:root {
    --bg-main: #020617;
    --bg-card: rgba(15, 23, 42, 0.96);
    --bg-card-soft: rgba(15, 23, 42, 0.85);
    --border-muted: #1f2937;
    --accent: #22c55e;
    --accent-soft: rgba(34, 197, 94, 0.15);
    --accent-alt: #38bdf8;
    --text-main: #e5e7eb;
    --text-soft: #9ca3af;
    --danger: #f97373;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    color: var(--text-main);
    background:
        radial-gradient(circle at 0% 0%, rgba(34, 197, 94, 0.18), transparent 50%),
        radial-gradient(circle at 100% 100%, rgba(56, 189, 248, 0.18), transparent 55%),
        linear-gradient(135deg, #020617 0%, #020617 40%, #020617 100%);
    min-height: 100vh;
}

body::before {
    content: "";
    position: fixed;
    inset: 0;
    background-image: linear-gradient(rgba(148, 163, 184, 0.1) 1px, transparent 1px),
                      linear-gradient(90deg, rgba(148, 163, 184, 0.06) 1px, transparent 1px);
    background-size: 40px 40px;
    opacity: 0.1;
    pointer-events: none;
    z-index: -1;
}

a {
    color: var(--accent-alt);
    text-decoration: none;
}
a:hover {
    text-decoration: underline;
}

.navbar {
    position: sticky;
    top: 0;
    z-index: 20;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 1.5rem;
    background: rgba(2, 6, 23, 0.96);
    border-bottom: 1px solid var(--border-muted);
    backdrop-filter: blur(10px);
}

.nav-left {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-logo {
    width: 28px;
    height: 28px;
    border-radius: 999px;
    border: 1px solid var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.85rem;
    background: radial-gradient(circle, var(--accent-soft), transparent 70%);
}

.nav-title {
    font-weight: 600;
    letter-spacing: 0.03em;
    font-size: 1rem;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.nav-link {
    font-size: 0.9rem;
    color: var(--text-soft);
}
.nav-link:hover {
    color: var(--accent-alt);
}

.nav-user {
    font-size: 0.85rem;
    color: var(--text-soft);
    display: flex;
    align-items: center;
    gap: 0.35rem;
}

.btn {
    border-radius: 999px;
    padding: 0.4rem 0.9rem;
    border: 1px solid transparent;
    font-size: 0.85rem;
    cursor: pointer;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent), #16a34a);
    color: #020617;
    font-weight: 600;
    box-shadow: 0 8px 18px rgba(34, 197, 94, 0.25);
}
.btn-primary:hover {
    filter: brightness(1.05);
    text-decoration: none;
}

.btn-ghost {
    background: transparent;
    color: var(--text-soft);
    border: 1px solid var(--border-muted);
}
.btn-ghost:hover {
    border-color: var(--accent-alt);
    color: var(--accent-alt);
    text-decoration: none;
}

.btn-complete {
    margin-top: 0.5rem;
    padding: 0.45rem 0.9rem;
    border-radius: 999px;
    border: 1px solid var(--accent-alt);
    background: rgba(15, 23, 42, 0.9);
    color: var(--accent-alt);
    font-size: 0.85rem;
    cursor: pointer;
}
.btn-complete.completed {
    border-color: var(--accent);
    color: var(--accent);
    background: rgba(22, 163, 74, 0.08);
}
.btn-complete:hover {
    background: rgba(15, 23, 42, 1);
}

.badge {
    padding: 0.1rem 0.45rem;
    border-radius: 999px;
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.badge-instructor {
    background: var(--accent-soft);
    color: var(--accent);
    border: 1px solid var(--accent);
}

.badge-student {
    background: rgba(56, 189, 248, 0.16);
    color: var(--accent-alt);
    border: 1px solid var(--accent-alt);
}

.container {
    max-width: 960px;
    margin: 1.7rem auto 2.5rem auto;
    padding: 0 1.25rem;
}

h1 {
    margin-top: 0;
    font-size: 1.9rem;
}

h2 {
    margin-top: 0;
    font-size: 1.25rem;
}

p {
    color: var(--text-soft);
}

.card {
    background: var(--bg-card);
    border-radius: 1rem;
    padding: 1.1rem 1.4rem;
    margin: 1rem 0;
    border: 1px solid var(--border-muted);
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.4);
}

.card-soft {
    background: var(--bg-card-soft);
}

.lab-list {
    padding-left: 1.2rem;
}

.lab-list li {
    margin: 0.3rem 0;
}

pre {
    background: #020617;
    padding: 0.75rem;
    border-radius: 0.7rem;
    border: 1px solid var(--border-muted);
    overflow-x: auto;
    font-size: 0.85rem;
}

code {
    font-family: "Fira Code", ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

.table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
}

.table th,
.table td {
    padding: 0.4rem 0.55rem;
    border-bottom: 1px solid var(--border-muted);
    text-align: left;
}

.table th {
    font-weight: 600;
    color: var(--text-soft);
}

.table tr:nth-child(even) td {
    background: rgba(15, 23, 42, 0.6);
}

.badge-complete {
    display: inline-block;
    padding: 0.1rem 0.4rem;
    border-radius: 999px;
    background: var(--accent-soft);
    color: var(--accent);
    font-size: 0.7rem;
}

.badge-missing {
    display: inline-block;
    padding: 0.1rem 0.4rem;
    border-radius: 999px;
    background: rgba(248, 113, 113, 0.14);
    color: var(--danger);
    font-size: 0.7rem;
}

.footer {
    border-top: 1px solid var(--border-muted);
    padding: 0.7rem 1.5rem;
    font-size: 0.75rem;
    color: var(--text-soft);
    text-align: center;
    background: rgba(2, 6, 23, 0.96);
}