/* ===== CSS Variables ===== */
:root {
    /* Colors */
    --bg-gradient-start: #0f0c29;
    --bg-gradient-mid: #302b63;
    --bg-gradient-end: #24243e;
    --primary-color: #6c5ce7;
    --secondary-color: #00b894;
    --danger-color: #d63031;
    --warning-color: #fdcb6e;
    --text-light: #ffffff;
    --text-dark: #2d3436;

    /* Cell Colors */
    --cell-bg: rgba(255, 255, 255, 0.1);
    --cell-bg-hover: rgba(255, 255, 255, 0.15);
    --cell-revealed: rgba(255, 255, 255, 0.95);
    --cell-flag: #ff7675;
    --cell-mine: linear-gradient(135deg, #e74c3c, #c0392b);

    /* Number Colors */
    --num-1: #0984e3;
    --num-2: #00b894;
    --num-3: #e17055;
    --num-4: #6c5ce7;
    --num-5: #d63031;
    --num-6: #00cec9;
    --num-7: #2d3436;
    --num-8: #636e72;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 20px rgba(108, 92, 231, 0.4);

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* ===== Reset & Base Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, var(--bg-gradient-start), var(--bg-gradient-mid), var(--bg-gradient-end));
    color: var(--text-light);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow-x: hidden;
    touch-action: manipulation;
    user-select: none;
    -webkit-user-select: none;
}

/* ===== Game Container ===== */
.game-container {
    width: 100%;
    max-width: 600px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    padding: var(--spacing-md);
    position: relative;
}

/* ===== Header ===== */
.game-header {
    text-align: center;
    margin-bottom: var(--spacing-md);
    animation: fadeInDown 0.6s ease;
}

.game-title {
    font-size: 2rem;
    font-weight: 800;
    background: linear-gradient(135deg, #a29bfe, #6c5ce7);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-xs);
    text-shadow: 0 4px 8px rgba(108, 92, 231, 0.3);
}

.game-subtitle {
    font-size: 0.75rem;
    color: rgba(255, 255, 255, 0.6);
    text-transform: uppercase;
    letter-spacing: 2px;
    font-weight: 500;
}

/* ===== Screen Management ===== */
.screen {
    display: none;
    flex-direction: column;
    flex: 1;
    animation: fadeIn 0.4s ease;
}

.screen.active {
    display: flex;
}

.screen-title {
    font-size: 1.25rem;
    text-align: center;
    margin-bottom: var(--spacing-md);
    font-weight: 700;
}

/* ===== Difficulty Selection ===== */
#difficulty-screen {
    justify-content: center;
}

/* Instructions */
.instructions {
    display: flex;
    gap: var(--spacing-sm);
    max-width: 400px;
    margin: 0 auto;
    width: 100%;
}

.instructions-separator {
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    max-width: 400px;
    margin: var(--spacing-lg) auto var(--spacing-md) auto;
}

.instruction-item {
    flex: 1;
    background: rgba(255, 255, 255, 0.08);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: var(--radius-sm);
    padding: var(--spacing-sm) var(--spacing-xs);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    animation: fadeInDown 0.6s ease;
}

.instruction-item:nth-child(1) {
    animation-delay: 0.1s;
}

.instruction-item:nth-child(2) {
    animation-delay: 0.2s;
}

.instruction-icon {
    font-size: 1.5rem;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.3));
}

.instruction-text {
    text-align: center;
}

.instruction-title {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-light);
    margin-bottom: 1px;
}

.instruction-desc {
    font-size: 0.7rem;
    color: rgba(255, 255, 255, 0.5);
    line-height: 1.2;
}

.difficulty-buttons {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    max-width: 400px;
    margin: 0 auto;
    width: 100%;
}

.difficulty-btn {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    color: var(--text-light);
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-normal);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    box-shadow: var(--shadow-md);
}

.difficulty-btn:hover,
.difficulty-btn:active {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    background: rgba(255, 255, 255, 0.15);
    border-color: var(--primary-color);
}

.btn-icon {
    font-size: 2.5rem;
    filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.3));
}

.btn-title {
    font-size: 1.25rem;
    font-weight: 700;
}

.btn-subtitle {
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.7);
}

/* ===== Game Stats ===== */
.game-stats {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    box-shadow: var(--shadow-sm);
}

.stat-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex: 1;
    justify-content: center;
}

.stat-icon {
    font-size: 1.5rem;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.3));
}

.stat-value {
    font-size: 1.25rem;
    font-weight: 700;
    min-width: 3ch;
    text-align: center;
    font-variant-numeric: tabular-nums;
}

.icon-btn {
    background: transparent;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    padding: var(--spacing-xs);
    transition: transform var(--transition-fast);
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.3));
}

.icon-btn:active {
    transform: scale(0.9);
}

.hidden {
    display: none !important;
}

/* ===== Game Board ===== */
.board-container {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
    overflow: auto;
    padding: var(--spacing-xs);
}

.game-board {
    display: grid;
    gap: 2px;
    background: rgba(0, 0, 0, 0.3);
    padding: 4px;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    backdrop-filter: blur(10px);
}

/* Cell Sizing - Responsive */
.game-board {
    width: fit-content;
    margin: 0 auto;
}

