/* ============================================================
   Piano 管理后台 - 极简白色风格
   ============================================================ */

:root {
    --primary: #2563eb;
    --primary-light: #eff6ff;
    --primary-hover: #1d4ed8;
    --danger: #dc2626;
    --danger-light: #fef2f2;
    --success: #16a34a;
    --success-light: #f0fdf4;
    --warning: #d97706;
    --warning-light: #fffbeb;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    --sidebar-w: 220px;
    --radius: 8px;
    --shadow-sm: 0 1px 2px rgba(0,0,0,.05);
    --shadow: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.04);
    --shadow-md: 0 4px 6px rgba(0,0,0,.06), 0 2px 4px rgba(0,0,0,.04);
}

* { margin:0; padding:0; box-sizing:border-box; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    font-size: 14px;
    color: var(--gray-800);
    background: var(--gray-50);
    line-height: 1.6;
}

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

/* ── Sidebar ── */
.sidebar {
    position: fixed;
    left: 0; top: 0; bottom: 0;
    width: var(--sidebar-w);
    background: #fff;
    border-right: 1px solid var(--gray-200);
    display: flex;
    flex-direction: column;
    z-index: 100;
}

.sidebar-logo {
    padding: 24px 20px 20px;
    font-size: 17px;
    font-weight: 700;
    color: var(--gray-900);
    letter-spacing: -.3px;
    border-bottom: 1px solid var(--gray-100);
}
.sidebar-logo small {
    display: block;
    font-size: 11px;
    font-weight: 400;
    color: var(--gray-400);
    margin-top: 2px;
}

.sidebar-nav {
    flex: 1;
    padding: 12px 0;
    overflow-y: auto;
}

.sidebar-nav a {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 20px;
    color: var(--gray-600);
    font-size: 13.5px;
    font-weight: 500;
    border-left: 3px solid transparent;
    transition: all .15s;
}
.sidebar-nav a:hover {
    background: var(--gray-50);
    color: var(--gray-800);
}
.sidebar-nav a.active {
    background: var(--primary-light);
    color: var(--primary);
    border-left-color: var(--primary);
    font-weight: 600;
}
.sidebar-nav a .nav-icon {
    width: 18px;
    height: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 15px;
    flex-shrink: 0;
}

.sidebar-footer {
    padding: 16px 20px;
    border-top: 1px solid var(--gray-100);
}
.sidebar-footer a {
    font-size: 13px;
    color: var(--gray-400);
}
.sidebar-footer a:hover { color: var(--danger); }

/* ── Main ── */
.main {
    margin-left: var(--sidebar-w);
    min-height: 100vh;
}

.topbar {
    background: #fff;
    border-bottom: 1px solid var(--gray-200);
    padding: 16px 28px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.topbar h1 {
    font-size: 18px;
    font-weight: 700;
    color: var(--gray-900);
}
.topbar .admin-info {
    font-size: 13px;
    color: var(--gray-500);
}

.content {
    padding: 24px 28px;
}

/* ── Cards / Stats ── */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
    margin-bottom: 24px;
}
.stat-card {
    background: #fff;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow-sm);
}
.stat-card .stat-label {
    font-size: 12.5px;
    color: var(--gray-500);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: .3px;
}
.stat-card .stat-value {
    font-size: 28px;
    font-weight: 700;
    color: var(--gray-900);
    margin-top: 4px;
}
.stat-card .stat-sub {
    font-size: 12px;
    color: var(--gray-400);
    margin-top: 2px;
}

/* ── Panel ── */
.panel {
    background: #fff;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    margin-bottom: 24px;
}
.panel-header {
    padding: 16px 20px;
    border-bottom: 1px solid var(--gray-100);
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.panel-header h2 {
    font-size: 15px;
    font-weight: 600;
    color: var(--gray-800);
}
.panel-body { padding: 20px; }

/* ── Table ── */
.data-table {
    width: 100%;
    border-collapse: collapse;
}
.data-table th,
.data-table td {
    padding: 10px 16px;
    text-align: left;
    border-bottom: 1px solid var(--gray-100);
    font-size: 13px;
}
.data-table th {
    font-weight: 600;
    color: var(--gray-500);
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: .3px;
    background: var(--gray-50);
}
.data-table tr:hover td { background: var(--gray-50); }
.data-table td:last-child { white-space: nowrap; }

/* ── Buttons ── */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    border: 1px solid var(--gray-300);
    border-radius: 6px;
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    background: #fff;
    color: var(--gray-700);
    transition: all .15s;
    text-decoration: none;
}
.btn:hover { background: var(--gray-50); border-color: var(--gray-400); color: var(--gray-800); }

