/* ============================================
   Universal Tools Platform - Refined Premium UI
   ============================================ */

* { box-sizing: border-box; }
body {
    color: var(--color-text-primary);
    background-color: var(--color-background);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    line-height: 1.5;
    margin: 0;
}

/* Category Background Tints (softer tints of category colors) */
.cat-calculators { color: var(--color-cat-calculators); }
.cat-business { color: var(--color-cat-business); }
.cat-converters { color: var(--color-cat-converters); }
.cat-text-tools { color: var(--color-cat-text-tools); }
.cat-date-time { color: var(--color-cat-date-time); }
.cat-pdf-docs { color: var(--color-cat-pdf-docs); }
.cat-image-tools { color: var(--color-cat-image-tools); }
.cat-dev-tools { color: var(--color-cat-dev-tools); }
.cat-generators { color: var(--color-cat-generators); }

.bg-cat-calculators { background-color: var(--color-cat-calculators); }
.bg-cat-business { background-color: var(--color-cat-business); }
.bg-cat-converters { background-color: var(--color-cat-converters); }
.bg-cat-text-tools { background-color: var(--color-cat-text-tools); }
.bg-cat-date-time { background-color: var(--color-cat-date-time); }
.bg-cat-pdf-docs { background-color: var(--color-cat-pdf-docs); }
.bg-cat-image-tools { background-color: var(--color-cat-image-tools); }
.bg-cat-dev-tools { background-color: var(--color-cat-dev-tools); }
.bg-cat-generators { background-color: var(--color-cat-generators); }

.tint-calculators { background-color: #eff6ff; }
.tint-business { background-color: #ecfdf5; }
.tint-converters { background-color: #fff7ed; }
.tint-text-tools { background-color: #f5f3ff; }
.tint-date-time { background-color: #eef2ff; }
.tint-pdf-docs { background-color: #fef2f2; }
.tint-image-tools { background-color: #fdf2f8; }
.tint-dev-tools { background-color: #ecfeff; }
.tint-generators { background-color: #fffbeb; }

/* Icon container system */
.icon-box {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 12px;
    flex-shrink: 0;
    transition: transform 200ms cubic-bezier(0.4, 0, 0.2, 1);
}

.icon-box svg {
    width: 22px;
    height: 22px;
    stroke-width: 2.25;
    color: white;
}

.icon-box-md { width: 56px; height: 56px; border-radius: 14px; }
.icon-box-md svg { width: 26px; height: 26px; }
.icon-box-lg { width: 64px; height: 64px; border-radius: 16px; }
.icon-box-lg svg { width: 30px; height: 30px; }

/* Premium tool card */
.tool-card {
    position: relative;
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 20px;
    box-shadow: var(--shadow-sm);
    transition: transform 200ms cubic-bezier(0.4, 0, 0.2, 1),
                box-shadow 200ms cubic-bezier(0.4, 0, 0.2, 1),
                border-color 200ms cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    flex-direction: column;
    height: 100%;
}

.tool-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 16px -4px rgba(15, 23, 42, 0.08), 0 4px 8px -2px rgba(15, 23, 42, 0.04);
    border-color: rgba(148, 163, 184, 0.4);
}

.tool-card:hover .icon-box {
    transform: scale(1.08);
}

.tool-card-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 16px;
}

.tool-card-title {
    font-size: 1.0625rem;
    font-weight: 600;
    line-height: 1.35;
    color: var(--color-text-primary);
    margin: 0;
    letter-spacing: -0.01em;
}

.tool-card-body {
    flex: 1;
    margin-bottom: 16px;
}

.tool-card-desc {
    font-size: 0.875rem;
    line-height: 1.55;
    color: var(--color-text-secondary);
    margin: 0;
}

.tool-card-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-top: auto;
    padding-top: 12px;
    border-top: 1px solid var(--color-border);
}

.category-badge {
    display: inline-flex;
    align-items: center;
    padding: 4px 10px;
    border-radius: 999px;
    font-size: 0.6875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-secondary);
    background-color: var(--color-surface-elevated);
}

.cta-link {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-primary);
    text-decoration: none;
    transition: gap 200ms cubic-bezier(0.4, 0, 0.2, 1);
}

.cta-link:hover {
    gap: 8px;
}

/* Favorite button */
.fav-btn {
    position: absolute;
    top: 16px;
    right: 16px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.125rem;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    transition: background-color 150ms, transform 150ms;
    z-index: 2;
}

.fav-btn:hover {
    background-color: rgba(241, 245, 249, 0.8);
    transform: scale(1.1);
}

.fav-btn:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Search field */
.search-field {
    width: 100%;
    max-width: 36rem;
    padding: 14px 18px;
    font-size: 1rem;
    border: 1px solid var(--color-border);
    border-radius: 12px;
    background-color: var(--color-surface);
    transition: border-color 150ms, box-shadow 150ms;
    box-shadow: var(--shadow-sm);
}

