/* Theme variables */
:root {
    --bg-gradient: linear-gradient(120deg, #232526 0%, #414345 100%);
    --panel-bg: rgba(40, 44, 52, 0.45);
    --panel-border: rgba(255,255,255,0.08);
    --primary: #8f94fb;
    --primary-dark: #4e54c8;
    --primary-light: #ffe082;
    --cell-bg: rgba(255,255,255,0.18);
    --cell-border: #8f94fb;
    --cell-hover: rgba(143, 148, 251, 0.22);
    --cell-text: #fff;
    --cell-text-win: #ffe082;
    --score-text: #fff;
    --status-text: #ffe082;
    --button-bg: linear-gradient(90deg, #4e54c8 0%, #8f94fb 100%);
    --button-bg-active: linear-gradient(90deg, #232526 0%, #4e54c8 100%);
    --button-text: #fff;
    --button-border: none;
    --button-shadow: 0 4px 16px #4e54c880;
    --input-bg: rgba(40, 44, 52, 0.45);
    --input-border: #8f94fb;
    --label-text: #ffe082;
}

body.theme-light {
    --bg-gradient: linear-gradient(120deg, #f8fafc 0%, #e2e8f0 100%);
    --panel-bg: rgba(255,255,255,0.85);
    --panel-border: #e2e8f0;
    --primary: #4e54c8;
    --primary-dark: #232526;
    --primary-light: #4e54c8;
    --cell-bg: #fff;
    --cell-border: #4e54c8;
    --cell-hover: #e2e8f0;
    --cell-text: #232526;
    --cell-text-win: #4e54c8;
    --score-text: #232526;
    --status-text: #4e54c8;
    --button-bg: linear-gradient(90deg, #8f94fb 0%, #4e54c8 100%);
    --button-bg-active: linear-gradient(90deg, #e2e8f0 0%, #8f94fb 100%);
    --button-text: #232526;
    --button-border: none;
    --button-shadow: 0 4px 16px #4e54c880;
    --input-bg: #fff;
    --input-border: #4e54c8;
    --label-text: #4e54c8;
}

body.theme-solarized {
    --bg-gradient: linear-gradient(120deg, #fdf6e3 0%, #eee8d5 100%);
    --panel-bg: #fdf6e3;
    --panel-border: #eee8d5;
    --primary: #268bd2;
    --primary-dark: #073642;
    --primary-light: #b58900;
    --cell-bg: #eee8d5;
    --cell-border: #268bd2;
    --cell-hover: #b58900;
    --cell-text: #073642;
    --cell-text-win: #b58900;
    --score-text: #073642;
    --status-text: #b58900;
    --button-bg: linear-gradient(90deg, #268bd2 0%, #b58900 100%);
    --button-bg-active: linear-gradient(90deg, #073642 0%, #268bd2 100%);
    --button-text: #073642;
    --button-border: none;
    --button-shadow: 0 4px 16px #268bd280;
    --input-bg: #eee8d5;
    --input-border: #268bd2;
    --label-text: #b58900;
}

body.theme-contrast {
    --bg-gradient: linear-gradient(120deg, #000 0%, #222 100%);
    --panel-bg: #000;
    --panel-border: #fff;
    --primary: #fff;
    --primary-dark: #000;
    --primary-light: #fff;
    --cell-bg: #111;
    --cell-border: #fff;
    --cell-hover: #fff;
    --cell-text: #fff;
    --cell-text-win: #ff0;
    --score-text: #fff;
    --status-text: #ff0;
    --button-bg: linear-gradient(90deg, #fff 0%, #ff0 100%);
    --button-bg-active: linear-gradient(90deg, #000 0%, #fff 100%);
    --button-text: #000;
    --button-border: #fff;
    --button-shadow: 0 4px 16px #fff8;
    --input-bg: #111;
    --input-border: #fff;
    --label-text: #ff0;
}

