:root {
    --primary: #4f46e5;
    --primary-dark: #3730a3;
    --bg: #f4f5f7;
    --surface: #ffffff;
    --border: #e5e7eb;
    --text: #1f2937;
    --text-muted: #6b7280;
    --danger: #dc2626;
    --success: #16a34a;
    --radius: 12px;
    box-sizing: border-box;
    padding-top: env(safe-area-inset-top, 0px);
    padding-bottom: env(safe-area-inset-bottom, 0px);
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --bg: #111318;
        --surface: #1a1d24;
        --border: #2a2e37;
        --text: #e5e7eb;
        --text-muted: #9ca3af;
    }
}
:root[data-theme="dark"] {
    --bg: #111318;
    --surface: #1a1d24;
    --border: #2a2e37;
    --text: #e5e7eb;
    --text-muted: #9ca3af;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html, body {
    height: 100%;
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
}

a { color: var(--primary); }

/* --- Auth / Legal pages --- */
.auth-page, .legal-page {
    min-height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
}
.auth-card, .legal-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px;
    width: 100%;
    max-width: 420px;
}
.legal-card { max-width: 640px; }
.brand {
    font-size: 22px;
    font-weight: 700;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 20px;
}
.auth-form label { display: block; margin: 14px 0 6px; font-size: 13px; color: var(--text-muted); }
.auth-form input[type="text"],
.auth-form input[type="email"],
.auth-form input[type="password"] {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--bg);
    color: var(--text);
    font-size: 15px;
}
.checkbox-line { display: flex; align-items: center; gap: 8px; font-size: 13px; margin-top: 16px; }
.checkbox-line input { width: auto; }
button {
    cursor: pointer;
    font-family: inherit;
}
.auth-form button[type="submit"] {
    width: 100%;
    margin-top: 20px;
    padding: 11px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}
.auth-form button[type="submit"]:hover { background: var(--primary-dark); }
.auth-footer { margin-top: 18px; font-size: 13px; color: var(--text-muted); text-align: center; }
.alert { padding: 10px 12px; border-radius: 8px; font-size: 13px; margin-bottom: 8px; }
.alert-error { background: #fef2f2; color: var(--danger); border: 1px solid #fecaca; }
.alert-success { background: #f0fdf4; color: var(--success); border: 1px solid #bbf7d0; }

/* --- App layout --- */
#app {
    display: flex;
    height: 100vh;
    height: 100dvh;
}
.sidebar {
    width: 300px;
    min-width: 260px;
    background: var(--surface);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
}
.sidebar-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px;
    border-bottom: 1px solid var(--border);
    padding-top: calc(16px + env(safe-area-inset-top, 0px));
}
.room-list { flex: 1; overflow-y: auto; }
.room-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    cursor: pointer;
    border-bottom: 1px solid transparent;
}
.room-item:hover { background: var(--bg); }
.room-item.active { background: var(--bg); border-left: 3px solid var(--primary); }
.room-item .meta { flex: 1; min-width: 0; }
.room-item .rname { font-weight: 600; font-size: 14px; }
.room-item .rlast { font-size: 12px; color: var(--text-muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.avatar {
    width: 38px; height: 38px; border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    color: #fff; font-weight: 700; font-size: 15px; flex-shrink: 0;
    background-size: cover; background-position: center;
}
.avatar-sm { width: 28px; height: 28px; font-size: 12px; }
.sidebar-footer {
    display: flex; align-items: center; justify-content: space-between;
    padding: 12px 16px; border-top: 1px solid var(--border);
    padding-bottom: calc(12px + env(safe-area-inset-bottom, 0px));
}
.me { display: flex; align-items: center; gap: 10px; cursor: pointer; font-size: 14px; font-weight: 600; }
.icon-btn {
    background: none; border: none; color: var(--text-muted);
    font-size: 18px; padding: 8px; border-radius: 8px; display: flex;
}
.icon-btn:hover { background: var(--bg); color: var(--text); }
.icon-btn.primary { background: var(--primary); color: #fff; }
.icon-btn.primary:hover { background: var(--primary-dark); }

.chat-area { flex: 1; display: flex; flex-direction: column; min-width: 0; }
.empty-state {
    flex: 1; display: flex; flex-direction: column; align-items: center;
    justify-content: center; color: var(--text-muted); gap: 10px;
}
.empty-state i { font-size: 48px; }

.chat-view { flex: 1; display: flex; flex-direction: column; min-height: 0; }
.chat-header {
    display: flex; align-items: center; justify-content: space-between;
    padding: 14px 20px; border-bottom: 1px solid var(--border); background: var(--surface);
    padding-top: calc(14px + env(safe-area-inset-top, 0px));
}
.chat-title { font-weight: 700; }
.chat-subtitle { font-size: 12px; color: var(--text-muted); }

