:root {
  --bg-primary: #FAF9F6;
  --bg-card: #FFFFFF;
  --border-color: #E8E6E1;
  --text-primary: #1A1A1A;
  --text-secondary: #6B6560;
  --text-muted: #9B9590;
  --accent-primary: #DA7756;
  --accent-primary-hover: #C75B39;
  --accent-success: #2D9F6F;
  --accent-danger: #DC3545;
  --accent-info: #3B82C4;
  --neon-green: var(--accent-success);
  --neon-cyan: var(--accent-info);
  --neon-amber: var(--accent-primary);
  --neon-purple: #8B5CF6;
  --text-main: var(--text-primary);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.07);
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font);
  font-size: 0.875rem;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -webkit-text-size-adjust: 100%;
  overflow-x: hidden;
}

/* ======== Layout ======== */
.app-container {
  width: 100%;
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 clamp(16px, 4vw, 32px) 48px;
}

.app-main {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* ======== Header ======== */
.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 0;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 20px;
  position: sticky;
  top: 0;
  background: var(--bg-primary);
  z-index: 100;
}

.brand-group {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.brand-group h1 {
  font-size: clamp(16px, 2.5vw, 20px);
  font-weight: 700;
  letter-spacing: -0.3px;
  color: var(--text-primary);
  white-space: nowrap;
}

.badge {
  display: inline-block;
  font-size: 10px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 20px;
  background: rgba(218, 119, 86, 0.1);
  color: var(--accent-primary);
  border: 1px solid rgba(218, 119, 86, 0.2);
  white-space: nowrap;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.status-indicator {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 12px;
  font-weight: 500;
  color: var(--accent-success);
}

.dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  display: inline-block;
  flex-shrink: 0;
}

.dot.online {
  background: var(--accent-success);
  box-shadow: 0 0 0 3px rgba(45, 159, 111, 0.12);
  animation: pulse-dot 2s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%, 100% { box-shadow: 0 0 0 3px rgba(45, 159, 111, 0.12); }
  50% { box-shadow: 0 0 0 5px rgba(45, 159, 111, 0.06); }
}

/* ======== Buttons ======== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 500;
  font-family: var(--font);
  cursor: pointer;
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-secondary);
  transition: all 0.15s ease;
  white-space: nowrap;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.btn:hover { border-color: #ccc; background: #f5f4f1; }
.btn:active { transform: scale(0.97); }

.btn-ghost { border: none; background: transparent; }
.btn-ghost:hover { background: rgba(0,0,0,0.04); }

.btn-outline { border: 1px solid var(--border-color); background: transparent; }

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

.btn-secondary { color: var(--accent-info); border-color: rgba(59,130,196,0.3); }
.btn-secondary:hover { background: rgba(59,130,196,0.06); }

.btn-danger { color: var(--accent-danger); border-color: rgba(220,53,69,0.3); }
.btn-danger:hover { background: rgba(220,53,69,0.06); }

.btn-large {
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-md);
  width: 100%;
}

/* ======== Cards ======== */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: clamp(16px, 3vw, 24px);
  box-shadow: var(--shadow-sm);
}

.card-header {
  margin-bottom: 16px;
}

.card-header h2 {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: -0.2px;
}

.card-header.flex-between {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
}

/* ======== IP Grid ======== */
.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

.metric-item {
  padding: clamp(10px, 2vw, 14px);
  border-radius: var(--radius-md);
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  min-width: 0;
}

.label {
  display: block;
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.value {
  font-size: clamp(13px, 2vw, 16px);
  font-weight: 600;
  color: var(--text-primary);
  word-break: break-all;
  line-height: 1.4;
}

.value small {
  font-size: 12px;
  font-weight: 400;
  color: var(--text-muted);
}

.sub-text {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 3px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* Risk badges */
.risk-badge {
  display: inline-block;
  font-size: 10px;
  font-weight: 600;
  padding: 1px 7px;
  border-radius: 10px;
  margin-left: 6px;
  vertical-align: middle;
}

.risk-low { background: rgba(45,159,111,0.1); color: var(--accent-success); }
.risk-med { background: rgba(218,119,86,0.1); color: var(--accent-primary); }
.risk-high { background: rgba(220,53,69,0.1); color: var(--accent-danger); }

/* ======== Mail Section ======== */
.mail-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
  flex-wrap: wrap;
}

.toolbar-left {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 1;
  min-width: 0;
}

.toolbar-left .label {
  flex-shrink: 0;
  margin-bottom: 0;
}

.toolbar-right {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
}

.select-input {
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  font-size: 13px;
  font-family: var(--font);
  background: var(--bg-card);
  color: var(--text-primary);
  min-width: 200px;
  max-width: 100%;
  outline: none;
  transition: border-color 0.15s;
}

.select-input:focus {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(218,119,86,0.08);
}

/* ======== Dashboard Grid ======== */
.dashboard-grid {
  display: grid;
  grid-template-columns: 42% 58%;
  gap: 20px;
  align-items: start;
}

.col {
  display: flex;
  flex-direction: column;
  gap: 16px;
  min-width: 0;
}

/* ======== Gauge ======== */
.gauge-container {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 12px 0 8px;
  max-width: 100%;
  overflow: hidden;
}

#gaugeCanvas {
  max-width: 100%;
  height: auto;
}

.gauge-overlay {
  position: absolute;
  text-align: center;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -30%);
  pointer-events: none;
}

