/* ==========================================================================
   BroadISP Design System
   --------------------------------------------------------------------------
   Signal — an ISP billing tool should feel like precise instrumentation,
   not a marketing site. The palette centers on a deep signal-teal (fiber /
   network, not generic Bootstrap blue), hairline borders instead of
   drop-shadows, and a monospace treatment for anything that's an
   identifier (invoice #, ticket #, customer code) so codes read distinctly
   from prose at a glance.
   ========================================================================== */

:root {
  --ink: #14181b;
  --ink-soft: #545b62;
  --ink-faint: #899299;
  --paper: #f5f6f4;
  --surface: #ffffff;
  --line: #e3e6e6;
  --line-strong: #cfd3d3;

  --signal: #0e7c86;
  --signal-deep: #0b5f67;
  --signal-tint: #e3f1f2;

  --amber: #b7791f;
  --amber-tint: #fbf0dd;
  --danger: #a8412c;
  --danger-tint: #fbe9e5;
  --success: #2f7d53;
  --success-tint: #e6f3ec;
  --info: #4a6fa5;
  --info-tint: #eaf0f9;

  --sidebar-bg: #0e1416;
  --sidebar-bg-active: #172023;
  --sidebar-text: #aab4b6;
  --sidebar-text-active: #ffffff;

  --radius-sm: 6px;
  --radius-md: 10px;
  --shadow-card: 0 1px 2px rgba(20, 24, 27, 0.04);
  --shadow-pop: 0 8px 24px rgba(20, 24, 27, 0.12);

  --font-display: 'Lexend', 'Inter', sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, monospace;

  --bs-primary: var(--signal);
  --bs-primary-rgb: 14, 124, 134;
  --bs-success: var(--success);
  --bs-success-rgb: 47, 125, 83;
  --bs-danger: var(--danger);
  --bs-danger-rgb: 168, 65, 44;
  --bs-warning: var(--amber);
  --bs-warning-rgb: 183, 121, 31;
  --bs-info: var(--info);
  --bs-info-rgb: 74, 111, 165;
  --bs-secondary: var(--ink-soft);
  --bs-body-color: var(--ink);
  --bs-body-bg: var(--paper);
  --bs-border-color: var(--line);
  --bs-border-radius: var(--radius-sm);
  --bs-border-radius-lg: var(--radius-md);
  --bs-body-font-family: var(--font-body);
  --bs-link-color: var(--signal);
  --bs-link-hover-color: var(--signal-deep);
}

[data-bs-theme='dark'] {
  --ink: #e7e9e8;
  --ink-soft: #a3acae;
  --paper: #10161a;
  --surface: #171e22;
  --line: #2a3338;
  --line-strong: #3a454b;
  --signal-tint: #102a2d;
  --bs-body-bg: var(--paper);
  --bs-body-color: var(--ink);
}

html, body {
  background: var(--paper);
  font-family: var(--font-body);
  color: var(--ink);
}

h1, h2, h3, h4, h5, h6, .display-font {
  font-family: var(--font-display);
  letter-spacing: -0.01em;
}

code, .font-mono, .table td code, .table th code {
  font-family: var(--font-mono);
  font-size: 0.85em;
}

.table td {
  font-variant-numeric: tabular-nums;
}

/* ---------- Top bar ---------- */
.topbar {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  position: relative;
}
.topbar::after {
  content: '';
  position: absolute;
  left: 0; right: 0; bottom: -1px;
  height: 2px;
  background: linear-gradient(90deg, var(--signal) 0%, transparent 60%);
  opacity: 0.5;
}
.topbar .menu-toggle {
  border: none;
  background: transparent;
  color: var(--ink-soft);
  font-size: 1.25rem;
  padding: 6px;
  border-radius: var(--radius-sm);
}
.topbar .menu-toggle:hover { background: var(--paper); color: var(--ink); }

.topbar .page-title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--ink);
  margin: 0;
}

.user-menu-trigger {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--ink);
  text-decoration: none;
  font-size: 0.9rem;
  padding: 6px 10px;
  border-radius: var(--radius-sm);
}
.user-menu-trigger:hover { background: var(--paper); color: var(--ink); }
.user-menu-trigger img {
  width: 28px; height: 28px; border-radius: 50%;
  border: 1px solid var(--line);
}

/* ---------- Sidebar ---------- */
.app-sidebar {
  background: var(--sidebar-bg);
  width: 240px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  transition: margin-left 0.2s ease;
}
.app-sidebar.collapsed { margin-left: -240px; }

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 18px 20px;
  color: #fff;
  text-decoration: none;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.sidebar-brand:hover { color: #fff; }
.sidebar-brand .brand-name {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
}

.signal-mark {
  display: inline-flex;
  align-items: flex-end;
  gap: 2px;
  height: 18px;
  flex-shrink: 0;
}
.signal-mark span {
  display: block;
  width: 4px;
  background: var(--signal);
  border-radius: 1px;
}
.signal-mark span:nth-child(1) { height: 7px; }
.signal-mark span:nth-child(2) { height: 12px; animation: signal-pulse 2.4s ease-in-out infinite; }
.signal-mark span:nth-child(3) { height: 18px; }
@keyframes signal-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.35; }
}
@media (prefers-reduced-motion: reduce) {
  .signal-mark span { animation: none !important; }
}