@import url('https://fonts.googleapis.com/css2?family=Press+Start+2P&display=swap');

body.theme-retro {
    --bg-gradient: linear-gradient(120deg, #111 0%, #222 100%);
    --panel-bg: rgba(0, 0, 0, 0.7);
    --panel-border: #0ff;
    --primary: #0ff;
    --primary-dark: #007777;
    --primary-light: #fff;
    --cell-bg: #111;
    --cell-border: #0ff;
    --cell-hover: #0ff;
    --cell-text: #fff;
    --cell-text-win: #0ff;
    --score-text: #fff;
    --status-text: #0ff;
    --button-bg: linear-gradient(90deg, #007777 0%, #0ff 100%);
    --button-bg-active: linear-gradient(90deg, #111 0%, #007777 100%);
    --button-text: #111;
    --button-border: 2px solid #0ff;
    --button-shadow: 0 0 8px #0ff, 0 0 2px #fff inset;
    --input-bg: #111;
    --input-border: #0ff;
    --label-text: #0ff;
    font-family: 'Press Start 2P', monospace, cursive, sans-serif;
}

body.theme-retro h1 {
    text-shadow: 2px 2px #000, 4px 4px #0ff;
    letter-spacing: 2px;
}

body.theme-retro .cell {
    box-shadow: 0 0 8px #0ff;
    text-shadow: 0 0 5px #0ff;
}

body.theme-retro .cell:hover,
body.theme-retro .cell:active {
    background: rgba(0, 255, 255, 0.25);  /* Cyan with low opacity */
    border-color: #0ff;
    box-shadow: 0 0 15px #0ff, 0 0 5px #fff inset;
}

body.theme-retro button,
body.theme-retro .symbol-btn,
body.theme-retro .board-size-btn,
body.theme-retro .difficulty-btn {
    box-shadow: 0 0 8px #0ff;
    text-shadow: none;
}

body.theme-retro button.selected,
body.theme-retro .symbol-btn.selected,
body.theme-retro .board-size-btn.selected,
body.theme-retro .difficulty-btn.selected {
    box-shadow: 0 0 15px #0ff, 0 0 2px #fff inset;
}

body.theme-retro #options-panel > div {
    border: 2px solid #0ff;
    box-shadow: 0 0 8px #0ff;
}

body.theme-retro #game-board {
    box-shadow: 0 0 20px #0ff, 0 0 5px #fff inset;
    border: 4px solid #0ff;
}

body {
    font-family: 'Inter', 'Segoe UI', Arial, sans-serif;
    background: var(--bg-gradient);
    color: var(--score-text);
    min-height: 100vh;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
}

h1 {
    margin-top: 2vh;
    font-size: 2.7rem;
    font-weight: 800;
    letter-spacing: 2px;
    color: var(--cell-text);
    text-shadow: 0 4px 24px #000a;
    background: var(--button-bg);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

#score-board, #game-mode-selection, #player-symbol-selection, #board-size-selection, #difficulty-selection {
    margin: 1.2em 0.5em 0.5em 0.5em;
    display: flex;
    flex-wrap: wrap;
    gap: 1.2em;
    justify-content: center;
    align-items: center;
    font-size: 1.1rem;
    font-weight: 500;
    backdrop-filter: blur(8px) saturate(1.2);
    background: var(--panel-bg);
    box-shadow: 0 4px 24px #0003;
    border: 1.5px solid var(--panel-border);
    padding: 0.7em 1.5em;
    /* No border-radius for sharp corners */
}

#board-size-selection {
    display: flex;
    align-items: center;
    gap: 0.7em;
    justify-content: center;
    margin: 1em 0;
}

#board-size-selection label {
    margin-right: 0.7em;
    font-size: 1.13rem;
    color: var(--label-text);
    font-weight: 600;
}

