/* ══════════════════════════════════════════════
   components.css — Shared UI components
   ══════════════════════════════════════════════ */

/* ─── NAV ─────────────────────────────────────── */
.nav {
  position: fixed; top: 0; left: 0; right: 0;
  z-index: 200;
  height: var(--nav-h);
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 2rem;
  background: var(--nav-bg);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--clr-border);
  transition: box-shadow var(--transition);
}
.nav--scrolled { box-shadow: 0 2px 24px rgba(0,0,0,.3); }

.nav__logo {
  font-family: var(--font-display);
  font-size: 1.35rem; font-weight: 800;
  letter-spacing: -0.03em;
  flex-shrink: 0;
}
.nav__logo a { color: var(--clr-text); }
.nav__logo span, .nav__logo a span {
  color: var(--clr-accent);
  display: inline-block;
}

.nav__links {
  display: flex; align-items: center; gap: 0.25rem;
}

.nav__link {
  color: var(--clr-text-2);
  font-size: 0.875rem; font-weight: 500;
  padding: 0.4rem 0.75rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}
.nav__link:hover, .nav__link--active {
  color: var(--clr-text);
  background: var(--clr-border-soft);
}

.nav__user {
  display: flex; align-items: center; gap: 0.5rem;
  font-size: 0.875rem; font-weight: 500;
  color: var(--clr-text);
}
.nav__avatar {
  width: 30px; height: 30px; border-radius: 50%;
  background: var(--grad-accent);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.75rem; font-weight: 700; color: #fff;
  flex-shrink: 0;
}

/* Mobile nav hamburger */
.nav__burger {
  display: none;
  flex-direction: column; gap: 5px;
  width: 28px; cursor: pointer; padding: 4px;
  background: none; border: none;
}
.nav__burger span {
  display: block; height: 2px; width: 100%;
  background: var(--clr-text);
  border-radius: 2px;
  transition: all var(--transition);
}
.nav__burger.open span:nth-child(1) { transform: rotate(45deg) translate(5px,5px); }
.nav__burger.open span:nth-child(2) { opacity: 0; }
.nav__burger.open span:nth-child(3) { transform: rotate(-45deg) translate(5px,-5px); }

/* Theme toggle */
.theme-toggle {
  width: 36px; height: 36px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--clr-border);
  background: transparent;
  color: var(--clr-text-2);
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: all var(--transition);
  font-size: 1rem;
  flex-shrink: 0;
}
.theme-toggle:hover {
  border-color: var(--clr-accent);
  color: var(--clr-accent);
  background: var(--clr-accent-glow);
}

/* ─── BUTTONS ─────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; gap: 0.45rem;
  padding: 0.55rem 1.25rem;
  border-radius: var(--radius);
  font-family: var(--font-body); font-size: 0.875rem; font-weight: 600;
  cursor: pointer; border: none;
  transition: all var(--transition);
  text-decoration: none; white-space: nowrap;
  position: relative; overflow: hidden;
  line-height: 1.4;
}
.btn:hover { text-decoration: none; }

.btn--primary {
  background: var(--grad-accent);
  color: #fff;
  box-shadow: var(--shadow-accent);
}
.btn--primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 32px rgba(var(--clr-accent-rgb),.35);
  color: #fff;
}
.btn--primary:active { transform: translateY(0); }

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

.btn--lg { padding: 0.75rem 2rem; font-size: 0.95rem; }
.btn--sm { padding: 0.35rem 0.75rem; font-size: 0.8rem; }

/* ─── MODAL ───────────────────────────────────── */
.modal-overlay {
  position: fixed; inset: 0; z-index: 500;
  background: rgba(0,0,0,.65);
  backdrop-filter: blur(8px);
  display: flex; align-items: center; justify-content: center;
  padding: 1rem;
  animation: fadeIn .2s ease;
}
@keyframes fadeIn { from { opacity:0; } to { opacity:1; } }

.modal {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-xl);
  padding: 2rem;
  width: 100%; max-width: 400px;
  position: relative;
  box-shadow: var(--shadow-float);
  animation: slideUp .25s cubic-bezier(.4,0,.2,1);
}
@keyframes slideUp {
  from { transform: translateY(20px); opacity:0; }
  to   { transform: translateY(0);    opacity:1; }
}

