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

:root {
    --black: #1a1a1a;
    --dark-gray: #333333;
    --medium-gray: #666666;
    --light-gray: #e0e0e0;
    --bg-gray: #f5f5f5;
    --white: #ffffff;
    --hover: #eeeeee;
}

body {
    font-family: 'Courier New', monospace;
    background-color: var(--white);
    color: var(--dark-gray);
    line-height: 1.6;
}

header {
    background: var(--black);
    color: var(--white);
    padding: 1.5rem 0;
    border-bottom: 2px solid var(--dark-gray);
}

header .container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header h1 {
    font-size: 1.4rem;
    font-weight: 700;
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

nav a {
    color: var(--white);
    text-decoration: none;
    margin-left: 2rem;
    padding: 0.5rem 1rem;
    border: 1px solid transparent;
    transition: all 0.2s;
}

nav a:hover {
    border: 1px solid var(--white);
}

nav a.active {
    border: 1px solid var(--white);
    background: var(--dark-gray);
}

main {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem;
}

.controls {
    background: var(--bg-gray);
    padding: 1.5rem;
    margin-bottom: 2rem;
    display: grid;
    grid-template-columns: 1fr 1fr auto;
    gap: 1rem;
    border: 1px solid var(--light-gray);
}

.controls input[type="text"],
.controls select {
    padding: 0.75rem;
    border: 1px solid var(--light-gray);
    background: var(--white);
    font-size: 1rem;
    font-family: 'Courier New', monospace;
}

.controls input[type="text"]:focus,
.controls select:focus {
    outline: 2px solid var(--dark-gray);
}

.controls button {
    padding: 0.75rem 1.5rem;
    background-color: var(--black);
    color: var(--white);
    border: 1px solid var(--black);
    cursor: pointer;
    font-size: 1rem;
    font-family: 'Courier New', monospace;
    transition: all 0.2s;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.controls button:hover {
    background-color: var(--white);
    color: var(--black);
}

#addFormContainer {
    background: var(--bg-gray);
    padding: 2rem;
    margin-bottom: 2rem;
    border: 1px solid var(--light-gray);
}

#addFormContainer h2 {
    margin-bottom: 1.5rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 1.2rem;
}

#addForm input,
#addForm textarea,
#addForm select {
    width: 100%;
    padding: 0.75rem;
    margin-bottom: 1rem;
    border: 1px solid var(--light-gray);
    background: var(--white);
    font-size: 1rem;
    font-family: 'Courier New', monospace;
}

#addForm input:focus,
#addForm textarea:focus,
#addForm select:focus {
    outline: 2px solid var(--dark-gray);
}

#addForm textarea {
    min-height: 120px;
    resize: vertical;
}

#addForm button {
    padding: 0.75rem 1.5rem;
    margin-right: 1rem;
    border: 1px solid var(--dark-gray);
    cursor: pointer;
    font-size: 1rem;
    font-family: 'Courier New', monospace;
    transition: all 0.2s;
    text-transform: uppercase;
    letter-spacing: 1px;
}

#addForm button[type="submit"] {
    background-color: var(--black);
    color: var(--white);
}

#addForm button[type="submit"]:hover {
    background-color: var(--white);
    color: var(--black);
}

#addForm button[type="button"] {
    background-color: var(--white);
    color: var(--black);
}

#addForm button[type="button"]:hover {
    background-color: var(--black);
    color: var(--white);
}

#termsList {
    border: 1px solid var(--light-gray);
    background: var(--white);
}

.term-card {
    padding: 1.5rem;
    border-bottom: 1px solid var(--light-gray);
    transition: background-color 0.2s;
}

.term-card:last-child {
    border-bottom: none;
}

.term-card:hover {
    background-color: var(--hover);
}

.term-card h3 {
    color: var(--black);
    margin-bottom: 0.75rem;
    font-size: 1.1rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 700;
}

.term-card .category {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: var(--black);
    color: var(--white);
    font-size: 0.75rem;
    margin-bottom: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.term-card .definition {
    color: var(--dark-gray);
    line-height: 1.6;
    margin-bottom: 0.75rem;
    border-left: 2px solid var(--light-gray);
    padding-left: 1rem;
}

.term-card .source {
    font-size: 0.85rem;
    color: var(--medium-gray);
    font-style: italic;
}

.term-card .actions {
    margin-top: 1rem;
    display: flex;
    gap: 0.5rem;
}

.term-card .actions button {
    padding: 0.5rem 1rem;
    border: 1px solid var(--dark-gray);
    cursor: pointer;
    font-size: 0.85rem;
    font-family: 'Courier New', monospace;
    transition: all 0.2s;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.term-card .actions .edit-btn {
    background-color: var(--white);
    color: var(--black);
}

.term-card .actions .edit-btn:hover {
    background-color: var(--black);
    color: var(--white);
}

.term-card .actions .delete-btn {
    background-color: var(--black);
    color: var(--white);
}

.term-card .actions .delete-btn:hover {
    background-color: var(--dark-gray);
}

#graph {
    background: var(--white);
    border: 1px solid var(--light-gray);
    height: calc(100vh - 200px);
    min-height: 600px;
}

.loading {
    text-align: center;
    padding: 3rem;
    color: var(--medium-gray);
    text-transform: uppercase;
    letter-spacing: 2px;
}

.error {
    background-color: var(--black);
    color: var(--white);
    padding: 1rem;
    margin-bottom: 1rem;
    border: 2px solid var(--dark-gray);
}

@media (max-width: 768px) {
    header .container {
        flex-direction: column;
        gap: 1rem;
    }
    
    nav {
        width: 100%;
    }
    
    nav a {
        margin-left: 0;
        margin-right: 1rem;
    }
    
    .controls {
        grid-template-columns: 1fr;
    }
    
    #graph {
        height: 500px;
    }
}