/* ────────────────────────────────────────────────────────────────────────── */
/*  Quantum TiqTaqToe — Level 3 Tactical UI                                   */
/*  DARK theme. Cartoon-bold pieces. Long-press = red underline animation     */
/*  → piece turns red on measure completion. Drag = grey outlined preview.    */
/* ────────────────────────────────────────────────────────────────────────── */

:root {
    /* Dark surface palette */
    --bg-color:      #0f172a;
    --card-bg:       #1e293b;
    --board-bg:      #1e293b;
    --cell-bg:       #0f172a;
    --cell-hover-bg: #1e293b;
    --text-color:    #f8fafc;
    --muted-text:    #94a3b8;
    --border-color:  #334155;
    --accent-color:  #38bdf8;

    /* Piece colors — dark theme palette
       Convention:
         • measured / locked         → RED
         • unmeasured-classical X    → GREEN
         • unmeasured-classical O    → BLUE
         • split / entangle ghost    → edge-slot color (variant by edge index)
       Glyph shapes carry the rest of the semantics:
         • solid X (×)        → classical X
         • solid O (ring)     → classical O
         • Y shape            → X in superposition (split/entangle)
         • C-with-tail        → O in superposition (split/entangle)              */
    --locked-color:     #ef4444;        /* RED for any measured piece            */
    --x-classical:      #22c55e;        /* GREEN unmeasured classical X          */
    --o-classical:      #3b82f6;        /* BLUE  unmeasured classical O          */
    --ghost-preview:    #64748b;        /* grey outline-only drag preview        */
    --piece-outline:    #f8fafc;        /* off-white cartoon outline on dark bg  */

    /* Edge slot colors */
    --edge-0: #22c55e;     /* green   */
    --edge-1: #f97316;     /* orange  */
    --edge-2: #a855f7;     /* purple  */
    --edge-3: #22d3ee;     /* cyan    */

    --measure-color:    #ef4444;        /* red underline animation               */
    --shadow-soft:      0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-pop:       0 4px 12px rgba(0, 0, 0, 0.45);
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", sans-serif;
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
}

header {
    padding: 1rem 1.25rem;
    background-color: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}
header h1 { font-size: 1.25rem; font-weight: 700; }

main { display: flex; flex: 1; overflow: hidden; }

#game-container {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem;
    position: relative;
}

/* ───── Board grid ──────────────────────────────────────────────────────── */

#board {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(3, 1fr);
    gap: 0.75rem;
    width: 420px;
    height: 420px;
    background-color: var(--board-bg);
    padding: 0.75rem;
    border-radius: 1rem;
    box-shadow: var(--shadow-soft);
}

.square {
    background-color: var(--cell-bg);
    border: 2px solid var(--border-color);
    border-radius: 0.75rem;
    position: relative;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    user-select: none;
    overflow: hidden;
    transition: background-color 0.18s ease, transform 0.12s ease,
                box-shadow 0.18s ease, border-color 0.18s ease;
}
.square:hover {
    background-color: var(--cell-hover-bg);
    box-shadow: var(--shadow-pop);
}
.square:active { transform: scale(0.97); }

.square::before {
    content: attr(data-sq);
    position: absolute;
    top: 0.4rem;
    left: 0.5rem;
    font-size: 0.7rem;
    color: var(--muted-text);
    font-family: ui-monospace, SFMono-Regular, "JetBrains Mono", monospace;
    pointer-events: none;
}

/* ───── Piece glyphs (cartoon-bold: white outline + colored stroke) ──────── */

.piece-svg {
    width: 72%;
    height: 72%;
    pointer-events: none;
    animation: piece-pop 220ms cubic-bezier(0.34, 1.56, 0.64, 1) both;
}

@keyframes piece-pop {
    0%   { opacity: 0; transform: scale(0.4);  }
    60%  { opacity: 1; transform: scale(1.10); }
    100% { opacity: 1; transform: scale(1);    }
}

