:root {
    --bg-color: #0f172a;
    --panel-bg: rgba(30, 41, 59, 0.7);
    --text-color: #f8fafc;
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --secondary: #10b981;
    --secondary-hover: #059669;
    --border: #334155;
    
    /* Board colors */
    --cell-bg: #1e293b;
    --cell-border: #475569;
}

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

body {
    font-family: 'Inter', system-ui, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    justify-content: center;
}

#app {
    width: 100%;
    max-width: 1200px;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

@media (max-width: 600px) {
    #app {
        padding: 0.5rem;
        gap: 1rem;
    }
    header {
        padding: 1rem;
        flex-direction: column;
        gap: 1rem;
    }
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--panel-bg);
    padding: 1rem 2rem;
    border-radius: 1rem;
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
}

.auth-controls {
    display: flex;
    gap: 1rem;
    align-items: center;
}

main {
    display: grid;
    grid-template-columns: 250px 1fr 300px;
    gap: 2rem;
}

@media (max-width: 1024px) {
    main {
        grid-template-columns: 1fr;
    }
}

.controls-panel, .scores-panel {
    background: var(--panel-bg);
    padding: 1.5rem;
    border-radius: 1rem;
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
    height: fit-content;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.game-container {
    position: relative;
    background: var(--panel-bg);
    padding: 2rem;
    border-radius: 1rem;
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    overflow-x: auto;
}

.timer {
    font-size: 1.2rem;
    font-family: monospace;
    font-weight: bold;
}

/* Board */
.board {
    display: grid;
    gap: 0;
    border: 3px solid var(--text-color);
    background: var(--cell-border);
    user-select: none;
    box-shadow: 0 10px 25px rgba(0,0,0,0.5);
}

.cell {
    width: 45px;
    height: 45px;
    background: var(--cell-bg);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    cursor: pointer;
    transition: filter 0.2s, transform 0.1s;
    position: relative;
}

@media (max-width: 600px) {
    .controls-panel, .scores-panel, .game-container {
        padding: 1rem;
    }
    .cell {
        width: 30px;
        height: 30px;
        font-size: 1rem;
    }
}

.cell:hover {
    filter: brightness(1.3);
}

.cell:active {
    transform: scale(0.95);
}

/* Region Borders (computed in JS and added via classes) */
.border-top { border-top: 3px solid var(--text-color) !important; }
.border-bottom { border-bottom: 3px solid var(--text-color) !important; }
.border-left { border-left: 3px solid var(--text-color) !important; }
.border-right { border-right: 3px solid var(--text-color) !important; }
.border-thin-top { border-top: 1px solid var(--cell-border); }
.border-thin-bottom { border-bottom: 1px solid var(--cell-border); }
.border-thin-left { border-left: 1px solid var(--cell-border); }
.border-thin-right { border-right: 1px solid var(--cell-border); }


/* Flags and Stars */
.cell.flag::after {
    content: "✕";
    color: #ef4444;
    font-size: 1rem;
    opacity: 0.8;
}
.cell.star::after {
    content: "⭐";
    font-size: 1.5rem;
    position: absolute;
    animation: popIn 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.3));
}
@media (max-width: 600px) {
    .cell.star::after {
        font-size: 1.1rem;
    }
}
@keyframes popIn {
    0% { transform: scale(0); }
    100% { transform: scale(1); }
}
.cell.error {
    background-color: #7f1d1d !important;
}

/* Form Controls */
button {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 0.5rem;
    cursor: pointer;
    font-weight: 600;
    font-family: inherit;
    transition: all 0.2s;
    background: #334155;
    color: white;
}
button:hover { background: #475569; }

.primary-btn {
    background: var(--primary);
    color: white;
}
.primary-btn:hover { background: var(--primary-hover); }
.secondary-btn {
    background: var(--secondary);
    color: white;
}
.secondary-btn:hover { background: var(--secondary-hover); }

select {
    padding: 0.5rem;
    border-radius: 0.5rem;
    background: var(--bg-color);
    color: var(--text-color);
    border: 1px solid var(--border);
    width: 100%;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

/* Toggle Switch */
.toggle {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    user-select: none;
}
.toggle input {
    display: none;
}
.slider {
    width: 40px;
    height: 20px;
    background: var(--cell-bg);
    border-radius: 10px;
    position: relative;
    transition: 0.3s;
    border: 1px solid var(--border);
}
.slider::before {
    content: "";
    position: absolute;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--text-color);
    top: 2px;
    left: 2px;
    transition: 0.3s;
}
.toggle input:checked + .slider {
    background: var(--primary);
}
.toggle input:checked + .slider::before {
    transform: translateX(20px);
}

/* Overlays */
#loading-overlay, #win-overlay {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(15, 23, 42, 0.9);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 10;
    border-radius: 1rem;
    backdrop-filter: blur(5px);
}
.hidden {
    display: none !important;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--cell-bg);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* Dialogs */
dialog {
    margin: auto;
    padding: 2rem;
    background: var(--bg-color);
    color: var(--text-color);
    border: 1px solid var(--border);
    border-radius: 1rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    max-width: 400px;
    width: 100%;
}
dialog::backdrop {
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}
.input-group {
    margin: 1rem 0;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}
.input-group input {
    padding: 0.5rem;
    border-radius: 0.5rem;
    border: 1px solid var(--border);
    background: var(--cell-bg);
    color: var(--text-color);
}
.dialog-actions {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
    margin-top: 1.5rem;
}
.error-message {
    color: #ef4444;
    font-size: 0.875rem;
    min-height: 1.2rem;
}

/* Scores table */
.score-size-group {
    margin-bottom: 1rem;
    background: rgba(0,0,0,0.2);
    padding: 1rem;
    border-radius: 0.5rem;
}
.score-size-group h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--primary);
    border-bottom: 1px solid var(--border);
    padding-bottom: 0.5rem;
}
.score-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}
.score-item {
    display: flex;
    justify-content: space-between;
    font-family: monospace;
    font-size: 1rem;
}
.score-item .rank {
    width: 25px;
    color: #94a3b8;
}
.score-item .name {
    flex-grow: 1;
}
.score-item .time {
    font-weight: bold;
    color: var(--secondary);
}