:root {
    /* Brand Colors - Unified C44C Indigo */
    --primary-color: #57c2f6;
    --primary-hover: #4338CA;
    --primary-light: rgba(79, 70, 229, 0.1);
    --bg-color: #f8fafc;
    --surface-color: #FFFFFF;
    --text-primary: #111827;
    --text-secondary: #6B7280;
    --text-muted: #9CA3AF;
    --danger: #DC2626;
    --border-color: #E5E7EB;

    /* Spacing & Radius */
    --nav-height: 72px;
    --container-max: 1200px;
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --border-radius-lg: 16px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
    transition: 0.2s;
}

.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
}

/* --- Global Navbar --- */
.global-navbar {
    position: sticky;
    top: 0;
    z-index: 50;
    height: var(--nav-height);
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0 24px;
}

.nav-container {
    width: 100%;
    max-width: var(--container-max);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.brand-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 800;
    font-size: 1.4rem;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

.nav-links { display: flex; gap: 1.5rem; align-items: center; }

.nav-link { font-size: 0.85rem; font-weight: 500; color: var(--text-secondary); transition: 0.3s; white-space: nowrap; }

.nav-link:hover,
.nav-link.active { color: var(--primary-color); font-weight: 600; }

.nav-link.active { color: var(--primary-color); font-weight: 600; }

/* --- Tool Specific Sub-Navigation --- */
.tool-subnav {
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    padding: 0 24px;
    overflow-x: auto;
    white-space: nowrap;
}

.subnav-container {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    gap: 24px;
    padding: 16px 0;
}

.subnav-item {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 500;
    padding-bottom: 16px;
    margin-bottom: -16px;
    border-bottom: 2px solid transparent;
    transition: all 0.2s;
}

.subnav-item:hover {
    color: var(--text-primary);
}

.subnav-item.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

/* --- Hero Section --- */
.hero-section {
    text-align: center;
    padding: 60px 0;
}

.hero-section h1 {
    font-size: 2.75rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    margin-bottom: 12px;
}

.hero-section p {
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* --- Grid System --- */
.tools-grid,
.doc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 24px;
    padding-bottom: 60px;
}

/* --- Tool Cards --- */
.tool-card,
.doc-card {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 32px;
    display: flex;
    flex-direction: column;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}

.tool-card:hover,
.doc-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.tool-icon,
.doc-icon {
    width: 48px;
    height: 48px;
    background: var(--primary-light);
    color: var(--primary-color);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.tool-card h3,
.doc-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.tool-card p,
.doc-card p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    flex-grow: 1;
}

/* --- Footer --- */
.global-footer {
    border-top: 1px solid var(--border-color);
    padding: 40px 0;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
    .hero-section h1 {
        font-size: 2rem;
    }

    .nav-links { display: flex; gap: 1.5rem; align-items: center; }
}