* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Arial, sans-serif;
}

body {
    background: #f0f2f5;
    color: #333;
}

/* ---------- Login / Form Sayfaları ---------- */
.auth-container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 20px;
}

.auth-box {
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    padding: 40px;
    width: 100%;
    max-width: 400px;
}

.auth-box h1 {
    text-align: center;
    color: #1a5276;
    font-size: 22px;
    margin-bottom: 5px;
}

.auth-logo {
    display: block;
    max-width: 100px;
    max-height: 100px;
    margin: 0 auto 12px auto;
}

.topbar-logo {
    height: 42px;
    width: auto;
    border-radius: 4px;
    background: #fff;
    padding: 2px;
}

.topbar-brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.report-logo {
    max-height: 60px;
    width: auto;
}

.auth-box .subtitle {
    text-align: center;
    color: #888;
    font-size: 13px;
    margin-bottom: 25px;
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-size: 14px;
    font-weight: 600;
    color: #444;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid #ccc;
    border-radius: 6px;
    font-size: 14px;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: #1a5276;
}

.btn {
    display: inline-block;
    width: 100%;
    padding: 11px;
    background: #1a5276;
    color: #fff;
    border: none;
    border-radius: 6px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    text-align: center;
    text-decoration: none;
    transition: background 0.2s;
}

.btn:hover { background: #154360; }

.btn-secondary {
    background: #7f8c8d;
}
.btn-secondary:hover { background: #626e6f; }

.btn-danger {
    background: #c0392b;
}
.btn-danger:hover { background: #962d22; }

.btn-small {
    width: auto;
    padding: 6px 12px;
    font-size: 13px;
}

.link-row {
    text-align: center;
    margin-top: 15px;
    font-size: 13px;
}

.link-row a {
    color: #1a5276;
    text-decoration: none;
}

.alert {
    padding: 10px 14px;
    border-radius: 6px;
    margin-bottom: 15px;
    font-size: 14px;
}

.alert-success {
    background: #d4efdf;
    color: #1e8449;
    border: 1px solid #a9dfbf;
}

.alert-error {
    background: #fadbd8;
    color: #c0392b;
    border: 1px solid #f5b7b1;
}

/* ---------- Panel Layout ---------- */
.topbar {
    background: #1a5276;
    color: #fff;
    padding: 15px 25px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.topbar h2 {
    font-size: 18px;
}

.topbar .user-info {
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 15px;
}

.topbar a {
    color: #fff;
    text-decoration: none;
    background: rgba(255,255,255,0.15);
    padding: 6px 12px;
    border-radius: 5px;
    font-size: 13px;
}

.topbar a:hover {
    background: rgba(255,255,255,0.25);
}

.container {
    max-width: 1100px;
    margin: 25px auto;
    padding: 0 20px;
}

.card {
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    padding: 25px;
    margin-bottom: 20px;
}

.card h3 {
    margin-bottom: 15px;
    color: #1a5276;
    font-size: 17px;
    border-bottom: 2px solid #eee;
    padding-bottom: 10px;
}

.nav-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.nav-tabs a {
    padding: 8px 16px;
    background: #fff;
    border-radius: 6px;
    text-decoration: none;
    color: #1a5276;
    font-size: 14px;
    font-weight: 600;
    box-shadow: 0 1px 4px rgba(0,0,0,0.06);
}

.nav-tabs a.active,
.nav-tabs a:hover {
    background: #1a5276;
    color: #fff;
}

/* ---------- Tablo ---------- */
table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
}

table th, table td {
    padding: 10px 12px;
    border-bottom: 1px solid #eee;
    text-align: left;
}

table th {
    background: #f8f9fa;
    color: #555;
    font-weight: 600;
}

table tr:hover {
    background: #f8f9fa;
}

.checkbox-cell {
    text-align: center;
}

.checkbox-cell input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.class-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 12px;
}

.class-card {
    background: #1a5276;
    color: #fff;
    text-align: center;
    padding: 20px 10px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 700;
    font-size: 16px;
    transition: transform 0.15s;
}

.class-card:hover {
    transform: translateY(-3px);
    background: #154360;
}

.badge {
    display: inline-block;
    padding: 3px 8px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 600;
}

.badge-red { background: #fadbd8; color: #c0392b; }
.badge-green { background: #d4efdf; color: #1e8449; }
.badge-gray { background: #eee; color: #777; }

.flex-row {
    display: flex;
    gap: 10px;
    align-items: center;
    flex-wrap: wrap;
}

.text-muted {
    color: #888;
    font-size: 12px;
}

@media (max-width: 600px) {
    .topbar { flex-direction: column; gap: 10px; text-align: center; }
    .container { padding: 0 10px; }
}