/* --- GLOBAL STYLES --- */
:root {
    --unity-blue: #0078d4;
    --dark-text: #1a1a1a;
    --light-gray: #f8f8f8;
    --border-color: #eeeeee;
    --nav-height: 80px;
}

* { box-sizing: border-box; }

body {
    font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #ffffff;
    color: var(--dark-text);
    line-height: 1.6;
}

/* --- NAVIGATION --- */
header {
    width: 100%;
    height: var(--nav-height);
    background: #ffffff;
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    height: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 25px;
}

.nav-brand {
    font-weight: 800;
    text-decoration: none;
    color: var(--dark-text);
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.2rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.back-link {
    text-decoration: none;
    color: #888;
    font-weight: 600;
    font-size: 0.9rem;
    transition: 0.3s;
    text-transform: uppercase;
}

.back-link:hover { color: var(--unity-blue); }

/* --- MAIN CONTENT --- */
main {
    max-width: 1200px;
    margin: 50px auto;
    padding: 0 25px;
}

.intro-section {
    margin-bottom: 50px;
    border-left: 6px solid var(--unity-blue);
    padding-left: 25px;
}

.intro-section h1 {
    font-size: 2.8rem;
    margin: 0;
    letter-spacing: -1px;
}

.intro-section p {
    color: #666;
    font-size: 1.1rem;
    margin-top: 5px;
}

/* --- FILTER BAR --- */
.filter-bar {
    margin-bottom: 40px;
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.filter-btn {
    background: #fff;
    border: 1px solid var(--border-color);
    padding: 10px 22px;
    border-radius: 30px;
    cursor: pointer;
    font-family: inherit;
    font-weight: 600;
    color: #777;
    transition: all 0.3s ease;
    font-size: 0.85rem;
}

.filter-btn:hover {
    border-color: var(--unity-blue);
    color: var(--unity-blue);
}

.filter-btn.active {
    background: var(--unity-blue);
    color: #ffffff;
    border-color: var(--unity-blue);
    box-shadow: 0 4px 12px rgba(0, 120, 212, 0.3);
}

/* --- PROJECT GRID & CARDS --- */
.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 35px;
}

.card {
    background: #fff;
    border: 1px solid var(--border-color);
    border-radius: 16px;
    overflow: hidden;
    transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.1);
}

.card img {
    width: 100%;
    height: 220px;
    object-fit: cover;
    background: #f0f0f0;
    border-bottom: 1px solid var(--border-color);
}

.card-content {
    padding: 25px;
}

.card-content h3 {
    margin: 0 0 12px 0;
    font-size: 1.3rem;
    color: var(--dark-text);
}

.card-content p {
    color: #666;
    font-size: 0.95rem;
    margin-bottom: 20px;
}

.tech-tags {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.tag {
    background: var(--light-gray);
    padding: 4px 12px;
    border-radius: 6px;
    font-size: 0.7rem;
    font-weight: 700;
    color: #555;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* --- FOOTER --- */
footer {
    background: var(--light-gray);
    padding: 60px 25px;
    text-align: center;
    margin-top: 100px;
    border-top: 1px solid var(--border-color);
}

footer p {
    color: #999;
    font-size: 0.85rem;
    letter-spacing: 1px;
    text-transform: uppercase;
}