/* VoiceTube TransLive - Theme System */
/* Default: dark. User can override via toggle. */
/* RULE: Only variables here. Zero component selectors. */

:root {
    color-scheme: dark;

    /* ===== Core Backgrounds ===== */
    --color-bg-primary: #1C1C1E;
    --color-bg-secondary: #2C2C2E;
    --color-bg-tertiary: #3A3A3C;
    --color-bg-elevated: #2C2C2E;
    --color-bg-input: #1C1C1E;

    /* ===== Text ===== */
    --color-text-primary: #FFFFFF;
    --color-text-secondary: #8E8E93;
    --color-text-tertiary: #636366;
    --color-text-on-brand: #FFFFFF; /* Text on solid brand/semantic backgrounds */

    /* ===== Borders ===== */
    --color-border: #3A3A3C;
    --color-border-hover: #48484A;
    --color-border-subtle: #38383A;

    /* ===== Brand / Semantic ===== */
    --color-brand: #007AFF;
    --color-brand-dark: #0051D0;
    --color-success: #34C759;
    --color-warning: #FF9500;
    --color-error: #FF3B30;
    --color-purple: #AF52DE;
    --color-info: #5AC8FA;

    /* ===== RGB Components for rgba() ===== */
    --overlay-rgb: 255, 255, 255;
    --shadow-rgb: 0, 0, 0;
    --brand-rgb: 0, 122, 255;
    --success-rgb: 52, 199, 89;
    --warning-rgb: 255, 149, 0;
    --error-rgb: 255, 59, 48;
    --purple-rgb: 175, 82, 222;
    --text-secondary-rgb: 142, 142, 147;

    /* ===== Shadows ===== */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.4);

    /* ===== Spacing ===== */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-xxl: 48px;

    /* ===== Animation ===== */
    --transition-fast: 0.2s;
    --transition-normal: 0.3s;
    --transition-slow: 0.5s;

    /* ===== Layout ===== */
    --header-height: 90px;

    /* ===== Border Radius ===== */
    --radius-xs: 6px;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;

    /* ===== Scrollbar ===== */
    --scrollbar-track: #1C1C1E;
    --scrollbar-thumb: #3A3A3C;
    --scrollbar-thumb-hover: #48484A;

    /* ===== Login ===== */
    --login-bg-start: #1a1a2e;
    --login-bg-end: #2C2C2E;
    --login-card-bg: #2C2C2E;
    --login-card-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    --login-input-border: #3A3A3C;
    --login-input-bg: #1C1C1E;
    --login-hint-bg: #3A3A3C;
    --login-hint-color: #8E8E93;

    /* ===== Component Semantic Tokens ===== */
    /* Header */
    --header-bg: linear-gradient(135deg, var(--color-bg-primary) 0%, var(--color-bg-secondary) 100%);
    --header-border: none;

    /* Brand icon */
    --brand-icon-bg: linear-gradient(135deg, var(--color-brand) 0%, var(--color-success) 100%);
    --brand-icon-shadow: 0 2px 8px rgba(var(--brand-rgb), 0.3);

    /* Active surfaces (tabs, active buttons) */
    --surface-active-bg: var(--color-brand);
    --surface-active-text: #FFFFFF;
    --surface-active-shadow: 0 2px 8px rgba(var(--brand-rgb), 0.3);
    --surface-active-border: transparent;

    /* Primary buttons */
    --btn-primary-bg: var(--color-brand);
    --btn-primary-text: var(--color-text-on-brand);
    --btn-primary-border: transparent;
    --btn-primary-hover-bg: var(--color-brand-dark);

    /* CTA buttons: always solid, high-emphasis actions */
    --btn-cta-bg: var(--color-brand);
    --btn-cta-text: var(--color-text-on-brand);
    --btn-cta-border: transparent;
    --btn-cta-hover-bg: var(--color-brand-dark);
    --btn-cta-shadow: 0 2px 8px rgba(var(--brand-rgb), 0.3);

    /* Secondary buttons */
    --btn-secondary-bg: rgba(var(--overlay-rgb), 0.08);
    --btn-secondary-text: var(--color-text-primary);
    --btn-secondary-border: rgba(var(--overlay-rgb), 0.12);
    --btn-secondary-hover-bg: rgba(var(--overlay-rgb), 0.15);

    /* User profile */
    --user-profile-bg: rgba(var(--overlay-rgb), 0.05);
    --user-profile-border: rgba(var(--overlay-rgb), 0.1);

    /* Toggle */
    --toggle-track: var(--color-border-hover);
    --toggle-knob: #FFFFFF;

    /* Slider */
    --slider-thumb-bg: var(--color-brand);
    --slider-thumb-border: rgba(var(--brand-rgb), 0.3);

