Convert / Open Notes button (shown when word typed in °F) ── */
#snc-convert-btn-row {
  margin-top: 10px;
  text-align: right;
}
#snc-convert-btn {
  background: var(--blue);
  color: #fff;
  border: none;
  border-radius: 6px;
  padding: 9px 18px;
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  transition: background .2s;
}
#snc-convert-btn:hover { background: #0d47a1; }

/* ── Chat close row (inside chat wrap, above header) ── */
#snc-chat-close-row {
  background: #fff3e0;
  border-bottom: 1px solid #ffe082;
  padding: 6px 12px;
  text-align: right;
  flex-shrink: 0;
}
#snc-chat-close-btn {
  background: transparent;
  border: 1px solid #e65100;
  color: #e65100;
  border-radius: 5px;
  padding: 4px 12px;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  transition: background .18s, color .18s;
}
#snc-chat-close-btn:hover { background: #e65100; color: #fff; }

/* ══════════════════════════════════════════════════════════════════════
   CHAT WIDGET (inside accordion, below gate)
   ══════════════════════════════════════════════════════════════════════ */
#snc-wrap {
  --green:   #2e7d32;
  --green-l: #e8f5e9;
  --amber:   #f57f17;
  --amber-l: #fff8e1;
  --paper:   #fafdf6;
  --border:  #c8e6c9;
  --text:    #1b1b1b;
  --muted:   #757575;
  --accent:  #1565c0;
  --accent-l:#e3f2fd;
  --radius:  6px;
  --shadow:  0 2px 8px rgba(0,0,0,.10);

  display: flex;
  flex-direction: column;
  width: 100%;
  height: 320px;
  background: var(--paper);
  border: 2px solid var(--border);
  border-radius: 10px;
  box-shadow: var(--shadow);
  font-size: 14px;
  color: var(--text);
  overflow: hidden;
  position: relative;
}

#snc-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: var(--green);
  color: #fff;
  flex-shrink: 0;
}
#snc-header-icon { font-size: 22px; }
#snc-header-text strong { display: block; font-size: 15px; }
#snc-header-text small  { font-size: 11px; opacity: .8; }
#snc-clear-btn {
  margin-left: auto;
  background: rgba(255,255,255,.18);
  border: none;
  color: #fff;
  border-radius: 4px;
  padding: 4px 8px;
  cursor: pointer;
  font-size: 13px;
}
#snc-clear-btn:hover { background: rgba(255,255,255,.32); }

#snc-feed {
  flex: 1;
  overflow-y: auto;
  padding: 12px 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  background:
    repeating-linear-gradient(transparent, transparent 27px, #d0e8d0 28px),
    var(--paper);
  background-attachment: local;
}

.snc-date-sep {
  text-align: center;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--green);
  margin: 8px 0 4px;
  position: relative;
}
.snc-date-sep::before, .snc-date-sep::after {
  content: "";
  position: absolute;
  top: 50%;
  width: 28%;
  height: 1px;
  background: var(--border);
}
.snc-date-sep::before { left: 0; }
.snc-date-sep::after  { right: 0; }

.snc-note {
  padding: 8px 12px 6px;
  border-radius: var(--radius);
  max-width: 78%;
  position: relative;
  cursor: pointer;
  line-height: 1.5;
  word-break: break-word;
  box-shadow: 0 1px 3px rgba(0,0,0,.08);
  border-left: 4px solid transparent;
}
.snc-note:hover { filter: brightness(.97); }
.snc-note.alpha { background: var(--green-l); border-left-color: var(--green); align-self: flex-start; }
.snc-note.beta  { background: var(--amber-l); border-left-color: var(--amber); align-self: flex-end; }

.snc-note-speaker {
  font-size: 10px; font-weight: 700; letter-spacing: .05em;
  text-transform: uppercase; display: block; margin-bottom: 3px; color: var(--muted);
}
.snc-note.alpha .snc-note-speaker { color: var(--green); }
.snc-note.beta  .snc-note-speaker { color: var(--amber); }

.snc-note-time { font-size: 10px; color: var(--muted); display: block; text-align: right; margin-top: 4px; }

.snc-reply-ref {
  display: block; background: rgba(0,0,0,.06); border-left: 3px solid var(--accent);
  padding: 4px 8px; font-size: 11px; color: #444; border-radius: 3px;
  margin-bottom: 5px; font-style: italic;
}

.snc-note.highlighted { outline: 2px solid var(--accent); outline-offset: 2px; }

#snc-popup {
  position: absolute; background: #fff; border: 1px solid #ddd;
  border-radius: 6px; box-shadow: 0 4px 14px rgba(0,0,0,.15);
  display: none; z-index: 999; min-width: 130px; overflow: hidden;
}
#snc-popup button {
  display: block; width: 100%; padding: 9px 14px; border: none;
  background: transparent; text-align: left; cursor: pointer; font-size: 13px; color: #333;
}
#snc-popup button:hover { background: #f5f5f5; }

#snc-reply-bar {
  display: flex; align-items: center; gap: 8px; padding: 6px 14px;
  background: var(--accent-l); border-top: 1px solid #c5d9f7; font-size: 12px; flex-shrink: 0;
}
#snc-reply-author { font-weight: 700; color: var(--accent); margin-right: 4px; }
#snc-reply-snippet { color: #555; flex: 1; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
#snc-reply-cancel { background: transparent; border: none; color: #555; cursor: pointer; font-size: 16px; line-height: 1; }

