/* ============================================================
   Byte Stack Solutions, components.css
   Nav, buttons, cards, footer, forms, accordion, marquee
   ============================================================ */

/* ============ NAV ============ */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-h);
  z-index: 100;
  display: flex;
  align-items: center;
  transition: background var(--t-med) var(--ease-out), backdrop-filter var(--t-med);
}

.nav.scrolled {
  background: rgba(10, 14, 26, 0.7);
  backdrop-filter: blur(var(--blur)) saturate(180%);
  -webkit-backdrop-filter: blur(var(--blur)) saturate(180%);
  border-bottom: 1px solid var(--border);
}

.nav__inner {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--s-5);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s-5);
}

.nav__brand {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.nav__brand svg {
  height: 36px;
  width: auto;
  transition: transform var(--t-med) var(--ease-out);
}

.nav__brand:hover svg {
  transform: scale(1.04);
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--s-2);
}

.nav__link {
  position: relative;
  padding: var(--s-2) var(--s-4);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-soft);
  border-radius: var(--r-2);
  transition: color var(--t-fast) var(--ease-out);
}

.nav__link::after {
  content: '';
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 0;
  height: 2px;
  background: var(--gradient-accent);
  border-radius: var(--r-full);
  transition: width var(--t-med) var(--ease-out), left var(--t-med) var(--ease-out);
}

.nav__link:hover,
.nav__link.active {
  color: var(--text);
}

.nav__link:hover::after,
.nav__link.active::after {
  width: 60%;
  left: 20%;
}

.nav__actions {
  display: flex;
  align-items: center;
  gap: var(--s-3);
}

/* Lang switcher */
.lang-switch {
  display: inline-flex;
  align-items: center;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-full);
  padding: 3px;
  position: relative;
}

.lang-switch__btn {
  position: relative;
  z-index: 1;
  padding: 4px 12px;
  font-size: 0.78rem;
  font-weight: 600;
  font-family: var(--font-mono);
  color: var(--text-muted);
  border-radius: var(--r-full);
  transition: color var(--t-fast) var(--ease-out);
}

.lang-switch__btn[aria-pressed="true"] {
  color: var(--bg);
  background: var(--gradient-accent);
}

/* Mobile menu */
.nav__toggle {
  display: none;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-3);
}

.nav__toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  position: relative;
  transition: all var(--t-med) var(--ease-out);
}

.nav__toggle span::before,
.nav__toggle span::after {
  content: '';
  position: absolute;
  width: 20px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: all var(--t-med) var(--ease-out);
}

.nav__toggle span::before { top: -7px; }
.nav__toggle span::after { top: 7px; }

.nav.open .nav__toggle span { background: transparent; }
.nav.open .nav__toggle span::before { top: 0; transform: rotate(45deg); }
.nav.open .nav__toggle span::after { top: 0; transform: rotate(-45deg); }

@media (max-width: 900px) {
  .nav__toggle { display: flex; }
  .nav__links {
    position: fixed;
    inset: var(--nav-h) 0 0 0;
    background: rgba(10, 14, 26, 0.96);
    backdrop-filter: blur(var(--blur));
    flex-direction: column;
    justify-content: flex-start;
    align-items: stretch;
    padding: var(--s-6) var(--s-5);
    gap: var(--s-1);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: transform var(--t-med) var(--ease-out), opacity var(--t-med) var(--ease-out);
  }
  .nav.open .nav__links {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
  .nav__link {
    padding: var(--s-4);
    font-size: 1.15rem;
    text-align: left;
    border-bottom: 1px solid var(--border);
    border-radius: 0;
  }
  .nav__link::after { display: none; }
}

/* ============ BUTTONS ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--s-2);
  padding: 0.9rem 1.6rem;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.98rem;
  letter-spacing: -0.01em;
  border-radius: var(--r-3);
  cursor: pointer;
  position: relative;
  transition: transform var(--t-med) var(--ease-out), box-shadow var(--t-med);
  white-space: nowrap;
  will-change: transform;
}

.btn svg {
  width: 18px;
  height: 18px;
  transition: transform var(--t-med) var(--ease-out);
}

.btn:hover svg {
  transform: translateX(4px);
}

.btn--primary {
  color: var(--bg);
  background: var(--gradient-accent);
  box-shadow: 0 8px 24px -8px rgba(0, 212, 255, 0.5);
}

.btn--primary:hover {
  color: var(--bg);
  transform: translateY(-2px);
  box-shadow: 0 16px 36px -10px rgba(0, 212, 255, 0.7);
}

