/* ============================================
   QUESTIONARY — FEATURES CSS
   Matches the main design system in styles.css
   ============================================ */

/* ── QUIZ ── */
.quiz-progress { height: 3px; background: var(--line); border-radius: 2px; overflow: hidden; margin-bottom: 1.5rem; }
.quiz-progress-bar { height: 100%; background: var(--accent); transition: width 0.3s ease; border-radius: 2px; }
.quiz-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1.25rem; font-size: 0.8rem; color: var(--fg2); }
.quiz-score { font-weight: 600; color: var(--fg); }
.quiz-question { text-align: center; padding: 1.5rem; background: var(--surface); border: 1px solid var(--line); border-radius: 10px; margin-bottom: 1rem; }
.quiz-question h3 { font-size: 1rem; color: var(--fg); margin: 0; font-weight: 600; }
.quiz-options { display: grid; gap: 0.5rem; }
.quiz-option {
    display: flex; align-items: center; gap: 0.75rem; padding: 0.7rem 1rem;
    background: var(--surface); border: 1px solid var(--line); border-radius: 8px;
    cursor: pointer; transition: all 0.15s; text-align: left; font-size: 0.85rem;
}
.quiz-option:hover:not(:disabled) { background: var(--hover); border-color: var(--accent); }
.quiz-option.correct { border-color: var(--green); background: rgba(22,163,74,0.06); }
.quiz-option.wrong { border-color: var(--red); background: rgba(220,38,38,0.06); }
.option-letter {
    width: 26px; height: 26px; display: flex; align-items: center; justify-content: center;
    background: var(--hover); border-radius: 6px; font-weight: 600; color: var(--fg2); font-size: 0.78rem;
}
.option-text { flex: 1; color: var(--fg); font-size: 0.85rem; }
.quiz-results { text-align: center; }
.quiz-grade { font-size: 3rem; font-weight: 700; margin: 1.25rem 0; }
.grade-a { color: var(--green); }
.grade-b { color: #84cc16; }
.grade-c { color: var(--yellow); }
.grade-d { color: #f97316; }
.grade-f { color: var(--red); }
.quiz-stats { display: grid; justify-content: center; gap: 0.75rem; margin-bottom: 1.5rem; }
.quiz-stat { background: var(--surface); padding: 0.85rem; border-radius: 8px; border: 1px solid var(--line); }
.stat-value { display: block; font-size: 1.15rem; font-weight: 600; color: var(--fg); }
.stat-label { font-size: 0.75rem; color: var(--fg3); margin-top: 0.3rem; }

/* ── VOICE NOTES ── */
.voice-notes-section { margin-top: 1.5rem; }
.voice-notes-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 0.6rem; margin-top: 0.75rem; }
.voice-record-controls { display: flex; align-items: center; gap: 0.75rem; }
.recording-time { font-size: 0.8rem; color: var(--fg3); font-family: 'JetBrains Mono', monospace; font-weight: 500; }
.voice-note-item {
    display: flex; align-items: center; gap: 0.75rem; padding: 0.75rem 1rem;
    background: var(--surface); border: 1px solid var(--line); border-radius: 8px;
    transition: all 0.15s;
}
.voice-note-item:hover { border-color: var(--accent); box-shadow: var(--shadow-sm); }
.voice-play {
    width: 34px; height: 34px; min-width: 34px; display: flex; align-items: center; justify-content: center;
    background: var(--accent-light); color: var(--accent); border: none; border-radius: 50%;
    cursor: pointer; transition: all 0.15s; font-size: 0.75rem;
}
.voice-play:hover { background: var(--accent); color: #fff; }
.voice-info { flex: 1; display: flex; flex-direction: column; min-width: 0; }
.voice-title { font-weight: 500; color: var(--fg); font-size: 0.82rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.voice-date { font-size: 0.72rem; color: var(--fg3); margin-top: 2px; }
.voice-delete {
    background: none; border: none; color: var(--fg3); cursor: pointer; padding: 4px;
    font-size: 0.7rem; border-radius: 4px; transition: all 0.1s;
}
.voice-delete:hover { color: var(--red); background: rgba(220,38,38,0.06); }
.voice-notes-list { display: flex; flex-direction: column; gap: 0.4rem; }

/* ── TAGS (settings list) ── */
.tag-item {
    display: flex; align-items: center; gap: 0.6rem;
    padding: 0.55rem 0.75rem; background: var(--surface); border: 1px solid var(--line);
    border-radius: 8px; margin-bottom: 0.35rem; transition: all 0.15s;
}
.tag-item:hover { border-color: var(--fg3); }
.tag-color { width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0; }
.tag-name { flex: 1; font-weight: 500; color: var(--fg); font-size: 0.82rem; }
.tag-count { font-size: 0.72rem; color: var(--fg3); padding: 0.15rem 0.4rem; background: var(--hover); border-radius: 4px; }
.tag-delete { background: none; border: none; color: var(--fg3); cursor: pointer; padding: 4px; font-size: 0.7rem; }
.tag-delete:hover { color: var(--red); }