.messages { flex: 1; overflow-y: auto; padding: 20px; display: flex; flex-direction: column; gap: 10px; }
.msg-row { display: flex; gap: 10px; max-width: 70%; }
.msg-row.mine { align-self: flex-end; flex-direction: row-reverse; }
.msg-bubble-wrap { display: flex; flex-direction: column; }
.msg-author { font-size: 12px; font-weight: 600; margin-bottom: 3px; color: var(--text-muted); }
.msg-row.mine .msg-author { text-align: right; }
.bubble {
    padding: 9px 13px; border-radius: 16px; background: var(--surface);
    border: 1px solid var(--border); font-size: 14px; line-height: 1.4;
    word-wrap: break-word; position: relative;
}
.msg-row.mine .bubble { background: var(--primary); color: #fff; border-color: var(--primary); }
.msg-row.mine .bubble a { color: #dbeafe; }
.bubble .edited-tag { font-size: 10px; opacity: .7; margin-left: 6px; }
.msg-meta { font-size: 10px; color: var(--text-muted); margin-top: 3px; }
.msg-row.mine .msg-meta { text-align: right; }
.reactions { display: flex; gap: 4px; margin-top: 4px; flex-wrap: wrap; }
.reaction-chip {
    font-size: 12px; background: var(--bg); border: 1px solid var(--border);
    border-radius: 10px; padding: 1px 7px; cursor: pointer;
}
.reaction-chip.mine { border-color: var(--primary); }
.msg-actions { display: none; gap: 4px; margin-top: 2px; }
.msg-row:hover .msg-actions { display: flex; }
.msg-actions button { font-size: 11px; background: none; border: none; color: var(--text-muted); cursor: pointer; padding: 2px 4px; }
.msg-actions button:hover { color: var(--text); }

.composer {
    display: flex; gap: 10px; padding: 14px 20px; border-top: 1px solid var(--border);
    background: var(--surface); padding-bottom: calc(14px + env(safe-area-inset-bottom, 0px));
}
.composer input {
    flex: 1; padding: 11px 14px; border-radius: 20px; border: 1px solid var(--border);
    background: var(--bg); color: var(--text); font-size: 14px;
}

/* --- Modal --- */
.modal-overlay {
    position: fixed; inset: 0; background: rgba(0,0,0,.5);
    display: flex; align-items: center; justify-content: center; z-index: 100; padding: 16px;
}
.modal {
    background: var(--surface); border-radius: var(--radius); padding: 24px;
    width: 100%; max-width: 480px; max-height: 85vh; overflow-y: auto;
}
.modal h2 { margin-top: 0; font-size: 18px; }
.modal label { display: block; margin: 12px 0 6px; font-size: 13px; color: var(--text-muted); }
.modal input[type="text"], .modal input[type="email"], .modal input[type="password"], .modal select {
    width: 100%; padding: 9px 11px; border: 1px solid var(--border); border-radius: 8px;
    background: var(--bg); color: var(--text); font-size: 14px;
}
.modal .actions { display: flex; justify-content: flex-end; gap: 10px; margin-top: 20px; }
.btn {
    padding: 9px 16px; border-radius: 8px; border: 1px solid var(--border);
    background: var(--bg); color: var(--text); font-size: 14px; cursor: pointer;
}
.btn-primary { background: var(--primary); color: #fff; border-color: var(--primary); }
.btn-danger { background: #fef2f2; color: var(--danger); border-color: #fecaca; }
.user-pick-list { max-height: 220px; overflow-y: auto; border: 1px solid var(--border); border-radius: 8px; margin-top: 6px; }
.user-pick-item { display: flex; align-items: center; gap: 8px; padding: 8px 10px; cursor: pointer; font-size: 14px; }
.user-pick-item:hover { background: var(--bg); }
.user-pick-item input { width: auto; }
table.admin-table { width: 100%; border-collapse: collapse; font-size: 13px; margin-top: 10px; }
table.admin-table th, table.admin-table td { text-align: left; padding: 6px 8px; border-bottom: 1px solid var(--border); }
.tabs { display: flex; gap: 6px; margin-bottom: 10px; }
.tab-btn { padding: 6px 12px; border-radius: 8px;  color: #fff;  border: 1px solid var(--border); background: var(--bg); cursor: pointer; font-size: 13px; }
.tab-btn.active { background: var(--primary); color: #fff; border-color: var(--primary); }
.qr-box { text-align: center; margin-top: 12px; }
.qr-box img { border: 1px solid var(--border); border-radius: 8px; }
.small-link { font-size: 12px; word-break: break-all; color: var(--text-muted); }

@media (max-width: 720px) {
    .sidebar { position: fixed; inset: 0; z-index: 20; width: 100%; transition: transform .2s; }
    .sidebar.hide-mobile { transform: translateX(-100%); }
    .chat-area { width: 100%; }
    .msg-row { max-width: 88%; }
}