.btn--primary::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(135deg, #ec4899 0%, #00d4ff 100%);
  opacity: 0;
  transition: opacity var(--t-med);
  z-index: -1;
}

.btn--primary:hover::before { opacity: 1; }

.btn--ghost {
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border-strong);
  backdrop-filter: blur(var(--blur));
  -webkit-backdrop-filter: blur(var(--blur));
}

.btn--ghost:hover {
  background: var(--surface-strong);
  border-color: var(--accent-cyan);
  color: var(--text);
  transform: translateY(-2px);
}

.btn--lg {
  padding: 1.1rem 2rem;
  font-size: 1.05rem;
}

.btn--sm {
  padding: 0.55rem 1rem;
  font-size: 0.88rem;
}

.btn-row {
  display: flex;
  gap: var(--s-3);
  flex-wrap: wrap;
}

/* ============ CARDS ============ */
.card {
  position: relative;
  padding: var(--s-6);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-4);
  backdrop-filter: blur(var(--blur));
  -webkit-backdrop-filter: blur(var(--blur));
  transition: transform var(--t-med) var(--ease-out), border-color var(--t-med);
  overflow: hidden;
  will-change: transform;
}

.card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(135deg, rgba(0, 212, 255, 0.4), rgba(168, 85, 247, 0.4), transparent 60%);
  -webkit-mask: linear-gradient(#000, #000) content-box, linear-gradient(#000, #000);
  -webkit-mask-composite: xor;
          mask-composite: exclude;
  opacity: 0;
  transition: opacity var(--t-med);
  pointer-events: none;
}

.card:hover::before { opacity: 1; }

.card:hover {
  border-color: transparent;
  transform: translateY(-4px);
}

.card[data-tilt] {
  transform-style: preserve-3d;
  perspective: 1000px;
}

.card__icon {
  width: 56px;
  height: 56px;
  border-radius: var(--r-3);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient-accent-soft);
  border: 1px solid var(--border);
  margin-bottom: var(--s-5);
  position: relative;
}

.card__icon svg {
  width: 28px;
  height: 28px;
  color: var(--accent-cyan);
}

.card__icon::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: var(--gradient-accent);
  filter: blur(20px);
  opacity: 0.3;
  z-index: -1;
}

.card__title {
  margin-bottom: var(--s-3);
}

.card__desc {
  color: var(--text-muted);
  font-size: 0.97rem;
}

.card__list {
  margin-top: var(--s-4);
  display: flex;
  flex-direction: column;
  gap: var(--s-2);
}

.card__list li {
  display: flex;
  align-items: flex-start;
  gap: var(--s-2);
  font-size: 0.92rem;
  color: var(--text-muted);
}

.card__list li::before {
  content: '';
  display: inline-block;
  width: 16px;
  height: 16px;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none'%3E%3Cpath d='M2 8L6 12L14 4' stroke='%2300d4ff' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") no-repeat center / contain;
  flex-shrink: 0;
  margin-top: 4px;
}

/* ============ GLASS PANEL ============ */
.glass {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-4);
  backdrop-filter: blur(var(--blur));
  -webkit-backdrop-filter: blur(var(--blur));
}

/* ============ FOOTER ============ */
.footer {
  position: relative;
  padding: var(--s-9) 0 var(--s-5);
  border-top: 1px solid var(--border);
  margin-top: var(--s-9);
  background: linear-gradient(180deg, transparent, rgba(0, 0, 0, 0.3));
}

.footer__grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: var(--s-6);
  margin-bottom: var(--s-7);
}

@media (max-width: 800px) {
  .footer__grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 500px) {
  .footer__grid { grid-template-columns: 1fr; }
}

.footer__col h4 {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--text-muted);
  margin-bottom: var(--s-4);
}

.footer__col ul {
  display: flex;
  flex-direction: column;
  gap: var(--s-2);
}

.footer__col a {
  color: var(--text-soft);
  font-size: 0.95rem;
}

.footer__col a:hover {
  color: var(--accent-cyan);
}

.footer__brand svg { height: 42px; margin-bottom: var(--s-4); }
.footer__brand p { font-size: 0.95rem; max-width: 32ch; }

.footer__bottom {
  padding-top: var(--s-5);
  border-top: 1px solid var(--border);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: var(--s-3);
  font-size: 0.85rem;
  color: var(--text-faint);
}

/* ============ FORMS ============ */
.form {
  display: flex;
  flex-direction: column;
  gap: var(--s-5);
}

