:root {
    /* Gemini 3.1 Premium Palette — Dark (default) */
    --bg-color: #131314;
    --sidebar-bg: #1e1e20;
    --sidebar-hover-bg: #2d2f31;
    --sidebar-active-bg: rgba(255, 255, 255, 0.1);
    --text-main: #e3e3e3;
    --text-secondary: #9e9e9e;
    --text-dim: #b4b4b4;
    --accent-blue: #4b90ff;
    --accent-gradient: linear-gradient(90deg, #4b90ff, #ff71cd, #ff9d6c);
    --input-bg: #1e1f20;
    --card-bg: #1e1f20;
    --card-hover: #2e2f30;
    --border-color: #333537;
    --glass-bg: rgba(30, 31, 32, 0.7);
    --glass-border: rgba(255, 255, 255, 0.05);

    /* Layout Tokens */
    --sidebar-width: 256px;
    --sidebar-collapsed: 68px;
    --sidebar-transition: width 280ms cubic-bezier(0.4, 0, 0.2, 1);
    --header-height: 64px;
    --input-max-width: 820px;

    /* Gem Avatar Theme Colors */
    --theme-blue: #448aff;
    --theme-purple: #a179ff;
    --theme-teal: #00b8d4;
    --theme-rose: #ff5252;
    --theme-amber: #ffc400;

    /* Chat Area */
    --user-bubble-bg: #1e2837;
    --code-bg: #3c4043;
    --code-block-bg: #1e1f20;

    /* Transitions & Shadow */
    --transition-smooth: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.2s ease;
    --premium-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}

/* ── Gray Theme ─────────────────────────────────── */
[data-theme="gray"] {
    --bg-color: #e8e9ec;
    --sidebar-bg: #dddee2;
    --sidebar-hover-bg: #d0d2d6;
    --sidebar-active-bg: rgba(0, 0, 0, 0.08);
    --text-main: #202124;
    --text-secondary: #5f6368;
    --text-dim: #444746;
    --accent-blue: #1967d2;
    --accent-gradient: linear-gradient(90deg, #1967d2, #c2185b, #e65100);
    --input-bg: #dddee2;
    --card-bg: #dddee2;
    --card-hover: #d0d2d6;
    --border-color: #c4c7cb;
    --glass-bg: rgba(232, 233, 236, 0.85);
    --glass-border: rgba(0, 0, 0, 0.08);
    --premium-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.14);
    --user-bubble-bg: #c8d4e8;
    --code-bg: #d0d2d6;
    --code-block-bg: #dddee2;
}

/* ── White Theme ────────────────────────────────── */
[data-theme="white"] {
    --bg-color: #f8f9fa;
    --sidebar-bg: #ffffff;
    --sidebar-hover-bg: #e8eaed;
    --sidebar-active-bg: rgba(0, 0, 0, 0.06);
    --text-main: #1f1f1f;
    --text-secondary: #5f6368;
    --text-dim: #444746;
    --accent-blue: #1a73e8;
    --accent-gradient: linear-gradient(90deg, #1a73e8, #d81b60, #e67c00);
    --input-bg: #ffffff;
    --card-bg: #ffffff;
    --card-hover: #f1f3f4;
    --border-color: #dadce0;
    --glass-bg: rgba(255, 255, 255, 0.85);
    --glass-border: rgba(0, 0, 0, 0.08);
    --premium-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.12);
    --user-bubble-bg: #e8f0fe;
    --code-bg: #f1f3f4;
    --code-block-bg: #f8f9fa;
}


* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    font-family: 'Noto Sans KR', 'Noto Sans', 'Google Sans', Roboto, Arial, sans-serif;
    overflow: hidden; /* 사이드바와 메인 영역의 독립 스크롤을 위함 */
}

/* Scrollbar Styling - Gemini Style */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: #3c4043;
    border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
    background: #5f6368;
}

[data-theme="gray"] ::-webkit-scrollbar-thumb { background: #b4b7bc; }
[data-theme="gray"] ::-webkit-scrollbar-thumb:hover { background: #9aa0a6; }

[data-theme="white"] ::-webkit-scrollbar-thumb { background: #c0c4c9; }
[data-theme="white"] ::-webkit-scrollbar-thumb:hover { background: #9aa0a6; }