/* Alta Lake Advisors — design system & layout
   Mountain/lake theme, premium B2B, 768px mobile breakpoint */

:root {
  /* Palette */
  --lake-deep: #1e3a5f;
  --lake-mid: #2d5a87;
  --lake-light: #4a7ba7;
  --slate: #1a2f47;
  --charcoal: #2c3e50;
  --mist: #6b7c8a;
  --mist-light: #9ca8b4;
  --off-white: #f8f9fa;
  --white: #ffffff;
  --brand-white: #ffffff;
  --gold: #c9a227;
  --gold-dim: #a68520;

  /* Typography */
  --font-system: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-editorial: Georgia, "Times New Roman", serif;
  --text-primary: var(--slate);
  --text-secondary: var(--mist);
  --text-muted: var(--mist-light);

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --section-pad: clamp(2rem, 5vw, 4rem);
  --content-max: 72rem;

  /* UI */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --shadow-sm: 0 2px 8px rgba(30, 58, 95, 0.08);
  --shadow-md: 0 4px 20px rgba(30, 58, 95, 0.12);
  --shadow-lg: 0 8px 40px rgba(30, 58, 95, 0.15);
  --border: 1px solid rgba(30, 58, 95, 0.12);
  --header-height: 72px;

  /* Transitions */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --duration: 0.25s;
}

@media (prefers-reduced-motion: reduce) {
  :root {
    --duration: 0.01ms;
  }
  .site-header {
    transition: none;
  }
}

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

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  margin: 0;
  padding-top: var(--header-height);
  font-family: var(--font-system);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--off-white);
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--lake-mid);
  text-decoration: none;
  transition: color var(--duration) var(--ease);
}
a:hover {
  color: var(--lake-deep);
}
a:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 2px;
}

h1, h2, h3, h4 {
  font-family: var(--font-editorial);
  font-weight: 600;
  line-height: 1.2;
  color: var(--slate);
}
h1 { font-size: clamp(2rem, 4vw, 3rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.25rem); margin-top: 0; }
h3 { font-size: clamp(1.2rem, 2vw, 1.5rem); }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-family: var(--font-system);
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--duration) var(--ease), transform var(--duration) var(--ease), box-shadow var(--duration) var(--ease);
}
.btn:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 2px;
}
.btn-primary {
  background: var(--lake-deep);
  color: var(--white);
}
.btn-primary:hover {
  background: var(--slate);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}
.btn-secondary {
  background: transparent;
  color: var(--lake-deep);
  border: 2px solid var(--lake-deep);
}
.btn-secondary:hover {
  background: rgba(30, 58, 95, 0.06);
}

/* Header — fixed, hide on scroll down, show on scroll up */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-height);
  padding: 0 var(--section-pad);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--brand-white);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: var(--border);
  transform: translateY(0);
  transition: transform 220ms var(--ease), background 220ms var(--ease), box-shadow 220ms var(--ease);
  will-change: transform;
}
.site-header.scrolled {
  box-shadow: var(--shadow-sm);
}
.site-header.is-hidden {
  transform: translateY(-100%);
}
/* Never hide while user is focusing inside header (keyboard nav) */
.site-header:focus-within {
  transform: translateY(0) !important;
}
.site-header .logo {
  height: 40px;
  width: auto;
  object-fit: contain;
}
.site-header .logo:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 4px;
}
.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}
.site-nav a {
  font-weight: 500;
  color: var(--charcoal);
}
.site-nav a:hover {
  color: var(--lake-deep);
}
.site-nav .btn {
  flex-shrink: 0;
}
.site-nav .btn-primary {
  color: var(--white);
}
.site-nav .btn-primary:hover {
  color: var(--white);
}

/* Mobile nav */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0;
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  aria-label: "Open menu";
}
.nav-toggle:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 2px;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--slate);
  border-radius: 1px;
  transition: transform var(--duration) var(--ease), opacity var(--duration) var(--ease);
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}
.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

@media (max-width: 767px) {
  .site-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    flex-direction: column;
    justify-content: flex-start;
    padding: var(--space-xl);
    padding-top: var(--space-2xl);
    background: var(--brand-white);
    backdrop-filter: blur(12px);
    border-top: var(--border);
    gap: var(--space-md);
    visibility: hidden;
    opacity: 0;
    transform: translateY(-10px);
    transition: visibility var(--duration) var(--ease), opacity var(--duration) var(--ease), transform var(--duration) var(--ease);
    overflow: auto;
  }
  .site-nav.is-open {
    visibility: visible;
    opacity: 1;
    transform: translateY(0);
  }
  .site-nav a {
    font-size: 1.1rem;
  }
  .nav-toggle {
    display: flex;
  }
}

