:root {
    --primary: #059669;
    --primary-dark: #047857;
    --primary-light: #d1fae5;
    --danger: #dc2626;
    --danger-light: #fee2e2;
    --text: #0f172a;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --bg: #f0fdf9;
    --card-bg: #ffffff;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg);
    color: var(--text);
    padding-top: 64px;
}

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

/* ============ Top-Navigation ============ */
.top-nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    height: 64px;
    z-index: 1000;
    background: linear-gradient(90deg, #064e3b 0%, #047857 100%);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.top-nav .brand {
    color: #ecfdf5;
    font-weight: 700;
    font-size: 20px;
    letter-spacing: -0.02em;
}
.top-nav .brand a { color: inherit; }
.top-nav .brand a:hover { text-decoration: none; }

.top-nav .nav-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

.top-nav .nav-user {
    color: #d1fae5;
    font-size: 14px;
}

.top-nav .btn-logout {
    color: #ecfdf5;
    background: rgba(255,255,255,0.12);
    border: 1px solid rgba(255,255,255,0.25);
    padding: 6px 14px;
    border-radius: 8px;
    font-size: 14px;
    cursor: pointer;
}
.top-nav .btn-logout:hover { background: rgba(255,255,255,0.22); text-decoration: none; }

/* ============ Layout ============ */
.page {
    max-width: 1000px;
    margin: 0 auto;
    padding: 32px 24px 64px;
}

.page-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 24px;
    flex-wrap: wrap;
    gap: 12px;
}
.page-header h1 { margin: 0; font-size: 24px; }
.page-header p.subtitle { margin: 4px 0 0; color: var(--text-muted); font-size: 14px; }

/* ============ Cards ============ */
.card {
    background: var(--card-bg);
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.07);
    padding: 24px;
    margin-bottom: 20px;
}
.card h2 { margin-top: 0; font-size: 17px; }

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 16px;
}

.group-card {
    background: var(--card-bg);
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.07);
    padding: 20px;
    display: block;
    color: var(--text);
    transition: transform 0.12s, box-shadow 0.12s;
}
.group-card:hover {
    text-decoration: none;
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0,0,0,0.10);
}
.group-card .group-name { font-weight: 600; font-size: 17px; margin-bottom: 4px; }
.group-card .group-meta { color: var(--text-muted); font-size: 13px; margin-bottom: 14px; }
.group-card .group-saldo { font-size: 15px; font-weight: 600; }

.empty-state {
    text-align: center;
    padding: 48px 24px;
    color: var(--text-muted);
}

/* ============ Buttons ============ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 9px 18px;
    border-radius: 8px;
    border: 1px solid transparent;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    text-decoration: none;
}
.btn:hover { text-decoration: none; }

.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }

.btn-secondary { background: #fff; color: var(--text); border-color: var(--border); }
.btn-secondary:hover { background: #f8fafc; }

.btn-danger { background: #fff; color: var(--danger); border-color: #fecaca; }
.btn-danger:hover { background: var(--danger-light); }

.btn-sm { padding: 5px 12px; font-size: 13px; }
.btn-lg { width: 100%; padding: 12px; font-size: 15px; }

.btn-icon {
    width: 32px; height: 32px; padding: 0;
    border-radius: 8px; border: 1px solid var(--border); background: #fff;
}

/* ============ Forms ============ */
.form-group { margin-bottom: 18px; }
.form-group label {
    display: block;
    font-size: 13px;
    font-weight: 600;
    color: var(--text-muted);
    margin-bottom: 6px;
}
.form-control {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 14px;
    font-family: inherit;
    background: #fff;
    color: var(--text);
}
.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}
.form-row { display: flex; gap: 16px; }
.form-row .form-group { flex: 1; }
.form-hint { font-size: 12px; color: var(--text-muted); margin-top: 4px; }

.form-error, .status-msg.error {
    background: var(--danger-light);
    color: var(--danger);
    padding: 10px 14px;
    border-radius: 8px;
    font-size: 14px;
    margin-bottom: 16px;
}
.status-msg.success {
    background: var(--primary-light);
    color: var(--primary-dark);
    padding: 10px 14px;
    border-radius: 8px;
    font-size: 14px;
    margin-bottom: 16px;
}

