:root {
  --color-bg: #F6F8FB;
  --color-surface: #FFFFFF;
  --color-text: #182230;
  --color-muted: #586474;
  --color-accent: #175CD3;
  --color-success: #087443;
  --color-error: #B42318;
  --shadow-soft: 0 20px 60px rgba(24, 34, 48, 0.12);
  --border-soft: rgba(88, 100, 116, 0.28);
  --surface-hover: rgba(23, 92, 211, 0.08);
  --step-1: 8px;
  --step-2: 16px;
  --step-3: 24px;
  --step-4: 32px;
  --section-space: 80px;
  --container: 1120px;
  color-scheme: light;
}

:root[data-theme="dark"] {
  --color-bg: #101820;
  --color-surface: #182230;
  --color-text: #F6F8FB;
  --color-muted: #B7C0CC;
  --color-accent: #76A9FF;
  --color-success: #36B37E;
  --color-error: #FF6B5F;
  --shadow-soft: 0 20px 60px rgba(16, 24, 32, 0.36);
  --border-soft: rgba(183, 192, 204, 0.30);
  --surface-hover: rgba(118, 169, 255, 0.12);
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 0;
  overflow-x: hidden;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 16px;
  font-weight: 400;
  line-height: 24px;
}

body.modal-open {
  overflow: hidden;
}

a {
  color: var(--color-accent);
  text-decoration-thickness: 2px;
  text-underline-offset: 4px;
}

button,
input,
select,
textarea {
  font: inherit;
}

button,
a,
input,
select,
textarea,
[role="switch"],
[role="tab"] {
  -webkit-tap-highlight-color: transparent;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
[role="switch"]:focus-visible,
[role="tab"]:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

button:disabled,
input:disabled,
select:disabled,
textarea:disabled {
  cursor: default;
  opacity: 0.45;
}

.container {
  width: min(100% - 48px, var(--container));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--border-soft);
  background: color-mix(in srgb, var(--color-surface) 92%, transparent);
  backdrop-filter: blur(16px);
}

.header__inner {
  display: flex;
  min-height: 72px;
  align-items: center;
  justify-content: space-between;
  gap: var(--step-3);
}

.brand {
  color: var(--color-text);
  font-size: 20px;
  font-weight: 700;
  line-height: 24px;
  text-decoration: none;
}

.header__nav,
.footer__links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--step-2);
}

.header__nav a,
.footer__links a {
  color: var(--color-muted);
  font-size: 14px;
  font-weight: 500;
  line-height: 20px;
  text-decoration: none;
}

.header__nav a:hover,
.footer__links a:hover {
  color: var(--color-accent);
}

.theme-control {
  display: flex;
  align-items: center;
  gap: var(--step-1);
  color: var(--color-muted);
  font-size: 14px;
  font-weight: 500;
  line-height: 20px;
  white-space: nowrap;
}

.theme-toggle,
.switch {
  display: inline-flex;
  align-items: center;
  gap: var(--step-1);
  min-height: 40px;
  border: 0;
  background: transparent;
  color: var(--color-text);
  cursor: pointer;
}

.theme-toggle__track,
.switch__track {
  position: relative;
  display: inline-flex;
  width: 52px;
  height: 30px;
  flex: 0 0 auto;
  align-items: center;
  border: 1px solid var(--border-soft);
  border-radius: 999px;
  background: var(--color-muted);
  transition: background 160ms ease, border-color 160ms ease;
}

.theme-toggle__thumb,
.switch__thumb {
  position: absolute;
  left: 3px;
  width: 22px;
  height: 22px;
  border-radius: 999px;
  background: var(--color-surface);
  box-shadow: 0 2px 6px rgba(24, 34, 48, 0.24);
  transition: transform 160ms ease;
}

[aria-pressed="true"] .theme-toggle__track,
[aria-checked="true"] .switch__track {
  border-color: var(--color-success);
  background: var(--color-success);
}

[aria-pressed="true"] .theme-toggle__thumb,
[aria-checked="true"] .switch__thumb {
  transform: translateX(22px);
}

.hero,
.section {
  padding: var(--section-space) 0;
}

.hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 420px);
  align-items: center;
  gap: 64px;
}