.glyph-outline {
    stroke: var(--piece-outline);
    stroke-width: 22;
    fill: none;
    stroke-linecap: round;
    stroke-linejoin: round;
    opacity: 0.18;       /* subtle dark-theme outline, not a full halo  */
}
.glyph-fill {
    fill: none;
    stroke-width: 14;
    stroke-linecap: round;
    stroke-linejoin: round;
}

/* ── Classical pieces: solid X (crossed strokes) and solid O (thick ring) ── */
.locked-x       .glyph-fill { stroke: var(--locked-color);  }
.locked-o       .glyph-fill { stroke: var(--locked-color);  }
.unmeasured-x   .glyph-fill { stroke: var(--x-classical);   }
.unmeasured-o   .glyph-fill { stroke: var(--o-classical);   }

/* ── Quantum (edge member) pieces: Y for X, C-with-tail for O ──────────────
   Coloring follows the edge slot index so multiple edges are distinguishable. */
.ghost-x .glyph-fill,
.ghost-o .glyph-fill {
    stroke: var(--ghost-slot-color, var(--edge-0));
    opacity: 0.95;
}

.ghost-layer {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
    pointer-events: none;
}
.ghost-svg {
    width: 60%;
    height: 60%;
    animation: piece-pop 220ms cubic-bezier(0.34, 1.56, 0.64, 1) both;
}

/* Edge-member cell border tint per slot */
.edge-member {
    border-color: var(--edge-cell-color, var(--edge-0));
}

/* 4-chain: outer glow ring same color as the border to distinguish from 3-chain */
.edge-member.quad-chain {
    box-shadow: 0 0 0 3px var(--edge-cell-color, var(--edge-0));
}

/* ── Drag preview: grey outline-only ghost of the piece you'd be placing ─── */
.drag-preview .glyph-fill {
    stroke: var(--ghost-preview);
    opacity: 0.65;
    stroke-dasharray: 8 4;
}
.drag-preview .glyph-outline { display: none; }

.drag-preview-el { pointer-events: none; }

.preview-svg {
    width: 72%;
    height: 72%;
    pointer-events: none;
    animation: preview-fade 180ms ease-out both;
}
.preview-svg.ghost-size { width: 60%; height: 60%; }

@keyframes preview-fade {
    0%   { opacity: 0; transform: scale(0.85); }
    100% { opacity: 1; transform: scale(1);    }
}

/* ── Long-press measure: red underline that fills from 0% to 100% over 600ms ─ */
.square.measuring {
    /* lock background so the animated underline reads clearly */
    background-color: var(--cell-hover-bg);
}
.square.measuring::after {
    content: '';
    position: absolute;
    left: 12%;
    right: 12%;
    bottom: 12%;
    height: 5px;
    background-color: var(--measure-color);
    border-radius: 3px;
    transform-origin: left center;
    animation: measure-fill 600ms linear forwards;
}
@keyframes measure-fill {
    0%   { transform: scaleX(0); }
    100% { transform: scaleX(1); }
}

/* ───── Side panel (analysis) ───────────────────────────────────────────── */

#analysis-panel {
    width: 360px;
    background-color: var(--card-bg);
    border-left: 1px solid var(--border-color);
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
}
.panel-section { margin-bottom: 1.5rem; }
.panel-section h2 {
    font-size: 0.75rem;
    text-transform: uppercase;
    color: var(--muted-text);
    margin-bottom: 0.5rem;
    letter-spacing: 0.08em;
    font-weight: 600;
}

#eval-value { font-size: 2rem; font-weight: 700; margin-bottom: 0.5rem; }

#eval-bar-container {
    height: 8px;
    background-color: var(--border-color);
    border-radius: 4px;
    overflow: hidden;
}
#eval-bar { height: 100%; width: 50%; transition: width 0.3s, background-color 0.3s; }

table { width: 100%; border-collapse: collapse; font-size: 0.875rem; }
th {
    text-align: left;
    padding: 0.5rem 0.4rem;
    color: var(--muted-text);
    border-bottom: 1px solid var(--border-color);
    font-weight: 600;
}
td { padding: 0.5rem 0.4rem; border-bottom: 1px solid var(--border-color); }

