/* PyLearn - Black & White Line Design */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --black: #000000;
    --dark: #333333;
    --medium: #666666;
    --light: #999999;
    --border: #E0E0E0;
    --bg: #FFFFFF;
    --text: #1A1A1A;
}

body {
    font-family: "Courier New", Courier, monospace;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text);
    background: var(--bg);
    min-height: 100vh;
}

/* Container */
.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    border-bottom: 2px solid var(--black);
    padding: 20px 0;
    margin-bottom: 40px;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    text-decoration: none;
    color: var(--black);
    letter-spacing: 2px;
}

.logo span {
    color: var(--medium);
}

.nav {
    display: flex;
    gap: 30px;
}

.nav a {
    color: var(--dark);
    text-decoration: none;
    padding: 5px 0;
    border-bottom: 1px solid transparent;
    transition: all 0.3s;
}

.nav a:hover {
    color: var(--black);
    border-bottom: 1px solid var(--black);
}

/* Main Content */
.main {
    min-height: calc(100vh - 200px);
    padding-bottom: 60px;
}

/* Typography */
h1 {
    font-size: 28px;
    margin-bottom: 20px;
    border-left: 4px solid var(--black);
    padding-left: 15px;
}

h2 {
    font-size: 22px;
    margin: 30px 0 15px;
    border-left: 3px solid var(--black);
    padding-left: 12px;
}

h3 {
    font-size: 18px;
    margin: 20px 0 10px;
}

p {
    margin-bottom: 15px;
}

ul, ol {
    margin: 15px 0 15px 25px;
}

li {
    margin-bottom: 8px;
}

/* Code Blocks */
code {
    background: var(--border);
    padding: 2px 6px;
    font-size: 14px;
    border: 1px solid var(--border);
}

pre {
    background: #f5f5f5;
    border: 1px solid var(--border);
    border-left: 4px solid var(--black);
    padding: 15px;
    margin: 15px 0;
    overflow-x: auto;
    font-size: 14px;
    line-height: 1.5;
}

pre code {
    background: none;
    border: none;
    padding: 0;
}

/* Cards */
.card {
    border: 1px solid var(--black);
    padding: 25px;
    margin-bottom: 20px;
    background: var(--bg);
}

.card-header {
    border-bottom: 1px solid var(--border);
    padding-bottom: 15px;
    margin-bottom: 15px;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 10px 25px;
    border: 2px solid var(--black);
    background: var(--bg);
    color: var(--black);
    text-decoration: none;
    font-family: inherit;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s;
    margin-right: 10px;
}

.btn:hover {
    background: var(--black);
    color: var(--bg);
}

.btn:disabled {
    border-color: var(--light);
    color: var(--light);
    cursor: not-allowed;
}

.btn:disabled:hover {
    background: var(--bg);
    color: var(--light);
}

.btn-small {
    padding: 6px 15px;
    font-size: 12px;
}

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

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

/* Forms */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
    color: var(--dark);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--black);
    font-family: inherit;
    font-size: 14px;
    background: var(--bg);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    box-shadow: 3px 3px 0 var(--black);
}

.form-group input[type="checkbox"] {
    width: auto;
}

/* Tables */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

th, td {
    border: 1px solid var(--black);
    padding: 12px;
    text-align: left;
}

th {
    background: var(--black);
    color: var(--bg);
    font-weight: bold;
}

tr:nth-child(even) {
    background: #f9f9f9;
}

/* Progress Bar */
.progress-bar {
    height: 20px;
    border: 1px solid var(--black);
    background: var(--bg);
    margin: 10px 0;
}

.progress-bar-fill {
    height: 100%;
    background: var(--black);
    transition: width 0.3s;
}

/* Chapter List */
.chapter-list {
    margin-top: 30px;
}

.chapter-item {
    border: 1px solid var(--black);
    margin-bottom: 15px;
}

.chapter-header {
    padding: 20px;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.chapter-header h3 {
    margin: 0;
}

