/* ============================================================
   Theme Variables — Light / Dark / Custom
   ============================================================ */

/* ---------- Light Theme (default) ---------- */
[data-theme="light"] {
    --color-primary: #6366f1;
    --color-primary-rgb: 99, 102, 241;
    --color-primary-light: #818cf8;
    --color-primary-dark: #4f46e5;

    --color-accent: #8b5cf6;
    --color-accent-rgb: 139, 92, 246;

    --color-bg: #ffffff;
    --color-bg-rgb: 255, 255, 255;
    --color-bg-secondary: #f8fafc;
    --color-bg-tertiary: #f1f5f9;

    --color-text: #1e293b;
    --color-text-rgb: 30, 41, 59;
    --color-text-secondary: #475569;
    --color-text-muted: #94a3b8;

    --color-border: #e2e8f0;
    --color-border-light: #f1f5f9;

    --color-surface: #ffffff;
    --color-surface-elevated: #ffffff;

    --color-card-bg: #ffffff;
    --color-card-shadow: rgba(0, 0, 0, 0.06);
    --color-card-shadow-hover: rgba(99, 102, 241, 0.12);

    --color-nav-bg: rgba(255, 255, 255, 0.85);
    --color-nav-shadow: rgba(0, 0, 0, 0.05);

    --color-hero-gradient-start: #eef2ff;
    --color-hero-gradient-end: #ffffff;

    --color-badge-conference: #6366f1;
    --color-badge-journal: #059669;
    --color-badge-preprint: #d97706;

    --color-code-bg: #f1f5f9;
    --color-bibtex-bg: #f8fafc;

    --color-timeline-line: #e2e8f0;
    --color-timeline-dot: #6366f1;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);

    --gradient-primary: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    --gradient-hero: linear-gradient(160deg, var(--color-hero-gradient-start) 0%, var(--color-hero-gradient-end) 100%);

    --color-scrollbar-thumb: #cbd5e1;
    --color-scrollbar-track: #f1f5f9;
}

/* ---------- Dark Theme ---------- */
[data-theme="dark"] {
    --color-primary: #818cf8;
    --color-primary-rgb: 129, 140, 248;
    --color-primary-light: #a5b4fc;
    --color-primary-dark: #6366f1;

    --color-accent: #a78bfa;
    --color-accent-rgb: 167, 139, 250;

    --color-bg: #0f172a;
    --color-bg-rgb: 15, 23, 42;
    --color-bg-secondary: #1e293b;
    --color-bg-tertiary: #334155;

    --color-text: #e2e8f0;
    --color-text-rgb: 226, 232, 240;
    --color-text-secondary: #94a3b8;
    --color-text-muted: #64748b;

    --color-border: #334155;
    --color-border-light: #1e293b;

    --color-surface: #1e293b;
    --color-surface-elevated: #1e293b;

    --color-card-bg: #1e293b;
    --color-card-shadow: rgba(0, 0, 0, 0.3);
    --color-card-shadow-hover: rgba(129, 140, 248, 0.15);

    --color-nav-bg: rgba(15, 23, 42, 0.9);
    --color-nav-shadow: rgba(0, 0, 0, 0.2);

    --color-hero-gradient-start: #0f172a;
    --color-hero-gradient-end: #1e293b;

    --color-badge-conference: #818cf8;
    --color-badge-journal: #34d399;
    --color-badge-preprint: #fbbf24;

    --color-code-bg: #1e293b;
    --color-bibtex-bg: #1e293b;

    --color-timeline-line: #334155;
    --color-timeline-dot: #818cf8;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -4px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 8px 10px -6px rgba(0, 0, 0, 0.3);

    --gradient-primary: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    --gradient-hero: linear-gradient(160deg, var(--color-hero-gradient-start) 0%, var(--color-hero-gradient-end) 100%);

    --color-scrollbar-thumb: #475569;
    --color-scrollbar-track: #1e293b;
}

/* ---------- Custom Theme (overridden by JS) ---------- */
[data-theme="custom"] {
    --color-primary: var(--custom-primary, #6366f1);
    --color-primary-rgb: var(--custom-primary-rgb, 99, 102, 241);
    --color-primary-light: var(--custom-primary-light, #818cf8);
    --color-primary-dark: var(--custom-primary-dark, #4f46e5);

    --color-accent: var(--custom-accent, #8b5cf6);
    --color-accent-rgb: var(--custom-accent-rgb, 139, 92, 246);

    --color-bg: var(--custom-bg, #ffffff);
    --color-bg-rgb: var(--custom-bg-rgb, 255, 255, 255);
    --color-bg-secondary: var(--custom-bg-secondary, #f8fafc);
    --color-bg-tertiary: var(--custom-bg-tertiary, #f1f5f9);

    --color-text: var(--custom-text, #1e293b);
    --color-text-rgb: var(--custom-text-rgb, 30, 41, 59);
    --color-text-secondary: var(--custom-text-secondary, #475569);
    --color-text-muted: var(--custom-text-muted, #94a3b8);

    --color-border: var(--custom-border, #e2e8f0);
    --color-border-light: var(--custom-border-light, #f1f5f9);

    --color-surface: var(--custom-bg, #ffffff);
    --color-surface-elevated: var(--custom-bg, #ffffff);

    --color-card-bg: var(--custom-bg, #ffffff);
    --color-card-shadow: rgba(0, 0, 0, 0.06);
    --color-card-shadow-hover: rgba(var(--custom-primary-rgb, 99, 102, 241), 0.12);