.search-field:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

/* Premium buttons */
.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    font-size: 0.9375rem;
    font-weight: 600;
    color: white;
    background: linear-gradient(180deg, #3b82f6 0%, #2563eb 100%);
    border: none;
    border-radius: 10px;
    cursor: pointer;
    box-shadow: 0 1px 2px rgba(0,0,0,0.05);
    transition: transform 150ms, box-shadow 150ms;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(37, 99, 235, 0.2);
}

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

.btn-primary:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Category filter button */
.filter-btn {
    display: inline-flex;
    align-items: center;
    padding: 8px 16px;
    font-size: 0.875rem;
    font-weight: 500;
    background-color: var(--color-surface);
    color: var(--color-text-secondary);
    border: 1px solid var(--color-border);
    border-radius: 999px;
    cursor: pointer;
    white-space: nowrap;
    transition: all 150ms;
}

.filter-btn:hover {
    background-color: var(--color-surface-elevated);
    color: var(--color-text-primary);
    border-color: rgba(148, 163, 184, 0.5);
}

.filter-btn.active {
    background-color: var(--color-text-primary);
    color: white;
    border-color: var(--color-text-primary);
    box-shadow: 0 1px 3px rgba(15, 23, 42, 0.1);
}

.filter-btn:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Hero section */
.hero {
    text-align: center;
    padding: 56px 16px 32px;
    background: radial-gradient(ellipse at top, rgba(59, 130, 246, 0.05) 0%, transparent 60%),
                radial-gradient(ellipse at bottom right, rgba(124, 58, 237, 0.04) 0%, transparent 50%);
}

.hero-eyebrow {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-primary);
    margin-bottom: 12px;
    padding: 4px 12px;
    background-color: rgba(59, 130, 246, 0.1);
    border-radius: 999px;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 800;
    line-height: 1.15;
    color: var(--color-text-primary);
    margin: 0 0 12px;
    letter-spacing: -0.025em;
}

@media (min-width: 768px) {
    .hero-title { font-size: 3.25rem; }
}

.hero-sub {
    font-size: 1.0625rem;
    color: var(--color-text-secondary);
    max-width: 36rem;
    margin: 0 auto 28px;
    line-height: 1.6;
}

/* Tool detail page header */
.tool-page-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 24px;
    padding: 20px 24px;
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
}

.tool-page-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0;
    color: var(--color-text-primary);
}

.tool-page-card {
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 28px;
    box-shadow: var(--shadow-sm);
}

.tool-input {
    width: 100%;
    padding: 11px 14px;
    font-size: 0.9375rem;
    border: 1px solid var(--color-border);
    border-radius: 8px;
    background-color: var(--color-surface);
    transition: border-color 150ms, box-shadow 150ms;
}

.tool-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.tool-label {
    display: block;
    margin-bottom: 6px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text-primary);
}

/* Empty state */
.empty-state {
    text-align: center;
    padding: 80px 16px;
}

.empty-state-icon {
    display: inline-flex;
    width: 64px;
    height: 64px;
    align-items: center;
    justify-content: center;
    background-color: var(--color-surface-elevated);
    border-radius: 50%;
    margin-bottom: 20px;
}

.empty-state h2 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text-primary);
    margin: 0 0 8px;
}

.empty-state p {
    color: var(--color-text-secondary);
    margin: 0;
}

/* Navbar */
.navbar {
    position: sticky;
    top: 0;
    z-index: 50;
    background-color: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--color-border);
}

.nav-container {
    max-width: 80rem;
    margin: 0 auto;
    padding: 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}

.nav-logo {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--color-text-primary);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
    letter-spacing: -0.02em;
}

.nav-logo-mark {
    display: inline-flex;
    width: 28px;
    height: 28px;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
    color: white;
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 800;
}

.nav-search {
    flex: 1;
    max-width: 24rem;
    padding: 8px 12px;
    font-size: 0.875rem;
    border: 1px solid var(--color-border);
    border-radius: 8px;
    background-color: var(--color-surface-elevated);
    transition: border-color 150ms;
}

.nav-search:focus {
    outline: none;
    border-color: var(--color-primary);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 16px;
}

.nav-link {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    text-decoration: none;
    transition: color 150ms;
}

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

.nav-link.active {
    color: var(--color-primary);
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Footer */
.footer {
    padding: 40px 16px;
    margin-top: 64px;
    border-top: 1px solid var(--color-border);
    text-align: center;
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

/* Responsive */
@media (max-width: 640px) {
    .tool-page-header { flex-direction: column; align-items: flex-start; }
    .nav-search { max-width: 12rem; }
}