#game-board {
    display: grid;
    grid-template-columns: repeat(var(--board-size, 3), minmax(60px, 1fr));
    grid-template-rows: repeat(var(--board-size, 3), minmax(60px, 1fr));
    gap: 12px;
    margin: 2vh 0 2vh 0;
    width: 92vw;
    max-width: 440px;
    aspect-ratio: 1 / 1;
    background: var(--panel-bg);
    box-shadow: 0 8px 40px #0007, 0 2px 0 var(--panel-border) inset;
    backdrop-filter: blur(16px) saturate(1.3);
    border: 2px solid var(--panel-border);
    /* No border-radius for sharp corners */
    transition: box-shadow 0.3s;
}

.cell {
    width: 100%;
    height: 100%;
    min-width: 44px;
    min-height: 44px;
    background: var(--cell-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: clamp(2.1rem, 8vw, 4.2rem);
    font-weight: 700;
    color: var(--cell-text);
    cursor: pointer;
    border: 2.5px solid var(--cell-border);
    box-shadow: 0 2px 12px var(--primary-dark)80;
    transition: background 0.3s, box-shadow 0.3s, border-color 0.3s, color 0.3s, transform 0.3s;
    /* No border-radius for sharp corners */
    user-select: none;
    will-change: background, box-shadow, color, transform;
}

.cell:hover, .cell:active {
    background: var(--cell-hover);
    border-color: var(--primary);
    color: var(--cell-text-win);
    box-shadow: 0 6px 24px var(--primary)99;
    transform: scale(1.06);
}

.cell.filled {
    animation: auraPulse 0.5s cubic-bezier(.68,-0.55,.27,1.55);
    box-shadow: 0 0 0px transparent;
}

@keyframes auraPulse {
    0% {
        box-shadow: 0 0 0px transparent;
        transform: scale(1);
    }
    30% {
        box-shadow: 0 0 18px 6px var(--primary, #0ff);
        transform: scale(1.01);
    }
    60% {
        box-shadow: 0 0 12px 3px var(--primary, #0ff);
        transform: scale(1.01);
    }
    100% {
        box-shadow: 0 0 0px transparent;
        transform: scale(1);
    }
}

.cell.filled:hover,
.cell.filled:active {
    background: var(--cell-bg) !important;
    color: var(--cell-text) !important;
    border-color: var(--cell-border) !important;
    transform: scale(1) !important;
    box-shadow: var(--button-shadow) !important;
    opacity: 1 !important;
}

body.theme-retro .cell.filled,
body.theme-retro .cell.filled:hover,
body.theme-retro .cell.filled:active {
    box-shadow: 0 0 8px #0ff;
    text-shadow: 0 0 5px #0ff;
}

@keyframes pop {
    0% { transform: scale(0.92); }
    80% { transform: scale(1.06); }
    100% { transform: scale(1); }
}

#status {
    margin: 1.2em 0 0.5em 0;
    font-size: 1.4rem;
    min-height: 1.5em;
    text-align: center;
    color: var(--status-text);
    text-shadow: 0 2px 8px #000a;
    font-weight: 600;
    letter-spacing: 1px;
    background: var(--panel-bg);
    box-shadow: 0 2px 12px #0002;
    padding: 0.5em 1.2em;
    backdrop-filter: blur(8px) saturate(1.2);
    border: 1.5px solid var(--panel-border);
    /* No border-radius for sharp corners */
}

#reset {
    padding: 0.8em 2.5em;
    font-size: 1.15rem;
    font-weight: 700;
    background: var(--button-bg);
    color: var(--button-text);
    border: var(--button-border);
    box-shadow: var(--button-shadow);
    cursor: pointer;
    margin-bottom: 2vh;
    letter-spacing: 1.2px;
    transition: background 0.2s, box-shadow 0.2s, opacity 0.2s, transform 0.12s;
    /* No border-radius for sharp corners */
}
#reset:active, #reset:focus {
    background: var(--button-bg-active);
    opacity: 0.85;
    transform: scale(0.97);
}

select, input[type="radio"] {
    font-size: 1.08rem;
    padding: 0.3em 0.9em;
    background: var(--input-bg);
    color: var(--score-text);
    border: 1.5px solid var(--input-border);
    outline: none;
    /* No border-radius for sharp corners */
    margin-left: 0.3em;
    margin-right: 0.3em;
    transition: border-color 0.2s, background 0.2s;
    font-weight: 500;
    box-shadow: 0 1px 4px #0002;
}
select:focus, input[type="radio"]:focus {
    border-color: var(--primary-light);
    background: var(--cell-hover);
}