.form__row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--s-4);
}

@media (max-width: 600px) {
  .form__row { grid-template-columns: 1fr; }
}

.field {
  display: flex;
  flex-direction: column;
  gap: var(--s-2);
}

.field label {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-soft);
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
}

.field input,
.field select,
.field textarea {
  width: 100%;
  padding: 0.85rem 1rem;
  background: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: var(--r-3);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 0.98rem;
  transition: border-color var(--t-fast) var(--ease-out), background var(--t-fast);
}

.field input:focus,
.field select:focus,
.field textarea:focus {
  outline: none;
  border-color: var(--accent-cyan);
  background: var(--surface-strong);
  box-shadow: 0 0 0 4px rgba(0, 212, 255, 0.12);
}

.field textarea {
  min-height: 140px;
  resize: vertical;
  font-family: inherit;
}

.field select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none'%3E%3Cpath d='M4 6L8 10L12 6' stroke='%2394a3b8' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 1rem center;
  padding-right: 2.5rem;
}

.field select option {
  background: var(--bg-2);
  color: var(--text);
}

/* ============ ACCORDION ============ */
.accordion {
  display: flex;
  flex-direction: column;
  gap: var(--s-3);
}

.accordion__item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-3);
  overflow: hidden;
  transition: border-color var(--t-fast);
}

.accordion__item:hover {
  border-color: var(--border-strong);
}

.accordion__item.open {
  border-color: rgba(0, 212, 255, 0.3);
}

.accordion__head {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s-3);
  padding: var(--s-5);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--text);
  text-align: left;
}

.accordion__head svg {
  width: 22px;
  height: 22px;
  flex-shrink: 0;
  color: var(--accent-cyan);
  transition: transform var(--t-med) var(--ease-out);
}

.accordion__item.open .accordion__head svg {
  transform: rotate(45deg);
}

.accordion__body {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows var(--t-med) var(--ease-out);
}

.accordion__item.open .accordion__body {
  grid-template-rows: 1fr;
}

.accordion__body > div {
  overflow: hidden;
}

.accordion__body p,
.accordion__body ul {
  padding: 0 var(--s-5) var(--s-5);
  color: var(--text-soft);
}

.accordion__body ul li {
  display: flex;
  gap: var(--s-2);
  padding: var(--s-1) 0;
}

.accordion__body ul li::before {
  content: '→';
  color: var(--accent-cyan);
}

/* ============ MARQUEE ============ */
.marquee {
  position: relative;
  overflow: hidden;
  padding: var(--s-5) 0;
  mask-image: linear-gradient(90deg, transparent, #000 10%, #000 90%, transparent);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 10%, #000 90%, transparent);
}

.marquee__track {
  display: flex;
  gap: var(--s-7);
  width: max-content;
  animation: marqueeScroll 36s linear infinite;
}

.marquee:hover .marquee__track {
  animation-play-state: paused;
}

.marquee__item {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--text-muted);
  white-space: nowrap;
}

.marquee__item::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--gradient-accent);
}

@keyframes marqueeScroll {
  from { transform: translateX(0); }
  to { transform: translateX(-50%); }
}

/* ============ CTA BAND ============ */
.cta-band {
  position: relative;
  padding: var(--s-8);
  border-radius: var(--r-5);
  background: linear-gradient(135deg, rgba(0, 212, 255, 0.12), rgba(168, 85, 247, 0.12));
  border: 1px solid var(--border-strong);
  overflow: hidden;
  text-align: center;
}

.cta-band::before {
  content: '';
  position: absolute;
  inset: -50%;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.18), transparent 60%);
  z-index: 0;
}

.cta-band > * { position: relative; z-index: 1; }

.cta-band h2 { margin-bottom: var(--s-4); }
.cta-band p { max-width: 50ch; margin: 0 auto var(--s-5); }
.cta-band .btn-row { justify-content: center; }

/* ============ TAG ============ */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent-cyan);
  background: rgba(0, 212, 255, 0.08);
  border: 1px solid rgba(0, 212, 255, 0.2);
  border-radius: var(--r-full);
}

/* ============ DIVIDER ============ */
.divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border-strong), transparent);
  margin: var(--s-7) 0;
}

/* ============ SKIP LINK ============ */
.skip-link {
  position: absolute;
  top: -100px;
  left: 0;
  padding: var(--s-3) var(--s-4);
  background: var(--accent-cyan);
  color: var(--bg);
  font-weight: 600;
  z-index: 1000;
}

.skip-link:focus { top: 0; }