.hero__content {
  min-width: 0;
}

.eyebrow {
  margin: 0 0 var(--step-1);
  color: var(--color-accent);
  font-size: 14px;
  font-weight: 700;
  line-height: 20px;
  text-transform: uppercase;
  letter-spacing: 0;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1 {
  margin: 0;
  color: var(--color-text);
  font-size: 48px;
  font-weight: 700;
  line-height: 56px;
  letter-spacing: 0;
}

h2 {
  margin: 0;
  color: var(--color-text);
  font-size: 30px;
  font-weight: 700;
  line-height: 38px;
  letter-spacing: 0;
}

h3 {
  margin: 0 0 var(--step-1);
  color: var(--color-text);
  font-size: 20px;
  font-weight: 700;
  line-height: 28px;
}

.hero__lead,
.section__intro p {
  max-width: 680px;
  color: var(--color-muted);
}

.hero__lead {
  margin: var(--step-3) 0 0;
  font-size: 18px;
  line-height: 28px;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--step-2);
  margin-top: var(--step-4);
}

.button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 11px 18px;
  font-size: 14px;
  font-weight: 700;
  line-height: 20px;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: transform 120ms ease, background 160ms ease, border-color 160ms ease, color 160ms ease;
}

.button:active,
.tab:active,
.theme-toggle:active,
.switch:active {
  transform: translateY(1px);
}

.button--primary {
  background: var(--color-accent);
  color: var(--color-surface);
}

.button--primary:hover {
  background: color-mix(in srgb, var(--color-accent) 86%, var(--color-text));
}

.button--secondary {
  border-color: var(--border-soft);
  background: var(--color-surface);
  color: var(--color-text);
}

.button--secondary:hover {
  border-color: var(--color-accent);
  background: var(--surface-hover);
}

.status-board,
.controls-grid,
.request-form,
.tabs,
.modal__dialog {
  border: 1px solid var(--border-soft);
  border-radius: 8px;
  background: var(--color-surface);
  box-shadow: var(--shadow-soft);
}

.status-board {
  display: grid;
  gap: var(--step-2);
  padding: var(--step-3);
}

.status-board__header,
.metric,
.device-list li,
.modal__status {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--step-2);
}

.status-board__header {
  padding-bottom: var(--step-2);
  border-bottom: 1px solid var(--border-soft);
  color: var(--color-muted);
  font-size: 14px;
  font-weight: 500;
  line-height: 20px;
}

.status-board__header strong {
  color: var(--color-text);
}

.metric {
  flex-wrap: wrap;
  border: 1px solid var(--border-soft);
  border-radius: 8px;
  padding: var(--step-2);
}

.metric span {
  color: var(--color-muted);
  font-size: 14px;
  font-weight: 500;
  line-height: 20px;
}

.metric strong {
  color: var(--color-text);
  font-size: 24px;
  font-weight: 700;
  line-height: 32px;
}

.metric small {
  width: 100%;
  color: var(--color-muted);
  font-size: 13px;
  font-weight: 500;
  line-height: 18px;
}

.metric--accent {
  border-color: var(--color-accent);
}

.metric--success {
  border-color: var(--color-success);
}

.metric--error {
  border-color: var(--color-error);
}

.section--surface {
  background: color-mix(in srgb, var(--color-surface) 70%, transparent);
}

.section__intro {
  margin-bottom: var(--step-4);
}

.section__intro p {
  margin: var(--step-2) 0 0;
}

.controls-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--step-3);
  padding: var(--step-4);
}

.field,
.fieldset {
  display: grid;
  min-width: 0;
  gap: var(--step-1);
}

.field label,
.fieldset legend,
.toggle-field > span {
  color: var(--color-text);
  font-size: 14px;
  font-weight: 700;
  line-height: 20px;
}

.field input:not([type="checkbox"]):not([type="radio"]):not([type="range"]),
.field select,
.field textarea {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--border-soft);
  border-radius: 8px;
  background: var(--color-surface);
  color: var(--color-text);
  padding: 10px 12px;
}

.field textarea {
  resize: vertical;
}

.field input:hover,
.field select:hover,
.field textarea:hover {
  border-color: var(--color-accent);
}

.field input[aria-invalid="true"],
.field textarea[aria-invalid="true"] {
  border-color: var(--color-error);
}

.field__hint,
.field__error {
  min-height: 18px;
  margin: 0;
  font-size: 13px;
  font-weight: 500;
  line-height: 18px;
}

.field__hint {
  color: var(--color-muted);
}

.field__error {
  color: var(--color-error);
}

.field--inline,
.choice-row {
  display: flex;
  align-items: center;
  gap: var(--step-1);
}

.field--inline {
  align-self: start;
  padding-top: 30px;
}

.fieldset {
  margin: 0;
  border: 1px solid var(--border-soft);
  border-radius: 8px;
  padding: var(--step-2);
}