.sidebar-nav {
  padding: 12px 10px;
  flex: 1;
  overflow-y: auto;
}
.sidebar-nav .nav-link {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--sidebar-text);
  font-size: 0.875rem;
  padding: 9px 12px;
  border-radius: var(--radius-sm);
  margin-bottom: 2px;
  border-left: 3px solid transparent;
  text-decoration: none;
}
.sidebar-nav .nav-link i { font-size: 1rem; width: 18px; text-align: center; }
.sidebar-nav .nav-link:hover { background: var(--sidebar-bg-active); color: #fff; }
.sidebar-nav .nav-link.active {
  background: var(--sidebar-bg-active);
  color: var(--sidebar-text-active);
  border-left-color: var(--signal);
}
.sidebar-nav .nav-link.disabled {
  opacity: 0.35;
  pointer-events: none;
}

/* ---------- Layout shell ---------- */
.app-shell { display: flex; min-height: 100vh; }
.app-main { flex: 1; min-width: 0; display: flex; flex-direction: column; }
.app-content { padding: 24px; flex: 1; }
.app-footer {
  padding: 14px 24px;
  color: var(--ink-faint);
  font-size: 0.8rem;
  border-top: 1px solid var(--line);
}

/* ---------- Cards ---------- */
.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
}
.card-header {
  background: transparent;
  border-bottom: 1px solid var(--line);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.95rem;
}
.card-footer { background: transparent; border-top: 1px solid var(--line); }

/* ---------- Tables ---------- */
.table {
  --bs-table-bg: transparent;
}
.table thead th {
  font-family: var(--font-display);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--ink-faint);
  font-weight: 600;
  border-bottom: 1px solid var(--line);
  padding-top: 0.4rem;
  padding-bottom: 0.4rem;
}
.table td { border-bottom: 1px solid var(--line); vertical-align: middle; }
.table-hover tbody tr:hover { background: var(--paper); }

/* ---------- Buttons ---------- */
.btn {
  font-weight: 500;
  border-radius: var(--radius-sm);
}
.btn-primary {
  background: var(--signal);
  border-color: var(--signal);
}
.btn-primary:hover, .btn-primary:focus {
  background: var(--signal-deep);
  border-color: var(--signal-deep);
}
.btn-outline-primary {
  color: var(--signal);
  border-color: var(--signal);
}
.btn-outline-primary:hover {
  background: var(--signal);
  border-color: var(--signal);
}

/* ---------- Badges ---------- */
.badge { font-weight: 500; font-size: 0.72rem; letter-spacing: 0.01em; padding: 0.35em 0.6em; }
.badge.bg-success { background: var(--success-tint) !important; color: var(--success) !important; }
.badge.bg-warning { background: var(--amber-tint) !important; color: var(--amber) !important; }
.badge.bg-danger { background: var(--danger-tint) !important; color: var(--danger) !important; }
.badge.bg-info { background: var(--info-tint) !important; color: var(--info) !important; }
.badge.bg-primary { background: var(--signal-tint) !important; color: var(--signal-deep) !important; }
.badge.bg-secondary { background: var(--paper) !important; color: var(--ink-soft) !important; border: 1px solid var(--line); }

/* ---------- Forms ---------- */
.form-control, .form-select {
  border-color: var(--line-strong);
  border-radius: var(--radius-sm);
}
.form-control:focus, .form-select:focus {
  border-color: var(--signal);
  box-shadow: 0 0 0 3px var(--signal-tint);
}
.form-label { font-size: 0.85rem; font-weight: 500; color: var(--ink-soft); }

.stat-value { font-family: var(--font-display); }

.pagination .page-link { color: var(--signal); border-color: var(--line); }
.pagination .page-item.active .page-link { background: var(--signal); border-color: var(--signal); }

::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--line-strong); border-radius: 20px; }

/* ---------- Auth pages ---------- */
.auth-shell {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--sidebar-bg);
  background-image:
    radial-gradient(circle at 15% 20%, rgba(14,124,134,0.25), transparent 45%),
    radial-gradient(circle at 85% 80%, rgba(14,124,134,0.15), transparent 40%);
  padding: 24px;
}
.auth-card {
  background: var(--surface);
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-pop);
  padding: 32px;
  width: 100%;
  max-width: 400px;
}
.auth-brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  margin-bottom: 24px;
  color: #fff;
  text-align: center;
}
.auth-brand .brand-name { font-family: var(--font-display); font-weight: 600; font-size: 1.3rem; }
.auth-brand .brand-tagline { font-size: 0.8rem; color: rgba(255,255,255,0.65); }

@media (max-width: 767px) {
  .app-sidebar { position: fixed; z-index: 1030; margin-left: -240px; }
  .app-sidebar.mobile-open { margin-left: 0; box-shadow: var(--shadow-pop); }
  .app-content { padding: 16px; }
}