/* ============================================
   VPN Gate PWA — Styles
   - Material 3 inspired + iOS-style smooth corners
   - Dark mode default, light via prefers-color-scheme
   - Mobile-first responsive
   ============================================ */

/* ---------- Design tokens ---------- */
:root {
  /* Spacing */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;

  /* Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 999px;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans Thai",
    "Noto Sans", "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Mono", "Roboto Mono", monospace;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.06), 0 1px 3px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 20px -5px rgba(0, 0, 0, 0.12), 0 6px 10px -6px rgba(0, 0, 0, 0.08);
  --shadow-glow: 0 0 24px rgba(79, 70, 229, 0.35);

  /* Transitions */
  --t-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --t-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --t-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);

  /* Z-index */
  --z-header: 50;
  --z-sheet: 100;
  --z-toast: 200;
}

/* Dark theme (default) */
:root,
[data-theme="dark"] {
  --bg: #0b1020;
  --bg-elev: #141a30;
  --bg-elev-2: #1c2240;
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.14);
  --text: #e6e9f5;
  --text-muted: #8b92ad;
  --text-dim: #5b637d;
  --primary: #6366f1;
  --primary-hover: #7c7ff3;
  --primary-text: #ffffff;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --gradient-1: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #ec4899 100%);
  --gradient-2: linear-gradient(135deg, #06b6d4 0%, #3b82f6 100%);
  --card-hover: rgba(255, 255, 255, 0.04);
}

/* Light theme */
[data-theme="light"] {
  --bg: #f6f7fb;
  --bg-elev: #ffffff;
  --bg-elev-2: #f0f1f7;
  --border: rgba(0, 0, 0, 0.08);
  --border-strong: rgba(0, 0, 0, 0.14);
  --text: #14182a;
  --text-muted: #5b637d;
  --text-dim: #8b92ad;
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --primary-text: #ffffff;
  --success: #059669;
  --warning: #d97706;
  --danger: #dc2626;
  --gradient-1: linear-gradient(135deg, #4f46e5 0%, #7c3aed 50%, #db2777 100%);
  --gradient-2: linear-gradient(135deg, #0891b2 0%, #2563eb 100%);
  --card-hover: rgba(0, 0, 0, 0.03);
}

/* ---------- Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

* { margin: 0; padding: 0; }

html, body { height: 100%; }

body {
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.5;
  color: var(--text);
  background: var(--bg);
  background-image:
    radial-gradient(at 0% 0%, rgba(99, 102, 241, 0.15) 0px, transparent 50%),
    radial-gradient(at 100% 100%, rgba(236, 72, 153, 0.10) 0px, transparent 50%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
  padding-bottom: env(safe-area-inset-bottom);
  overflow-x: hidden;
}

button { font: inherit; color: inherit; cursor: pointer; background: none; border: none; }
input { font: inherit; color: inherit; }
h1, h2, h3, h4 { font-weight: 600; letter-spacing: -0.01em; }
a { color: var(--primary); text-decoration: none; }

/* ---------- Layout ---------- */
.app-header,
.conn-panel,
.filters,
.server-list {
  max-width: 760px;
  margin-inline: auto;
  padding-inline: var(--space-4);
}

/* ---------- Header ---------- */
.app-header {
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  padding-block: var(--space-4);
  padding-top: calc(var(--space-4) + env(safe-area-inset-top));
  background: color-mix(in oklab, var(--bg) 80%, transparent);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}

.brand { display: flex; align-items: center; gap: var(--space-3); }
.brand-logo {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  border-radius: var(--radius-md);
  background: var(--gradient-1);
  color: white;
  box-shadow: var(--shadow-glow);
}
.brand-logo svg { width: 22px; height: 22px; }
.brand-text h1 { font-size: 18px; line-height: 1.1; }
.brand-sub { font-size: 12px; color: var(--text-muted); margin-top: 2px; }

.header-actions { display: flex; gap: var(--space-1); }

.icon-btn {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  border-radius: var(--radius-md);
  color: var(--text-muted);
  transition: background var(--t-fast), color var(--t-fast), transform var(--t-fast);
}
.icon-btn:hover { background: var(--card-hover); color: var(--text); }
.icon-btn:active { transform: scale(0.92); }
.icon-btn svg { width: 20px; height: 20px; }
.icon-btn[hidden] { display: none; }
.icon-btn.spinning svg { animation: spin 0.6s linear; }

@keyframes spin { to { transform: rotate(360deg); } }

/* ---------- Connection panel ---------- */
.conn-panel { padding-top: var(--space-4); }

.conn-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-5);
  border-radius: var(--radius-xl);
  background: var(--bg-elev);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-md);
  transition: border-color var(--t-base);
}
.conn-card.is-connected { border-color: color-mix(in oklab, var(--success) 50%, var(--border)); }