.fieldset legend {
  padding: 0 var(--step-1);
}

.choice-row label,
.field--inline label {
  font-weight: 500;
}

input[type="checkbox"],
input[type="radio"] {
  width: 20px;
  height: 20px;
  margin: 0;
  accent-color: var(--color-accent);
}

input[type="range"] {
  width: 100%;
  accent-color: var(--color-accent);
}

.toggle-field {
  align-content: start;
}

.switch {
  justify-self: start;
  padding: 0;
  font-size: 14px;
  font-weight: 700;
  line-height: 20px;
}

.tabs {
  padding: var(--step-3);
}

.tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--step-1);
  margin-bottom: var(--step-3);
  border-bottom: 1px solid var(--border-soft);
}

.tab {
  border: 0;
  border-bottom: 3px solid transparent;
  background: transparent;
  color: var(--color-muted);
  padding: 12px 14px;
  font-size: 14px;
  font-weight: 700;
  line-height: 20px;
  cursor: pointer;
}

.tab:hover {
  color: var(--color-accent);
  background: var(--surface-hover);
}

.tab.is-active {
  border-bottom-color: var(--color-accent);
  color: var(--color-accent);
}

.tab-panel p {
  max-width: 720px;
  margin: 0 0 var(--step-3);
  color: var(--color-muted);
}

.device-list {
  display: grid;
  gap: var(--step-1);
  margin: 0;
  padding: 0;
  list-style: none;
}

.device-list li {
  flex-wrap: wrap;
  border: 1px solid var(--border-soft);
  border-radius: 8px;
  padding: var(--step-2);
}

.device-list span {
  color: var(--color-muted);
}

.state {
  color: var(--color-accent);
}

.state--success {
  color: var(--color-success);
}

.state--error {
  color: var(--color-error);
}

.request-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(320px, 1fr);
  gap: var(--step-4);
  align-items: start;
}

.request-form {
  display: grid;
  gap: var(--step-2);
  padding: var(--step-4);
}

.form-status {
  display: none;
  border: 1px solid var(--color-success);
  border-radius: 8px;
  padding: 12px 14px;
  color: var(--color-success);
  font-size: 14px;
  font-weight: 700;
  line-height: 20px;
}

.form-status.is-visible {
  display: block;
}

.site-footer {
  border-top: 1px solid var(--border-soft);
  padding: var(--step-4) 0;
  background: var(--color-surface);
}

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

.footer__inner strong {
  font-size: 20px;
  font-weight: 700;
  line-height: 24px;
}

.modal[hidden] {
  display: none;
}

.modal {
  position: fixed;
  inset: 0;
  z-index: 30;
  display: grid;
  place-items: center;
  padding: var(--step-2);
}

.modal__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(16, 24, 32, 0.72);
}

.modal__dialog {
  position: relative;
  z-index: 1;
  width: min(100%, 520px);
  padding: var(--step-4);
}

.modal__dialog p:not(.eyebrow) {
  color: var(--color-muted);
}

.modal__close {
  position: absolute;
  top: var(--step-2);
  right: var(--step-2);
  display: inline-flex;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border-soft);
  border-radius: 8px;
  background: var(--color-surface);
  color: var(--color-text);
  font-size: 28px;
  line-height: 1;
  cursor: pointer;
}

.modal__close:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.modal__status {
  margin: var(--step-3) 0;
  border: 1px solid var(--border-soft);
  border-radius: 8px;
  padding: var(--step-2);
}

@media (max-width: 760px) {
  :root {
    --section-space: 40px;
  }

  .container {
    width: min(100% - 32px, var(--container));
  }

  .header__inner,
  .footer__inner {
    align-items: flex-start;
    flex-direction: column;
    gap: var(--step-2);
    padding: var(--step-2) 0;
  }

  .header__nav {
    width: 100%;
  }

  .hero__grid,
  .controls-grid,
  .request-layout {
    grid-template-columns: 1fr;
  }

  .hero__grid {
    gap: var(--step-4);
  }

  h1 {
    font-size: 34px;
    line-height: 42px;
  }

  h2 {
    font-size: 30px;
    line-height: 38px;
  }

  .hero__lead {
    font-size: 16px;
    line-height: 24px;
  }

  .status-board,
  .controls-grid,
  .request-form,
  .tabs,
  .modal__dialog {
    padding: var(--step-2);
  }

  .field--inline {
    padding-top: 0;
  }

  .button {
    width: 100%;
  }

  .modal__dialog .button {
    width: auto;
  }
}