:root {
    --bg: #ffffff;
    --text: #1f2d3d;
    --muted: #6b7280;
    --primary: #0a66c2;
    --primary-600: #084c91;
    --surface: #f7fbff;
    --accent: #e8f1ff;
    --radius: 10px;
    --container: 1100px;
    --max-width: 1200px;
    --shadow: 0 6px 20px rgba(9, 30, 66, 0.08);
}

:root[data-theme='dark'] {
    --bg: #0b1221;
    --text: #e6eef8;
    --muted: #b6c1cf;
    --primary: #58a6ff;
    --primary-600: #2c6fb8;
    --surface: #07101a;
    --accent: rgba(88, 166, 255, 0.08);
}

* {
    box-sizing: border-box;
}

html,
body {
    height: 100%;
}

body {
    margin: 0;
    font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial;
    background: linear-gradient(180deg, var(--surface), var(--bg));
    color: var(--text);
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 20px;
}

.skip-link {
    position: absolute;
    left: -9999px;
    top: auto;
    width: 1px;
    height: 1px;
    overflow: hidden;
}

.skip-link:focus {
    left: 10px;
    top: 10px;
    width: auto;
    height: auto;
    padding: 10px 14px;
    border-radius: 6px;
    background: var(--primary);
    color: white;
    z-index: 99;
}

.site-header {
    background: transparent;
    padding: 20px 0;
}

.header-inner {
    display: flex;
    gap: 20px;
    align-items: center;
    justify-content: space-between;
}

.brand h1 {
    font-size: 20px;
    margin: 0;
    color: var(--primary);
}

.brand a {
    color: var(--primary);
    text-decoration: none;
}

.tagline {
    margin: 0;
    color: var(--muted);
    font-size: 13px;
}

.nav {
    display: flex;
    gap: 12px;
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav a {
    padding: 8px 10px;
    color: var(--muted);
    text-decoration: none;
    border-radius: 6px;
    font-weight: 600;
}

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

.controls {
    display: flex;
    gap: 10px;
    align-items: center;
}

input[type="search"] {
    padding: 10px 12px;
    border-radius: 8px;
    border: 1px solid rgba(15, 23, 42, 0.06);
    min-width: 220px;
    background: transparent;
    color: var(--text);
}

button#theme-toggle {
    padding: 8px 10px;
    border-radius: 8px;
    border: none;
    background: var(--accent);
    cursor: pointer;
    color: var(--primary);
}

.hero {
    padding: 50px 0;
    background: linear-gradient(180deg, rgba(10, 102, 194, 0.06), transparent);
}

.hero h2 {
    font-size: 28px;
    margin: 0 0 8px;
}

.lead {
    color: var(--muted);
    margin-bottom: 16px;
}

.hero-cta {
    display: flex;
    gap: 12px;
}

.btn {
    display: inline-block;
    padding: 10px 14px;
    border-radius: 8px;
    text-decoration: none;
    color: var(--primary);
    border: 1px solid transparent;
}

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

.btn-ghost {
    background: transparent;
    border: 1px solid rgba(15, 23, 42, 0.06);
    padding: 8px 10px;
    border-radius: 8px;
    color: var(--muted);
    text-decoration: none;
}

.categories {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    justify-content: center;
    padding: 40px 0 80px;
}

.card {
    width: 220px;
    background: var(--surface);
    padding: 20px;
    text-align: center;
    text-decoration: none;
    color: var(--primary);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    gap: 8px;
    align-items: center;
    transition: transform .15s ease, box-shadow .15s ease;
}

.card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 30px rgba(10, 66, 194, 0.08);
}

.card-icon {
    font-size: 28px;
}

.file-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    grid-template-columns: 1fr;
    gap: 12px;
}

.file {
    padding: 14px 18px;
    border-radius: 10px;
    background: var(--surface);
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow);
    border: 1px solid rgba(15, 23, 42, 0.03);
}

.file .file-title {
    font-weight: 600;
}

.file .muted {
    color: var(--muted);
    font-size: 13px;
}

.file .btn-small {
    padding: 6px 10px;
    border-radius: 8px;
    background: var(--primary);
    color: white;
    text-decoration: none;
}

.btn-small:hover {
    background: var(--primary-600);
}

/* file-type icons using attribute selectors */
.file[data-type='pdf']::before {
    content: "📄";
    margin-right: 10px;
    font-size: 18px;
}

.file[data-type='docx']::before {
    content: "📃";
    margin-right: 10px;
    font-size: 18px;
}


footer {
    padding: 20px 0;
    color: var(--muted);
    text-align: center;
}

/* Utility */
.muted {
    color: var(--muted);
}

.visually-hidden {
    position: absolute;
    left: -9999px;
    width: 1px;
    height: 1px;
    overflow: hidden;
}

/* Responsive */
@media (min-width: 720px) {
    .file-list {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1000px) {
    .hero h2 {
        font-size: 40px;
    }

    .card {
        width: 260px;
    }
}

/* Focus outlines for accessibility */
a:focus,
button:focus,
input:focus {
    outline: 3px solid rgba(10, 66, 194, 0.12);
    outline-offset: 3px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, sans-serif;
}

body {
    background: #ffffff;
    color: #1f1f1f;
}

header {
    padding: 20px;
    background: #0A66C2;
    color: white;
    text-align: center;
}

header input {
    margin-top: 15px;
    padding: 10px;
    width: 60%;
    max-width: 400px;
    border: none;
    border-radius: 5px;
}

.categories {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    padding: 30px;
    gap: 20px;
}

.card {
    background: #e8f1ff;
    padding: 40px 30px;
    width: 200px;
    text-align: center;
    text-decoration: none;
    color: #0A66C2;
    font-size: 20px;
    border-radius: 8px;
    transition: 0.2s ease;
    border: 1px solid #bcd2ff;
}

.card:hover {
    background: #d7e7ff;
    transform: scale(1.05);
    cursor: pointer;
}

footer {
    text-align: center;
    padding: 20px;
    margin-top: 30px;
    color: #4d4d4d;
}

.file-list {
    list-style: none;
    padding: 30px;
    max-width: 600px;
    margin: auto;
}

.file {
    background: #e8f1ff;
    padding: 15px 20px;
    border-radius: 6px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
    border: 1px solid #bcd2ff;
}

.file a {
    background: #0A66C2;
    padding: 8px 15px;
    border-radius: 5px;
    color: white;
    text-decoration: none;
}

.file a:hover {
    background: #084c91;
}