:root {
    --logo-invert: 100%;  /* 100% for white, 0% for black */
    --bg-primary: #121212;
    --bg-secondary: #2f2f2f;
    --episode-container: #e85a5a;
    --episode-container-rgb: 232, 90, 90;
    --button-color: #232323;
    --text-primary: #ffffff;
    --text-secondary: #b3b3b3;
    --accent-color: #1b1b1b;
    --header-bg: #242424;
    --blend-color: #121212;
    --search-bar-color: #e7e7e7;
}

.dark-theme:root {
    --logo-invert: 100%;
    --bg-primary: #15171c; 
    --bg-secondary: #1c1f26;
    --episode-container: #a14d69;
    --episode-container-rgb: 161, 77, 105;
    --button-color: #252830;
    --text-primary: #e1e3e8;
    --text-secondary: #9498a4;
    --accent-color: #191c22;
    --header-bg: #15171c;
    --blend-color: #15171c;
    --search-bar-color: #e6e8ed;
}

.light-theme:root {
    --logo-invert: 0%;
    --bg-primary: #f5efe6;
    --bg-secondary: #e8e0d4;
    --episode-container: #d4776a;
    --episode-container-rgb: 212, 119, 106;
    --button-color: #ded5c7;
    --text-primary: #382e27;
    /* old was 6b5c51 */
    --text-secondary: #6b5c51;
    --accent-color: #cfc3b4;
    --header-bg: rgba(245, 239, 230, 1);
    --search-bar-color: #2c241f;
}

.amoled-theme:root {
    --logo-invert: 100%;
    --bg-primary: #000000;
    --bg-secondary: #121212;
    --episode-container: #8B3A3A;
    --episode-container-rgb: 139, 58, 58;
    --button-color: #222222;
    --text-primary: #e0e0e0;
    --text-secondary: #8a8a8a;
    --accent-color: #141414;
    --header-bg: #000000;
    --blend-color: #000000;
    --search-bar-color: #d4d4d4;
}

/* ❄️ Winter/Christmas Theme */
.winter-theme:root {
    --logo-invert: 100%;
    --bg-primary: #0f1a2b;
    --bg-secondary: #162236;
    --episode-container: #5b8fb9;
    --episode-container-rgb: 91, 143, 185;
    --button-color: #1d2d44;
    --text-primary: #e8f1f8;
    --text-secondary: #8aacc8;
    --accent-color: #1a2840;
    --header-bg: #0f1a2b;
    --blend-color: #0f1a2b;
    --search-bar-color: #c9dbe8;
}

/* ===== KAI THEME — Modern Premium Dark ===== */
.kai-theme:root {
    --logo-invert: 100%;
    --bg-primary: #101216;
    --bg-secondary: #1A1C22;
    --bg-hover: #2C2F36;
    --text-primary: #FFFFFF;
    --text-secondary: #8B919D;
    --accent-color: #EF6342;
    --accent-primary: #EF6342;
    --accent-secondary: #26A355;
    --accent-color-rgb: 239, 99, 66;
    --accent-color-hover: #d4552e;
    --accent-color-transparent: rgba(239, 99, 66, 0.15);
    --button-color: #2C2F36;
    --button-hover-color: #d4552e;
    --header-bg: #1A1C22;
    --episode-container: #EF6342;
    --episode-container-rgb: 239, 99, 66;
    --blend-color: #101216;
    --search-bar-color: #e6e8ed;
    --border-color: rgba(255, 255, 255, 0.05);
}

/* ✅ Utility Classes for Kai Theme */
.kai-theme .btn-primary {
    background-color: #EF6342;
    color: #FFFFFF;
}
.kai-theme .btn-secondary {
    background-color: #1A1C22;
    color: #FFFFFF;
}
.kai-theme .search-bar-hero {
    background-color: #FFFFFF;
    color: #101216;
}
.kai-theme .badge-age {
    background-color: #26A355;
}
.kai-theme .badge-episode {
    background-color: #EF6342;
}

/* ===== SPRING THEME — Cherry Blossom (Light) ===== */
.spring-theme:root {
    --logo-invert: 0%;
    --bg-primary: #FFF5F7;
    --bg-secondary: #F8EDF0;
    --episode-container: #E880A8;
    --episode-container-rgb: 232, 128, 168;
    --button-color: #E8D5DD;
    --text-primary: #2D1B29;
    --text-secondary: #8A6B7E;
    --accent-color: #E880A8;
    --accent-secondary: #7EC89B;
    --header-bg: rgba(255, 245, 247, 0.95);
    --blend-color: #FFF5F7;
    --search-bar-color: #2D1B29;
}

/* ===== AUTUMN THEME — Warm Dark / Moody Autumn ===== */
.autumn-theme:root {
    --logo-invert: 100%;
    --bg-primary: #1C1816;
    --bg-secondary: #2A2420;
    --episode-container: #C76B1E;
    --episode-container-rgb: 199, 107, 30;
    --button-color: #3A322C;
    --text-primary: #E8DCC8;
    --text-secondary: #A6957C;
    --accent-color: #D47A2E;
    --accent-secondary: #8B4513;
    --header-bg: rgba(28, 24, 22, 0.95);
    --blend-color: #1C1816;
    --search-bar-color: #E8DCC8;
}