#theme-select {
    border-radius: 0 !important;
}

label {
    font-size: 1.13rem;
    color: var(--label-text);
    margin-right: 0.2em;
    font-weight: 600;
}

#score-board span {
    font-size: 1.13rem;
    color: var(--score-text);
    text-shadow: 0 1px 4px #0008;
    font-weight: 600;
}

.symbol-btn {
    font-size: 1.25rem;
    font-weight: 700;
    padding: 0.45em 1.3em;
    margin: 0 0.3em;
    background: var(--cell-bg);
    color: var(--cell-text);
    border: 2px solid var(--cell-border);
    cursor: pointer;
    transition: background 0.18s, color 0.18s, border-color 0.18s, box-shadow 0.18s;
    box-shadow: 0 1px 6px var(--primary-dark)50;
    outline: none;
    /* No border-radius for sharp corners */
}
.symbol-btn.selected {
    background: var(--button-bg);
    color: var(--primary-light);
    border-color: var(--primary-light);
    box-shadow: 0 2px 12px var(--primary)99;
    z-index: 1;
}
.symbol-btn:focus {
    border-color: var(--primary-light);
    background: var(--cell-hover);
}

.board-size-btn {
    font-size: 1.15rem;
    font-weight: 700;
    padding: 0.5em 1.4em;
    margin: 0 0.3em;
    background: var(--cell-bg);
    color: var(--cell-text);
    border: 2px solid var(--cell-border);
    cursor: pointer;
    transition: background 0.18s, color 0.18s, border-color 0.18s, box-shadow 0.18s, transform 0.12s;
    box-shadow: 0 1px 6px var(--primary-dark)50;
    outline: none;
    letter-spacing: 1px;
    /* No border-radius for sharp corners */
    min-width: 3.5em;
    min-height: 2.2em;
    display: inline-block;
}
.board-size-btn.selected {
    background: var(--button-bg);
    color: var(--primary-light);
    border-color: var(--primary-light);
    box-shadow: 0 2px 12px var(--primary)99;
    z-index: 1;
    transform: scale(1.08);
}
.board-size-btn:focus {
    border-color: var(--primary-light);
    background: var(--cell-hover);
}

.mini-board {
    display: inline-block;
    line-height: 1.1;
    font-size: 0;
    margin: 0;
    padding: 0.1em 0.2em;
}
.mini-board span {
    display: inline-block;
    width: 0.7em;
    height: 0.7em;
    margin: 0.08em;
    background: var(--primary);
    opacity: 0.7;
    border: 1px solid var(--panel-border);
    /* No border-radius for sharp corners */
}
.mini-3 span { width: 0.7em; height: 0.7em; }
.mini-4 span { width: 0.6em; height: 0.6em; }
.mini-5 span { width: 0.5em; height: 0.5em; }

.difficulty-btn {
    background: var(--cell-bg);
    border: 2px solid var(--cell-border);
    margin: 0 0.3em;
    padding: 0.2em 0.6em;
    cursor: pointer;
    transition: border-color 0.18s, box-shadow 0.18s, background 0.18s;
    box-shadow: 0 1px 6px var(--primary-dark)50;
    outline: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    /* No border-radius for sharp corners */
}
.difficulty-btn.selected {
    border-color: var(--primary-light);
    background: var(--button-bg);
    box-shadow: 0 2px 12px var(--primary)99;
    z-index: 1;
}
.difficulty-btn:focus {
    border-color: var(--primary-light);
}
.difficulty-icon {
    font-size: 1.5em;
    line-height: 1;
    pointer-events: none;
}