/* ── REMINDERS ── */
.reminder-item {
    display: flex; align-items: center; gap: 0.75rem;
    padding: 0.75rem 1rem; background: var(--surface); border: 1px solid var(--line);
    border-radius: 8px; transition: all 0.15s; margin-bottom: 0.4rem;
}
.reminder-item:hover { border-color: var(--fg3); }
.reminder-item.disabled { opacity: 0.45; }
.reminder-toggle { flex-shrink: 0; }
/* Toggle used by reminders (.switch/.slider) */
.switch { position: relative; display: inline-block; width: 36px; height: 20px; }
.switch input { opacity: 0; width: 0; height: 0; }
.switch .slider {
    position: absolute; cursor: pointer; inset: 0;
    background: var(--line); border-radius: 10px; transition: 0.15s;
}
.switch .slider:before {
    position: absolute; content: ""; height: 14px; width: 14px;
    left: 3px; bottom: 3px; background: white; border-radius: 50%; transition: 0.15s;
}
.switch input:checked + .slider { background: var(--accent); }
.switch input:checked + .slider:before { transform: translateX(16px); }
.reminder-info { flex: 1; display: flex; align-items: center; gap: 0.5rem; flex-wrap: wrap; min-width: 0; }
.reminder-title { font-weight: 600; color: var(--fg); font-size: 0.85rem; }
.reminder-time { font-size: 0.78rem; color: var(--accent); font-weight: 500; font-family: 'JetBrains Mono', monospace; }
.reminder-days { font-size: 0.72rem; color: var(--fg3); }
.reminder-actions { display: flex; gap: 0.3rem; flex-shrink: 0; }
.reminder-tag-btn, .reminder-delete {
    background: none; border: none; color: var(--fg3); cursor: pointer;
    width: 28px; height: 28px; display: flex; align-items: center; justify-content: center;
    border-radius: 6px; transition: all 0.1s; font-size: 0.75rem;
}
.reminder-tag-btn:hover { color: var(--accent); background: var(--accent-light); }
.reminder-delete:hover { color: var(--red); background: rgba(220,38,38,0.06); }

/* ── ALARM NOTIFICATION (Toast) ── */
.alarm-notification {
    position: fixed; bottom: 1.25rem; left: 1.25rem;
    z-index: 10000; animation: alarmSlideIn 0.3s ease;
}
.alarm-notification-content {
    display: flex; align-items: center; gap: 0.75rem;
    padding: 0.85rem 1.25rem; background: var(--surface);
    border: 1px solid var(--line); border-radius: 12px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.18);
    min-width: 280px;
}
[data-theme="dark"] .alarm-notification-content { box-shadow: 0 8px 32px rgba(0,0,0,0.5); }
.alarm-bell-icon {
    font-size: 1.1rem; color: var(--accent);
    width: 36px; height: 36px; display: flex; align-items: center; justify-content: center;
    background: var(--accent-light); border-radius: 50%; flex-shrink: 0;
}
.alarm-bell-icon.ringing { animation: bellRing 0.5s ease infinite; }
.alarm-notification-text { flex: 1; font-weight: 600; font-size: 0.85rem; color: var(--fg); }
.alarm-dismiss-btn {
    background: var(--hover); border: 1px solid var(--line); color: var(--fg);
    padding: 0.4rem 0.85rem; border-radius: 6px; cursor: pointer;
    font-size: 0.78rem; font-weight: 500; transition: all 0.15s;
    display: flex; align-items: center; gap: 0.35rem; white-space: nowrap;
}
.alarm-dismiss-btn:hover { background: var(--accent); color: #fff; border-color: var(--accent); }
@keyframes alarmSlideIn { from { transform: translateY(20px); opacity: 0; } to { transform: translateY(0); opacity: 1; } }
@keyframes bellRing {
    0% { transform: rotate(0); } 25% { transform: rotate(15deg); }
    50% { transform: rotate(-15deg); } 75% { transform: rotate(8deg); } 100% { transform: rotate(0); }
}

/* ── PDF LIBRARY ── */
.library-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); gap: 0.75rem; }
.library-item {
    padding: 0.85rem 0.6rem; display: flex; flex-direction: column; align-items: center; gap: 0.35rem;
    cursor: pointer; transition: all 0.15s; position: relative; min-height: 90px;
    background: var(--surface); border: 1px solid var(--line); border-radius: 10px;
    overflow: hidden;
}
.library-item:hover { border-color: var(--accent); box-shadow: 0 2px 12px rgba(99,102,241,0.12); transform: translateY(-2px); }
.library-item-icon { font-size: 1.5rem; color: var(--fg2); margin-top: 0.2rem; }
.library-folder .library-item-icon { color: #3b82f6; }
.library-pdf .library-item-icon { color: #ef4444; }
.library-item-name {
    font-weight: 500; color: var(--fg); text-align: center; font-size: 0.78rem;
    line-height: 1.3; max-width: 100%; overflow: hidden; text-overflow: ellipsis;
    display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical;
}
.library-item-meta { font-size: 0.68rem; color: var(--fg3); }
.library-item-date { font-size: 0.68rem; color: var(--fg3); }
.library-item-actions {
    display: flex; gap: 0.25rem; margin-top: 0.25rem;
    padding-top: 0.35rem; border-top: 1px solid var(--line); width: 100%;
    justify-content: center;
}
.lib-action-btn {
    background: none; border: none; color: var(--fg3); cursor: pointer;
    padding: 0.25rem 0.35rem; border-radius: 4px; font-size: 0.72rem;
    transition: all 0.15s; line-height: 1;
}
.lib-action-btn:hover { background: var(--hover); color: var(--fg); }
.lib-action-btn.danger:hover { background: rgba(239,68,68,0.1); color: #ef4444; }

