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

:root {
    --primary-black: #ffffff;
    --primary-white: #000000;
    --gray-light: #1a1a1a;
    --gray-medium: #666666;
    --gray-dark: #cccccc;
    --shadow-light: rgba(255, 255, 255, 0.1);
    --shadow-medium: rgba(255, 255, 255, 0.2);
    --transition-fast: 0.2s ease;
    --transition-smooth: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font-mono: 'Fira Code', 'Monaco', 'Consolas', monospace;
    --font-sans: 'Inter', -apple-system, system-ui, sans-serif;
}

body {
    font-family: var(--font-sans);
    background: var(--primary-white);
    color: var(--primary-black);
    line-height: 1.6;
    overflow-x: hidden;
}


.bg-particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
}

.particle {
    position: absolute;
    width: 2px;
    height: 2px;
    background: var(--primary-black);
    opacity: 0.3;
    border-radius: 50%;
    animation: float 20s infinite linear;
}

@keyframes float {
    0% {
        transform: translateY(100vh) rotate(0deg);
        opacity: 0;
    }
    10% {
        opacity: 0.3;
    }
    90% {
        opacity: 0.3;
    }
    100% {
        transform: translateY(-100px) rotate(360deg);
        opacity: 0;
    }
}


h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    letter-spacing: -0.02em;
}

.title-xl {
    font-size: clamp(2.5rem, 8vw, 4rem);
    font-weight: 900;
    letter-spacing: -0.05em;
    line-height: 0.9;
}

.title-lg {
    font-size: clamp(1.8rem, 5vw, 2.5rem);
    font-weight: 800;
}

.text-mono {
    font-family: var(--font-mono);
    font-size: 0.9rem;
}


.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 4rem 0;
}


.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(0, 0, 0, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--gray-light);
    transition: var(--transition-smooth);
}

.header.scrolled {
    background: rgba(0, 0, 0, 0.98);
    box-shadow: 0 4px 20px var(--shadow-light);
}

.navbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 2rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: 900;
    color: var(--primary-black);
    text-decoration: none;
    transition: var(--transition-fast);
}

.logo:hover {
    transform: scale(1.05);
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-link {
    color: var(--primary-black);
    text-decoration: none;
    font-weight: 500;
    position: relative;
    transition: var(--transition-fast);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-black);
    transition: var(--transition-fast);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}


.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: 2px solid var(--primary-black);
    background: transparent;
    color: var(--primary-black);
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
    font-family: inherit;
    font-size: 1rem;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: var(--primary-black);
    transition: var(--transition-smooth);
    z-index: -1;
}

.btn:hover {
    color: var(--primary-white);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px var(--shadow-medium);
}

.btn:hover::before {
    left: 0;
}

.btn:active {
    transform: translateY(0);
}

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

.btn-primary::before {
    background: var(--primary-white);
}

.btn-primary:hover {
    color: var(--primary-black);
}


.number-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 1rem;
    margin: 2rem auto;
    max-width: 400px;
}

.number-btn {
    aspect-ratio: 1;
    border: 2px solid var(--primary-black);
    background: transparent;
    color: var(--primary-black);
    font-size: 1.5rem;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition-fast);
    position: relative;
    overflow: hidden;
}

.number-btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: var(--primary-black);
    border-radius: 50%;
    transition: var(--transition-smooth);
    transform: translate(-50%, -50%);
    z-index: -1;
}

.number-btn:hover {
    color: var(--primary-white);
    transform: scale(1.1);
}

.number-btn:hover::before {
    width: 200%;
    height: 200%;
}

.number-btn:active {
    transform: scale(0.95);
}

.number-btn.selected {
    background: var(--primary-black);
    color: var(--primary-white);
}


.card {
    background: var(--primary-white);
    border: 2px solid var(--primary-black);
    color: var(--primary-black);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    border-radius: 12px;
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 4px;
    background: var(--primary-black);
    transition: var(--transition-smooth);
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px var(--shadow-medium);
}

.card:hover::before {
    left: 0;
}


.game-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 6rem 2rem 2rem;
}

.game-header {
    text-align: center;
    margin-bottom: 3rem;
}

.game-status {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-bottom: 3rem;
}

.score-card {
    text-align: center;
    padding: 1.5rem;
    border: 2px solid var(--primary-black);
    background: var(--primary-white);
    transition: var(--transition-fast);
    position: relative;
    overflow: hidden;
}

.score-card::before {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    background: linear-gradient(45deg, transparent, var(--primary-black), transparent);
    z-index: -1;
    opacity: 0;
    transition: var(--transition-fast);
}

.score-card:hover::before {
    opacity: 0.1;
    animation: pulse 2s ease-in-out infinite;
}