.cell {
    aspect-ratio: 1;
    background: var(--cell-bg);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    user-select: none;
    -webkit-user-select: none;
    touch-action: manipulation;
}

/* Dynamic cell sizing based on difficulty */
.game-board.easy .cell {
    width: min(10vw, 42px);
    font-size: 1.1rem;
}

.game-board.medium .cell {
    width: min(8.5vw, 36px);
    font-size: 0.95rem;
}

.game-board.hard .cell {
    width: min(7.2vw, 30px);
    font-size: 0.85rem;
}

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

.cell.revealed {
    background: var(--cell-revealed);
    color: var(--text-dark);
    cursor: default;
    border-color: rgba(0, 0, 0, 0.1);
}

.cell.flagged {
    background: rgba(255, 118, 117, 0.3);
    animation: flagPop 0.3s ease;
}

.cell.flagged::before {
    content: '🚩';
    font-size: 1.2em;
}

.cell.mine {
    background: var(--cell-mine);
    animation: explode 0.4s ease;
}

.cell.mine::before {
    content: '💣';
    font-size: 1.3em;
    animation: shake 0.4s ease;
}

.cell.mine-wrong {
    background: rgba(255, 107, 107, 0.5);
}

.cell.mine-wrong::before {
    content: '❌';
}

/* Number Colors */
.cell[data-count="1"] {
    color: var(--num-1);
}

.cell[data-count="2"] {
    color: var(--num-2);
}

.cell[data-count="3"] {
    color: var(--num-3);
}

.cell[data-count="4"] {
    color: var(--num-4);
}

.cell[data-count="5"] {
    color: var(--num-5);
}

.cell[data-count="6"] {
    color: var(--num-6);
}

.cell[data-count="7"] {
    color: var(--num-7);
}

.cell[data-count="8"] {
    color: var(--num-8);
}

/* ===== Game Controls ===== */
.game-controls {
    display: flex;
    gap: var(--spacing-md);
}

.control-btn {
    flex: 1;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    border: none;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    box-shadow: var(--shadow-md);
}

.control-btn span:first-child {
    font-size: 1.3rem;
}

.control-btn.primary {
    background: linear-gradient(135deg, var(--primary-color), #a29bfe);
    color: var(--text-light);
}

.control-btn.primary:hover,
.control-btn.primary:active {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.control-btn.secondary {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    color: var(--text-light);
    border: 2px solid rgba(255, 255, 255, 0.2);
}

.control-btn.secondary:hover,
.control-btn.secondary:active {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-2px);
}

/* ===== Modal ===== */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(10px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
    animation: fadeIn var(--transition-normal);
}

.modal.active {
    display: flex;
}

.modal-content {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.15), rgba(255, 255, 255, 0.05));
    backdrop-filter: blur(20px);
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    max-width: 400px;
    width: 100%;
    text-align: center;
    box-shadow: var(--shadow-lg);
    animation: modalSlideUp 0.4s ease;
}

.modal-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
    animation: bounceIn 0.6s ease;
}

.modal-title {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
}

.modal-message {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-lg);
    color: rgba(255, 255, 255, 0.8);
}

.modal-stats {
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.modal-stat {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-stat-label {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.7);
}

.modal-stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--secondary-color);
}

.modal-buttons {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

/* ===== Animations ===== */
@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes flagPop {

    0%,
    100% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.2);
    }
}

@keyframes explode {
    0% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.3);
    }

    100% {
        transform: scale(1);
    }
}

@keyframes shake {

    0%,
    100% {
        transform: rotate(0deg);
    }

    25% {
        transform: rotate(-15deg);
    }

    75% {
        transform: rotate(15deg);
    }
}

@keyframes modalSlideUp {
    from {
        opacity: 0;
        transform: translateY(30px) scale(0.9);
    }

    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

@keyframes bounceIn {
    0% {
        transform: scale(0);
    }

    50% {
        transform: scale(1.2);
    }

    100% {
        transform: scale(1);
    }
}

/* ===== Responsive Design ===== */
@media (max-width: 480px) {
    .game-container {
        padding: var(--spacing-sm);
    }

    .game-title {
        font-size: 2rem;
    }

    .instructions {
        gap: var(--spacing-sm);
    }

    .instruction-item {
        padding: var(--spacing-sm);
    }

    .instruction-icon {
        font-size: 1.5rem;
    }

    .instruction-title {
        font-size: 0.85rem;
    }

    .instruction-desc {
        font-size: 0.75rem;
    }

    .difficulty-btn {
        padding: var(--spacing-md);
    }

    .btn-icon {
        font-size: 2.5rem;
    }

    .btn-title {
        font-size: 1.25rem;
    }
}

@media (max-height: 700px) {
    .game-header {
        margin-bottom: var(--spacing-md);
    }

    .game-title {
        font-size: 2rem;
    }

    .game-subtitle {
        font-size: 0.75rem;
    }
}

/* ===== Touch Feedback ===== */
.cell.touching {
    background: var(--cell-bg-hover);
    transform: scale(0.95);
}

/* Game over state */
.game-over .cell:not(.revealed) {
    pointer-events: none;
}