:root {
    --color-bg: #f5f6f8;
    --color-surface: #ffffff;
    --color-border: #e2e5ea;
    --color-text: #1f2430;
    --color-muted: #6b7280;
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-success-bg: #e7f7ee;
    --color-success-text: #1a7f4e;
    --color-error-bg: #fdecec;
    --color-error-text: #b3261e;
    --radius: 8px;
    --shadow: 0 1px 2px rgba(16, 24, 40, 0.06), 0 1px 3px rgba(16, 24, 40, 0.08);
}

* { box-sizing: border-box; }

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

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

.page { max-width: 1000px; margin: 0 auto; padding: 24px 20px 64px; }

h1 { font-size: 1.6rem; margin: 0 0 4px; }
h2 { font-size: 1.25rem; margin: 0 0 16px; }

.muted { color: var(--color-muted); }
.small { font-size: 0.85rem; }

.topbar {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 10;
}
.topbar-inner {
    max-width: 1000px;
    margin: 0 auto;
    padding: 12px 20px;
    display: flex;
    align-items: center;
    gap: 24px;
}
.brand { font-weight: 700; color: var(--color-text); font-size: 1.05rem; }
.mainnav { display: flex; gap: 16px; flex: 1; }
.mainnav a { color: var(--color-muted); font-weight: 500; padding: 6px 2px; border-bottom: 2px solid transparent; }
.mainnav a.active, .mainnav a:hover { color: var(--color-text); border-bottom-color: var(--color-primary); text-decoration: none; }
.topbar-user { display: flex; align-items: center; gap: 12px; color: var(--color-muted); font-size: 0.9rem; }

.page-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 20px;
}

.breadcrumb { color: var(--color-muted); font-size: 0.9rem; margin: 0 0 12px; }

.card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 20px;
}

.form-card { max-width: 640px; display: flex; flex-direction: column; gap: 16px; }

.table { width: 100%; border-collapse: collapse; }
.table th, .table td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--color-border); }
.table th { color: var(--color-muted); font-weight: 600; font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.02em; }
.table tbody tr:last-child td { border-bottom: none; }
.row-clickable { cursor: pointer; transition: background 0.15s ease; }
.row-clickable:hover { background: var(--color-bg); }
.align-right { text-align: right; }

.badge { display: inline-block; padding: 2px 10px; border-radius: 999px; font-size: 0.8rem; font-weight: 600; }
.badge-success { background: var(--color-success-bg); color: var(--color-success-text); }
.badge-muted { background: var(--color-bg); color: var(--color-muted); }

.empty-state { color: var(--color-muted); padding: 32px 0; text-align: center; }

.alert { padding: 10px 14px; border-radius: var(--radius); font-size: 0.9rem; }
.alert-success { background: var(--color-success-bg); color: var(--color-success-text); }
.alert-error { background: var(--color-error-bg); color: var(--color-error-text); }

label { display: flex; flex-direction: column; gap: 6px; font-size: 0.9rem; font-weight: 500; color: var(--color-text); }
label.inline { flex-direction: row; align-items: center; gap: 8px; font-weight: 400; }

input[type="text"], input[type="email"], input[type="password"], input[type="date"], input[type="number"], select, textarea {
    font: inherit;
    padding: 9px 10px;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    background: var(--color-surface);
    color: var(--color-text);
}
input:focus, select:focus, textarea:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 1px;
}

fieldset.participant-toggle { border: none; padding: 0; margin: 0; display: flex; gap: 20px; }
fieldset.participant-toggle legend { font-weight: 600; margin-bottom: 6px; padding: 0; }

.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 12px 16px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px 16px; }
@media (max-width: 640px) {
    .grid-2, .grid-3 { grid-template-columns: 1fr; }
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 9px 16px;
    border-radius: 6px;
    border: 1px solid transparent;
    font: inherit;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--color-primary); color: #fff; }
.btn-primary:hover { background: var(--color-primary-dark); }
.btn-ghost { background: transparent; color: var(--color-text); border-color: var(--color-border); }
.btn-ghost:hover { background: var(--color-bg); }
.btn-sm { padding: 5px 12px; font-size: 0.85rem; }
.btn-block { width: 100%; }

