/* Sötét, minimalista stílus a gyakorló platformhoz */

:root {
    --bg: #0f1115;
    --bg-elevated: #171a21;
    --border: #262b34;
    --text: #e4e6ea;
    --text-muted: #8a919e;
    --accent: #5b8def;
    --accent-hover: #7aa3f2;
    --ok: #4caf7d;
    --ok-bg: rgba(76, 175, 125, 0.1);
    --bad: #e0655f;
    --bad-bg: rgba(224, 101, 95, 0.1);
    --radius: 10px;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: -apple-system, "Segoe UI", system-ui, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.5;
}

.topbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--bg-elevated);
    border-bottom: 1px solid var(--border);
    padding: 0.9rem 1.75rem;
}
.topbar a { color: var(--text-muted); text-decoration: none; transition: color 0.15s; }
.topbar a:hover { color: var(--text); }
.logo { font-weight: 600; letter-spacing: -0.01em; }
.who { color: var(--text-muted); margin-right: 1rem; font-size: 0.9rem; }

.topbar nav { display: flex; align-items: center; gap: 1.25rem; }
.nav-links { display: flex; align-items: center; gap: 0.5rem; }
.nav-links > a {
    padding: 0.4rem 0.7rem;
    border-radius: 7px;
    font-size: 0.9rem;
}
.nav-links > a:hover { background: var(--bg); }

.nav-dropdown { position: relative; }
.nav-dropdown summary {
    cursor: pointer;
    list-style: none;
    color: var(--text-muted);
    padding: 0.4rem 0.7rem;
    border-radius: 7px;
    font-size: 0.9rem;
    user-select: none;
}
.nav-dropdown summary::-webkit-details-marker { display: none; }
.nav-dropdown summary:hover { color: var(--text); background: var(--bg); }
.nav-dropdown[open] summary { color: var(--text); background: var(--bg); }
.badge {
    display: inline-block;
    background: var(--accent);
    color: #fff;
    font-size: 0.7rem;
    font-weight: 600;
    padding: 0.05rem 0.4rem;
    border-radius: 999px;
    margin-left: 0.3rem;
    vertical-align: middle;
}
.dropdown-menu {
    position: absolute;
    top: calc(100% + 6px);
    right: 0;
    min-width: 300px;
    max-height: 60vh;
    overflow-y: auto;
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 0.4rem;
    box-shadow: 0 12px 28px rgba(0, 0, 0, 0.45);
    z-index: 30;
}
.dropdown-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    padding: 0.55rem 0.7rem;
    border-radius: 7px;
    color: var(--text);
    text-decoration: none;
    font-size: 0.9rem;
}
.dropdown-item:hover { background: var(--bg); }
.dropdown-item.current { background: rgba(91, 141, 239, 0.12); }
.dropdown-item span:last-child { font-size: 0.8rem; white-space: nowrap; }
.dropdown-empty { display: block; padding: 0.6rem 0.7rem; color: var(--text-muted); font-size: 0.88rem; }

.container { max-width: 920px; margin: 2.5rem auto; padding: 0 1.5rem; }

h1 { font-size: 1.5rem; font-weight: 600; letter-spacing: -0.01em; margin-bottom: 0.5rem; }
h2 { font-size: 1.1rem; font-weight: 600; margin: 1.75rem 0 0.75rem; color: var(--text); }

a { color: var(--accent); }
a:hover { color: var(--accent-hover); }

.card {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}
.login-card { max-width: 360px; margin: 4rem auto; }

.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}
.profile-points { background: var(--bg-elevated); border: 1px solid var(--accent); border-radius: var(--radius); padding: 0.8rem 1.2rem; text-align: center; }
.profile-points strong { display: block; color: var(--accent-hover); font-size: 1.6rem; }
.assignment-type-badge { display: inline-block; color: var(--accent-hover); border: 1px solid var(--border); border-radius: 999px; padding: 0.2rem 0.6rem; font-size: 0.8rem; }

label { display: block; margin: 1rem 0 0.35rem; font-weight: 500; font-size: 0.9rem; color: var(--text-muted); }
label.checkbox { display: block; font-weight: 400; margin: 0.4rem 0; color: var(--text); font-size: 1rem; }

input[type="text"], input[type="password"], input[type="datetime-local"],
select, textarea {
    width: 100%;
    padding: 0.6rem 0.7rem;
    border: 1px solid var(--border);
    border-radius: 7px;
    font-size: 0.95rem;
    background: var(--bg);
    color: var(--text);
    font-family: inherit;
    transition: border-color 0.15s;
}
input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--accent);
}
input[type="radio"] { accent-color: var(--accent); margin-right: 0.4rem; }

.btn {
    display: inline-block;
    padding: 0.6rem 1.2rem;
    border: 1px solid var(--border);
    border-radius: 7px;
    background: var(--bg-elevated);
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    text-decoration: none;
    color: var(--text);
    margin-top: 1rem;
    transition: border-color 0.15s, background 0.15s;
}
.btn:hover { border-color: var(--accent); }
.btn-primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); }
.btn-danger { background: transparent; border-color: var(--bad); color: var(--bad); }
.btn-danger:hover { background: var(--bad-bg); }

