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

:root {
    --primary-color: #007AFF;
    --secondary-color: #5856D6;
    --text-color: #1D1D1F;
    --text-secondary: #86868B;
    --text-tertiary: #C7C7CC;
    --bg-primary: #FFFFFF;
    --bg-secondary: #F5F5F7;
    --bg-tertiary: #E5E5EA;
    --border-color: #D1D1D6;
    --separator-color: #C6C6C8;
    --shadow-light: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-medium: 0 4px 20px rgba(0, 0, 0, 0.08);
    --shadow-large: 0 8px 40px rgba(0, 0, 0, 0.12);
    --success-color: #34C759;
    --warning-color: #FF9500;
    --danger-color: #FF3B30;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'SF Pro Text', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.47;
    letter-spacing: -0.01em;
    color: var(--text-color);
    background: var(--bg-secondary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 980px;
    margin: 0 auto;
    padding: 0 22px;
}

.header {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 0.5px solid var(--separator-color);
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px 22px;
}

.logo {
    font-size: 21px;
    font-weight: 600;
    color: var(--text-color);
    letter-spacing: -0.02em;
}

.nav {
    display: flex;
    gap: 28px;
}

.nav a {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 15px;
    font-weight: 400;
    transition: color 0.2s ease;
    position: relative;
    padding: 4px 0;
}

.nav a:hover {
    color: var(--text-color);
}

.nav a.active {
    color: var(--text-color);
    font-weight: 500;
}

.hero {
    background: var(--bg-primary);
    color: var(--text-color);
    padding: 80px 0 60px;
    text-align: center;
}

.hero h2 {
    font-size: 48px;
    font-weight: 600;
    margin-bottom: 12px;
    letter-spacing: -0.03em;
}

.hero p {
    font-size: 21px;
    color: var(--text-secondary);
    font-weight: 400;
    letter-spacing: -0.01em;
}

.btn {
    display: inline-block;
    padding: 12px 24px;
    background: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 980px;
    font-size: 17px;
    font-weight: 400;
    transition: all 0.2s ease;
    border: none;
    cursor: pointer;
    font-family: inherit;
}

.btn:hover {
    background: #0066CC;
    transform: scale(1.02);
}

.btn:active {
    transform: scale(0.98);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-color);
}

.btn-secondary:hover {
    background: #D1D1D6;
}

.features {
    padding: 80px 0;
    background: var(--bg-secondary);
}

.features h2 {
    text-align: center;
    margin-bottom: 56px;
    font-size: 32px;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.feature-card {
    background: var(--bg-primary);
    padding: 40px 32px;
    border-radius: 18px;
    text-align: center;
    box-shadow: var(--shadow-light);
    transition: all 0.3s cubic-bezier(0.25, 0.1, 0.25, 1);
    text-decoration: none;
    color: inherit;
    display: block;
    border: 0.5px solid transparent;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-medium);
    border-color: var(--border-color);
}

.card-icon {
    font-size: 56px;
    margin-bottom: 20px;
    display: block;
}

.feature-card h3 {
    margin-bottom: 8px;
    color: var(--text-color);
    font-size: 21px;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 15px;
    line-height: 1.5;
}

.footer {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    text-align: center;
    padding: 40px 0;
    margin-top: 0;
    font-size: 14px;
}

.tools-section,
.games-section,
.blog-section {
    padding: 60px 0;
    background: var(--bg-secondary);
}

.tool-card,
.game-card,
.blog-post {
    background: var(--bg-primary);
    padding: 48px;
    border-radius: 18px;
    box-shadow: var(--shadow-light);
    margin-bottom: 24px;
    border: 0.5px solid transparent;
}

.tool-card:hover,
.game-card:hover,
.blog-post:hover {
    border-color: var(--border-color);
}

.tool-header,
.game-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    flex-wrap: wrap;
    gap: 16px;
    margin-bottom: 40px;
}

.tool-header h3,
.game-header h3 {
    font-size: 28px;
    color: var(--text-color);
    font-weight: 600;
    letter-spacing: -0.02em;
}

.currency-converter {
    max-width: 560px;
    margin: 0 auto;
}

.converter-row {
    display: flex;
    gap: 16px;
    align-items: flex-end;
    margin-bottom: 24px;
    flex-wrap: wrap;
}

.input-group {
    flex: 1;
    min-width: 200px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.input-field {
    width: 100%;
    padding: 14px 16px;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    font-size: 17px;
    font-family: inherit;
    transition: all 0.2s ease;
    background: var(--bg-primary);
}

.input-field:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(0, 122, 255, 0.1);
}

.swap-btn {
    font-size: 24px;
    cursor: pointer;
    padding: 12px;
    transition: transform 0.3s cubic-bezier(0.25, 0.1, 0.25, 1);
    user-select: none;
    color: var(--primary-color);
    background: var(--bg-secondary);
    border-radius: 100%;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.swap-btn:hover {
    transform: rotate(180deg);
    background: var(--bg-tertiary);
}

.result {
    text-align: center;
    padding: 32px;
    background: var(--bg-secondary);
    border-radius: 16px;
    margin-top: 24px;
}

.result-value {
    font-size: 34px;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 8px;
    letter-spacing: -0.02em;
}

