/* Five selectable colour themes. The admin picks one in 会话管理; the server writes it
   to <html data-theme="...">. Each theme has a light and a dark variant.
   --accent   = creator colour (header, own bubbles)
   --accent-2 = participant colour
   --hero     = gradient used on page headers */

/* 1. 晨雾蓝 mist — calm indigo on cool grey */
:root[data-theme="mist"]{
    --bg:#eef1f7;--surface:#ffffff;--surface-2:#f3f5fa;--surface-3:#e1e6f0;
    --text:#1b2333;--text-2:#667085;--border:#e3e8f1;
    --primary:#4f6bed;--accent:#4f6bed;--accent-2:#2f9e8f;
    --bubble-me:#4f6bed;--bubble-you:#ffffff;--bubble-you-text:#1b2333;
    --hero:linear-gradient(135deg,#5b7cfa 0%,#7b61ff 100%);
    --chat-bg:#eef1f7;--shadow:0 8px 30px rgba(31,45,90,.10);
}
@media (prefers-color-scheme:dark){:root[data-theme="mist"]{
    --bg:#0e1220;--surface:#171c2c;--surface-2:#1f2538;--surface-3:#2a3148;
    --text:#e8ecf6;--text-2:#9aa3b8;--border:#283048;
    --primary:#7b93ff;--accent:#5b74f0;--accent-2:#2fae9c;
    --bubble-me:#5b74f0;--bubble-you:#1f2538;--bubble-you-text:#e8ecf6;
    --hero:linear-gradient(135deg,#3a4fc4 0%,#5a43c9 100%);--chat-bg:#0e1220;
}}

/* 2. 薄荷 mint — fresh teal on soft mint */
:root[data-theme="mint"]{
    --bg:#ecf6f3;--surface:#ffffff;--surface-2:#f1f8f6;--surface-3:#d8ebe5;
    --text:#13302a;--text-2:#5c7a73;--border:#dcece7;
    --primary:#0f9d8a;--accent:#0f9d8a;--accent-2:#3d7bd9;
    --bubble-me:#0f9d8a;--bubble-you:#ffffff;--bubble-you-text:#13302a;
    --hero:linear-gradient(135deg,#12b39c 0%,#0c8f9e 100%);
    --chat-bg:#ecf6f3;--shadow:0 8px 30px rgba(10,80,70,.10);
}
@media (prefers-color-scheme:dark){:root[data-theme="mint"]{
    --bg:#0b1715;--surface:#13221f;--surface-2:#1a2d29;--surface-3:#24403a;
    --text:#e4f3ef;--text-2:#8fb0a8;--border:#22372f;
    --primary:#2ec4ae;--accent:#139f8c;--accent-2:#4a86e0;
    --bubble-me:#139f8c;--bubble-you:#1a2d29;--bubble-you-text:#e4f3ef;
    --hero:linear-gradient(135deg,#0d7d6f 0%,#0b6875 100%);--chat-bg:#0b1715;
}}

/* 3. 暖杏 apricot — warm coral on cream */
:root[data-theme="apricot"]{
    --bg:#fbf4ee;--surface:#ffffff;--surface-2:#fbf6f1;--surface-3:#f1e3d6;
    --text:#33221a;--text-2:#8a6f62;--border:#f0e3d8;
    --primary:#e8664a;--accent:#e8664a;--accent-2:#7a6ad8;
    --bubble-me:#e8664a;--bubble-you:#ffffff;--bubble-you-text:#33221a;
    --hero:linear-gradient(135deg,#f6866a 0%,#e85d75 100%);
    --chat-bg:#fbf4ee;--shadow:0 8px 30px rgba(120,60,30,.10);
}
@media (prefers-color-scheme:dark){:root[data-theme="apricot"]{
    --bg:#1a1310;--surface:#241b17;--surface-2:#2e231e;--surface-3:#3d2f28;
    --text:#f7ebe4;--text-2:#b89c8f;--border:#3a2c25;
    --primary:#ff8a6e;--accent:#d85c42;--accent-2:#7d6ee0;
    --bubble-me:#d85c42;--bubble-you:#2e231e;--bubble-you-text:#f7ebe4;
    --hero:linear-gradient(135deg,#b84a35 0%,#a63d55 100%);--chat-bg:#1a1310;
}}

/* 4. 墨金 ink — deep navy with gold, dark in both modes */
:root[data-theme="ink"]{
    --bg:#0d1017;--surface:#161a24;--surface-2:#1e2330;--surface-3:#2a3040;
    --text:#ece7da;--text-2:#9b968a;--border:#262c3a;
    --primary:#d4a94f;--accent:#c79a3d;--accent-2:#5f8fd6;
    --bubble-me:#c79a3d;--bubble-me-text:#161106;--bubble-you:#1e2330;--bubble-you-text:#ece7da;
    --hero:linear-gradient(135deg,#232a3b 0%,#11151f 100%);
    --chat-bg:#0d1017;--shadow:0 8px 30px rgba(0,0,0,.5);--mask:rgba(0,0,0,.65);
    color-scheme:dark;
}
:root[data-theme="ink"] .header,:root[data-theme="ink"] .card-head{border-bottom:1px solid rgba(212,169,79,.35)}

/* 5. 樱紫 lilac — soft violet and rose */
:root[data-theme="lilac"]{
    --bg:#f6f1fa;--surface:#ffffff;--surface-2:#f8f4fb;--surface-3:#e9def2;
    --text:#2a1e36;--text-2:#7d6b8c;--border:#ece2f3;
    --primary:#9b5de5;--accent:#9b5de5;--accent-2:#e0558f;
    --bubble-me:#9b5de5;--bubble-you:#ffffff;--bubble-you-text:#2a1e36;
    --hero:linear-gradient(135deg,#a66cf0 0%,#e86fa8 100%);
    --chat-bg:#f6f1fa;--shadow:0 8px 30px rgba(80,40,110,.10);
}
@media (prefers-color-scheme:dark){:root[data-theme="lilac"]{
    --bg:#150f1c;--surface:#1f1729;--surface-2:#291f35;--surface-3:#372a47;
    --text:#f1e9f8;--text-2:#a993bb;--border:#33263f;
    --primary:#b88af0;--accent:#8a4fd6;--accent-2:#d24c86;
    --bubble-me:#8a4fd6;--bubble-you:#291f35;--bubble-you-text:#f1e9f8;
    --hero:linear-gradient(135deg,#6e3cb5 0%,#a3407a 100%);--chat-bg:#150f1c;
}}

/* Light themes: incoming bubbles are white on a tinted background; give them an edge. */
:root[data-theme="mist"] .msg-row.you .bubble,:root[data-theme="mint"] .msg-row.you .bubble,
:root[data-theme="apricot"] .msg-row.you .bubble,:root[data-theme="lilac"] .msg-row.you .bubble{box-shadow:0 1px 2px rgba(0,0,0,.06);border:1px solid var(--border)}