/* Library Drop Zone */
.library-drop-zone {
    border: 2px dashed var(--line); border-radius: 10px; padding: 1.25rem;
    text-align: center; color: var(--fg3); transition: all 0.2s;
    cursor: pointer; font-size: 0.82rem;
}
.library-drop-zone:hover,
.library-drop-zone.drag-over {
    border-color: var(--accent); background: rgba(99,102,241,0.04);
    color: var(--accent);
}
.library-drop-zone i { font-size: 1.4rem; display: block; margin-bottom: 0.4rem; opacity: 0.6; }
.library-drop-zone p { margin: 0; font-size: 0.78rem; }

/* Library Breadcrumb */
.library-breadcrumb {
    display: flex; align-items: center; gap: 0.25rem; flex-wrap: wrap;
    margin-bottom: 0.75rem; font-size: 0.78rem;
}
.library-breadcrumb .breadcrumb-item {
    background: var(--surface); border: 1px solid var(--line); border-radius: 6px;
    padding: 0.25rem 0.6rem; cursor: pointer; color: var(--fg2);
    font-size: 0.75rem; transition: all 0.15s; white-space: nowrap;
}
.library-breadcrumb .breadcrumb-item:hover { border-color: var(--accent); color: var(--accent); }
.library-breadcrumb .breadcrumb-item.active { color: var(--fg); font-weight: 500; }
.library-breadcrumb .breadcrumb-separator { color: var(--fg3); font-size: 0.6rem; }

/* Library Empty State */
.library-empty-state {
    display: flex; flex-direction: column; align-items: center;
    text-align: center; padding: 2rem; color: var(--fg3); font-size: 0.8rem;
}
.library-empty-state i { font-size: 2rem; display: block; margin-bottom: 0.5rem; opacity: 0.3; }

/* Library Drag States */
.library-folder.drag-over { border-color: var(--accent); background: rgba(99,102,241,0.06); }

/* ── CHARTS ── */
.chart-bars { display: flex; align-items: flex-end; justify-content: space-around; height: 150px; gap: 0.75rem; padding: 1rem; }
.bar-container { flex: 1; display: flex; flex-direction: column; align-items: center; height: 100%; }
.bar-fill { width: 100%; background: var(--accent); border-radius: 4px 4px 0 0; transition: height 0.3s ease; margin-top: auto; }
.bar-label { font-size: 0.65rem; color: var(--fg3); margin-top: 0.35rem; }

/* ── FORM EXTRAS ── */
.form-group.checkbox-group { display: flex; align-items: center; margin: 1.25rem 0; }
.checkbox-label { display: flex; align-items: center; gap: 0.5rem; cursor: pointer; font-size: 0.82rem; color: var(--fg2); }
.checkbox-label input[type="checkbox"] { accent-color: var(--accent); width: 15px; height: 15px; }
.error-message {
    background: rgba(220,38,38,0.06); color: var(--red); padding: 0.75rem 1rem;
    border-radius: 8px; margin-top: 0.75rem; display: none;
    border-left: 3px solid var(--red); font-size: 0.82rem;
}

/* ============================================================
   STUDY ROOM — Live Collaborative Sessions (Experimental)
   ============================================================ */

/* --- Lobby --- */
.sr-lobby { max-width: 720px; margin: 0 auto; padding: 1.5rem 0; }
.sr-lobby-header { text-align: center; margin-bottom: 2rem; }
.sr-lobby-icon { font-size: 2.5rem; color: var(--accent); margin-bottom: 0.75rem; }
.sr-lobby-subtitle { color: var(--fg3); font-size: 0.9rem; margin-top: 0.5rem; max-width: 500px; margin-inline: auto; }
.sr-exp-badge {
    display: inline-block; font-size: 0.62rem; font-weight: 600; text-transform: lowercase;
    letter-spacing: 0.04em; color: var(--fg3); background: var(--hover);
    border: 1px solid var(--line); padding: 2px 8px; border-radius: 8px;
    margin-top: 0.25rem;
}

.sr-lobby-cards { display: grid; grid-template-columns: 1fr; gap: 1rem; margin-bottom: 2rem; }
@media (min-width: 540px) { .sr-lobby-cards { grid-template-columns: 1fr 1fr; } }
.sr-lobby-card {
    background: var(--card); border: 1px solid var(--line); border-radius: 14px;
    padding: 1.25rem; transition: box-shadow 0.2s, border-color 0.2s;
    display: flex; flex-direction: column;
}
.sr-lobby-card:hover { border-color: var(--accent); box-shadow: 0 4px 20px rgba(99,102,241,0.1); }
.sr-lobby-card:first-child { grid-column: 1 / -1; }
.sr-lobby-card h3 { font-size: 0.95rem; font-weight: 600; margin: 0 0 0.75rem; color: var(--fg); }
.sr-lobby-card h3 i { color: var(--accent); margin-right: 6px; }
.sr-lobby-card p { font-size: 0.82rem; color: var(--fg3); margin: 0 0 0.75rem; }