#snc-inputs {
  padding: 10px 14px 12px;
  background: #f1f8f1;
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex-shrink: 0;
}
.snc-input-row { display: flex; align-items: flex-end; gap: 8px; }
.snc-label { font-size: 11px; font-weight: 700; color: var(--muted); min-width: 52px; text-transform: uppercase; letter-spacing: .04em; padding-bottom: 10px; }
.snc-input-row textarea {
  flex: 1; padding: 8px 12px; border: 1px solid var(--border); border-radius: 6px;
  background: #fff; font-size: 13px; resize: none; min-height: 38px;
  max-height: 100px; overflow-y: hidden; font-family: inherit; color: var(--text); line-height: 1.4;
}
.snc-input-row textarea:focus { outline: none; border-color: var(--green); box-shadow: 0 0 0 2px rgba(46,125,50,.15); }
.snc-send-btn { padding: 8px 16px; background: var(--green); color: #fff; border: none; border-radius: 6px; cursor: pointer; font-size: 13px; font-weight: 600; letter-spacing: .03em; white-space: nowrap; }
.snc-send-btn:hover { background: #1b5e20; }

/* ══════════════════════════════════════════════════════════════════════
   MEDIA — Shared Photos & Videos (sits below the chat, same password gate)
   ══════════════════════════════════════════════════════════════════════ */
#snc-media-wrap {
  margin-top: 14px;
  background: var(--paper);
  border: 2px solid var(--border);
  border-radius: 10px;
  box-shadow: var(--shadow);
  overflow: hidden;
}

#snc-media-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: var(--amber);
  color: #fff;
}
#snc-media-header-icon { font-size: 20px; }
#snc-media-header-text strong { display: block; font-size: 14px; }
#snc-media-header-text small  { font-size: 11px; opacity: .85; }

#snc-media-upload-btn {
  margin-left: auto;
  background: rgba(255,255,255,.22);
  border: none;
  color: #fff;
  border-radius: 6px;
  padding: 7px 14px;
  cursor: pointer;
  font-size: 12px;
  font-weight: 700;
  white-space: nowrap;
  transition: background .18s;
  display: inline-flex;
  align-items: center;
}
#snc-media-upload-btn:hover { background: rgba(255,255,255,.36); }

#snc-media-upload-status {
  margin: 0;
  padding: 6px 14px 0;
  font-size: 12px;
  min-height: 18px;
  color: var(--muted);
}
#snc-media-upload-status.snc-media-ok  { color: var(--green); font-weight: 600; }
#snc-media-upload-status.snc-media-err { color: var(--red); font-weight: 600; }

#snc-media-empty {
  padding: 18px 14px;
  text-align: center;
  color: var(--muted);
  font-size: 13px;
  margin: 0;
}

#snc-media-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 10px;
  padding: 12px 14px 14px;
}

.snc-media-item {
  position: relative;
  border-radius: 8px;
  overflow: hidden;
  background: #000;
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
}

.snc-media-thumb {
  width: 100%;
  aspect-ratio: 1 / 1;
  background: #111;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.snc-media-thumb img,
.snc-media-thumb video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.snc-media-actions {
  position: static;
  display: flex;
  gap: 6px;
  padding: 6px;
  background: var(--paper);
  border-top: 1px solid var(--border);
}

.snc-media-btn {
  flex: 1;
  height: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  background: #eef3ee;
  color: var(--text);
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-size: 11px;
  font-weight: 600;
  text-decoration: none;
  line-height: 1;
  transition: background .18s, color .18s;
}
.snc-media-btn:hover { background: var(--blue-l); color: var(--blue); }
.snc-media-delete:hover { background: #fdeaea; color: var(--red); }

.snc-media-time {
  font-size: 10px;
  color: #fff;
  background: rgba(0,0,0,.5);
  padding: 3px 6px;
  text-align: right;
}

/* ══════════════════════════════════════════════════════════════════════
   MOBILE RESPONSIVE
   ══════════════════════════════════════════════════════════════════════ */
@media (max-width: 600px) {
  .snc-acc-head { padding: 11px 12px; font-size: 13px; }
  .snc-acc-body { padding: 12px 10px; }

  .snc-subject-grid { grid-template-columns: 1fr; }

  .snc-conv-row { gap: 8px; }
  .snc-conv-col { flex: 1 1 80px; min-width: 75px; }
  .snc-conv-eq { display: none; }

  #snc-wrap { height: 400px; }

  #snc-gate-inner { padding: 16px 14px; }
  #snc-gate-pw-row { flex-direction: column; }
  #snc-gate-btn { width: 100%; }

  .snc-note { max-width: 90%; }

  .snc-label { min-width: 40px; font-size: 10px; }
  .snc-send-btn { padding: 8px 10px; font-size: 12px; }

  #snc-float-close { bottom: 12px; right: 12px; padding: 8px 16px; font-size: 13px; }

  #snc-media-grid { grid-template-columns: repeat(auto-fill, minmax(105px, 1fr)); gap: 8px; }
  #snc-media-header { padding: 9px 10px; }
  #snc-media-upload-btn { padding: 6px 10px; font-size: 11px; }
}