/* ============ Login/Register ============ */
.login-page {
    min-height: calc(100vh - 64px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
}
.login-card {
    background: var(--card-bg);
    border-radius: 16px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.10);
    padding: 40px 36px;
    width: 100%;
    max-width: 380px;
}
.login-card h1 { text-align: center; margin: 0 0 4px; color: var(--primary-dark); }
.login-card .subtitle { text-align: center; color: var(--text-muted); margin: 0 0 24px; font-size: 14px; }
.login-card .form-group { margin-bottom: 16px; }
.login-card .btn { margin-top: 8px; }
.login-card .switch-link { text-align: center; margin-top: 20px; font-size: 14px; color: var(--text-muted); }

/* ============ Tabs (Gruppenseite) ============ */
.tabs {
    display: flex;
    gap: 4px;
    border-bottom: 1px solid var(--border);
    margin-bottom: 24px;
}
.tab-link {
    padding: 10px 18px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-muted);
    border-bottom: 2px solid transparent;
    cursor: pointer;
    background: none;
    border-top: none; border-left: none; border-right: none;
}
.tab-link:hover { text-decoration: none; color: var(--text); }
.tab-link.active { color: var(--primary-dark); border-bottom-color: var(--primary); }
.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* ============ Salden / Balances ============ */
.saldo-list { list-style: none; padding: 0; margin: 0; }
.saldo-list li {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
}
.saldo-list li:last-child { border-bottom: none; }
.saldo-name { font-weight: 500; }
.saldo-betrag.positiv { color: var(--primary-dark); font-weight: 600; }
.saldo-betrag.negativ { color: var(--danger); font-weight: 600; }
.saldo-betrag.neutral { color: var(--text-muted); }

.ausgleich-list { list-style: none; padding: 0; margin: 0; }
.ausgleich-list li {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
    font-size: 14px;
}
.ausgleich-list li:last-child { border-bottom: none; }
.ausgleich-arrow { color: var(--text-muted); }
.ausgleich-betrag { margin-left: auto; font-weight: 600; color: var(--primary-dark); }

/* ============ Ausgaben-Liste ============ */
.ausgabe-list { list-style: none; padding: 0; margin: 0; }
.ausgabe-item {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 14px 0;
    border-bottom: 1px solid var(--border);
}
.ausgabe-item:last-child { border-bottom: none; }
.ausgabe-icon {
    width: 40px; height: 40px;
    border-radius: 10px;
    background: var(--primary-light);
    color: var(--primary-dark);
    display: flex; align-items: center; justify-content: center;
    font-weight: 700;
    flex-shrink: 0;
}
.ausgabe-info { flex: 1; min-width: 0; }
.ausgabe-titel { font-weight: 600; }
.ausgabe-meta { font-size: 13px; color: var(--text-muted); }
.ausgabe-betrag { font-weight: 600; white-space: nowrap; }

/* ============ Mitglieder ============ */
.mitglied-list { list-style: none; padding: 0; margin: 0; }
.mitglied-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
}
.mitglied-item:last-child { border-bottom: none; }
.avatar {
    width: 36px; height: 36px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    display: flex; align-items: center; justify-content: center;
    font-weight: 600; font-size: 14px;
    flex-shrink: 0;
}
.mitglied-name { flex: 1; font-weight: 500; }
.badge { font-size: 11px; padding: 2px 8px; border-radius: 999px; background: var(--border); color: var(--text-muted); }
.badge.registriert { background: var(--primary-light); color: var(--primary-dark); }

/* ============ Verlauf ============ */
.verlauf-list { list-style: none; padding: 0; margin: 0; }
.verlauf-item {
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
    font-size: 14px;
}
.verlauf-item:last-child { border-bottom: none; }
.verlauf-zeit { color: var(--text-muted); font-size: 12px; }

/* ============ Split-Auswahl (Ausgabe erfassen) ============ */
.split-mode-toggle { display: flex; gap: 8px; margin-bottom: 14px; }
.split-list { border: 1px solid var(--border); border-radius: 8px; padding: 4px 14px; }
.split-row {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
}
.split-row:last-child { border-bottom: none; }
.split-row label { flex: 1; margin: 0; font-size: 14px; font-weight: 500; color: var(--text); }
.split-row input[type="number"] { width: 100px; }

@media (max-width: 640px) {
    .form-row { flex-direction: column; gap: 0; }
    .page { padding: 20px 16px 48px; }
    .top-nav .nav-user { display: none; }
}