/* ──────────────────────────────────────────────────────────────
   Provеr.Скорость — main stylesheet.
   Dark navy aesthetic. Designed to look like a proper Russian
   speedtest site (competitive with sibnet.ru / speedtest.net).
   Mobile-first, prefers-reduced-motion respected, WCAG AA.
   ────────────────────────────────────────────────────────────── */

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

:root {
  --bg:           #0b1422;
  --bg-elev:      #101d31;
  --bg-card:      #13223a;
  --border:       #1f3252;
  --text:         #e6ecff;
  --text-dim:     #9fb0cd;
  --text-mute:    #6b7a96;
  --accent:       #3aa0ff;
  --accent-2:     #7cf5c4;
  --warn:         #ffb648;
  --danger:       #ff6470;
  --radius:       10px;
  --shadow-sm:    0 1px 2px rgba(0,0,0,.35);
  --shadow-md:    0 8px 28px -12px rgba(0,0,0,.5);
}

html, body { margin: 0; padding: 0; min-height: 100%; background: var(--bg); color: var(--text); }
body { font: 400 15px/1.55 "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }

h1, h2, h3 { margin: 0; font-weight: 700; letter-spacing: -0.01em; }
p { margin: 0 0 12px; }
a { color: var(--accent); text-decoration: none; }
a:hover, a:focus-visible { text-decoration: underline; text-underline-offset: 2px; }

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 22px; }

/* Skip link for keyboard users. */
.skip {
  position: absolute; left: -9999px; top: 0;
  background: var(--accent); color: #000; padding: 8px 12px; border-radius: 0 0 8px 0;
  z-index: 999;
}
.skip:focus { left: 0; }

/* ─── Site header ─────────────────────────────────────────── */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(11, 20, 34, .85);
  backdrop-filter: saturate(1.4) blur(12px);
  -webkit-backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid var(--border);
}
.head-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--text); font-weight: 600; font-size: 16px; }
.brand b { color: var(--accent); font-weight: 700; }
.brand-mark { color: var(--accent); flex-shrink: 0; }
.primary-nav { display: flex; gap: 22px; }
.primary-nav a { color: var(--text-dim); font-size: 14px; font-weight: 500; }
.primary-nav a:hover { color: var(--text); text-decoration: none; }
@media (max-width: 640px) { .primary-nav { display: none; } }

/* ─── Hero / test panel ───────────────────────────────────── */
.hero { padding: 48px 0 24px; }
.hero h1 { font-size: clamp(26px, 4vw, 38px); line-height: 1.15; margin-bottom: 14px; }
.hero .lead { color: var(--text-dim); max-width: 540px; margin-bottom: 32px; font-size: 16px; }

.panel {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 32px;
  box-shadow: var(--shadow-md);
  display: grid;
  grid-template-columns: minmax(260px, 1fr) 2fr;
  gap: 32px;
  align-items: center;
}
@media (max-width: 820px) { .panel { grid-template-columns: 1fr; padding: 24px; gap: 24px; } }

.gauge-block { display: flex; flex-direction: column; align-items: center; gap: 12px; }
.gauge { width: 100%; max-width: 280px; height: auto; filter: drop-shadow(0 6px 18px rgba(58,160,255,.15)); }
.gauge-phase {
  font: 500 12px "JetBrains Mono", ui-monospace, monospace;
  color: var(--text-mute); letter-spacing: 0.12em; text-transform: uppercase;
  min-height: 18px;
}

.stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  align-self: center;
}
.stat {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 16px;
  transition: border-color .2s, box-shadow .2s;
}
.stat.is-active {
  border-color: rgba(58, 160, 255, .55);
  box-shadow: 0 0 0 3px rgba(58, 160, 255, .12);
}
.stat-label {
  font: 500 11px "JetBrains Mono", ui-monospace, monospace;
  color: var(--text-mute); letter-spacing: 0.08em; text-transform: uppercase;
}
.stat-value {
  display: flex; align-items: baseline; gap: 6px;
  font: 700 22px/1 "Inter", sans-serif; color: var(--text); margin-top: 4px;
}
.stat-unit { font: 400 11px "JetBrains Mono", monospace; color: var(--text-mute); letter-spacing: 0.04em; }

.btn {
  grid-column: 1 / -1;
  display: inline-flex; align-items: center; justify-content: center;
  padding: 14px 24px; border-radius: 999px; border: 0;
  font: 600 15px/1 "Inter", sans-serif; cursor: pointer;
  transition: transform .1s, box-shadow .15s, background .15s, opacity .2s;
  min-height: 48px;
}
.btn-primary {
  background: linear-gradient(120deg, #3aa0ff, #2e88ff 60%, #1e5ed1);
  color: #fff; box-shadow: 0 10px 30px -12px rgba(58, 160, 255, .7);
}
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 14px 36px -14px rgba(58, 160, 255, .85); }
.btn-primary:active { transform: translateY(0); }
.btn[disabled] { opacity: .55; cursor: not-allowed; }

