/* ===== CSS Reset & Variables ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    --primary:      #0084ff;
    --primary-dark: #0066cc;
    --bg:           #f5f7fa;
    --surface:      #ffffff;
    --border:       #e4e8ef;
    --text:         #1a1a2e;
    --text-muted:   #6b7280;
    --danger:       #ef4444;
    --success:      #22c55e;
    --radius:       12px;
    --radius-sm:    8px;
    --shadow:       0 2px 12px rgba(0,0,0,.08);
    --shadow-lg:    0 8px 32px rgba(0,0,0,.12);
    --font:         -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', sans-serif;
}

html { font-size: 16px; -webkit-text-size-adjust: 100%; }
body { font-family: var(--font); background: var(--bg); color: var(--text); line-height: 1.5; }
a { color: var(--primary); text-decoration: none; }

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 10px 20px;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: background .15s, opacity .15s, transform .1s;
    white-space: nowrap;
    font-family: var(--font);
}
.btn:active { transform: scale(.97); }
.btn:disabled { opacity: .55; cursor: not-allowed; transform: none; }
.btn-primary  { background: var(--primary); color: #fff; }
.btn-primary:hover:not(:disabled) { background: var(--primary-dark); }
.btn-ghost    { background: transparent; color: var(--text-muted); border: 1px solid var(--border); }
.btn-ghost:hover:not(:disabled) { background: var(--bg); }
.btn-danger   { background: var(--danger); color: #fff; }
.btn-block    { width: 100%; }
.btn-sm       { padding: 6px 12px; font-size: 13px; }

/* ===== Forms ===== */
.form-group { margin-bottom: 16px; }
.form-group label { display: block; font-size: 13px; font-weight: 500; color: var(--text-muted); margin-bottom: 6px; }
.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 10px 14px;
    border: 1.5px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-family: var(--font);
    background: var(--surface);
    color: var(--text);
    transition: border-color .15s;
    outline: none;
}
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus { border-color: var(--primary); }

/* ===== Alerts ===== */
.alert { padding: 10px 14px; border-radius: var(--radius-sm); font-size: 14px; margin-bottom: 16px; }
.alert-error   { background: #fef2f2; color: #b91c1c; border: 1px solid #fecaca; }
.alert-success { background: #f0fdf4; color: #15803d; border: 1px solid #bbf7d0; }

/* ===== Badge ===== */
.badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 20px;
    height: 20px;
    padding: 0 6px;
    background: var(--primary);
    color: #fff;
    border-radius: 10px;
    font-size: 12px;
    font-weight: 600;
}

/* ===== Modal ===== */
.modal {
    position: fixed; inset: 0;
    display: flex; align-items: center; justify-content: center;
    z-index: 1000;
}
.modal-backdrop {
    position: absolute; inset: 0;
    background: rgba(0,0,0,.45);
    backdrop-filter: blur(2px);
}
.modal-box {
    position: relative;
    background: var(--surface);
    border-radius: var(--radius);
    padding: 28px;
    width: min(480px, 92vw);
    box-shadow: var(--shadow-lg);
}
.modal-box h2 { font-size: 18px; margin-bottom: 8px; }
.modal-desc { color: var(--text-muted); font-size: 14px; margin-bottom: 16px; }
.link-display { display: flex; gap: 8px; margin-bottom: 16px; }
.link-display input { flex: 1; font-size: 13px; }

/* ===== Scrollbar ===== */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #d1d5db; border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #9ca3af; }

/* ===== Responsive ===== */
@media (max-width: 600px) {
    .btn { padding: 9px 16px; }
}