/* Design Tokens & Variables */
:root {
    --bg-canvas: #f8fafc;
    --surface-card: #ffffff;
    --surface-hover: #f1f5f9;
    --accent-aiml: #6d28d9; /* Deep-Tech Purple */
    --accent-light: #f5f3ff;
    --text-heading: #0f172a;
    --text-body: #334155;
    --text-muted: #64748b;
    --border-line: #e2e8f0;
    --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

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

body {
    font-family: var(--font-main);
    background-color: var(--bg-canvas);
    color: var(--text-body);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem 1rem;
    line-height: 1.5;
}

/* Master Card Container */
.curriculum-card {
    background-color: var(--surface-card);
    border: 1px solid var(--border-line);
    border-radius: 16px;
    width: 100%;
    max-width: 800px;
    padding: 2.5rem;
    box-shadow: 0 10px 25px -5px rgba(15, 23, 42, 0.05), 0 8px 10px -6px rgba(15, 23, 42, 0.05);
}

/* Header Elements */
.card-header {
    margin-bottom: 2.25rem;
    border-bottom: 2px solid var(--bg-canvas);
    padding-bottom: 1.5rem;
}

.vertical-tag {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--accent-aiml);
    background-color: var(--accent-light);
    padding: 0.25rem 0.75rem;
    border-radius: 6px;
    margin-bottom: 0.75rem;
}

h1 {
    font-size: 2rem;
    font-weight: 800;
    color: var(--text-heading);
    letter-spacing: -0.02em;
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1rem;
}

/* Menu Items & List Layouts */
.course-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.65rem;
}

.course-item {
    border: 1px solid var(--border-line);
    border-radius: 10px;
    transition: all 0.2s ease-in-out;
}

.course-item:hover {
    background-color: var(--surface-hover);
    border-color: var(--accent-aiml);
    transform: translateX(4px);
}

.course-link {
    display: flex;
    align-items: center;
    padding: 1rem 1.25rem;
    text-decoration: none;
    color: var(--text-body);
    width: 100%;
}

/* Numeric Subject Code Boxes */
.course-code {
    font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--accent-aiml);
    background-color: rgba(109, 40, 217, 0.06);
    padding: 0.35rem 0.65rem;
    border-radius: 6px;
    margin-right: 1.25rem;
    flex-shrink: 0;
    border: 1px solid rgba(109, 40, 217, 0.15);
}

.course-title {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-heading);
    flex-grow: 1;
}

.course-details {
    display: block;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
    font-weight: 400;
}

.arrow-icon {
    color: var(--text-muted);
    margin-left: 1rem;
    transition: color 0.2s ease;
    font-weight: bold;
}

.course-item:hover .arrow-icon {
    color: var(--accent-aiml);
}

/* Responsive Adaptive Layout Rules */
@media (max-width: 640px) {
    .curriculum-card {
        padding: 1.5rem;
    }
    h1 {
        font-size: 1.6rem;
    }
    .course-link {
        padding: 0.85rem;
    }
    .course-code {
        margin-right: 0.75rem;
        font-size: 0.85rem;
    }
    .course-title {
        font-size: 0.95rem;
    }
}