.modal h3 {
  font-size: 1.3rem; margin-bottom: 0.5rem;
}
.modal p {
  font-size: 0.875rem; margin-bottom: 1.5rem;
}

.modal__close {
  position: absolute; top: 1rem; right: 1rem;
  width: 32px; height: 32px;
  border-radius: 50%; border: 1px solid var(--clr-border);
  background: var(--clr-card);
  color: var(--clr-muted);
  cursor: pointer; font-size: 0.85rem;
  display: flex; align-items: center; justify-content: center;
  transition: all var(--transition);
}
.modal__close:hover { background: var(--clr-border); color: var(--clr-text); }

.modal__note {
  font-size: 0.75rem;
  color: var(--clr-muted);
  margin-top: 1rem;
  margin-bottom: 0;
  border-top: 1px solid var(--clr-border-soft);
  padding-top: 0.75rem;
}

/* ─── AUTH NOTICE BANNER ─────────────────────── */
.auth-notice {
  display: flex; align-items: center; gap: 0.75rem;
  justify-content: space-between;
  background: var(--clr-card);
  border: 1px solid var(--clr-accent);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  margin: 1rem 0;
  font-size: 0.875rem;
}

/* ─── PLATFORM BADGES ─────────────────────────── */
.badge {
  display: inline-flex; align-items: center; gap: 0.3rem;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem; font-weight: 600;
}
.badge--yandex { background: rgba(255,176,26,.15); color: var(--clr-yellow); }
.badge--mesh   { background: rgba(59,146,255,.15); color: var(--clr-blue); }
.badge--kompege{ background: rgba(34,211,122,.15); color: var(--clr-green); }
.badge--answer { background: rgba(34,211,122,.12); color: var(--clr-green); border: 1px solid rgba(34,211,122,.2); }

/* ─── CARD ────────────────────────────────────── */
.card {
  background: var(--clr-card);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.card:hover {
  border-color: rgba(var(--clr-accent-rgb),.3);
  box-shadow: 0 0 0 1px rgba(var(--clr-accent-rgb),.08), var(--shadow-card);
}

/* ─── FOOTER ─────────────────────────────────── */
.footer {
  border-top: 1px solid var(--clr-border);
  padding: 3rem 0 2rem;
  margin-top: 4rem;
}
.footer__grid {
  display: grid; grid-template-columns: 1fr 2fr;
  gap: 2rem; margin-bottom: 2rem;
}
.footer__logo {
  font-family: var(--font-display);
  font-size: 1.3rem; font-weight: 800;
  margin-bottom: 0.5rem;
}
.footer__logo span { color: var(--clr-accent); }
.footer__brand p { font-size: 0.875rem; }
.footer__links {
  display: flex; flex-wrap: wrap; gap: 0.5rem 1.5rem;
  align-content: flex-start;
}
.footer__links a {
  font-size: 0.875rem; color: var(--clr-text-2);
  transition: color var(--transition);
}
.footer__links a:hover { color: var(--clr-accent); }
.footer__bottom {
  display: flex; align-items: center; justify-content: space-between;
  font-size: 0.8rem; color: var(--clr-muted);
  border-top: 1px solid var(--clr-border-soft);
  padding-top: 1.5rem;
}
.footer__security {
  display: flex; align-items: center; gap: 0.4rem;
}

/* ─── RESPONSIVE NAV ─────────────────────────── */
@media (max-width: 768px) {
  .nav {
    padding: 0 1rem;
  }
  .nav__links {
    position: fixed;
    top: var(--nav-h); left: 0; right: 0;
    background: var(--clr-surface);
    border-bottom: 1px solid var(--clr-border);
    padding: 1rem;
    flex-direction: column; align-items: stretch;
    gap: 0.25rem;
    transform: translateY(-110%);
    opacity: 0;
    transition: all var(--transition-slow);
    z-index: 199;
  }
  .nav__links.open {
    transform: translateY(0);
    opacity: 1;
  }
  .nav__link { padding: 0.65rem 0.75rem; }
  .nav__burger { display: flex; }

