:root {
  --primary: #2563EB;
  --primary-hover: #1D4ED8;
  --bg: #F8FAFC;
  --surface: #FFFFFF;
  --text: #1E293B;
  --text-secondary: #64748B;
  --border: #E2E8F0;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  --nav-height: 64px;
  --success: #10B981;
  --secondary-hover: #CBD5E1;
  --z-navbar: 1000;
  --z-toast: 2000;
  --z-modal: 3000;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  padding-top: var(--nav-height);
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
img { max-width: 100%; display: block; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

.navbar {
  position: fixed; top: 0; left: 0; right: 0;
  height: var(--nav-height);
  background: var(--surface);
  box-shadow: var(--shadow);
  display: flex; align-items: center; z-index: var(--z-navbar);
}
.navbar .container {
  display: flex; align-items: center; justify-content: space-between;
  width: 100%;
}
.logo { font-size: 20px; font-weight: 700; color: var(--primary); }
.nav-links { display: flex; gap: 24px; }
.nav-links a { font-size: 15px; color: var(--text-secondary); transition: color .2s; }
.nav-links a:hover, .nav-links a.active { color: var(--primary); }
.footer {
  background: var(--surface); border-top: 1px solid var(--border);
  padding: 32px 0; text-align: center; color: var(--text-secondary); font-size: 14px;
  margin-top: 60px;
}

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 10px 20px; border-radius: 8px; border: none; cursor: pointer;
  font-size: 14px; font-weight: 500; transition: background-color .2s, color .2s, transform .2s;
}
.btn-primary { background: var(--primary); color: #FFF; }
.btn-primary:hover { background: var(--primary-hover); }
.btn-secondary { background: var(--border); color: var(--text); }
.btn-secondary:hover { background: var(--secondary-hover); }
.btn-success { background: var(--success); color: #FFF; }
.btn-block { width: 100%; }

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

.form-group { margin-bottom: 16px; }
.form-group label { display: block; margin-bottom: 6px; font-size: 14px; font-weight: 500; }
.form-control {
  width: 100%; padding: 10px 12px; border: 1px solid var(--border);
  border-radius: 8px; font-size: 14px; transition: border-color .2s;
}
.form-control:focus { outline: none; border-color: var(--primary); }
textarea.form-control { resize: vertical; min-height: 100px; }

.empty-state {
  text-align: center; padding: 60px 20px; color: var(--text-secondary);
}
.empty-state svg { width: 80px; height: 80px; margin-bottom: 16px; opacity: .5; }

.toast {
  position: fixed; top: 80px; left: 50%; transform: translateX(-50%) translateY(-20px);
  background: var(--text); color: #FFF; padding: 12px 24px; border-radius: 8px;
  font-size: 14px; opacity: 0; pointer-events: none; transition: all .3s; z-index: var(--z-toast);
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

.modal-overlay {
  position: fixed; inset: 0; background: rgba(0, 0, 0, 0.5);
  display: none; align-items: center; justify-content: center; z-index: var(--z-modal);
}
.modal-overlay.active { display: flex; }
.modal {
  background: var(--surface); border-radius: var(--radius);
  width: 90%; max-width: 400px; padding: 24px; box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
}
.modal-title { font-size: 18px; font-weight: 600; margin-bottom: 12px; }
.modal-actions { display: flex; gap: 12px; justify-content: flex-end; margin-top: 20px; }

@media (max-width: 768px) {
  .container { padding: 0 16px; }
  .nav-links { gap: 16px; }
  .nav-links a { font-size: 14px; }
}