#top-row-panel {
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: center;
    gap: 1.5em;
    margin-bottom: 0.7em;
}
#top-row-panel #status {
    margin: 0;
    font-size: 1.2rem;
    min-width: 120px;
    text-align: right;
    flex: 1 1 auto;
    background: none;
    box-shadow: none;
    padding: 0;
    border: none;
    color: var(--status-text);
    font-weight: 600;
    letter-spacing: 1px;
}
#top-row-panel #reset {
    margin: 0;
    flex: 0 0 auto;
}
@media (max-width: 600px) {
    h1 {
        font-size: 1.5rem;
    }
    #game-board {
        max-width: 99vw;
        gap: 5px;
    }
    .cell {
        font-size: clamp(1.3rem, 10vw, 2.5rem);
        min-width: 28px;
        min-height: 28px;
    }
    #reset {
        padding: 0.6em 1.2em;
        font-size: 1rem;
    }
    #score-board span {
        font-size: 1rem;
    }
    #score-board, #game-mode-selection, #player-symbol-selection, #board-size-selection, #difficulty-selection {
        padding: 0.5em 0.5em;
        font-size: 1rem;
    }
    .mini-board span { width: 0.55em; height: 0.55em; }
    .mini-3 span { width: 0.55em; height: 0.55em; }
    .mini-4 span { width: 0.45em; height: 0.45em; }
    .mini-5 span { width: 0.38em; height: 0.38em; }
    #top-row-panel {
        flex-direction: column;
        gap: 0.5em;
        align-items: stretch;
    }
    #top-row-panel #status {
        text-align: center;
        min-width: 0;
        font-size: 1.05rem;
    }
    .board-size-btn {
        font-size: 1rem;
        padding: 0.4em 1em;
        min-width: 2.5em;
        min-height: 1.7em;
    }
    #board-size-selection label {
        font-size: 1rem;
    }
}

/* Winning cell styles - base properties that work with all themes */
.winning-cell {
    animation: celebrateWin 1.5s ease-in-out 0s 1 both;
    position: relative;
    z-index: 10;
}

@keyframes celebrateWin {
    0% { transform: scale(1); }
    10% { transform: scale(1.08); }
    20% { transform: scale(0.98); }
    30% { transform: scale(1.04); }
    40% { transform: scale(1); }
    100% { transform: scale(1); }
}

/* Default theme winning cell style */
.winning-cell {
    background: linear-gradient(45deg, var(--primary), var(--primary-dark)) !important;
    color: var(--primary-light) !important;
    border-color: var(--primary-light) !important;
    box-shadow: 0 0 15px var(--primary) !important;
}

/* Retro theme winning cell style overrides */
body.theme-retro .winning-cell {
    background: #000 !important;
    color: #0ff !important;
    border-color: #0ff !important;
    animation: retroWin 1.5s ease-in-out 0s infinite both;
    text-shadow: 0 0 10px #0ff, 0 0 15px #0ff !important;
    box-shadow: 0 0 20px #0ff !important;
}

@keyframes retroWin {
    0% { box-shadow: 0 0 10px #0ff; }
    50% { box-shadow: 0 0 18px #0ff, 0 0 24px #0ff; }
    100% { box-shadow: 0 0 10px #0ff; }
}

/* Light theme winning cell style overrides */
body.theme-light .winning-cell {
    background: linear-gradient(45deg, #4e54c8, #8f94fb) !important;
    color: #fff !important;
}

/* Solarized theme winning cell style overrides */
body.theme-solarized .winning-cell {
    background: linear-gradient(45deg, #268bd2, #b58900) !important;
    color: #fff !important;
}

/* High Contrast theme winning cell style overrides */
body.theme-contrast .winning-cell {
    background: #fff !important;
    color: #000 !important;
    border: 4px double #ff0 !important;
}