.score-number {
    font-size: 3rem;
    font-weight: 900;
    font-family: var(--font-mono);
    color: var(--primary-black);
}

.score-label {
    font-size: 0.9rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--gray-medium);
}


.game-history {
    max-height: 300px;
    overflow-y: auto;
    margin: 2rem 0;
    border: 2px solid var(--primary-black);
    padding: 1rem;
}

.history-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--gray-light);
    font-family: var(--font-mono);
    font-size: 0.9rem;
}

.history-item:last-child {
    border-bottom: none;
}


.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-smooth);
    backdrop-filter: blur(10px);
}

.modal.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: var(--primary-white);
    border: 3px solid var(--primary-black);
    padding: 3rem;
    max-width: 500px;
    width: 90%;
    text-align: center;
    transform: scale(0.8);
    transition: var(--transition-smooth);
}

.modal.active .modal-content {
    transform: scale(1);
}


.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    margin: 1.5rem 0;
}

.stat-item {
    text-align: center;
    padding: 1.25rem;
    border: 2px solid var(--primary-black);
    border-radius: 8px;
    transition: var(--transition-fast);
}

.achievement-item {
    border-radius: 10px !important;
    margin-bottom: 1rem;
}

.rank-item {
    border-radius: 8px;
    padding: 1rem;
    border: 1px solid var(--gray-light);
    transition: all 0.3s ease;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 900;
    font-family: var(--font-mono);
    color: var(--primary-black);
    display: block;
}

.stat-label {
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--gray-medium);
    margin-top: 0.5rem;
}


.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--gray-light);
    border: 1px solid var(--primary-black);
    overflow: hidden;
    margin: 1rem 0;
}

.progress-fill {
    height: 100%;
    background: var(--primary-black);
    transition: width var(--transition-smooth);
    transform-origin: left;
}


.coin-container {
    display: flex;
    justify-content: center;
    align-items: center;
    perspective: 1000px;
}

.coin {
    width: 120px;
    height: 120px;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 1s ease-in-out;
    cursor: pointer;
}

.coin-side {
    position: absolute;
    width: 100%;
    height: 100%;
    border: 3px solid var(--primary-black);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    font-weight: bold;
    font-family: var(--font-mono);
    background: var(--primary-white);
    color: var(--primary-black);
    backface-visibility: hidden;
}

.coin-side.heads {
    transform: rotateY(0deg);
}

.coin-side.tails {
    transform: rotateY(180deg);
}

.coin.flip {
    animation: coinFlip 2s ease-in-out;
}

@keyframes coinFlip {
    0% {
        transform: rotateY(0deg) rotateX(0deg);
    }
    25% {
        transform: rotateY(180deg) rotateX(90deg);
    }
    50% {
        transform: rotateY(360deg) rotateX(180deg);
    }
    75% {
        transform: rotateY(540deg) rotateX(270deg);
    }
    100% {
        transform: rotateY(720deg) rotateX(360deg);
    }
}

.coin.heads-result {
    transform: rotateY(0deg);
}

.coin.tails-result {
    transform: rotateY(180deg);
}

.toss-btn {
    min-width: 120px;
    padding: 0.75rem 1.5rem;
    font-size: 1.1rem;
    font-weight: 600;
}

.toss-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px var(--shadow-medium);
}


@keyframes slideInUp {
    from {
        transform: translateY(30px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

@keyframes slideInDown {
    from {
        transform: translateY(-30px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

@keyframes flash {
    0%, 100% {
        background-color: var(--primary-white);
    }
    50% {
        background-color: #ffeeee;
    }
}

.animate-slide-up {
    animation: slideInUp 0.6s ease forwards;
}

.animate-slide-down {
    animation: slideInDown 0.6s ease forwards;
}

.animate-fade-in {
    animation: fadeIn 0.6s ease forwards;
}

.animate-pulse {
    animation: pulse 2s ease-in-out infinite;
}


@media (max-width: 768px) {
    .navbar {
        padding: 1rem;
    }
    
    .nav-links {
        gap: 1rem;
    }
    
    .container {
        padding: 0 1rem;
    }
    
    .number-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 0.5rem;
    }
    
    .number-btn {
        font-size: 1.2rem;
    }
    
    .game-status {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 1rem;
    }
    
    .modal-content {
        padding: 2rem;
    }
}


.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--gray-light);
    border-radius: 50%;
    border-top-color: var(--primary-black);
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}


.hidden {
    display: none !important;
}


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

.text-mono {
    font-family: var(--font-mono);
}

.font-bold {
    font-weight: 700;
}

.mb-4 {
    margin-bottom: 2rem;
}

.mt-4 {
    margin-top: 2rem;
}


footer {
    background: var(--primary-black) !important;
    color: var(--primary-white) !important;
}