.sr-input {
    width: 100%; padding: 0.6rem 0.8rem; font-size: 0.85rem; border: 1px solid var(--line);
    border-radius: 10px; background: var(--bg); color: var(--fg); font-family: inherit;
    outline: none; transition: border-color 0.15s, box-shadow 0.15s; box-sizing: border-box;
}
.sr-input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(99,102,241,0.12); }
.sr-code-input { font-family: 'JetBrains Mono', monospace; font-size: 1.1rem; letter-spacing: 0.25em; text-align: center; text-transform: uppercase; max-width: 170px; }

.sr-join-row { display: flex; gap: 0.5rem; align-items: center; }

.sr-pw-row {
    display: flex; align-items: center; gap: 0; margin-top: 0.5rem;
    border: 1px solid var(--line); border-radius: 10px; overflow: hidden;
    background: var(--bg); transition: border-color 0.15s, box-shadow 0.15s;
}
.sr-pw-row:focus-within { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(99,102,241,0.12); }
.sr-pw-row .sr-input { border: none; border-radius: 0; box-shadow: none; }
.sr-pw-row .sr-input:focus { box-shadow: none; }
.sr-pw-toggle {
    display: flex; align-items: center; justify-content: center;
    width: 36px; min-width: 36px; height: 100%; padding: 0;
    background: transparent; border: none; border-left: 1px solid var(--line);
    color: var(--fg3); cursor: pointer; font-size: 0.82rem; transition: color 0.15s;
}
.sr-pw-toggle:hover { color: var(--accent); }

.sr-card-create .sr-btn,
.sr-card-join .sr-btn { margin-top: auto; }
.sr-card-create .sr-btn { width: 100%; justify-content: center; margin-top: 0.75rem; }

.sr-btn {
    display: inline-flex; align-items: center; gap: 6px; padding: 0.55rem 1.1rem;
    font-size: 0.82rem; font-weight: 600; border-radius: 10px; border: none; cursor: pointer;
    font-family: inherit; transition: all 0.15s; white-space: nowrap;
}
.sr-btn-primary { background: var(--accent); color: #fff; box-shadow: 0 2px 8px rgba(99,102,241,0.25); }
.sr-btn-primary:hover { filter: brightness(1.1); transform: translateY(-1px); box-shadow: 0 4px 16px rgba(99,102,241,0.35); }
.sr-btn-accent { background: #10b981; color: #fff; box-shadow: 0 2px 8px rgba(16,185,129,0.25); }
.sr-btn-accent:hover { filter: brightness(1.1); transform: translateY(-1px); }
.sr-btn-sm { font-size: 0.78rem; padding: 0.4rem 0.9rem; }
.sr-btn-icon { padding: 0.55rem; min-width: unset; }

/* --- Features grid in lobby --- */
.sr-features-grid {
    display: flex; flex-wrap: wrap; justify-content: center; gap: 0.75rem;
    max-width: max-content; margin: 0 auto;
}
@media (min-width: 540px) { .sr-features-grid { display: flex; flex-wrap: nowrap; justify-content: center; } }
.sr-feature-item {
    display: flex; flex-direction: column; align-items: center; gap: 6px;
    padding: 0.75rem 0.5rem; background: var(--card); border: 1px solid var(--line);
    border-radius: 12px; font-size: 0.72rem; color: var(--fg3); text-align: center;
}
.sr-feature-item i { font-size: 1.2rem; color: var(--accent); }

/* === Active Session === */
.sr-session { display: flex; flex-direction: column; height: calc(100vh - 140px); min-height: 400px; }

.sr-session-bar {
    display: flex; justify-content: space-between; align-items: center;
    padding: 0.6rem 1rem; background: var(--card); border: 1px solid var(--line);
    border-radius: 14px; margin-bottom: 0.75rem; flex-shrink: 0;
}
.sr-session-bar-left { display: flex; align-items: center; gap: 1rem; }
.sr-session-bar-right { display: flex; align-items: center; gap: 0.4rem; }

.sr-room-code-badge {
    font-family: 'JetBrains Mono', monospace; font-size: 0.85rem; font-weight: 600;
    background: var(--hover); color: var(--accent); padding: 4px 12px;
    border-radius: 8px; cursor: pointer; transition: background 0.15s; letter-spacing: 0.08em;
}
.sr-room-code-badge:hover { background: var(--accent); color: #fff; }

.sr-pw-badge {
    font-size: 0.8rem; font-weight: 500;
    background: rgba(34, 197, 94, 0.12); color: #22c55e; padding: 4px 10px;
    border-radius: 8px; display: inline-flex; align-items: center; gap: 5px;
    letter-spacing: 0.02em;
}
.sr-pw-badge.sr-pw-open {
    background: rgba(250, 204, 21, 0.1); color: #facc15;
}
.sr-pw-hidden {
    font-family: 'JetBrains Mono', monospace; letter-spacing: 0.15em;
    user-select: none;
}