    /* Input focus */
    --input-focus-border: var(--color-brand);
    --input-focus-shadow: 0 0 0 3px rgba(var(--brand-rgb), 0.2);

    /* Toast */
    --toast-bg: var(--color-bg-secondary);
    --toast-border: var(--color-border);
    --toast-shadow: var(--shadow-md);

    /* Quick session switcher */
    --session-switcher-bg: rgba(var(--overlay-rgb), 0.05);
    --session-switcher-border: rgba(var(--overlay-rgb), 0.1);

    /* Panel section header */
    --panel-section-header-bg: rgba(var(--overlay-rgb), 0.03);

    /* Select/dropdown */
    --select-bg: var(--color-bg-input);

    /* Header divider */
    --header-divider: rgba(255, 255, 255, 0.12);
}

/* ===== Light Theme ===== */
[data-theme="light"] {
    color-scheme: light;

    /* Core Backgrounds */
    --color-bg-primary: #F8F9FA;
    --color-bg-secondary: #FFFFFF;
    --color-bg-tertiary: #F1F3F5;
    --color-bg-elevated: #FFFFFF;
    --color-bg-input: #F8F9FA;

    /* Text */
    --color-text-primary: #1A1D23;
    --color-text-secondary: #6B7280;
    --color-text-tertiary: #9CA3AF;

    /* Borders */
    --color-border: #E5E7EB;
    --color-border-hover: #D1D5DB;
    --color-border-subtle: #F3F4F6;

    /* Muted semantic colors (GitHub Primer inspired) */
    --color-brand: #0969DA;
    --color-brand-dark: #0550AE;
    --color-success: #1A7F37;
    --color-warning: #BF8700;
    --color-error: #CF222E;
    --color-purple: #8250DF;
    --color-info: #0969DA;

    /* RGB */
    --overlay-rgb: 0, 0, 0;
    --brand-rgb: 9, 105, 218;
    --success-rgb: 26, 127, 55;
    --warning-rgb: 191, 135, 0;
    --error-rgb: 207, 34, 46;
    --purple-rgb: 130, 80, 223;

    /* Subtle shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04), 0 1px 1px rgba(0, 0, 0, 0.02);
    --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.08), 0 2px 8px rgba(0, 0, 0, 0.04);

    /* Scrollbar */
    --scrollbar-track: #F1F3F5;
    --scrollbar-thumb: #CED4DA;
    --scrollbar-thumb-hover: #ADB5BD;

    /* Login */
    --login-bg-start: #F0F2F5;
    --login-bg-end: #E4E8EE;
    --login-card-bg: #FFFFFF;
    --login-card-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
    --login-input-border: #E5E7EB;
    --login-input-bg: #FFFFFF;
    --login-hint-bg: #F8F9FA;
    --login-hint-color: #6B7280;

    /* ===== Component Semantic Tokens (Light) ===== */
    /* Header: flat white (Vercel/Linear style) */
    --header-bg: #FFFFFF;
    --header-border: 1px solid var(--color-border);

    /* Brand icon: tinted */
    --brand-icon-bg: linear-gradient(135deg, rgba(var(--brand-rgb), 0.12) 0%, rgba(var(--success-rgb), 0.12) 100%);
    --brand-icon-shadow: none;

    /* Active surfaces: tinted instead of solid */
    --surface-active-bg: rgba(var(--brand-rgb), 0.1);
    --surface-active-text: var(--color-brand);
    --surface-active-shadow: none;
    --surface-active-border: var(--color-brand);

    /* Primary buttons: tinted in light mode */
    --btn-primary-bg: rgba(var(--brand-rgb), 0.1);
    --btn-primary-text: var(--color-brand);
    --btn-primary-border: rgba(var(--brand-rgb), 0.3);
    --btn-primary-hover-bg: rgba(var(--brand-rgb), 0.18);

    /* CTA buttons: solid even in light mode */
    --btn-cta-bg: var(--color-brand);
    --btn-cta-text: #ffffff;
    --btn-cta-border: transparent;
    --btn-cta-hover-bg: var(--color-brand-dark);
    --btn-cta-shadow: 0 2px 12px rgba(var(--brand-rgb), 0.25);

    /* Secondary buttons */
    --btn-secondary-bg: var(--color-bg-tertiary);
    --btn-secondary-text: var(--color-text-primary);
    --btn-secondary-border: var(--color-border);
    --btn-secondary-hover-bg: var(--color-border);

    /* User profile */
    --user-profile-bg: var(--color-bg-tertiary);
    --user-profile-border: var(--color-border);

    /* Toggle */
    --toggle-track: var(--color-border);

    /* Slider: branded thumb visible on white bg */
    --slider-thumb-bg: var(--color-brand);
    --slider-thumb-border: rgba(var(--brand-rgb), 0.3);