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

/* ── Yandex OAuth button ─────────────────────── */
.btn--yandex {
  background: #fc3f1d;
  color: #fff;
  border: none;
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  justify-content: center;
  font-weight: 600;
  transition: background var(--transition), transform var(--transition);
}
.btn--yandex:hover {
  background: #e03012;
  transform: translateY(-1px);
}

/* ── Modal improvements ──────────────────────── */
.modal__logo {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.4rem;
  color: var(--clr-text);
  margin-bottom: .5rem;
  letter-spacing: -.04em;
}
.modal__logo span { color: var(--clr-accent); }

/* ── Formula rendering ───────────────────────── */
.formula-raw {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  padding: .1em .3em;
  border-radius: 4px;
  font-family: var(--font-mono, 'JetBrains Mono', monospace);
  font-size: .9em;
  color: var(--clr-accent2);
}

.katex-display {
  overflow-x: auto;
  overflow-y: hidden;
  padding: .5rem 0;
  margin: .5rem 0;
}

.katex {
  font-size: 1.05em;
}

/* ── Task images ─────────────────────────────── */
.task-img-wrap {
  margin: .75rem 0;
  display: block;
}

.task-img {
  max-width: 100%;
  border-radius: 8px;
  display: block;
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
}

/* ── Nav avatar image (Yandex) ───────────────── */
.nav__avatar-img {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--clr-accent);
}

/* ══════════════════════════════════════════════
   MOBILE IMPROVEMENTS
   ══════════════════════════════════════════════ */

/* Solver page mobile */
@media (max-width: 600px) {
  .solver-page {
    padding: 1rem;
  }
  .solver-header h1 {
    font-size: 1.4rem;
  }
  .solver-url-row {
    flex-direction: column;
    gap: .5rem;
  }
  .solver-url-input {
    width: 100%;
  }
  #solver-btn {
    width: 100%;
  }
  .solver-platforms {
    flex-wrap: wrap;
    gap: .25rem;
  }
}

/* Test page mobile */
@media (max-width: 768px) {
  .test-layout {
    display: flex;
    flex-direction: column;
  }
  .test-sidenav {
    display: none !important;
  }
  .test-sidebar-right {
    display: none !important;
  }
  .test-main {
    padding: .75rem;
    max-width: 100%;
  }
  .test-header h1 {
    font-size: 1.2rem;
    word-break: break-word;
  }
  .test-search-bar {
    flex-wrap: wrap;
    gap: .25rem;
  }
  .task-box {
    margin-bottom: .75rem;
  }
  .task-box__header {
    padding: .75rem;
  }
  .task-box__body {
    padding: .75rem;
  }
  .task-box__instruction {
    font-size: .9rem;
  }
  .katex-display {
    font-size: .9em;
  }
  .katex {
    font-size: .95em;
  }
}

/* Nav mobile fixes */
@media (max-width: 600px) {
  .nav__user span {
    display: none;
  }
  .nav__user .btn {
    font-size: .75rem;
    padding: .25rem .5rem;
  }
  .hero__title {
    font-size: clamp(1.8rem, 8vw, 2.5rem);
  }
  .hero__cta {
    flex-direction: column;
    width: 100%;
  }
  .hero__cta .btn {
    width: 100%;
    text-align: center;
    justify-content: center;
  }
  .stats__grid {
    grid-template-columns: repeat(2, 1fr);
    gap: .75rem;
  }
  .features__grid {
    grid-template-columns: 1fr;
  }
  .how__steps {
    flex-direction: column;
  }
  .how__connector {
    display: none;
  }
  .platforms__grid {
    grid-template-columns: 1fr;
  }
  .footer__grid {
    flex-direction: column;
    gap: 1.5rem;
  }
  .footer__links {
    flex-direction: column;
    gap: .5rem;
  }
  .modal {
    margin: 1rem;
    padding: 1.5rem;
    width: calc(100% - 2rem);
  }
}

/* Search page mobile */
@media (max-width: 600px) {
  .search-results__item {
    padding: .75rem;
  }
  .search-header h1 {
    font-size: 1.3rem;
  }
  .search-filters {
    flex-wrap: wrap;
    gap: .25rem;
  }
}