/* --- Internet Mode Toggle --- */
.sr-toggle-row {
    display: flex; align-items: center; gap: 10px; cursor: pointer;
    margin: 0.5rem 0 0.25rem; user-select: none;
}
.sr-toggle-check { display: none; }
.sr-toggle-slider {
    position: relative; width: 38px; height: 20px; border-radius: 12px;
    background: var(--line); transition: background 0.2s; flex-shrink: 0;
}
.sr-toggle-slider::after {
    content: ''; position: absolute; top: 2px; left: 2px;
    width: 16px; height: 16px; border-radius: 50%;
    background: var(--fg3); transition: transform 0.2s, background 0.2s;
}
.sr-toggle-check:checked + .sr-toggle-slider { background: var(--accent); }
.sr-toggle-check:checked + .sr-toggle-slider::after { transform: translateX(18px); background: #fff; }
.sr-toggle-label {
    font-size: 0.82rem; font-weight: 600; color: var(--fg2);
}
.sr-toggle-label i { color: var(--accent); margin-right: 4px; }

.sr-relay-row {
    margin: 0.4rem 0 0; padding: 0;
}
.sr-relay-hint {
    display: block; font-size: 0.72rem; color: var(--fg3); margin-top: 4px;
}
.sr-relay-hint code {
    font-family: 'JetBrains Mono', monospace; font-size: 0.7rem;
    background: var(--hover); padding: 1px 4px; border-radius: 3px;
}

.sr-join-hint {
    display: block; font-size: 0.72rem; color: var(--fg3); margin-top: 6px;
}
.sr-join-hint code {
    font-family: 'JetBrains Mono', monospace; font-size: 0.7rem;
    background: var(--hover); padding: 1px 4px; border-radius: 3px;
}

/* --- Mode badge in session bar --- */
.sr-mode-badge {
    font-size: 0.72rem; font-weight: 600; padding: 3px 9px; border-radius: 6px;
    display: inline-flex; align-items: center; gap: 4px;
    text-transform: uppercase; letter-spacing: 0.06em;
}
.sr-mode-lan { background: rgba(99, 102, 241, 0.12); color: var(--accent); }
.sr-mode-inet { background: rgba(16, 185, 129, 0.12); color: #10b981; }

.sr-session-timer {
    font-family: 'JetBrains Mono', monospace; font-size: 0.95rem; font-weight: 600; color: var(--fg);
}

/* --- Controls --- */
.sr-ctrl-btn {
    width: 38px; height: 38px; border-radius: 50%; border: 1px solid var(--line);
    background: var(--card); color: var(--fg2); display: flex; align-items: center;
    justify-content: center; cursor: pointer; transition: all 0.15s; font-size: 0.9rem;
}
.sr-ctrl-btn:hover { background: var(--hover); border-color: var(--fg3); }
.sr-ctrl-off { background: #ef4444; border-color: #ef4444; color: #fff; }
.sr-ctrl-off:hover { background: #dc2626; border-color: #dc2626; }
.sr-ctrl-active { background: var(--accent); border-color: var(--accent); color: #fff; }
.sr-ctrl-active:hover { filter: brightness(1.1); }
.sr-ctrl-danger { background: #ef4444; border-color: #ef4444; color: #fff; }
.sr-ctrl-danger:hover { background: #dc2626; }

/* --- Session body layout --- */
.sr-session-body { display: flex; gap: 0.75rem; flex: 1; min-height: 0; }

/* --- Video area --- */
.sr-video-area { flex: 1; min-width: 0; }
.sr-video-grid {
    display: grid; gap: 0.5rem; height: 100%; border-radius: 14px; overflow: hidden;
}
.sr-grid-1 { grid-template-columns: 1fr; }
.sr-grid-2 { grid-template-columns: 1fr 1fr; }
.sr-grid-3 { grid-template-columns: 1fr 1fr; grid-template-rows: 1fr 1fr; }
.sr-grid-4plus { grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); }

.sr-video-tile {
    position: relative; background: #1a1a2e; border-radius: 12px; overflow: hidden;
    min-height: 180px;
}
.sr-video-tile video {
    width: 100%; height: 100%; object-fit: cover; display: block;
}
.sr-video-label {
    position: absolute; bottom: 8px; left: 8px;
    background: rgba(0,0,0,0.6); color: #fff; font-size: 0.72rem; font-weight: 600;
    padding: 3px 10px; border-radius: 6px; -webkit-backdrop-filter: blur(4px); backdrop-filter: blur(4px);
}
.sr-video-off {
    position: absolute; inset: 0; display: flex; align-items: center; justify-content: center;
    background: #1a1a2e; color: #64748b; font-size: 3rem;
}

/* --- Sidebar (chat / participants / progress) --- */
.sr-sidebar {
    width: 300px; min-width: 260px; background: var(--card); border: 1px solid var(--line);
    border-radius: 14px; display: flex; flex-direction: column; overflow: hidden;
}

.sr-sidebar-tabs {
    display: flex; border-bottom: 1px solid var(--line); flex-shrink: 0;
}
.sr-tab-btn {
    flex: 1; padding: 0.6rem 0.25rem; font-size: 0.72rem; font-weight: 600;
    background: transparent; border: none; color: var(--fg3); cursor: pointer;
    border-bottom: 2px solid transparent; transition: all 0.15s; font-family: inherit;
}
.sr-tab-btn:hover { color: var(--fg2); background: var(--hover); }
.sr-tab-btn.active { color: var(--accent); border-bottom-color: var(--accent); }
.sr-tab-btn .sr-count {
    display: inline-block; background: var(--accent); color: #fff; font-size: 0.6rem;
    width: 18px; height: 18px; line-height: 18px; text-align: center; border-radius: 50%;
    margin-left: 4px; font-weight: 700;
}

