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

body {
    background: #0d1117;
    font-family: 'Fira Code', 'Courier New', monospace;
    color: #c9d1d9;
    line-height: 1.6;
    padding: 2rem 1.5rem;
}

.container {
    max-width: 1300px;
    margin: 0 auto;
}

/* header / terminal style */
.header {
    margin-bottom: 3rem;
    border-left: 4px solid #58a6ff;
    padding-left: 1.5rem;
}

.header h1 {
    font-size: 2.5rem;
    font-weight: 500;
    letter-spacing: -0.5px;
    color: #f0f6fc;
}

.header h1 span {
    color: #58a6ff;
}

.header .diagram {
    background: #161b22;
    padding: 1.2rem 1.5rem;
    border-radius: 12px;
    margin-top: 1.2rem;
    font-family: inherit;
    border: 1px solid #30363d;
    box-shadow: 0 4px 12px rgba(0,0,0,0.6);
    display: inline-block;
}

.header .diagram pre {
    color: #7d8590;
    font-size: 0.95rem;
}

.subtitle {
    color: #8b949e;
    margin-top: 0.5rem;
    font-size: 1.1rem;
}

.subtitle a {
    color: #58a6ff;
    text-decoration: none;
    border-bottom: 1px dashed #3b434b;
}

/* grid */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.8rem;
    margin-top: 2rem;
}

/* card */
.card {
    background: #161b22;
    border: 1px solid #30363d;
    border-radius: 20px;
    padding: 1.5rem 1.2rem;
    transition: transform 0.15s, border-color 0.15s, box-shadow 0.2s;
    box-shadow: 0 6px 10px rgba(0,0,0,0.5);
    backdrop-filter: blur(2px);
    display: flex;
    flex-direction: column;
}

.card:hover {
    border-color: #58a6ff;
    transform: translateY(-5px);
    box-shadow: 0 16px 24px rgba(0, 100, 200, 0.2);
}

.card-header {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    margin-bottom: 1.2rem;
    border-bottom: 1px solid #2a2f36;
    padding-bottom: 0.6rem;
}

.card-header .icon {
    font-size: 1.8rem;
    line-height: 1;
}

.card-header h2 {
    font-size: 1.5rem;
    font-weight: 500;
    color: #f0f6fc;
}

.api-list {
    list-style: none;
    margin-top: 0.4rem;
    flex: 1;
}

.api-list li {
    background: #0d1117;
    margin-bottom: 0.9rem;
    padding: 0.8rem 1rem;
    border-radius: 12px;
    border-left: 3px solid;
    font-size: 0.95rem;
    border-color: #3b434b;
    transition: border-color 0.1s;
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.5);
}

.api-list li strong {
    color: #ffa657;
    font-weight: 600;
    display: inline-block;
    min-width: 100px;
    font-family: 'Fira Code', monospace;
}

.api-list li .desc {
    color: #b1bac4;
    margin-top: 0.25rem;
    font-size: 0.9rem;
    padding-left: 0.2rem;
    border-left: 2px solid #30363d;
    padding-left: 0.7rem;
}

/* different accent per category */
.card[data-category="memory"] li { border-left-color: #79c0ff; }
.card[data-category="process"] li { border-left-color: #d2a8ff; }
.card[data-category="ipc"] li { border-left-color: #7ee3b8; }
.card[data-category="access"] li { border-left-color: #f69d50; }
.card[data-category="interact"] li { border-left-color: #ff7b72; }

.footer {
    margin-top: 4rem;
    text-align: center;
    color: #6e7681;
    font-size: 0.9rem;
    border-top: 1px solid #21262d;
    padding-top: 2rem;
}

.footer .gh-link {
    color: #58a6ff;
    text-decoration: none;
}

.footer .gh-link:hover {
    text-decoration: underline;
}

/* small adjustments */
@media (max-width: 500px) {
    body { padding: 1rem; }
    .header h1 { font-size: 2rem; }
}