.meta {
  margin-top: 14px; color: var(--text-mute); font-size: 13px;
}

/* ─── History table ───────────────────────────────────────── */
.history { margin-top: 48px; }
.history h2 { font-size: 18px; margin-bottom: 14px; }
.history table {
  width: 100%; border-collapse: collapse;
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden;
}
.history th, .history td { padding: 12px 14px; text-align: left; font-size: 14px; }
.history th {
  background: var(--bg-card); color: var(--text-mute);
  font: 500 11px "JetBrains Mono", monospace; letter-spacing: 0.08em; text-transform: uppercase;
}
.history td { border-top: 1px solid var(--border); color: var(--text-dim); }
.history td:first-child { color: var(--text-mute); font: 400 13px "JetBrains Mono", monospace; }

/* ─── Info section ────────────────────────────────────────── */
.info { margin: 56px auto 32px; }
.info h2 { font-size: 20px; margin-bottom: 18px; }
.info-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px;
}
@media (max-width: 820px) { .info-grid { grid-template-columns: 1fr; } }
.info-grid article {
  background: var(--bg-elev); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 20px;
}
.info-grid h3 { font-size: 15px; margin-bottom: 8px; color: var(--text); }
.info-grid p { color: var(--text-dim); font-size: 14px; margin: 0; }

/* ─── Content pages (about, faq, contact) ─────────────────── */
.content {
  max-width: 720px; margin: 48px auto; padding: 0 22px;
  font-size: 16px; line-height: 1.65;
}
.content h1 { font-size: 28px; margin-bottom: 16px; }
.content h2 { font-size: 20px; margin: 32px 0 12px; }
.content p, .content li { color: var(--text-dim); }
.content ul { padding-left: 20px; }
.content details {
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 14px 18px; margin-bottom: 10px;
}
.content details summary { cursor: pointer; font-weight: 500; color: var(--text); }
.content details p { margin: 10px 0 0; }
.content form { display: grid; gap: 14px; max-width: 460px; }
.content form label { display: flex; flex-direction: column; gap: 6px; font-size: 14px; color: var(--text-dim); }
.content form input, .content form textarea {
  background: var(--bg-elev); color: var(--text); border: 1px solid var(--border);
  border-radius: 8px; padding: 10px 12px; font: 400 15px "Inter", sans-serif;
}
.content form input:focus, .content form textarea:focus {
  outline: 2px solid var(--accent); outline-offset: 1px; border-color: transparent;
}
.content form button { justify-self: start; }
.content form .form-note { font-size: 13px; color: var(--text-mute); }

/* ─── About page extras ───────────────────────────────────── */
.lead-muted { color: var(--text-dim); margin: -4px 0 24px; font-size: 15px; }

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin: 12px 0 24px;
}
@media (max-width: 640px) { .stats-grid { grid-template-columns: repeat(2, 1fr); } }
.stat-box {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  text-align: center;
}
.stat-num {
  font: 700 22px/1 "Inter", sans-serif;
  color: var(--accent);
}
.stat-cap {
  margin-top: 6px;
  font: 500 11px "JetBrains Mono", monospace;
  color: var(--text-mute);
  letter-spacing: 0.04em;
}

.back-link { margin-top: 32px; }
.back-link a { color: var(--text-dim); }
.back-link a:hover { color: var(--accent); }

/* ─── Contacts grid + form states ─────────────────────────── */
.contacts-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin-top: 8px;
}
@media (max-width: 720px) { .contacts-grid { grid-template-columns: 1fr; } }
.contact-box {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
}
.contact-box h2 {
  font-size: 15px;
  color: var(--text);
  margin: 0 0 8px;
}
.contact-box p { margin: 0 0 6px; font-size: 14px; color: var(--text-dim); }
.contact-box .dim { color: var(--text-mute); font-size: 13px; margin-top: 4px; }

.address {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  font-style: normal;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-dim);
}

.form-status { margin: 8px 0 0; font-size: 13px; }
.form-status.ok  { color: var(--accent-2); }
.form-status.err { color: var(--danger); }

.content form select {
  background: var(--bg-elev); color: var(--text); border: 1px solid var(--border);
  border-radius: 8px; padding: 10px 12px; font: 400 15px "Inter", sans-serif;
  appearance: none; -webkit-appearance: none;
  background-image: linear-gradient(45deg, transparent 50%, var(--text-dim) 50%), linear-gradient(135deg, var(--text-dim) 50%, transparent 50%);
  background-position: calc(100% - 18px) 50%, calc(100% - 13px) 50%;
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
  padding-right: 36px;
}
.content form select:focus {
  outline: 2px solid var(--accent); outline-offset: 1px; border-color: transparent;
}

/* "aria-current=page" → highlight the active nav item. */
.primary-nav a[aria-current="page"] { color: var(--accent); }

/* ─── Footer ──────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 26px 0; margin-top: 72px;
  color: var(--text-mute); font-size: 13px;
}
.foot-inner { display: flex; justify-content: space-between; gap: 16px; align-items: center; flex-wrap: wrap; }
.foot-inner nav { display: flex; gap: 16px; }
.foot-inner nav a { color: var(--text-mute); }
.foot-inner nav a:hover { color: var(--text); }

/* ─── Reduced motion ──────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important; animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important; scroll-behavior: auto !important;
  }
}