.conn-status { display: flex; align-items: center; gap: var(--space-3); min-width: 0; flex: 1; }
.conn-led {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--text-dim);
  box-shadow: 0 0 0 0 currentColor;
  flex-shrink: 0;
  transition: background var(--t-base), box-shadow var(--t-base);
}
.conn-led[data-status="connected"] {
  background: var(--success);
  color: var(--success);
  box-shadow: 0 0 0 6px color-mix(in oklab, var(--success) 20%, transparent);
  animation: pulse 2s ease-in-out infinite;
}
.conn-led[data-status="connecting"] {
  background: var(--warning);
  color: var(--warning);
  box-shadow: 0 0 0 6px color-mix(in oklab, var(--warning) 20%, transparent);
  animation: pulse 1s ease-in-out infinite;
}
.conn-led[data-status="error"] {
  background: var(--danger);
  color: var(--danger);
  box-shadow: 0 0 0 6px color-mix(in oklab, var(--danger) 20%, transparent);
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}

.conn-text { min-width: 0; flex: 1; }
.conn-state { font-weight: 600; font-size: 15px; }
.conn-server {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 2px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.conn-actions { display: flex; gap: var(--space-2); flex-shrink: 0; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 10px var(--space-4);
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 600;
  line-height: 1;
  white-space: nowrap;
  transition: transform var(--t-fast), background var(--t-fast), opacity var(--t-fast);
  min-height: 40px;
}
.btn svg { width: 16px; height: 16px; }
.btn:active { transform: scale(0.96); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; pointer-events: none; }

.btn-primary {
  background: var(--gradient-1);
  color: var(--primary-text);
  box-shadow: var(--shadow-md);
}
.btn-primary:hover { box-shadow: var(--shadow-lg); }

.btn-secondary {
  background: var(--bg-elev-2);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-secondary:hover { background: var(--card-hover); }

.btn-ghost {
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border);
}
.btn-ghost:hover { background: var(--card-hover); color: var(--text); }

/* ---------- Traffic ---------- */
.traffic-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-2);
  margin-top: var(--space-3);
  padding: var(--space-3);
  border-radius: var(--radius-lg);
  background: var(--bg-elev);
  border: 1px solid var(--border);
  animation: slideUp var(--t-base);
}
.traffic-item { text-align: center; padding: var(--space-2); }
.traffic-label { font-size: 11px; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.05em; }
.traffic-value { font-size: 15px; font-weight: 600; font-variant-numeric: tabular-nums; margin-top: 4px; font-family: var(--font-mono); }
.traffic-grid[hidden] { display: none; }

@keyframes slideUp {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ---------- Filters ---------- */
.filters { padding-top: var(--space-5); }

.search-wrap {
  position: relative;
  margin-bottom: var(--space-3);
}
.search-icon {
  position: absolute;
  left: var(--space-3);
  top: 50%;
  transform: translateY(-50%);
  width: 18px;
  height: 18px;
  color: var(--text-muted);
  pointer-events: none;
}
#searchInput {
  width: 100%;
  padding: 12px var(--space-3) 12px calc(var(--space-3) + 24px);
  border-radius: var(--radius-md);
  background: var(--bg-elev);
  border: 1px solid var(--border);
  outline: none;
  transition: border-color var(--t-fast), background var(--t-fast);
}
#searchInput:focus { border-color: var(--primary); background: var(--bg-elev-2); }
#searchInput::placeholder { color: var(--text-dim); }

.chip-row {
  display: flex;
  gap: var(--space-2);
  overflow-x: auto;
  scrollbar-width: none;
  padding-bottom: var(--space-2);
  margin-bottom: var(--space-2);
  -webkit-overflow-scrolling: touch;
}
.chip-row::-webkit-scrollbar { display: none; }

.chip {
  flex-shrink: 0;
  padding: 8px 14px;
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  background: var(--bg-elev);
  border: 1px solid var(--border);
  transition: all var(--t-fast);
}
.chip:hover { color: var(--text); }
.chip.active {
  background: var(--primary);
  color: var(--primary-text);
  border-color: var(--primary);
}

.filter-meta {
  font-size: 12px;
  color: var(--text-muted);
  padding: var(--space-2) 0;
  display: flex;
  gap: var(--space-2);
  align-items: center;
}
.filter-meta .dot { color: var(--text-dim); }

/* ---------- Server list ---------- */
.server-list {
  padding-top: var(--space-2);
  padding-bottom: calc(var(--space-8) + env(safe-area-inset-bottom));
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.server-card {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: var(--space-3);
  align-items: center;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-lg);
  background: var(--bg-elev);
  border: 1px solid var(--border);
  transition: transform var(--t-fast), background var(--t-fast), border-color var(--t-fast);
  cursor: pointer;
  text-align: left;
  width: 100%;
  animation: fadeIn var(--t-base) backwards;
}
.server-card:hover { background: var(--card-hover); border-color: var(--border-strong); }
.server-card:active { transform: scale(0.99); }
.server-card.is-active {
  border-color: var(--primary);
  background: color-mix(in oklab, var(--primary) 8%, var(--bg-elev));
}