.table { width: 100%; border-collapse: collapse; margin: 0.5rem 0 2rem; font-size: 0.92rem; }
.table th, .table td { border-bottom: 1px solid var(--border); padding: 0.65rem 0.75rem; text-align: left; }
.table th { color: var(--text-muted); font-weight: 500; font-size: 0.82rem; text-transform: uppercase; letter-spacing: 0.03em; }
.table tr:last-child td { border-bottom: none; }
.table-actions { display: flex; align-items: center; gap: 0.75rem; flex-wrap: wrap; }
.table-actions form, .page-actions form { display: inline; margin: 0; }
.link-button { padding: 0; border: 0; background: transparent; color: var(--accent); cursor: pointer; font: inherit; }
.danger-link { color: var(--bad); }
.page-actions { display: flex; gap: 0.75rem; align-items: center; margin: 1rem 0; }
.class-panel h2 { margin: 0; }
.class-table-wrap { overflow-x: auto; }
.class-table { min-width: 720px; }
.class-table th small { display: block; color: var(--text-muted); font-weight: 400; text-transform: none; letter-spacing: 0; margin-top: 0.25rem; }
.class-filter { max-width: 430px; margin: 1rem 0 1.5rem; }

.stats-cards {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0.75rem;
    margin: 1.5rem 0 2rem;
}
.stats-card {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1rem;
}
.stats-label { display: block; color: var(--text-muted); font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.04em; }
.stats-card strong { display: block; margin-top: 0.25rem; font-size: 1.5rem; }
.stats-panel {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem;
    margin: 1rem 0 2rem;
}
.section-heading { display: flex; justify-content: space-between; align-items: flex-start; gap: 1rem; }
.section-heading h2 { margin-top: 0; margin-bottom: 0.25rem; }
.section-heading p { margin-top: 0; font-size: 0.88rem; }
.chart-legend { color: var(--text-muted); font-size: 0.8rem; white-space: nowrap; }
.legend-swatch { display: inline-block; width: 0.65rem; height: 0.65rem; border-radius: 2px; background: var(--bad); margin-right: 0.3rem; }
.error-chart { display: grid; gap: 1rem; margin-top: 1.5rem; }
.error-chart-row { display: grid; grid-template-columns: minmax(180px, 1fr) minmax(160px, 2fr) 3.5rem; align-items: center; gap: 0.85rem; }
.error-chart-label { display: flex; align-items: center; gap: 0.55rem; min-width: 0; font-size: 0.9rem; }
.error-chart-label .math-content { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.question-number { display: inline-grid; place-items: center; flex: 0 0 auto; width: 1.6rem; height: 1.6rem; border-radius: 5px; background: var(--bg); color: var(--text-muted); font-size: 0.78rem; }
.error-track { height: 0.65rem; overflow: hidden; border-radius: 999px; background: var(--bg); }
.error-bar { display: block; height: 100%; min-width: 0.2rem; border-radius: inherit; background: var(--accent); transition: width 0.35s ease; }
.error-bar.high { background: var(--bad); }
.error-value { text-align: right; font-size: 0.88rem; }

.question-block {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.1rem 1.4rem;
    margin: 1rem 0;
}
.question-block.solved { border-color: var(--ok); background: var(--ok-bg); }
.question-block legend { font-weight: 600; padding: 0 0.4rem; color: var(--text-muted); font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.03em; }
.prompt { font-size: 1.05rem; margin: 0.5rem 0 0.75rem; }

.alert { padding: 0.75rem 1rem; border-radius: 7px; font-size: 0.92rem; margin-bottom: 1rem; }
.alert-error { background: var(--bad-bg); color: var(--bad); border: 1px solid rgba(224, 101, 95, 0.3); }
.alert-info { background: rgba(91, 141, 239, 0.1); color: var(--accent-hover); border: 1px solid rgba(91, 141, 239, 0.3); }

.ok { color: var(--ok); font-weight: 600; }
.bad { color: var(--bad); font-weight: 600; }
.muted { color: var(--text-muted); }

.student-picker { columns: 2; }
.inline-controls { display: flex; gap: 0.5rem; align-items: end; }
.inline-controls select { flex: 1; }
.assignment-student-picker { max-height: 260px; overflow-y: auto; columns: 2; margin-top: 1rem; padding: 0.75rem; border: 1px solid var(--border); border-radius: 7px; }

@media (max-width: 680px) {
    .stats-cards { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .section-heading { display: block; }
    .chart-legend { display: inline-block; margin-top: 0.5rem; }
    .error-chart-row { grid-template-columns: minmax(0, 1fr) 4rem; gap: 0.5rem 0.75rem; }
    .error-chart-label { grid-column: 1 / -1; }
    .error-track { grid-column: 1; }
    .error-value { grid-column: 2; grid-row: 2; }
    .inline-controls { display: grid; grid-template-columns: 1fr 1fr; }
    .inline-controls select { grid-column: 1 / -1; }
    .assignment-student-picker { columns: 1; }
}