/* CSS Variables for theming */
:root {
    --primary-color: #007AFF;
    --primary-dark: #0051D5;
    --background: #000000;
    --surface: #1C1C1E;
    --surface-light: #2C2C2E;
    --text-primary: #FFFFFF;
    --text-secondary: #EBEBF5;
    --text-tertiary: #ABABAB;
    --border-color: #38383A;
    --accent-gold: #FFD700;
    --accent-green: #34C759;
    --accent-red: #FF3B30;
}

/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--background);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Header */
header {
    background: var(--surface);
    border-bottom: 1px solid var(--border-color);
    padding: 16px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    background: rgba(28, 28, 30, 0.9);
}

.logo h1 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-primary);
}

/* Hero Section */
.hero {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--background) 0%, var(--surface) 100%);
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-content h2 {
    font-size: 48px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 24px;
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--primary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-description {
    font-size: 20px;
    color: var(--text-secondary);
    margin-bottom: 40px;
    line-height: 1.6;
}

/* Buttons */
.cta-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    padding: 14px 32px;
    font-size: 18px;
    font-weight: 600;
    text-decoration: none;
    border-radius: 12px;
    transition: all 0.3s ease;
    cursor: pointer;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(0, 122, 255, 0.3);
}

.app-store-icon {
    width: 24px;
    height: 24px;
}

/* Hero Image / Mockup */
.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.app-mockup {
    background: var(--surface);
    border-radius: 24px;
    padding: 60px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
    border: 1px solid var(--border-color);
}

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

.emoji {
    font-size: 60px;
    display: flex;
    justify-content: center;
    align-items: center;
    background: var(--surface-light);
    border-radius: 16px;
    padding: 20px;
    transition: transform 0.3s ease;
}

.emoji:hover {
    transform: scale(1.1) rotate(5deg);
}

/* Features Section */
.features {
    padding: 80px 0;
    background: var(--surface);
}

.features h2,
.difficulty-system h2,
.highlights h2,
.perfect-for h2 {
    font-size: 40px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 60px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
}

.feature {
    background: var(--surface-light);
    padding: 40px;
    border-radius: 16px;
    border: 1px solid var(--border-color);
}

.feature-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.feature h3 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 16px;
}

.feature ul {
    list-style: none;
    padding-left: 0;
}

.feature li {
    padding: 8px 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 24px;
}

.feature li:before {
    content: "•";
    position: absolute;
    left: 8px;
    color: var(--primary-color);
    font-weight: bold;
}

/* Difficulty System */
.difficulty-system {
    padding: 80px 0;
}

.section-description {
    text-align: center;
    font-size: 20px;
    color: var(--text-secondary);
    margin-bottom: 40px;
}

.difficulty-levels {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 32px;
    margin-bottom: 40px;
}

.difficulty-card {
    background: var(--surface);
    padding: 40px;
    border-radius: 16px;
    text-align: center;
    border: 2px solid var(--border-color);
    transition: transform 0.3s ease, border-color 0.3s ease;
}

.difficulty-card:hover {
    transform: translateY(-4px);
    border-color: var(--primary-color);
}

.difficulty-icon {
    font-size: 56px;
    margin-bottom: 20px;
}

.difficulty-card h3 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 12px;
}

.accuracy {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 18px;
    margin-bottom: 8px;
}

.difficulty-card p:last-child {
    color: var(--text-secondary);
}

.system-note {
    text-align: center;
    color: var(--text-secondary);
    font-size: 18px;
    max-width: 800px;
    margin: 0 auto;
}

/* Highlights */
.highlights {
    padding: 80px 0;
    background: var(--surface);
}

.highlights-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.highlight {
    background: var(--surface-light);
    padding: 24px 32px;
    border-radius: 12px;
    font-size: 18px;
    border-left: 4px solid var(--primary-color);
}

/* Perfect For */
.perfect-for {
    padding: 80px 0;
}

.perfect-for-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.perfect-item {
    background: var(--surface);
    padding: 32px;
    border-radius: 16px;
    font-size: 20px;
    text-align: center;
    border: 1px solid var(--border-color);
}

/* CTA Section */
.cta-section {
    padding: 100px 0;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    text-align: center;
}

.cta-section h2 {
    font-size: 40px;
    font-weight: 700;
    margin-bottom: 16px;
}

.cta-section p {
    font-size: 20px;
    margin-bottom: 40px;
    color: var(--text-secondary);
}

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

.cta-section .btn-primary:hover {
    background: var(--text-secondary);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(255, 255, 255, 0.3);
}

/* Footer */
footer {
    background: var(--surface);
    border-top: 1px solid var(--border-color);
    padding: 40px 0;
    text-align: center;
}

footer p {
    color: var(--text-tertiary);
}

/* Responsive Design */
@media (max-width: 968px) {
    .hero .container {
        grid-template-columns: 1fr;
        gap: 40px;
    }

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

    .hero-description {
        font-size: 18px;
    }

    .app-mockup {
        padding: 40px;
    }

    .emoji {
        font-size: 48px;
        padding: 16px;
    }
}

@media (max-width: 640px) {
    .hero {
        padding: 40px 0;
    }

    .hero-content h2 {
        font-size: 32px;
    }

    .hero-description {
        font-size: 16px;
    }

    .features,
    .difficulty-system,
    .highlights,
    .perfect-for {
        padding: 60px 0;
    }

    .features h2,
    .difficulty-system h2,
    .highlights h2,
    .perfect-for h2 {
        font-size: 32px;
        margin-bottom: 40px;
    }

    .cta-section {
        padding: 60px 0;
    }

    .cta-section h2 {
        font-size: 32px;
    }

    .app-mockup {
        padding: 30px;
    }

    .emoji-grid {
        gap: 16px;
    }

    .emoji {
        font-size: 36px;
        padding: 12px;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }
}