    --color-nav-bg: rgba(var(--custom-bg-rgb, 255, 255, 255), 0.85);
    --color-nav-shadow: rgba(0, 0, 0, 0.05);

    --color-hero-gradient-start: var(--custom-bg-secondary, #eef2ff);
    --color-hero-gradient-end: var(--custom-bg, #ffffff);

    --color-badge-conference: var(--custom-primary, #6366f1);
    --color-badge-journal: #059669;
    --color-badge-preprint: #d97706;

    --color-code-bg: var(--custom-bg-tertiary, #f1f5f9);
    --color-bibtex-bg: var(--custom-bg-secondary, #f8fafc);

    --color-timeline-line: var(--custom-border, #e2e8f0);
    --color-timeline-dot: var(--custom-primary, #6366f1);

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);

    --gradient-primary: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    --gradient-hero: linear-gradient(160deg, var(--color-hero-gradient-start) 0%, var(--color-hero-gradient-end) 100%);

    --color-scrollbar-thumb: var(--custom-border, #cbd5e1);
    --color-scrollbar-track: var(--custom-bg-secondary, #f1f5f9);
}

/* ---------- System preference fallback ---------- */
@media (prefers-color-scheme: dark) {
    [data-theme="system"] {
        --color-primary: #818cf8;
        --color-primary-rgb: 129, 140, 248;
        --color-primary-light: #a5b4fc;
        --color-primary-dark: #6366f1;
        --color-accent: #a78bfa;
        --color-accent-rgb: 167, 139, 250;
        --color-bg: #0f172a;
        --color-bg-rgb: 15, 23, 42;
        --color-bg-secondary: #1e293b;
        --color-bg-tertiary: #334155;
        --color-text: #e2e8f0;
        --color-text-rgb: 226, 232, 240;
        --color-text-secondary: #94a3b8;
        --color-text-muted: #64748b;
        --color-border: #334155;
        --color-border-light: #1e293b;
        --color-surface: #1e293b;
        --color-surface-elevated: #1e293b;
        --color-card-bg: #1e293b;
        --color-card-shadow: rgba(0, 0, 0, 0.3);
        --color-card-shadow-hover: rgba(129, 140, 248, 0.15);
        --color-nav-bg: rgba(15, 23, 42, 0.9);
        --color-nav-shadow: rgba(0, 0, 0, 0.2);
        --color-hero-gradient-start: #0f172a;
        --color-hero-gradient-end: #1e293b;
        --color-badge-conference: #818cf8;
        --color-badge-journal: #34d399;
        --color-badge-preprint: #fbbf24;
        --color-code-bg: #1e293b;
        --color-bibtex-bg: #1e293b;
        --color-timeline-line: #334155;
        --color-timeline-dot: #818cf8;
        --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
        --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
        --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -4px rgba(0, 0, 0, 0.3);
        --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
        --gradient-primary: linear-gradient(135deg, var(--color-primary), var(--color-accent));
        --gradient-hero: linear-gradient(160deg, var(--color-hero-gradient-start) 0%, var(--color-hero-gradient-end) 100%);
        --color-scrollbar-thumb: #475569;
        --color-scrollbar-track: #1e293b;
    }
}

@media (prefers-color-scheme: light) {
    [data-theme="system"] {
        --color-primary: #6366f1;
        --color-primary-rgb: 99, 102, 241;
        --color-primary-light: #818cf8;
        --color-primary-dark: #4f46e5;
        --color-accent: #8b5cf6;
        --color-accent-rgb: 139, 92, 246;
        --color-bg: #ffffff;
        --color-bg-rgb: 255, 255, 255;
        --color-bg-secondary: #f8fafc;
        --color-bg-tertiary: #f1f5f9;
        --color-text: #1e293b;
        --color-text-rgb: 30, 41, 59;
        --color-text-secondary: #475569;
        --color-text-muted: #94a3b8;
        --color-border: #e2e8f0;
        --color-border-light: #f1f5f9;
        --color-surface: #ffffff;
        --color-surface-elevated: #ffffff;
        --color-card-bg: #ffffff;
        --color-card-shadow: rgba(0, 0, 0, 0.06);
        --color-card-shadow-hover: rgba(99, 102, 241, 0.12);
        --color-nav-bg: rgba(255, 255, 255, 0.85);
        --color-nav-shadow: rgba(0, 0, 0, 0.05);
        --color-hero-gradient-start: #eef2ff;
        --color-hero-gradient-end: #ffffff;
        --color-badge-conference: #6366f1;
        --color-badge-journal: #059669;
        --color-badge-preprint: #d97706;
        --color-code-bg: #f1f5f9;
        --color-bibtex-bg: #f8fafc;
        --color-timeline-line: #e2e8f0;
        --color-timeline-dot: #6366f1;
        --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
        --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
        --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
        --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
        --gradient-primary: linear-gradient(135deg, var(--color-primary), var(--color-accent));
        --gradient-hero: linear-gradient(160deg, var(--color-hero-gradient-start) 0%, var(--color-hero-gradient-end) 100%);
        --color-scrollbar-thumb: #cbd5e1;
        --color-scrollbar-track: #f1f5f9;
    }
}

/* ---------- Print ---------- */
@media print {
    :root,
    [data-theme] {
        --color-bg: #ffffff !important;
        --color-text: #000000 !important;
        --color-text-secondary: #333333 !important;
        --color-border: #cccccc !important;
        --color-card-bg: #ffffff !important;
        --shadow-sm: none !important;
        --shadow-md: none !important;
        --shadow-lg: none !important;
        --shadow-xl: none !important;
    }
}