.status-tag {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  color: var(--accent-primary);
  margin-bottom: 2px;
}

.speed-value {
  font-size: clamp(32px, 6vw, 44px);
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1;
}

.speed-unit {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  margin-top: 2px;
}

.action-container {
  padding-top: 4px;
}

/* ======== Metric Cards Row ======== */
.metrics-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}

.metric-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: clamp(12px, 2vw, 16px);
  box-shadow: var(--shadow-sm);
  transition: border-color 0.2s, box-shadow 0.2s;
  min-width: 0;
}

.metric-card.active-testing {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(218,119,86,0.08);
}

.metric-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 6px;
}

.tag {
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
}

.icon {
  color: var(--text-muted);
  font-size: 13px;
}

.metric-value {
  font-size: clamp(20px, 3vw, 26px);
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
}

.metric-value small {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-muted);
}

.metric-sub {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 3px;
}

/* ======== Tables ======== */
.table-responsive {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border-radius: var(--radius-sm);
}

.table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  min-width: 480px;
}

.table thead th {
  text-align: left;
  padding: 8px 10px;
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-primary);
  white-space: nowrap;
  position: sticky;
  top: 0;
}

.table tbody td {
  padding: 8px 10px;
  border-bottom: 1px solid rgba(0,0,0,0.03);
  color: var(--text-secondary);
  font-size: 12px;
}

.table tbody tr:hover {
  background: rgba(0,0,0,0.012);
}

.table tbody tr:last-child td {
  border-bottom: none;
}

.empty-state {
  text-align: center;
  padding: 28px 12px !important;
  color: var(--text-muted);
  font-style: italic;
  font-size: 13px;
}

.code-badge {
  display: inline-block;
  font-size: 14px;
  font-weight: 700;
  padding: 2px 10px;
  border-radius: var(--radius-sm);
  background: rgba(45,159,111,0.1);
  color: var(--accent-success);
  letter-spacing: 1.5px;
  font-family: 'SF Mono', 'Cascadia Code', monospace;
}

/* ======== Upload Zone ======== */
.file-container {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.upload-dropzone {
  border: 2px dashed var(--border-color);
  border-radius: var(--radius-md);
  padding: clamp(24px, 4vw, 40px) 16px;
  text-align: center;
  cursor: pointer;
  transition: all 0.15s ease;
  background: var(--bg-primary);
}

.upload-dropzone:hover {
  border-color: var(--accent-primary);
  background: rgba(218,119,86,0.02);
}

.icon-large {
  font-size: 28px;
  color: var(--text-muted);
  margin-bottom: 8px;
  display: block;
}

.text-main {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
}

.text-sub {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 3px;
}

.hidden-input { display: none; }
.mt-4 { margin-top: 14px; }

/* ======== Tablet (769px ~ 1024px) ======== */
@media (max-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }

  .dashboard-grid {
    grid-template-columns: 1fr;
  }

  .metrics-row {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ======== Mobile (≤ 768px) ======== */
@media (max-width: 768px) {
  .app-header {
    padding: 12px 0;
    margin-bottom: 14px;
  }

  .brand-group h1 { font-size: 16px; }
  .badge { font-size: 9px; padding: 1px 6px; }

  .app-main { gap: 14px; }

  .card {
    border-radius: var(--radius-md);
    padding: 14px;
  }

  .card-header { margin-bottom: 12px; }

  .grid-4 {
    grid-template-columns: 1fr 1fr;
    gap: 8px;
  }

  .metric-item { padding: 10px; }
  .value { font-size: 13px; }
  .sub-text { font-size: 10px; }

  .mail-toolbar {
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
  }

  .toolbar-left {
    flex-direction: column;
    align-items: stretch;
    gap: 6px;
  }

  .toolbar-left .label { margin-bottom: 0; }

  .toolbar-right {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6px;
    width: 100%;
  }

  .select-input {
    width: 100%;
    min-width: unset;
  }

  .dashboard-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .metrics-row {
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
  }

  .metric-card { padding: 10px; }
  .metric-value { font-size: 20px; }
  .tag { font-size: 9px; }
  .metric-sub { font-size: 10px; }

  .gauge-container { padding: 8px 0 4px; }
  .speed-value { font-size: 36px; }

  .btn-large {
    padding: 11px 20px;
    font-size: 14px;
  }

  .table { min-width: 420px; font-size: 12px; }
  .table thead th { padding: 6px 8px; font-size: 9px; }
  .table tbody td { padding: 6px 8px; font-size: 11px; }

  .upload-dropzone { padding: 20px 12px; }
  .icon-large { font-size: 24px; }
  .text-main { font-size: 12px; }

  .hide-mobile { display: none; }
}

/* ======== Small phones (≤ 400px) ======== */
@media (max-width: 400px) {
  .app-container { padding: 0 12px 32px; }
  .brand-group h1 { font-size: 15px; }

  .grid-4 {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .metrics-row {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .toolbar-right {
    grid-template-columns: 1fr;
  }

  .card-header.flex-between {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }
}

/* ======== Wide desktop (≥ 1200px) ======== */
@media (min-width: 1200px) {
  .app-container {
    max-width: 1200px;
    padding: 0 40px 60px;
  }

  .card { padding: 28px; }

  .dashboard-grid {
    grid-template-columns: 40% 60%;
    gap: 24px;
  }

  .speed-value { font-size: 48px; }
  .metric-value { font-size: 28px; }
}