:root{color-scheme:light}html[data-theme="sombre"]{color-scheme:dark;--bg:#212121;--paper:#2d2d2d;--ink:#f1f1f1;--muted:#a2a2a2;--line:#424242;--soft:#333;background:var(--bg);color:var(--ink)}html[data-theme="sombre"] body,html[data-theme="sombre"] .landing,html[data-theme="sombre"] .workspace{background:var(--bg);color:var(--ink)}html[data-theme="sombre"] .public-header,html[data-theme="sombre"] .site-header,html[data-theme="sombre"] .topbar{background:#212121;border-color:#383838;color:#d7d7d7}html[data-theme="sombre"] .sidebar{background:#1b1b1b;border-color:#383838}html[data-theme="sombre"] .new-chat,html[data-theme="sombre"] .nav-link.active,html[data-theme="sombre"] .nav-link:hover,html[data-theme="sombre"] .new-chat:hover{background:#303030;border-color:#444;color:var(--ink)}html[data-theme="sombre"] .hero-preview,html[data-theme="sombre"] .card,html[data-theme="sombre"] .notice,html[data-theme="sombre"] .content-block,html[data-theme="sombre"] .metric,html[data-theme="sombre"] .auth-card{background:var(--paper);border-color:var(--line);color:var(--ink)}html[data-theme="sombre"] .preview-user,html[data-theme="sombre"] .chat-message.user,html[data-theme="sombre"] .chat-form{background:#3a3a3a;color:var(--ink)}html[data-theme="sombre"] .preview-input,html[data-theme="sombre"] .auth-card input{background:#333;border-color:#515151;color:var(--ink)}html[data-theme="sombre"] .value-section,html[data-theme="sombre"] .closing{background:#292929;color:var(--ink)}html[data-theme="sombre"] .site-footer,html[data-theme="sombre"] .public-footer{border-color:#424242;color:#b0b0b0}html[data-theme="sombre"] .hero-copy>p,html[data-theme="sombre"] .preview-answer,html[data-theme="sombre"] .lead,html[data-theme="sombre"] .card p,html[data-theme="sombre"] .value-grid p{color:#b5b5b5}html[data-theme="sombre"] .chat-form textarea{color:var(--ink)}html[data-theme="sombre"] .theme-toggle{background:#333;border-color:#4c4c4c;color:#eee}.theme-toggle{width:36px;height:36px;flex:0 0 36px;border:1px solid #e1e2e4;border-radius:50%;background:#fff;color:#3d4045;display:grid;place-items:center;cursor:pointer;font-size:19px;line-height:1}.public-header .theme-toggle{margin-left:2px}.site-header .theme-toggle{margin-left:auto}.topbar .theme-toggle{margin-left:auto}.theme-only-toggle{position:fixed;z-index:10;top:18px;right:18px}.brand-image{display:block;width:166px;height:auto;max-height:46px;object-fit:contain;object-position:left center}.auth-card .brand-image{width:190px;margin:0 auto 18px}.welcome-logo{display:block;width:190px;height:auto;margin:0 auto 18px}.public-footer .brand-image{width:138px;max-height:40px}.site-footer .brand-image{width:138px;max-height:40px}@media(max-width:680px){.public-header .theme-toggle{margin-left:0}.brand-image{width:145px}.welcome-logo{width:165px}}