.source-badge {
    font-size: 0.7rem;
    padding: 0.15rem 0.45rem;
    border-radius: 999px;
    background-color: var(--border-color);
    color: var(--text-color);
    font-weight: 600;
    letter-spacing: 0.02em;
}

/* ───── Best-move highlight (subtle, not the measure animation) ─────────── */
.best-move-highlight { outline: 3px solid #fbbf24; outline-offset: -2px; }

/* ───── Footer + spinner + help modal ───────────────────────────────────── */

footer {
    padding: 0.75rem 1.25rem;
    background-color: var(--card-bg);
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.875rem;
}
#status-text { font-weight: 500; }
#last-move-text { color: var(--muted-text); }
.help-toggle { cursor: pointer; color: var(--accent-color); font-size: 0.875rem; font-weight: 500; }

#help-modal {
    display: none;
    position: fixed;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: 2rem;
    z-index: 100;
    border-radius: 1rem;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.6);
    max-width: 520px;
}
#help-modal h2 { margin-bottom: 1rem; }
#help-modal table td { padding: 0.5rem 1rem; border-bottom-color: var(--border-color); }

.overlay {
    display: none;
    position: fixed;
    inset: 0;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 90;
}

#spinner {
    display: none;
    width: 1rem;
    height: 1rem;
    border: 2px solid var(--text-color);
    border-top-color: transparent;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-left: 0.5rem;
}
@keyframes spin { to { transform: rotate(360deg); } }

.game-over-banner {
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    background-color: var(--card-bg);
    padding: 2rem 3rem;
    border-radius: 1rem;
    text-align: center;
    z-index: 20;
    border: 2px solid var(--accent-color);
    box-shadow: var(--shadow-pop);
}
.game-over-banner h2 { font-size: 2.5rem; margin-bottom: 1rem; font-weight: 800; letter-spacing: 0.02em; }

/* ───── Setup Position controls bar ─────────────────────────────────────── */

#setup-controls {
    display: none;
    align-items: center;
    gap: 0.75rem;
    padding: 0.6rem 1.25rem;
    background-color: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    font-size: 0.875rem;
    flex-wrap: wrap;
}
#setup-controls label {
    display: flex;
    align-items: center;
    gap: 0.3rem;
    cursor: pointer;
}
.setup-divider { margin-left: 1rem; }

/* ───── Setup button (secondary style) ──────────────────────────────────── */
button.setup-btn {
    background-color: transparent;
    color: var(--accent-color);
    border: 1.5px solid var(--accent-color);
    padding: 0.5rem 1.25rem;
    border-radius: 0.5rem;
    font-weight: 600;
    font-size: 0.875rem;
    cursor: pointer;
    transition: background-color 0.15s ease, transform 0.1s ease;
}
button.setup-btn:hover  { background-color: rgba(56, 189, 248, 0.1); }
button.setup-btn:active { transform: scale(0.97); }

/* ───── Cancel button override ───────────────────────────────────────────── */
button.setup-cancel-btn {
    background-color: var(--border-color);
    color: var(--text-color);
}
button.setup-cancel-btn:hover { filter: brightness(1.15); }

/* ───── Board squares in setup mode ──────────────────────────────────────── */
.square.setup-mode {
    border-style: dashed;
    cursor: cell;
}
.square.setup-mode:hover { border-color: var(--accent-color); }

/* Source square highlight while dragging to create an edge */
.square.setup-drag-hint {
    border-color: var(--accent-color);
    border-style: solid;
    background-color: rgba(56, 189, 248, 0.12);
}

button.new-game-btn {
    background-color: var(--accent-color);
    color: var(--bg-color);
    border: none;
    padding: 0.5rem 1.25rem;
    border-radius: 0.5rem;
    font-weight: 600;
    font-size: 0.875rem;
    cursor: pointer;
    transition: filter 0.15s ease, transform 0.1s ease;
}
button.new-game-btn:hover  { filter: brightness(1.08); }
button.new-game-btn:active { transform: scale(0.97); }