/* Material 3 Expressive Design System */
:root {
  /* M3 Color Tokens */
  --m3-sys-color-primary: #38bdf8;
  --m3-sys-color-on-primary: #00344d;
  --m3-sys-color-primary-container: #004c6d;
  --m3-sys-color-on-primary-container: #c8e6ff;
  
  --m3-sys-color-secondary: #c0c7d5;
  --m3-sys-color-secondary-container: #3f4753;
  --m3-sys-color-on-secondary-container: #dce3f2;
  
  --m3-sys-color-surface: #0f172a;
  --m3-sys-color-surface-container: #1e293b;
  --m3-sys-color-surface-container-high: #283548;
  --m3-sys-color-surface-container-highest: #334155;
  
  --m3-sys-color-on-surface: #f8fafc;
  --m3-sys-color-on-surface-variant: #94a3b8;
  --m3-sys-color-outline: #475569;
  --m3-sys-color-outline-variant: #334155;
  
  --m3-sys-color-error: #f87171;
  --m3-sys-color-error-container: #7f1d1d;
  --m3-sys-color-on-error-container: #fecaca;
  
  --m3-sys-color-success: #34d399;
  --m3-sys-color-success-container: #064e3b;
  
  /* M3 Tokens */
  --m3-shape-corner-extra-large: 28px;
  --m3-shape-corner-large: 20px;
  --m3-shape-corner-medium: 16px;
  --m3-shape-corner-small: 12px;
  --m3-shape-corner-full: 9999px;
  
  --m3-elevation-1: 0 4px 20px rgba(0, 0, 0, 0.3);
  --m3-elevation-2: 0 8px 32px rgba(0, 0, 0, 0.4);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'Roboto', -apple-system, BlinkMacSystemFont, sans-serif;
  -webkit-tap-highlight-color: transparent;
}

body {
  background-color: var(--m3-sys-color-surface);
  color: var(--m3-sys-color-on-surface);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* AUTH MODAL */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.88);
  backdrop-filter: blur(20px);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 9999;
  padding: 20px;
}

.modal-card {
  background: var(--m3-sys-color-surface-container);
  border: 1px solid var(--m3-sys-color-outline-variant);
  border-radius: var(--m3-shape-corner-extra-large);
  padding: 36px;
  width: 100%;
  max-width: 440px;
  box-shadow: var(--m3-elevation-2);
}

.auth-title {
  font-size: 24px;
  font-weight: 700;
  color: var(--m3-sys-color-on-surface);
  margin-bottom: 4px;
}

.auth-subtitle {
  font-size: 14px;
  color: var(--m3-sys-color-on-surface-variant);
  margin-bottom: 24px;
}

.auth-toggle {
  margin-top: 20px;
  text-align: center;
  font-size: 14px;
  color: var(--m3-sys-color-on-surface-variant);
}

/* FORM ELEMENTS */
.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 18px;
}

.form-group label {
  font-size: 13px;
  font-weight: 600;
  color: var(--m3-sys-color-primary);
}

.form-control {
  background: var(--m3-sys-color-surface-container-high);
  border: 1px solid var(--m3-sys-color-outline-variant);
  border-radius: var(--m3-shape-corner-medium);
  padding: 14px 18px;
  color: var(--m3-sys-color-on-surface);
  font-size: 15px;
  outline: none;
  width: 100%;
  transition: all 0.2s ease;
}

.form-control:focus {
  border-color: var(--m3-sys-color-primary);
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.2);
}

.alert-danger {
  background: var(--m3-sys-color-error-container);
  color: var(--m3-sys-color-on-error-container);
  padding: 12px 16px;
  border-radius: var(--m3-shape-corner-medium);
  font-size: 13px;
  margin-bottom: 16px;
}

/* BUTTONS */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--m3-shape-corner-full);
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  border: none;
  transition: all 0.2s ease;
}

.btn-primary {
  background: var(--m3-sys-color-primary);
  color: var(--m3-sys-color-on-primary);
}

.btn-primary:hover {
  background: #7dd3fc;
  transform: translateY(-2px);
}

.btn-outlined {
  background: transparent;
  color: var(--m3-sys-color-on-surface);
  border: 1px solid var(--m3-sys-color-outline);
}

.btn-outlined:hover {
  background: rgba(255, 255, 255, 0.08);
}

.btn-danger {
  background: var(--m3-sys-color-error-container);
  color: var(--m3-sys-color-on-error-container);
}

.btn-text {
  background: none;
  border: none;
  color: var(--m3-sys-color-primary);
  font-weight: 700;
  cursor: pointer;
}

.btn-full { width: 100%; }
.btn-sm { padding: 8px 16px; font-size: 12px; }

/* HEADER NAVBAR */
.app-header {
  background: var(--m3-sys-color-surface-container);
  border-bottom: 1px solid var(--m3-sys-color-outline-variant);
  padding: 16px 24px;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-icon {
  font-size: 24px;
}