    /* Input focus */
    --input-focus-shadow: 0 0 0 3px rgba(var(--brand-rgb), 0.1);

    /* Toast */
    --toast-bg: var(--color-bg-secondary);
    --toast-border: var(--color-border);
    --toast-shadow: var(--shadow-lg);

    /* Quick session switcher */
    --session-switcher-bg: var(--color-bg-tertiary);
    --session-switcher-border: var(--color-border);

    /* Panel section header */
    --panel-section-header-bg: var(--color-bg-tertiary);

    /* Select/dropdown */
    --select-bg: var(--color-bg-input);

    /* Header divider */
    --header-divider: rgba(0, 0, 0, 0.12);
}

/* ===== System preference auto-detection ===== */
@media (prefers-color-scheme: light) {
    :root:not([data-theme]) {
        --color-bg-primary: #F8F9FA;
        --color-bg-secondary: #FFFFFF;
        --color-bg-tertiary: #F1F3F5;
        --color-bg-elevated: #FFFFFF;
        --color-bg-input: #F8F9FA;

        --color-text-primary: #1A1D23;
        --color-text-secondary: #6B7280;
        --color-text-tertiary: #9CA3AF;

        --color-border: #E5E7EB;
        --color-border-hover: #D1D5DB;
        --color-border-subtle: #ECEDF0;

        --color-brand: #0969DA;
        --color-brand-dark: #0550AE;
        --color-success: #1A7F37;
        --color-warning: #BF8700;
        --color-error: #CF222E;
        --color-purple: #8250DF;
        --color-info: #0969DA;

        --overlay-rgb: 0, 0, 0;
        --brand-rgb: 9, 105, 218;
        --success-rgb: 26, 127, 55;
        --warning-rgb: 191, 135, 0;
        --error-rgb: 207, 34, 46;
        --purple-rgb: 130, 80, 223;

        --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04), 0 1px 1px rgba(0, 0, 0, 0.02);
        --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
        --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.08), 0 2px 8px rgba(0, 0, 0, 0.04);

        --scrollbar-track: #F1F3F5;
        --scrollbar-thumb: #CED4DA;
        --scrollbar-thumb-hover: #ADB5BD;

        --login-bg-start: #F0F2F5;
        --login-bg-end: #E4E8EE;
        --login-card-bg: #FFFFFF;
        --login-card-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
        --login-input-border: #E5E7EB;
        --login-input-bg: #FFFFFF;
        --login-hint-bg: #F8F9FA;
        --login-hint-color: #6B7280;

        /* Component tokens */
        --header-bg: #FFFFFF;
        --header-border: 1px solid var(--color-border);
        --brand-icon-bg: linear-gradient(135deg, rgba(var(--brand-rgb), 0.12) 0%, rgba(var(--success-rgb), 0.12) 100%);
        --brand-icon-shadow: none;
        --surface-active-bg: rgba(var(--brand-rgb), 0.1);
        --surface-active-text: var(--color-brand);
        --surface-active-shadow: none;
        --surface-active-border: var(--color-brand);
        --btn-primary-bg: rgba(var(--brand-rgb), 0.1);
        --btn-primary-text: var(--color-brand);
        --btn-primary-border: rgba(var(--brand-rgb), 0.3);
        --btn-primary-hover-bg: rgba(var(--brand-rgb), 0.18);
        --btn-cta-bg: var(--color-brand);
        --btn-cta-text: #ffffff;
        --btn-cta-border: transparent;
        --btn-cta-hover-bg: var(--color-brand-dark);
        --btn-cta-shadow: 0 2px 12px rgba(var(--brand-rgb), 0.25);
        --btn-secondary-bg: var(--color-bg-tertiary);
        --btn-secondary-text: var(--color-text-primary);
        --btn-secondary-border: var(--color-border);
        --btn-secondary-hover-bg: var(--color-border);
        --user-profile-bg: var(--color-bg-tertiary);
        --user-profile-border: var(--color-border);
        --toggle-track: var(--color-border);
        --slider-thumb-bg: var(--color-brand);
        --slider-thumb-border: rgba(var(--brand-rgb), 0.3);
        --input-focus-shadow: 0 0 0 3px rgba(var(--brand-rgb), 0.1);
        --toast-bg: var(--color-bg-secondary);
        --toast-border: var(--color-border);
        --toast-shadow: var(--shadow-lg);
        --session-switcher-bg: var(--color-bg-tertiary);
        --session-switcher-border: var(--color-border);
        --panel-section-header-bg: var(--color-bg-tertiary);
        --select-bg: var(--color-bg-input);
        --header-divider: rgba(0, 0, 0, 0.12);
    }
}