.header {
    position: sticky;
    top: 0;
    background-color: var(--color-parchment);
    border-bottom: 1px solid var(--color-border-cream);
    z-index: 100;
    transition: all 0.3s ease;
}

.header.scrolled {
    box-shadow: var(--shadow-whisper);
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 12px 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    font-family: var(--font-serif);
    font-size: 1.3rem;
    font-weight: 500;
    color: var(--color-anthropic-black);
    text-decoration: none;
}

.logo:hover {
    color: var(--color-terracotta);
}

.hero {
    padding: 40px 16px;
    text-align: center;
    background-color: var(--color-parchment);
}

.hero-title {
    font-family: var(--font-serif);
    font-size: 2rem;
    font-weight: 500;
    color: var(--color-anthropic-black);
    line-height: 1.2;
    margin-bottom: 12px;
}

.hero-subtitle {
    font-size: 1rem;
    color: var(--color-olive-gray);
    line-height: 1.6;
    max-width: 400px;
    margin: 0 auto;
}

.category-nav {
    padding: 16px 16px;
    background-color: var(--color-ivory);
    border-bottom: 1px solid var(--color-border-cream);
}

.category-list {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    gap: 8px;
    overflow-x: auto;
    overflow-y: hidden;
    padding-bottom: 4px;
    scrollbar-width: none;
    -ms-overflow-style: none;
    -webkit-overflow-scrolling: touch;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    user-select: none;
}

.category-list::-webkit-scrollbar {
    display: none;
}

.category-item {
    flex-shrink: 0;
    padding: 10px 16px;
    background-color: var(--color-parchment);
    border: 1px solid var(--color-border-cream);
    border-radius: var(--radius-generous);
    color: var(--color-olive-gray);
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s ease;
    white-space: nowrap;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
    -ms-touch-action: manipulation;
}

.category-item:hover {
    background-color: var(--color-warm-sand);
    border-color: var(--color-border-warm);
    color: var(--color-charcoal-warm);
}

.category-item.active {
    background-color: var(--color-terracotta);
    border-color: var(--color-terracotta);
    color: var(--color-ivory);
}

.category-item.touched {
    background-color: var(--color-warm-sand);
    border-color: var(--color-border-warm);
    color: var(--color-charcoal-warm);
    transform: scale(0.95);
}

.category-item.dragging {
    opacity: 0.7;
    transform: scale(0.95);
}

.tools-grid {
    padding: 24px 16px;
    max-width: 1200px;
    margin: 0 auto;
}

.tools-container {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
}

.tool-card {
    background-color: var(--color-ivory);
    border: 1px solid var(--color-border-cream);
    border-radius: var(--radius-generous);
    padding: 20px;
    cursor: pointer;
    transition: all 0.2s ease;
    position: relative;
    overflow: hidden;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
    -ms-touch-action: manipulation;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    user-select: none;
    -webkit-transform: translateZ(0);
    transform: translateZ(0);
    will-change: transform, box-shadow, border-color;
}

.tool-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--color-terracotta), var(--color-coral));
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.tool-card:hover::before {
    transform: scaleX(1);
}

.tool-card:hover {
    box-shadow: var(--shadow-whisper);
    border-color: var(--color-border-warm);
}

.tool-card:active,
.tool-card.touched {
    box-shadow: var(--shadow-whisper);
    border-color: var(--color-border-warm);
    transform: scale(0.98);
}

.tool-card.touched::before {
    transform: scaleX(1);
}

.tool-card.dragging {
    opacity: 0.7;
    transform: scale(0.96);
}

.tool-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-comfortable);
    background-color: var(--color-warm-sand);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 14px;
    font-size: 20px;
    transition: all 0.2s ease;
}

.tool-card:hover .tool-icon,
.tool-card.touched .tool-icon {
    background-color: var(--color-terracotta);
    color: var(--color-ivory);
}

.tool-name {
    font-family: var(--font-serif);
    font-size: 1.15rem;
    font-weight: 500;
    color: var(--color-anthropic-black);
    margin-bottom: 8px;
    pointer-events: none;
}

.tool-desc {
    font-size: 14px;
    color: var(--color-stone-gray);
    line-height: 1.6;
    margin-bottom: 12px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    pointer-events: none;
}

.tool-category {
    display: inline-block;
    padding: 4px 12px;
    background-color: var(--color-parchment);
    border-radius: var(--radius-subtle);
    font-size: 12px;
    color: var(--color-charcoal-warm);
    letter-spacing: 0.12px;
    pointer-events: none;
}

@media (min-width: 480px) {
    .header-content {
        padding: 14px 20px;
    }

    .logo {
        font-size: 1.4rem;
    }

    .hero {
        padding: 60px 24px;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.1rem;
        max-width: 500px;
    }

    .tools-container {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
        gap: 20px;
    }
}

@media (min-width: 640px) {
    .header-content {
        padding: 16px 24px;
    }

    .logo {
        font-size: 1.5rem;
    }

    .hero {
        padding: 80px 24px;
    }

    .hero-title {
        font-size: 3rem;
    }

    .hero-subtitle {
        font-size: 1.15rem;
        max-width: 600px;
    }

    .category-nav {
        padding: 20px 24px;
    }

    .category-list {
        gap: 10px;
    }

    .tools-grid {
        padding: 32px 24px;
    }

    .tools-container {
        gap: 24px;
    }

    .tool-card {
        padding: 24px;
    }
}

@media (min-width: 768px) {
    .hero-title {
        font-size: 3.5rem;
    }

    .tools-container {
        grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    }
}

@media (min-width: 992px) {
    .hero-title {
        font-size: 4rem;
    }

    .tools-container {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 30px 16px;
    }

    .hero-title {
        font-size: 1.8rem;
    }

    .hero-subtitle {
        font-size: 0.95rem;
    }

    .category-nav {
        padding: 12px 16px;
    }

    .tools-grid {
        padding: 16px 12px;
    }

    .tool-card {
        padding: 16px;
    }

    .tool-icon {
        width: 40px;
        height: 40px;
        font-size: 18px;
    }

    .tool-name {
        font-size: 1.05rem;
    }
}

.site-footer {
    background-color: var(--color-ivory);
    border-top: 1px solid var(--color-border-cream);
    padding: 24px 16px;
    margin-top: 40px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    text-align: center;
}

.footer-links a {
    color: var(--color-stone-gray);
    text-decoration: none;
    font-size: 14px;
    transition: color 0.2s ease;
}

.footer-links a:hover {
    color: var(--color-terracotta);
}

@media (max-width: 480px) {
    .site-footer {
        padding: 20px 12px;
    }
    
    .footer-links a {
        font-size: 13px;
    }
}