.unit-list {
    padding: 0 20px;
}

.unit-item {
    padding: 15px 0;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.unit-item:last-child {
    border-bottom: none;
}

.unit-item.locked {
    color: var(--light);
}

.unit-item.locked a {
    color: var(--light);
    pointer-events: none;
}

.unit-item.completed .status {
    color: var(--black);
}

.badge {
    display: inline-block;
    padding: 3px 10px;
    font-size: 11px;
    border: 1px solid var(--black);
    margin-left: 10px;
}

.badge-success {
    background: var(--black);
    color: var(--bg);
}

/* Quiz */
.quiz-container {
    max-width: 700px;
    margin: 0 auto;
}

.quiz-question {
    border: 1px solid var(--black);
    padding: 25px;
    margin-bottom: 20px;
}

.quiz-question h4 {
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border);
}

.quiz-options {
    margin-top: 15px;
}

.quiz-option {
    display: block;
    padding: 12px 15px;
    border: 1px solid var(--border);
    margin-bottom: 10px;
    cursor: pointer;
    transition: all 0.2s;
}

.quiz-option:hover {
    border-color: var(--black);
    background: #f9f9f9;
}

.quiz-option.selected {
    border-color: var(--black);
    border-width: 2px;
    background: #f0f0f0;
}

.quiz-option input {
    margin-right: 10px;
}

/* Results */
.result-box {
    border: 2px solid var(--black);
    padding: 30px;
    text-align: center;
    margin: 30px 0;
}

.result-score {
    font-size: 48px;
    font-weight: bold;
    margin: 15px 0;
}

.result-pass {
    color: var(--black);
}

.result-fail {
    color: var(--medium);
}

/* Alert Messages */
.alert {
    padding: 15px 20px;
    border: 1px solid var(--black);
    margin: 20px 0;
}

.alert-error {
    background: #f5f5f5;
    border-left: 4px solid var(--black);
}

.alert-success {
    background: var(--black);
    color: var(--bg);
}

/* Dashboard Grid */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin-top: 30px;
}

.stat-card {
    border: 1px solid var(--black);
    padding: 20px;
    text-align: center;
}

.stat-value {
    font-size: 36px;
    font-weight: bold;
    margin: 10px 0;
}

.stat-label {
    color: var(--medium);
    font-size: 14px;
}

/* Login/Register Form */
.auth-form {
    max-width: 400px;
    margin: 50px auto;
    border: 1px solid var(--black);
    padding: 40px;
}

.auth-form h1 {
    text-align: center;
    border: none;
    padding: 0;
    margin-bottom: 30px;
}

/* Lesson Content */
.lesson-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 30px;
    border: 1px solid var(--black);
}

.lesson-nav {
    display: flex;
    justify-content: space-between;
    padding: 20px;
    border-top: 1px solid var(--border);
    margin-top: 30px;
}

/* Decorative Lines */
.decoration-line {
    height: 2px;
    background: linear-gradient(to right, var(--black), var(--border), var(--black));
    margin: 30px 0;
}

/* Footer */
.footer {
    border-top: 2px solid var(--black);
    padding: 30px 0;
    text-align: center;
    color: var(--medium);
    font-size: 14px;
    margin-top: 60px;
}

/* ASCII Decorations */
.ascii-border {
    font-size: 12px;
    color: var(--light);
    text-align: center;
    margin: 20px 0;
    letter-spacing: 2px;
}

/* Utility Classes */
.text-center {
    text-align: center;
}

.text-right {
    text-align: right;
}

.mt-20 {
    margin-top: 20px;
}

.mb-20 {
    margin-bottom: 20px;
}

.hidden {
    display: none;
}

/* Responsive */
@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: 15px;
    }

    .nav {
        gap: 15px;
    }

    h1 {
        font-size: 22px;
    }

    .dashboard-grid {
        grid-template-columns: 1fr;
    }

    .auth-form {
        margin: 20px;
        padding: 25px;
    }
}