/* =====================================================
   Christopher Sefcik — Modern Academic Theme (2026)
   Clean, minimal, research-grade UI
   ===================================================== */

/* -----------------------------
   DESIGN TOKENS
------------------------------ */

:root {
    --bg: #f6f8fc;
    --surface: rgba(255,255,255,0.75);
    --surface-solid: #ffffff;

    --text: #0f172a;
    --muted: #64748b;

    --primary: #2563eb;
    --primary-dark: #1d4ed8;

    --border: rgba(15, 23, 42, 0.08);

    --shadow-sm: 0 4px 12px rgba(0,0,0,0.06);
    --shadow-md: 0 12px 30px rgba(0,0,0,0.08);

    --radius: 16px;

    --max: 1200px;
}

/* -----------------------------
   RESET
------------------------------ */

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

body {
    font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
}

/* -----------------------------
   LAYOUT
------------------------------ */

.container {
    width: 92%;
    max-width: var(--max);
    margin: auto;
}

/* -----------------------------
   NAVIGATION (GLASS STYLE)
------------------------------ */

.header {
    position: sticky;
    top: 0;
    z-index: 1000;

    background: rgba(255,255,255,0.7);
    backdrop-filter: blur(12px);

    border-bottom: 1px solid var(--border);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px 0;
}

.logo h1 {
    font-size: 1.3rem;
    font-weight: 700;
}

.logo span {
    font-size: 0.8rem;
    color: var(--muted);
}

nav ul {
    display: flex;
    gap: 18px;
    list-style: none;
}

nav a {
    text-decoration: none;
    color: var(--text);
    font-weight: 500;
    font-size: 0.95rem;
    transition: 0.2s;
}

nav a:hover {
    color: var(--primary);
}

/* -----------------------------
   MOBILE NAV
------------------------------ */

.menu-toggle {
    display: none;
    font-size: 1.6rem;
    background: none;
    border: none;
    cursor: pointer;
}

@media (max-width: 900px) {

    .menu-toggle {
        display: block;
    }

    nav {
        display: none;
        width: 100%;
        margin-top: 10px;
    }

    nav.active {
        display: block;
    }

    nav ul {
        flex-direction: column;
        gap: 10px;
    }
}

/* -----------------------------
   HERO
------------------------------ */

.hero {
    padding: 110px 20px;
    text-align: center;

    background:
        radial-gradient(circle at top,
        rgba(37,99,235,0.15),
        transparent 60%);
}

.hero h2 {
    font-size: 2.8rem;
    font-weight: 800;
}

.hero p {
    margin-top: 10px;
    color: var(--muted);
    font-size: 1.1rem;
}

/* -----------------------------
   BUTTONS
------------------------------ */

.btn-primary,
.btn-secondary {
    display: inline-block;
    padding: 12px 18px;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 600;
    transition: 0.2s;
}

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

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

.btn-secondary {
    border: 1px solid var(--border);
    color: var(--text);
    background: white;
}

.btn-secondary:hover {
    transform: translateY(-2px);
}

/* -----------------------------
   SECTIONS
------------------------------ */

section {
    padding: 70px 0;
}

section h2 {
    font-size: 1.6rem;
    margin-bottom: 25px;
}

/* -----------------------------
   CARDS (MODERN TILE STYLE)
------------------------------ */

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 18px;
}

.card {
    background: var(--surface);
    backdrop-filter: blur(10px);

    border: 1px solid var(--border);
    border-radius: var(--radius);

    padding: 20px;

    box-shadow: var(--shadow-sm);

    transition: 0.25s ease;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

/* -----------------------------
   PAGE HEADER
------------------------------ */

.page-header {
    padding: 80px 20px;
    text-align: center;
}

.page-header h1 {
    font-size: 2.4rem;
}

.page-header p {
    color: var(--muted);
    margin-top: 10px;
}

/* -----------------------------
   TAGS
------------------------------ */

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.tag {
    padding: 6px 12px;
    border-radius: 999px;

    font-size: 0.85rem;

    background: rgba(37,99,235,0.08);
    color: var(--primary);
}

/* -----------------------------
   FORMS (MODERN CLEAN)
------------------------------ */

form {
    display: flex;
    flex-direction: column;
    gap: 12px;
    max-width: 700px;
}

input, textarea {
    padding: 12px;
    border-radius: 12px;

    border: 1px solid var(--border);
    background: white;

    outline: none;
}

textarea {
    min-height: 140px;
}

button {
    padding: 12px;
    border: none;
    border-radius: 12px;

    background: var(--primary);
    color: white;

    font-weight: 600;
    cursor: pointer;
}

/* -----------------------------
   BLOG POSTS
------------------------------ */

.blog-post {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius);

    padding: 22px;

    margin-bottom: 16px;
}

.blog-post .date {
    font-size: 0.85rem;
    color: var(--muted);
}

/* -----------------------------
   FOOTER
------------------------------ */

footer {
    text-align: center;
    padding: 40px;
    color: var(--muted);
}

/* -----------------------------
   ANIMATION
------------------------------ */

.card,
.blog-post {
    animation: fadeUp 0.5s ease;
}

@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}