.sr-tab-panel { display: none; flex: 1; flex-direction: column; overflow: hidden; }
.sr-tab-panel.active { display: flex; }

/* --- Chat --- */
.sr-chat-messages { flex: 1; overflow-y: auto; padding: 0.75rem; display: flex; flex-direction: column; gap: 0.4rem; }
.sr-chat-empty { display: flex; flex-direction: column; align-items: center; justify-content: center; height: 100%; color: var(--fg3); opacity: 0.5; }
.sr-chat-empty i { font-size: 2rem; margin-bottom: 0.5rem; }

.sr-chat-msg { max-width: 85%; padding: 0.45rem 0.7rem; border-radius: 12px; font-size: 0.8rem; word-break: break-word; }
.sr-chat-me { background: var(--accent); color: #fff; align-self: flex-end; border-bottom-right-radius: 4px; }
.sr-chat-other { background: var(--hover); color: var(--fg); align-self: flex-start; border-bottom-left-radius: 4px; }
.sr-chat-system { align-self: center; background: transparent; color: var(--fg3); font-size: 0.72rem; font-style: italic; }
.sr-chat-sender { display: block; font-size: 0.68rem; font-weight: 700; margin-bottom: 2px; opacity: 0.85; }
.sr-chat-me .sr-chat-sender { display: none; }
.sr-chat-time { display: block; font-size: 0.6rem; opacity: 0.6; text-align: right; margin-top: 2px; }

.sr-chat-input-row { display: flex; gap: 0.4rem; padding: 0.6rem; border-top: 1px solid var(--line); flex-shrink: 0; }
.sr-chat-input-row .sr-input { flex: 1; margin: 0; }

/* --- Participants list --- */
.sr-participant-item {
    display: flex; align-items: center; gap: 0.75rem; padding: 0.65rem 0.85rem;
    border-bottom: 1px solid var(--line);
}
.sr-participant-avatar {
    width: 36px; height: 36px; border-radius: 50%; background: var(--hover);
    display: flex; align-items: center; justify-content: center; color: var(--accent); font-size: 0.9rem;
    flex-shrink: 0;
}
.sr-participant-info { display: flex; flex-direction: column; }
.sr-participant-name { font-size: 0.82rem; font-weight: 600; color: var(--fg); }
.sr-participant-status { font-size: 0.7rem; color: var(--fg3); }
.sr-status-on { color: #10b981; font-size: 0.5rem; margin-right: 4px; }
.sr-host-icon { color: #f59e0b; margin-left: 4px; font-size: 0.72rem; }

/* --- Progress panel --- */
.sr-progress-self { padding: 0.85rem; border-bottom: 1px solid var(--line); }
.sr-progress-self h4 { font-size: 0.8rem; font-weight: 600; color: var(--fg2); margin: 0 0 0.5rem; }
.sr-progress-self .sr-input { margin-bottom: 0.5rem; }
.sr-progress-list { flex: 1; overflow-y: auto; padding: 0.5rem; }
.sr-progress-item {
    padding: 0.65rem; background: var(--hover); border-radius: 10px; margin-bottom: 0.5rem;
}
.sr-progress-user { font-size: 0.8rem; font-weight: 600; color: var(--fg); margin-bottom: 0.25rem; }
.sr-progress-user i { color: var(--accent); margin-right: 4px; }
.sr-progress-goal { font-size: 0.78rem; color: var(--fg3); margin-bottom: 0.2rem; }
.sr-progress-time { font-size: 0.75rem; color: var(--accent); font-weight: 600; font-family: 'JetBrains Mono', monospace; }

/* --- Loading overlay --- */
.sr-loading-overlay {
    position: fixed; inset: 0; background: rgba(0,0,0,0.5); z-index: 10000;
    display: flex; align-items: center; justify-content: center; -webkit-backdrop-filter: blur(4px); backdrop-filter: blur(4px);
}
.sr-loading-box {
    background: var(--card); padding: 2rem 3rem; border-radius: 16px; text-align: center;
    box-shadow: 0 8px 32px rgba(0,0,0,0.3);
}
.sr-loading-box p { margin: 1rem 0 0; color: var(--fg2); font-size: 0.9rem; }
.sr-spinner {
    width: 40px; height: 40px; border: 3px solid var(--line); border-top-color: var(--accent);
    border-radius: 50%; animation: sr-spin 0.8s linear infinite; margin: 0 auto;
}
@keyframes sr-spin { to { transform: rotate(360deg); } }