/* ===== SUMMER THEME — Golden Sun (Light) ===== */
.summer-theme:root {
    --logo-invert: 0%;
    --bg-primary: #FFFBF0;
    --bg-secondary: #F5F0E5;
    --episode-container: #F4A261;
    --episode-container-rgb: 244, 162, 97;
    --button-color: #EBE5D8;
    --text-primary: #1F1B14;
    --text-secondary: #8A7E6B;
    --accent-color: #F4A261;
    --accent-secondary: #E8923F;
    --header-bg: rgba(255, 251, 240, 0.95);
    --blend-color: #FFFBF0;
    --search-bar-color: #1F1B14;
}

/* ❄️ Subtle snowfall background for winter theme - GPU optimized */
.winter-theme body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 9999;
    contain: strict;
    background-image: 
        radial-gradient(2.5px 2.5px at 20% 20%, rgba(255, 255, 255, 0.4) 50%, transparent 50%),
        radial-gradient(2.5px 2.5px at 60% 40%, rgba(255, 255, 255, 0.35) 50%, transparent 50%),
        radial-gradient(2px 2px at 80% 15%, rgba(255, 255, 255, 0.4) 50%, transparent 50%),
        radial-gradient(2px 2px at 40% 70%, rgba(255, 255, 255, 0.35) 50%, transparent 50%);
    background-size: 250px 250px;
    opacity: 0.5;
    will-change: transform;
    animation: snowfall 20s linear infinite;
    transform: translateZ(0);
}

@keyframes snowfall {
    from {
        transform: translateY(-250px) translateZ(0);
    }
    to {
        transform: translateY(0) translateZ(0);
    }
}

/* 🌸 Cherry blossom petal background for spring theme - GPU optimized */
.spring-theme body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 9999;
    contain: strict;
    background-image:
        radial-gradient(5px 5px at 15% 10%, rgba(199, 80, 130, 0.4) 50%, transparent 50%),
        radial-gradient(4px 4px at 55% 5%, rgba(199, 80, 130, 0.3) 50%, transparent 50%),
        radial-gradient(6px 6px at 85% 15%, rgba(199, 80, 130, 0.35) 50%, transparent 50%),
        radial-gradient(3.5px 3.5px at 30% 25%, rgba(199, 80, 130, 0.25) 50%, transparent 50%),
        radial-gradient(4.5px 4.5px at 70% 20%, rgba(199, 80, 130, 0.3) 50%, transparent 50%),
        radial-gradient(3px 3px at 45% 40%, rgba(199, 80, 130, 0.2) 50%, transparent 50%);
    background-size: 300px 300px;
    opacity: 0.55;
    will-change: transform;
    animation: petal-fall 22s linear infinite;
    transform: translateZ(0);
}

@keyframes petal-fall {
    0% {
        transform: translateY(-300px) translateX(0) translateZ(0);
    }
    25% {
        transform: translateY(-150px) translateX(15px) translateZ(0);
    }
    50% {
        transform: translateY(0) translateX(-10px) translateZ(0);
    }
    75% {
        transform: translateY(150px) translateX(20px) translateZ(0);
    }
    100% {
        transform: translateY(300px) translateX(-5px) translateZ(0);
    }
}

/* ☀️ Golden sun sparkle background for summer theme - GPU optimized */
.summer-theme body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 9999;
    contain: strict;
    background-image:
        radial-gradient(3px 3px at 12% 8%, rgba(212, 150, 40, 0.4) 50%, transparent 50%),
        radial-gradient(2.5px 2.5px at 48% 15%, rgba(212, 150, 40, 0.3) 50%, transparent 50%),
        radial-gradient(4px 4px at 78% 5%, rgba(212, 150, 40, 0.35) 50%, transparent 50%),
        radial-gradient(2px 2px at 22% 30%, rgba(212, 150, 40, 0.25) 50%, transparent 50%),
        radial-gradient(3px 3px at 65% 22%, rgba(244, 162, 97, 0.3) 50%, transparent 50%),
        radial-gradient(2.5px 2.5px at 38% 45%, rgba(212, 150, 40, 0.2) 50%, transparent 50%);
    background-size: 280px 280px;
    opacity: 0.5;
    will-change: transform;
    animation: sun-sparkle 18s linear infinite;
    transform: translateZ(0);
}

@keyframes sun-sparkle {
    0% {
        transform: translateY(-280px) translateZ(0);
        opacity: 0.5;
    }
    50% {
        opacity: 0.8;
    }
    100% {
        transform: translateY(280px) translateZ(0);
        opacity: 0.5;
    }
}

/* 🌧️ Subtle rain streaks background for autumn theme - GPU optimized */
.autumn-theme body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 9999;
    contain: strict;
    background-image:
        repeating-linear-gradient(96deg,
            transparent 0px, transparent 17px,
            rgba(200, 210, 225, 0.07) 17px, rgba(200, 210, 225, 0.07) 17.3px,
            transparent 17.3px, transparent 34px),
        repeating-linear-gradient(84deg,
            transparent 0px, transparent 32px,
            rgba(190, 200, 215, 0.04) 32px, rgba(190, 200, 215, 0.04) 32.4px,
            transparent 32.4px, transparent 64px),
        repeating-linear-gradient(105deg,
            transparent 0px, transparent 55px,
            rgba(210, 220, 235, 0.03) 55px, rgba(210, 220, 235, 0.03) 55.6px,
            transparent 55.6px, transparent 110px);
    background-size: 100% 100%;
    opacity: 0.7;
    will-change: background-position;
    animation: autumn-rain 1.8s linear infinite;
}

@keyframes autumn-rain {
    0% { background-position: 0 0, 0 0, 0 0; }
    100% { background-position: 0 -34px, 0 -64px, 0 -110px; }
}