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

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

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

.btn-sm {
    padding: 4px 10px;
    font-size: 12px;
    border-radius: 4px;
}

/* ── Forms ── */
.form-group { margin-bottom: 16px; }
.form-group label {
    display: block;
    font-size: 13px;
    font-weight: 600;
    color: var(--gray-700);
    margin-bottom: 6px;
}
.form-control {
    width: 100%;
    padding: 9px 12px;
    border: 1px solid var(--gray-300);
    border-radius: 6px;
    font-size: 14px;
    color: var(--gray-800);
    background: #fff;
    transition: border-color .15s;
    outline: none;
    font-family: inherit;
}
.form-control:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37,99,235,.1); }

select.form-control { height: 40px; }
textarea.form-control { min-height: 100px; resize: vertical; }

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

/* ── Badges / Tags ── */
.badge {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 10px;
    font-size: 11px;
    font-weight: 600;
}
.badge-active   { background: var(--success-light); color: var(--success); }
.badge-inactive { background: var(--danger-light);  color: var(--danger); }
.badge-pending  { background: var(--warning-light); color: var(--warning); }
.badge-info     { background: var(--primary-light); color: var(--primary); }

/* ── Flash messages ── */
.flash {
    padding: 12px 16px;
    border-radius: 6px;
    margin-bottom: 16px;
    font-size: 13px;
    font-weight: 500;
}
.flash-success { background: var(--success-light); color: var(--success); border: 1px solid #bbf7d0; }
.flash-error   { background: var(--danger-light);  color: var(--danger);  border: 1px solid #fecaca; }
.flash-info    { background: var(--primary-light); color: var(--primary); border: 1px solid #bfdbfe; }

/* ── Pagination ── */
.pagination {
    display: flex;
    align-items: center;
    gap: 4px;
    margin-top: 16px;
    justify-content: center;
}
.pagination a, .pagination span {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 32px;
    height: 32px;
    padding: 0 8px;
    border: 1px solid var(--gray-200);
    border-radius: 6px;
    font-size: 13px;
    color: var(--gray-600);
}
.pagination a:hover { background: var(--gray-50); border-color: var(--gray-300); }
.pagination .current {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
    font-weight: 600;
}

/* ── Achievement Badge (medal) ── */
.medal {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    position: relative;
    box-shadow: 0 2px 8px rgba(0,0,0,.1);
}
.medal::after {
    content: '';
    position: absolute;
    inset: 3px;
    border-radius: 50%;
    border: 2px solid rgba(255,255,255,.4);
}
.medal svg { color: #fff; position: relative; z-index: 1; }

.medal-lg {
    width: 64px;
    height: 64px;
}
.medal-lg svg { width: 32px; height: 32px; }

.medal-sm {
    width: 36px;
    height: 36px;
}
.medal-sm svg { width: 16px; height: 16px; }

/* ── Utilities ── */
.text-center { text-align: center; }
.text-muted { color: var(--gray-400); }
.text-danger { color: var(--danger); }
.text-success { color: var(--success); }
.mt-2 { margin-top: 8px; }
.mt-4 { margin-top: 16px; }
.mb-4 { margin-bottom: 16px; }
.mr-2 { margin-right: 8px; }
.flex { display: flex; }
.gap-2 { gap: 8px; }
.gap-3 { gap: 12px; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.w-full { width: 100%; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

.empty-state {
    text-align: center;
    padding: 48px 20px;
    color: var(--gray-400);
}
.empty-state p { font-size: 14px; margin-top: 8px; }

/* ── Login Page ── */
.login-wrap {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gray-50);
}
.login-box {
    width: 380px;
    background: #fff;
    border: 1px solid var(--gray-200);
    border-radius: 12px;
    padding: 40px 32px;
    box-shadow: var(--shadow-md);
}
.login-box h1 {
    font-size: 22px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 8px;
    color: var(--gray-900);
}
.login-box p.subtitle {
    text-align: center;
    color: var(--gray-400);
    font-size: 13px;
    margin-bottom: 28px;
}
.login-box .btn-primary { width: 100%; justify-content: center; padding: 10px; font-size: 14px; }

/* ── File content viewer ── */
.file-viewer {
    background: var(--gray-50);
    border: 1px solid var(--gray-200);
    border-radius: 6px;
    padding: 16px;
    font-family: "SF Mono", Monaco, "Cascadia Code", Consolas, monospace;
    font-size: 12px;
    max-height: 400px;
    overflow: auto;
    white-space: pre-wrap;
    word-break: break-all;
    line-height: 1.7;
    color: var(--gray-700);
}

/* ── Toggle switch ── */
.toggle-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 0;
    border-bottom: 1px solid var(--gray-100);
}
.toggle-row:last-child { border-bottom: none; }
.toggle-label { font-size: 14px; color: var(--gray-700); }
.toggle-desc { font-size: 12px; color: var(--gray-400); margin-top: 2px; }