/* --- Responsive --- */
@media (max-width: 768px) {
    .sr-session-body { flex-direction: column; }
    .sr-sidebar { width: 100%; min-width: unset; max-height: 280px; }
    .sr-session { height: auto; min-height: unset; }
    .sr-video-tile { min-height: 140px; }
    .sr-session-bar { flex-direction: column; gap: 0.5rem; }
    .sr-session-bar-left, .sr-session-bar-right { justify-content: center; }
    .sr-wb-body { flex-direction: column; }
    .sr-wb-canvas-wrap { min-height: 250px; }
    .sr-wb-questions { max-height: 220px; border-left: none; border-top: 1px solid var(--line); }
    .sr-lobby { padding: 1rem 0; }
    .sr-lobby-header { margin-bottom: 1.25rem; }
    .sr-lobby-icon { font-size: 2rem; }
    .sr-lobby-subtitle { font-size: 0.82rem; }
}
@media (max-width: 500px) {
    .sr-lobby-cards { gap: 0.75rem; }
    .sr-lobby-card { padding: 1rem; }
    .sr-features-grid { justify-content: center; gap: 0.5rem; }
    .sr-feature-item { padding: 0.55rem 0.35rem; font-size: 0.65rem; }
    .sr-feature-item i { font-size: 1rem; }
    .sr-join-row { flex-direction: column; }
    .sr-code-input { max-width: 100%; }
}

/* ============================================================
   WHITEBOARD — drawing canvas + question workspace
   ============================================================ */
.sr-wb-panel {
    flex: 1; display: flex; flex-direction: column; min-height: 0;
    background: var(--card); border: 1px solid var(--line); border-radius: 14px; overflow: hidden;
}

/* --- Toolbar --- */
.sr-wb-toolbar {
    display: flex; justify-content: space-between; align-items: center;
    padding: 0.5rem 0.75rem; border-bottom: 1px solid var(--line); flex-shrink: 0;
    gap: 0.5rem; flex-wrap: wrap;
}
.sr-wb-tools { display: flex; align-items: center; gap: 0.35rem; flex-wrap: wrap; }
.sr-wb-actions { display: flex; align-items: center; gap: 0.4rem; }

.sr-wb-tool-btn {
    width: 34px; height: 34px; border-radius: 8px; border: 1px solid var(--line);
    background: var(--bg); color: var(--fg2); display: flex; align-items: center;
    justify-content: center; cursor: pointer; transition: all 0.15s; font-size: 0.82rem;
}
.sr-wb-tool-btn:hover { background: var(--hover); border-color: var(--fg3); }
.sr-wb-tool-btn.active { background: var(--accent); border-color: var(--accent); color: #fff; }

.sr-wb-color-pick {
    width: 34px; height: 34px; border: 1px solid var(--line); border-radius: 8px;
    background: var(--bg); cursor: pointer; padding: 2px;
}
.sr-wb-color-pick::-webkit-color-swatch-wrapper { padding: 2px; }
.sr-wb-color-pick::-webkit-color-swatch { border-radius: 4px; border: none; }

.sr-wb-sep {
    width: 1px; height: 22px; background: var(--line); margin: 0 2px; flex-shrink: 0;
}

.sr-wb-range-group {
    display: flex; align-items: center; gap: 0.35rem; font-size: 0.72rem;
    color: var(--fg2); white-space: nowrap;
}
.sr-wb-range-group label { font-weight: 600; font-size: 0.7rem; }
.sr-wb-range-group span { min-width: 18px; text-align: center; font-family: 'JetBrains Mono', monospace; font-size: 0.7rem; }

.sr-wb-range {
    -webkit-appearance: none; appearance: none;
    width: 70px; height: 6px; border-radius: 3px;
    background: var(--line); outline: none; cursor: pointer;
}
.sr-wb-range::-webkit-slider-thumb {
    -webkit-appearance: none; appearance: none;
    width: 14px; height: 14px; border-radius: 50%;
    background: var(--accent); border: 2px solid var(--bg);
    box-shadow: 0 1px 3px rgba(0,0,0,0.2); cursor: pointer;
}
.sr-wb-range::-moz-range-thumb {
    width: 14px; height: 14px; border-radius: 50%;
    background: var(--accent); border: 2px solid var(--bg);
    box-shadow: 0 1px 3px rgba(0,0,0,0.2); cursor: pointer;
}

.sr-wb-size-select {
    height: 34px; padding: 0 0.5rem; font-size: 0.78rem; font-family: inherit;
    border: 1px solid var(--line); border-radius: 8px; background: var(--bg);
    color: var(--fg); cursor: pointer; outline: none;
}
.sr-wb-size-select:focus { border-color: var(--accent); }

/* --- Body: canvas + questions side by side --- */
.sr-wb-body { display: flex; flex: 1; min-height: 0; }

.sr-wb-canvas-wrap {
    flex: 1; min-width: 0; position: relative; background: #1e1e2e;
    overflow: hidden; cursor: crosshair; /* clip the oversized canvas */
}
.sr-wb-canvas-wrap canvas {
    position: absolute; top: 0; left: 0;
    display: block; touch-action: none;
    image-rendering: auto;
}
#srWbOverlay {
    pointer-events: none; /* overlay is transparent to clicks */
}

/* --- Zoom controls in toolbar --- */
.sr-wb-zoom-group {
    display: flex; align-items: center; gap: 0.2rem;
}
.sr-wb-zoom-label {
    font-size: 0.72rem; font-weight: 700; font-family: 'JetBrains Mono', monospace;
    color: var(--fg2); min-width: 40px; text-align: center; -webkit-user-select: none; user-select: none;
}