.filter-bar { display: flex; gap: 16px; margin-bottom: 16px; align-items: flex-end; }

.zahlung-form { display: flex; gap: 6px; justify-content: flex-end; align-items: center; }
.zahlung-ist-input { width: 90px; padding: 6px 8px; }

.payment-card { margin-bottom: 20px; }
.payment-card-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    flex-wrap: wrap;
    gap: 8px 20px;
    margin-bottom: 14px;
}
.payment-card-title { margin: 0; font-size: 1rem; }
.payment-card-summary { display: flex; gap: 20px; font-size: 0.85rem; color: var(--color-text); }

.gantt-zoom-group { display: flex; align-items: center; gap: 8px; margin-bottom: 16px; }
.gantt-zoom-btn {
    font: inherit;
    padding: 6px 12px;
    border-radius: 6px;
    border: 1px solid var(--color-border);
    background: var(--color-surface);
    color: var(--color-text);
    font-size: 0.82rem;
    cursor: pointer;
}
.gantt-zoom-btn:hover { background: var(--color-bg); }
.gantt-zoom-btn.active { background: var(--color-primary); border-color: var(--color-primary); color: #fff; }

.gantt-controls {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    flex-wrap: wrap;
    gap: 16px;
    margin-bottom: 16px;
}
.gantt-controls .filter-bar,
.gantt-controls .gantt-zoom-group { margin-bottom: 0; }

.auth-wrap { display: flex; justify-content: center; padding-top: 10vh; }
.auth-card { width: 100%; max-width: 360px; display: flex; flex-direction: column; gap: 16px; }
.auth-card h1 { text-align: center; margin-bottom: 4px; }

.section-title { margin: 28px 0 12px; font-size: 1.1rem; }

.course-detail-card { margin-bottom: 20px; }
.course-detail-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 8px;
}
.course-detail-title { margin: 0; padding-left: 10px; font-size: 1rem; }
.course-detail-total { font-size: 0.85rem; color: var(--color-muted); }
.course-detail-total strong { color: var(--color-text); }
.course-chart-wrap { overflow-x: auto; }
.course-chart { display: block; }
.chart-value { font-size: 11px; font-weight: 700; fill: var(--color-text); font-family: inherit; }
.chart-axis-label {
    font-size: 11px;
    fill: var(--color-muted);
    font-family: inherit;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}
.chart-baseline { stroke: var(--color-border); stroke-width: 1; }

.kpi-section { margin-bottom: 28px; }
.kpi-group-title {
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--color-muted);
    margin: 0 0 10px;
}
.kpi-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    gap: 16px;
}
.kpi-tile {
    display: block;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-left: 4px solid var(--color-border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 18px 20px;
    color: inherit;
    text-decoration: none;
    transition: box-shadow 0.15s ease, transform 0.15s ease;
}
a.kpi-tile:hover {
    box-shadow: 0 4px 14px rgba(16, 24, 40, 0.12);
    transform: translateY(-1px);
    text-decoration: none;
}
.kpi-tile-blue { border-left-color: #2563eb; }
.kpi-tile-green { border-left-color: #15803d; }
.kpi-tile-purple { border-left-color: #7c3aed; }
.kpi-label { font-size: 0.82rem; color: var(--color-muted); font-weight: 600; }
.kpi-value {
    font-size: 1.6rem;
    font-weight: 600;
    color: var(--color-text);
    line-height: 1.25;
    margin-top: 4px;
    white-space: nowrap;
}
.kpi-hint { font-size: 0.75rem; color: var(--color-muted); margin-top: 4px; }

