/* --- Google Font & Font Awesome --- */
@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;700&display=swap');
@import url('https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.2.0/css/all.min.css');

/* --- Root Variables for Easy Themeing --- */
:root {
    --red-hat-red: #cc0000;
    --primary-text: #212529;
    --secondary-text: #5a5a5a;
    --background-color: #f8f9fa;
    --content-bg: #ffffff;
    --border-color: #dee2e6;
    --link-color: #0066cc;
    --code-bg: #f1f3f5;
    --note-bg: #fff9e6;
    --note-border: #ffc107;
    --warning-bg: #fff0f1;
    --warning-border: #d9534f;
}

/* --- General Body & Layout --- */
body {
    font-family: 'Roboto', -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
    line-height: 1.7;
    color: var(--primary-text);
    background-color: var(--background-color);
    margin: 0;
    padding: 0;
}

.container {
    max-width: 950px;
    margin: 20px auto;
    padding: 20px;
}

/* --- Header & Navigation --- */
header {
    background-color: var(--content-bg);
    padding: 20px 40px;
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 1000;
}

header .logo {
    font-size: 1.5em;
    font-weight: 700;
    color: var(--red-hat-red);
}

header .logo i {
    margin-right: 10px;
}

header nav a {
    color: var(--secondary-text);
    text-decoration: none;
    margin-left: 25px;
    font-weight: 700;
    transition: color 0.3s ease;
}

header nav a:hover, header nav a.active {
    color: var(--red-hat-red);
}

/* --- Main Content & Cards --- */
main {
    padding: 20px;
    background: var(--content-bg);
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
}

h1, h2, h3 {
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 10px;
}

h1 {
    color: var(--red-hat-red);
    font-size: 2.2em;
    margin-bottom: 20px;
}

h2 {
    font-size: 1.8em;
    margin-top: 40px;
}

h3 {
    font-size: 1.4em;
    margin-top: 30px;
    border-bottom-style: dashed;
}

.chapter-summary, .day-links, .note, .warning {
    background: #fdfdfd;
    border: 1px solid var(--border-color);
    border-left: 5px solid var(--red-hat-red);
    padding: 20px;
    margin: 25px 0;
    border-radius: 5px;
    transition: box-shadow 0.3s ease;
}

.chapter-summary:hover {
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.day-links {
    border-left-color: var(--link-color);
}
.day-links a {
    color: var(--link-color);
    text-decoration: none;
    font-weight: bold;
}
.day-links a:hover {
    text-decoration: underline;
}

/* --- Special Boxes --- */
.note {
    background-color: var(--note-bg);
    border-left-color: var(--note-border);
}

.warning {
    background-color: var(--warning-bg);
    border-left-color: var(--warning-border);
    color: var(--primary-text);
}

/* --- Code & Tables --- */
code {
    background-color: var(--code-bg);
    padding: 3px 7px;
    border-radius: 4px;
    font-family: "Courier New", Courier, monospace;
    font-size: 0.9em;
    border: 1px solid var(--border-color);
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 25px 0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

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

th {
    background-color: #f2f2f2;
    font-weight: 700;
}

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

/* --- Footer --- */
footer {
    text-align: center;
    margin-top: 40px;
    padding: 20px;
    color: var(--secondary-text);
    font-size: 0.9em;
}