.server-flag {
  font-size: 28px;
  line-height: 1;
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border-radius: var(--radius-md);
  background: var(--bg-elev-2);
}

.server-info { min-width: 0; }
.server-name {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 600;
  font-size: 14px;
  margin-bottom: 4px;
}
.server-host { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.server-badges { display: flex; gap: 4px; flex-shrink: 0; }
.badge {
  font-size: 10px;
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.badge-no-log { background: color-mix(in oklab, var(--success) 20%, transparent); color: var(--success); }
.badge-vip    { background: color-mix(in oklab, var(--warning) 20%, transparent); color: var(--warning); }

.server-meta {
  display: flex;
  gap: var(--space-3);
  font-size: 12px;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
}
.server-meta span { display: inline-flex; align-items: center; gap: 4px; }

.server-stats { text-align: right; }
.server-speed {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}
.server-score {
  font-size: 11px;
  color: var(--text-dim);
  font-variant-numeric: tabular-nums;
}
.server-speed-unit { font-weight: 400; color: var(--text-muted); }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ---------- Empty state ---------- */
.empty-state {
  text-align: center;
  padding: var(--space-8) var(--space-4);
  color: var(--text-muted);
}
.empty-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto var(--space-4);
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--bg-elev);
  color: var(--text-dim);
}
.empty-icon svg { width: 32px; height: 32px; }
.empty-state h2 { font-size: 16px; color: var(--text); margin-bottom: var(--space-2); }
.empty-state p { font-size: 13px; }

/* ---------- Toast ---------- */
.toast {
  position: fixed;
  bottom: calc(var(--space-6) + env(safe-area-inset-bottom));
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  padding: 12px var(--space-4);
  background: var(--bg-elev-2);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-md);
  color: var(--text);
  font-size: 14px;
  box-shadow: var(--shadow-lg);
  z-index: var(--z-toast);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--t-base), transform var(--t-base);
  max-width: calc(100vw - 32px);
}
.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}
.toast.error { border-color: color-mix(in oklab, var(--danger) 50%, var(--border)); }
.toast.success { border-color: color-mix(in oklab, var(--success) 50%, var(--border)); }

/* ---------- Bottom sheet ---------- */
.sheet {
  position: fixed;
  inset: 0;
  z-index: var(--z-sheet);
  display: flex;
  align-items: flex-end;
  justify-content: center;
}
.sheet[hidden] { display: none; }
.sheet-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  animation: fadeIn var(--t-base);
}
.sheet-card {
  position: relative;
  width: 100%;
  max-width: 480px;
  background: var(--bg-elev);
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
  padding: var(--space-5);
  padding-bottom: calc(var(--space-5) + env(safe-area-inset-bottom));
  box-shadow: 0 -10px 40px rgba(0, 0, 0, 0.3);
  animation: slideUp var(--t-slow);
}
.sheet-handle {
  width: 40px;
  height: 4px;
  background: var(--border-strong);
  border-radius: 2px;
  margin: 0 auto var(--space-4);
}
.sheet-card h3 { font-size: 18px; margin-bottom: var(--space-2); }
.sheet-desc { font-size: 13px; color: var(--text-muted); margin-bottom: var(--space-4); }
.sheet-desc code {
  background: var(--bg-elev-2);
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 12px;
}
.sheet-server {
  padding: var(--space-3);
  background: var(--bg-elev-2);
  border-radius: var(--radius-md);
  font-size: 14px;
  margin-bottom: var(--space-4);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}
.sheet-actions {
  display: flex;
  gap: var(--space-2);
}
.sheet-actions .btn { flex: 1; }

/* ---------- Skeleton loading ---------- */
.skeleton-card {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: var(--space-3);
  align-items: center;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-lg);
  background: var(--bg-elev);
  border: 1px solid var(--border);
  height: 76px;
}
.skeleton-block {
  background: linear-gradient(90deg,
    var(--bg-elev-2) 0%,
    var(--border-strong) 50%,
    var(--bg-elev-2) 100%);
  background-size: 200% 100%;
  border-radius: var(--radius-sm);
  animation: shimmer 1.4s linear infinite;
}
.skeleton-flag { width: 44px; height: 44px; border-radius: var(--radius-md); }
.skeleton-line { height: 12px; margin-bottom: 8px; }
.skeleton-line.w-70 { width: 70%; }
.skeleton-line.w-40 { width: 40%; }
.skeleton-stat { width: 60px; height: 12px; }

@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* ---------- Responsive ---------- */
@media (min-width: 600px) {
  .traffic-grid { grid-template-columns: repeat(4, 1fr); }
  .conn-card { padding: var(--space-6); }
}

@media (max-width: 380px) {
  .traffic-grid { grid-template-columns: repeat(2, 1fr); }
  .brand-text h1 { font-size: 16px; }
  .brand-sub { display: none; }
}

/* ---------- Accessibility ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ---------- Skeleton: hide after load ---------- */
.server-list.loaded .skeleton-card { display: none; }