.gantt-board {
    display: grid;
    grid-template-columns: 240px 1fr;
    background: var(--color-surface);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid var(--color-border);
    overflow: hidden;
}
.gantt-sidebar-header {
    height: 52px;
    display: flex;
    align-items: center;
    padding: 0 16px;
    font-weight: 700;
    font-size: 0.8rem;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    color: var(--color-muted);
    border-bottom: 1px solid var(--color-border);
}
.gantt-course-label {
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 10px 16px;
    border-bottom: 1px solid var(--color-border);
    gap: 2px;
    overflow: hidden;
}
.gantt-course-time {
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.03em;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.gantt-course-name {
    font-size: 0.9rem;
    font-weight: 700;
    line-height: 1.25;
    color: var(--color-text);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.gantt-course-count { font-size: 0.72rem; color: var(--color-muted); }
.gantt-summary-label {
    display: flex;
    align-items: center;
    padding: 10px 16px;
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--color-muted);
    border-top: 1px solid var(--color-border);
}
.gantt-timeline-scroll { overflow-x: auto; }
.gantt-timeline-inner { position: relative; }
.gantt-month-header { display: flex; height: 52px; border-bottom: 1px solid var(--color-border); }
.gantt-month {
    flex: none;
    display: flex;
    align-items: center;
    gap: 4px;
    padding-left: 12px;
    font-weight: 700;
    font-size: 0.78rem;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    color: var(--color-text);
    border-right: 1px solid var(--color-border);
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
}
.gantt-month-year { font-weight: 500; color: var(--color-muted); text-transform: none; }
.gantt-course-row { position: relative; border-bottom: 1px solid var(--color-border); }
.gantt-grid-lines { position: absolute; inset: 0; }
.gantt-gl { position: absolute; top: 0; bottom: 0; border-right: 1px solid var(--color-border); }
.gantt-bar-wrap {
    position: absolute;
    display: flex;
    align-items: center;
    cursor: pointer;
}
.gantt-bar-pill {
    flex: none;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    padding: 3px 10px;
    color: #fff;
    box-shadow: 0 1px 2px rgba(16, 24, 40, 0.2);
}
.gantt-bar-pill-text {
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    white-space: normal;
    word-break: break-word;
    font-size: 0.72rem;
    font-weight: 600;
    line-height: 1.25;
}
.gantt-bar-wrap:hover .gantt-bar-pill { filter: brightness(1.1); }
.gantt-bar-wrap:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 2px; border-radius: var(--radius); }
.gantt-summary-row { display: flex; }
.gantt-summary-cell { flex: none; padding: 10px 16px; border-right: 1px solid var(--color-border); border-top: 1px solid var(--color-border); }
.gantt-summary-u { font-size: 0.78rem; font-weight: 700; }
.gantt-summary-t { font-size: 0.72rem; color: var(--color-muted); margin-top: 2px; }

.modal {
    border: none;
    border-radius: var(--radius);
    box-shadow: 0 10px 40px rgba(16, 24, 40, 0.2);
    padding: 0;
    width: 100%;
    max-width: 440px;
}
.modal::backdrop { background: rgba(15, 23, 42, 0.45); }
.modal-inner { padding: 24px; display: flex; flex-direction: column; gap: 16px; }
.modal-actions { display: flex; justify-content: flex-end; gap: 10px; margin-top: 4px; }
.modal-actions-split { justify-content: space-between; align-items: center; }
.modal-actions-right { display: flex; gap: 10px; }
.btn-danger-link {
    background: none;
    border: none;
    color: var(--color-error-text);
    font-weight: 600;
    font-size: 0.82rem;
    cursor: pointer;
    padding: 6px 0;
    font-family: inherit;
}
.btn-danger-link:hover { text-decoration: underline; }
.hidden-form { display: none; }

.actions-cell { display: flex; align-items: center; gap: 8px; }
.icon-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 30px;
    height: 30px;
    border-radius: 6px;
    border: 1px solid var(--color-border);
    background: var(--color-surface);
    color: var(--color-muted);
    cursor: pointer;
    padding: 0;
}
.icon-btn:hover { background: var(--color-bg); color: var(--color-text); }