/* --- Fullscreen overrides --- */
.sr-wb-panel:fullscreen {
    border-radius: 0; border: none;
    background: var(--card);
}
.sr-wb-panel:fullscreen .sr-wb-canvas-wrap {
    background: #1e1e2e;
}

/* --- Image Viewer --- */
.image-viewer-body {
    flex: 1; display: flex; align-items: center; justify-content: center;
    overflow: auto; background: var(--bg); padding: 1rem;
    min-height: 0;
}
.image-viewer-body img {
    max-width: 100%; max-height: 100%; object-fit: contain;
    border-radius: 10px; box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}
#imageViewerContainer {
    display: flex; flex-direction: column; height: 100%;
}

/* --- Questions sidebar --- */
.sr-wb-questions {
    width: 280px; min-width: 220px; display: flex; flex-direction: column;
    border-left: 1px solid var(--line); overflow: hidden; background: var(--card);
}
.sr-wb-q-header {
    display: flex; align-items: center; justify-content: space-between;
    padding: 0.6rem 0.75rem; border-bottom: 1px solid var(--line); flex-shrink: 0;
}
.sr-wb-q-header h4 { margin: 0; font-size: 0.82rem; font-weight: 600; color: var(--fg); }
.sr-wb-q-header h4 i { color: var(--accent); margin-right: 6px; }

.sr-wb-q-list {
    flex: 1; overflow-y: auto; padding: 0.5rem;
    display: flex; flex-direction: column; gap: 0.6rem;
}
.sr-wb-q-empty {
    display: flex; flex-direction: column; align-items: center; justify-content: center;
    height: 100%; color: var(--fg3); opacity: 0.5; text-align: center; padding: 1rem;
}
.sr-wb-q-empty i { font-size: 1.8rem; margin-bottom: 0.5rem; }
.sr-wb-q-empty p { font-size: 0.78rem; }

.sr-wb-q-item {
    background: var(--hover); border-radius: 10px; padding: 0.6rem;
    border: 1px solid var(--line); transition: border-color 0.15s;
}
.sr-wb-q-item:focus-within { border-color: var(--accent); }

.sr-wb-q-num {
    display: flex; align-items: center; justify-content: space-between;
    font-size: 0.72rem; font-weight: 700; color: var(--accent);
    margin-bottom: 0.4rem; text-transform: uppercase; letter-spacing: 0.04em;
}
.sr-wb-q-del {
    width: 22px; height: 22px; border-radius: 6px; border: none;
    background: transparent; color: var(--fg3); cursor: pointer; display: flex;
    align-items: center; justify-content: center; font-size: 0.7rem;
    transition: all 0.15s;
}
.sr-wb-q-del:hover { background: #ef4444; color: #fff; }

.sr-wb-q-textarea {
    width: 100%; border: 1px solid var(--line); border-radius: 8px;
    background: var(--bg); color: var(--fg); font-family: inherit;
    font-size: 0.8rem; padding: 0.45rem 0.6rem; resize: vertical;
    outline: none; transition: border-color 0.15s; box-sizing: border-box;
    margin-bottom: 0.35rem;
}
.sr-wb-q-textarea:focus { border-color: var(--accent); box-shadow: 0 0 0 2px rgba(99,102,241,0.1); }
.sr-wb-q-answer { background: var(--card); border-style: dashed; }

/* =============================================
   Keyboard Shortcuts Settings
   ============================================= */
.kb-list { display: flex; flex-direction: column; gap: 1rem; }

.kb-category { display: flex; flex-direction: column; gap: 0.35rem; }
.kb-cat-label {
    font-size: 0.72rem; font-weight: 700; text-transform: uppercase;
    letter-spacing: 0.06em; color: var(--accent); margin-bottom: 0.15rem;
    padding-bottom: 0.3rem; border-bottom: 1px solid var(--line);
}

.kb-row {
    display: flex; align-items: center; justify-content: space-between;
    padding: 0.4rem 0.6rem; border-radius: 8px; background: var(--hover);
    border: 1px solid transparent; transition: border-color 0.15s;
}
.kb-row:hover { border-color: var(--line); }

.kb-action {
    font-size: 0.82rem; color: var(--fg); font-weight: 500;
}

.kb-key-btn {
    display: inline-flex; align-items: center; gap: 0.25rem;
    padding: 0.3rem 0.7rem; font-size: 0.75rem; font-family: 'JetBrains Mono', monospace;
    font-weight: 600; color: var(--fg); background: var(--bg);
    border: 1px solid var(--line); border-radius: 6px; cursor: pointer;
    transition: all 0.15s; min-width: 60px; justify-content: center;
    box-shadow: 0 1px 2px rgba(0,0,0,0.06);
}
.kb-key-btn:hover { border-color: var(--accent); background: var(--card); }
.kb-key-btn.kb-listening {
    border-color: var(--accent); background: rgba(99,102,241,0.1);
    color: var(--accent); animation: kbPulse 1s ease-in-out infinite;
}

@keyframes kbPulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(99,102,241,0.3); }
    50% { box-shadow: 0 0 0 4px rgba(99,102,241,0.1); }
}

.kb-actions {
    margin-top: 0.75rem; padding-top: 0.75rem; border-top: 1px solid var(--line);
    display: flex; justify-content: flex-end;
}