.brand-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--m3-sys-color-primary);
}

.user-menu {
  display: flex;
  align-items: center;
  gap: 16px;
}

.user-name {
  font-size: 14px;
  color: var(--m3-sys-color-on-surface-variant);
}

/* MAIN CONTAINER */
.main-container {
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: 24px 20px 80px 20px;
}

/* TABS */
.nav-tabs {
  display: flex;
  gap: 12px;
  margin-bottom: 24px;
  background: var(--m3-sys-color-surface-container);
  padding: 8px;
  border-radius: var(--m3-shape-corner-large);
  border: 1px solid var(--m3-sys-color-outline-variant);
}

.tab-btn {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: transparent;
  border: none;
  color: var(--m3-sys-color-on-surface-variant);
  font-size: 15px;
  font-weight: 700;
  padding: 14px 20px;
  border-radius: var(--m3-shape-corner-medium);
  cursor: pointer;
  transition: all 0.2s ease;
}

.tab-btn:hover {
  background: rgba(255, 255, 255, 0.05);
}

.tab-btn.active {
  background: var(--m3-sys-color-primary-container);
  color: var(--m3-sys-color-on-primary-container);
}

/* CARDS & PANELS */
.card {
  background: var(--m3-sys-color-surface-container);
  border: 1px solid var(--m3-sys-color-outline-variant);
  border-radius: var(--m3-shape-corner-extra-large);
  padding: 28px;
  margin-bottom: 24px;
  box-shadow: var(--m3-elevation-1);
}

.card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--m3-sys-color-primary);
}

.section-desc {
  font-size: 14px;
  color: var(--m3-sys-color-on-surface-variant);
  margin-bottom: 24px;
}

/* TOOLBAR & CONTROLS */
.toolbar {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  align-items: center;
  margin-bottom: 20px;
}

.search-box {
  flex: 2;
  min-width: 260px;
}

.filter-box {
  flex: 1;
  min-width: 220px;
}

.actions-box {
  display: flex;
  align-items: center;
  gap: 16px;
}

.auto-refresh-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--m3-sys-color-on-surface-variant);
  cursor: pointer;
}

/* MESSAGES LIST */
.messages-grid {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.message-card {
  background: var(--m3-sys-color-surface-container-high);
  border: 1px solid var(--m3-sys-color-outline-variant);
  border-radius: var(--m3-shape-corner-medium);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.message-card:hover {
  border-color: var(--m3-sys-color-primary);
}

.msg-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.msg-sender {
  font-size: 16px;
  font-weight: 700;
  color: var(--m3-sys-color-primary);
}

.msg-time {
  font-size: 13px;
  color: var(--m3-sys-color-on-surface-variant);
}

.msg-body {
  font-size: 15px;
  line-height: 1.6;
  white-space: pre-wrap;
}

.msg-footer {
  display: flex;
  gap: 20px;
  font-size: 12px;
  color: var(--m3-sys-color-on-surface-variant);
  border-top: 1px dashed var(--m3-sys-color-outline-variant);
  padding-top: 10px;
}

/* DEVICES GRID */
.form-row {
  display: flex;
  gap: 16px;
  align-items: flex-end;
  flex-wrap: wrap;
}

.flex-grow { flex: 1; min-width: 250px; }
.btn-align { margin-bottom: 18px; }

.devices-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 18px;
  margin-top: 18px;
}

.device-card {
  background: var(--m3-sys-color-surface-container-high);
  border: 1px solid var(--m3-sys-color-outline-variant);
  border-radius: var(--m3-shape-corner-medium);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.device-name {
  font-weight: 700;
  font-size: 16px;
}

.device-role {
  font-size: 12px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: var(--m3-shape-corner-full);
  background: var(--m3-sys-color-primary-container);
  color: var(--m3-sys-color-on-primary-container);
}

.token-box {
  background: #070c14;
  padding: 10px 14px;
  border-radius: var(--m3-shape-corner-small);
  font-family: monospace;
  font-size: 13px;
  color: var(--m3-sys-color-success);
  word-break: break-all;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 15px;
  cursor: pointer;
}

.empty-state {
  text-align: center;
  padding: 40px 20px;
  color: var(--m3-sys-color-on-surface-variant);
  font-size: 15px;
}

/* RESPONSIVE MOBILE ADAPTATION */
@media (max-width: 768px) {
  .main-container {
    padding: 16px 12px 90px 12px;
  }
  .toolbar {
    flex-direction: column;
    align-items: stretch;
  }
  .nav-tabs {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    margin-bottom: 0;
    border-radius: 0;
    z-index: 1000;
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.4);
  }
  .tab-btn {
    flex-direction: column;
    gap: 4px;
    font-size: 12px;
    padding: 10px 4px;
  }
}