.result-rate {
    color: var(--text-secondary);
    font-size: 15px;
}

.game-stats {
    display: flex;
    gap: 16px;
}

.stat {
    background: var(--bg-secondary);
    padding: 12px 20px;
    border-radius: 12px;
    text-align: center;
    min-width: 100px;
}

.stat-label {
    display: block;
    font-size: 12px;
    color: var(--text-secondary);
    margin-bottom: 4px;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.stat-value {
    display: block;
    font-size: 24px;
    font-weight: 600;
    color: var(--text-color);
    letter-spacing: -0.02em;
}

.game-instructions {
    text-align: center;
    padding: 16px 20px;
    background: var(--bg-secondary);
    border-radius: 12px;
    margin-bottom: 24px;
    font-size: 15px;
    color: var(--text-secondary);
}

.game-instructions strong {
    color: var(--text-color);
    font-weight: 500;
}

.game-container {
    position: relative;
    display: flex;
    justify-content: center;
}

.grid-container {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
    background: var(--bg-tertiary);
    padding: 12px;
    border-radius: 16px;
}

.grid-cell {
    width: 84px;
    height: 84px;
    background: var(--bg-secondary);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 32px;
    font-weight: 700;
    color: var(--text-color);
    letter-spacing: -0.02em;
}

.tile-2 { background: #F5F5F7; color: #1D1D1F; }
.tile-4 { background: #E5E5EA; color: #1D1D1F; }
.tile-8 { background: #007AFF; color: #FFFFFF; }
.tile-16 { background: #5856D6; color: #FFFFFF; }
.tile-32 { background: #AF52DE; color: #FFFFFF; }
.tile-64 { background: #FF2D55; color: #FFFFFF; }
.tile-128 { background: #FF9500; color: #FFFFFF; }
.tile-256 { background: #FF3B30; color: #FFFFFF; }
.tile-512 { background: #34C759; color: #FFFFFF; font-size: 28px; }
.tile-1024 { background: #007AFF; color: #FFFFFF; font-size: 24px; }
.tile-2048 { background: #1D1D1F; color: #FFFFFF; font-size: 24px; }
.tile-4096, .tile-8192 { background: #1D1D1F; color: #FFFFFF; font-size: 20px; }

.game-over,
.game-win {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border-radius: 16px;
}

.game-over h2,
.game-win h2 {
    font-size: 40px;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 12px;
    letter-spacing: -0.03em;
}

.game-over p,
.game-win p {
    font-size: 19px;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.post-header {
    margin-bottom: 32px;
    padding-bottom: 24px;
    border-bottom: 0.5px solid var(--separator-color);
}

.post-date {
    color: var(--text-secondary);
    font-size: 15px;
    display: block;
    margin-bottom: 8px;
}

.post-title {
    font-size: 34px;
    color: var(--text-color);
    font-weight: 600;
    letter-spacing: -0.03em;
    line-height: 1.2;
}

.post-content {
    font-size: 17px;
    line-height: 1.6;
    color: var(--text-color);
}

.post-content h2 {
    font-size: 24px;
    margin: 40px 0 16px;
    color: var(--text-color);
    font-weight: 600;
    letter-spacing: -0.02em;
}

.post-content p {
    margin-bottom: 20px;
    color: var(--text-color);
}

.post-content ul {
    margin: 20px 0;
    padding-left: 24px;
}

.post-content li {
    margin-bottom: 12px;
    color: var(--text-color);
}

.coming-soon {
    text-align: center;
    padding: 60px 40px;
    background: var(--bg-primary);
    border-radius: 18px;
    box-shadow: var(--shadow-light);
}

.coming-soon h3 {
    font-size: 21px;
    color: var(--text-secondary);
    margin-bottom: 8px;
    font-weight: 500;
}

.coming-soon p {
    color: var(--text-tertiary);
    font-size: 15px;
}

@media (max-width: 734px) {
    .container {
        padding: 0 16px;
    }

    .header .container {
        flex-direction: column;
        gap: 12px;
        padding: 12px 16px;
    }

    .logo {
        font-size: 19px;
    }

    .nav {
        gap: 18px;
        flex-wrap: wrap;
        justify-content: center;
    }

    .nav a {
        font-size: 14px;
    }

    .hero {
        padding: 60px 0 48px;
    }

    .hero h2 {
        font-size: 36px;
    }

    .hero p {
        font-size: 17px;
    }

    .features {
        padding: 56px 0;
    }

    .features h2 {
        font-size: 24px;
        margin-bottom: 40px;
    }

    .feature-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .feature-card {
        padding: 32px 24px;
    }

    .tool-card,
    .game-card,
    .blog-post {
        padding: 32px 24px;
    }

    .tool-header,
    .game-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .game-stats {
        width: 100%;
        justify-content: space-between;
    }

    .stat {
        flex: 1;
    }

    .grid-cell {
        width: 68px;
        height: 68px;
        font-size: 26px;
    }

    .tile-512,
    .tile-1024,
    .tile-2048 {
        font-size: 20px;
    }

    .converter-row {
        flex-direction: column;
        align-items: stretch;
    }

    .swap-btn {
        align-self: center;
        transform: rotate(90deg);
    }

    .swap-btn:hover {
        transform: rotate(270deg);
    }

    .post-title {
        font-size: 28px;
    }

    .post-content {
        font-size: 16px;
    }
}