/* Hero */
.hero {
  position: relative;
  min-height: 90vh;
  min-height: 90dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  padding: var(--section-pad);
  padding-top: clamp(3rem, 8vh, 6rem);
  padding-bottom: 0;
  background: linear-gradient(180deg, rgba(30, 58, 95, 0.75) 0%, rgba(30, 58, 95, 0.5) 40%, rgba(26, 47, 71, 0.85) 100%);
  background-size: cover;
  background-position: center;
  color: var(--white);
  text-align: center;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(0,0,0,0.35) 0%, transparent 50%, rgba(0,0,0,0.4) 100%);
  pointer-events: none;
}
.hero .hero-bg {
  position: absolute;
  inset: 0;
  object-fit: cover;
  width: 100%;
  height: 100%;
  z-index: -1;
  transform-origin: 50% 0%;
  transition: transform 0.1s ease-out;
}
.hero .hero-fade {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 0;
  background: linear-gradient(to top, var(--brand-white) 0%, rgba(255, 255, 255, 0.6) 40%, transparent 100%);
  pointer-events: none;
  z-index: 0;
}
.hero .hero-to-white {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 48px;
  background: linear-gradient(to top, var(--brand-white) 0%, rgba(255, 255, 255, 0.35) 55%, transparent 100%);
  pointer-events: none;
  z-index: 0;
}
.hero .hero-inner {
  position: relative;
  z-index: 1;
  max-width: 42rem;
}
.hero h1 {
  color: var(--white);
  margin-bottom: var(--space-lg);
}
.hero .subcopy {
  font-size: 1.1rem;
  line-height: 1.65;
  opacity: 0.95;
  margin-bottom: var(--space-2xl);
}
.hero .cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  justify-content: center;
}
.hero .btn-primary {
  background: var(--white);
  color: var(--lake-deep);
}
.hero .btn-primary:hover {
  background: var(--off-white);
  color: var(--slate);
}
.hero .btn-secondary {
  border-color: var(--white);
  color: var(--white);
}
.hero .btn-secondary:hover {
  background: rgba(255,255,255,0.15);
}

/* Inner page intro (no hero image — Services, Why HK, About, Contact) */
.page-intro {
  padding: var(--space-3xl) var(--section-pad);
  background: var(--white);
  border-bottom: var(--border);
}
.page-intro .page-intro-inner {
  max-width: var(--content-max);
  margin: 0 auto;
}
.page-intro h1 {
  margin-bottom: var(--space-md);
  color: var(--slate);
}
.page-intro .subcopy {
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1.6;
  max-width: 40rem;
  margin-bottom: var(--space-xl);
}
.page-intro .btn {
  margin-top: var(--space-sm);
}

/* Section blocks */
.section {
  padding: var(--section-pad) var(--section-pad);
}
.section-inner {
  max-width: var(--content-max);
  margin: 0 auto;
}
.section-title {
  text-align: center;
  margin-bottom: var(--space-2xl);
}
.section-title p {
  color: var(--text-secondary);
  max-width: 36rem;
  margin-left: auto;
  margin-right: auto;
  margin-top: var(--space-sm);
}

/* Trust bar (when inside hero: no white block, lake extends behind) */
.trust-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
  padding: var(--space-xl) var(--section-pad);
  padding-bottom: var(--space-2xl);
  background: transparent;
  border-bottom: none;
  position: relative;
  z-index: 1;
}
.trust-chip {
  text-align: center;
  padding: var(--space-md);
}
.trust-chip .icon {
  width: 48px;
  height: 48px;
  margin: 0 auto var(--space-sm);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
}
.trust-chip strong {
  display: block;
  font-size: 0.95rem;
  color: var(--white);
}
.trust-chip span {
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.92);
}

@media (max-width: 767px) {
  .trust-bar {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-md);
  }
}

/* Tiles grid */
.tiles {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-lg);
}
.tile {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  border: var(--border);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--duration) var(--ease), transform var(--duration) var(--ease);
}
.tile:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.tile h3 {
  margin-bottom: var(--space-sm);
}
.tile p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: var(--space-md);
}
.tile a:not(.btn) {
  font-weight: 600;
  font-size: 0.9rem;
}

/* Process steps */
.process {
  counter-reset: step;
}
.process-step {
  display: flex;
  gap: var(--space-xl);
  align-items: flex-start;
  padding: var(--space-lg) 0;
  border-bottom: var(--border);
}
.process-step:last-child {
  border-bottom: none;
}
.process-step::before {
  counter-increment: step;
  content: counter(step);
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--lake-deep);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.2rem;
}
.process-step h3 {
  margin-bottom: var(--space-xs);
}
.process-step p {
  color: var(--text-secondary);
  margin: 0;
}

@media (max-width: 767px) {
  .process-step {
    flex-direction: column;
    gap: var(--space-md);
  }
}

/* Cards */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-lg);
}
.card {
  background: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: var(--border);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--duration) var(--ease);
}
.card:hover {
  box-shadow: var(--shadow-md);
}
.card-image {
  aspect-ratio: 16/10;
  background: linear-gradient(135deg, var(--lake-mid) 0%, var(--lake-deep) 100%);
  object-fit: cover;
}
.card-body {
  padding: var(--space-xl);
}
.card h3 {
  margin-bottom: var(--space-sm);
}
.card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: var(--space-md);
}

/* FAQ */
.faq-list {
  max-width: 48rem;
  margin: 0 auto;
}
.faq-item {
  border-bottom: var(--border);
}
.faq-item summary {
  padding: var(--space-lg) 0;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-md);
}
.faq-item summary::-webkit-details-marker {
  display: none;
}
.faq-item summary::after {
  content: "+";
  font-size: 1.5rem;
  color: var(--mist);
  flex-shrink: 0;
  transition: transform var(--duration) var(--ease);
}
.faq-item[open] summary::after {
  transform: rotate(45deg);
}
.faq-item summary:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 2px;
}
.faq-item .faq-answer {
  padding-bottom: var(--space-lg);
  color: var(--text-secondary);
  padding-left: 0;
}

/* CTA band */
.cta-band {
  background: var(--lake-deep);
  color: var(--white);
  padding: var(--space-3xl) var(--section-pad);
  text-align: center;
}
.cta-band h2 {
  color: var(--white);
  margin-bottom: var(--space-md);
}
.cta-band p {
  opacity: 0.9;
  margin-bottom: var(--space-xl);
}
.cta-band .btn-primary {
  background: var(--white);
  color: var(--lake-deep);
}
.cta-band .btn-primary:hover {
  background: var(--off-white);
  color: var(--slate);
}

/* Footer */
.site-footer {
  background: var(--slate);
  color: var(--mist-light);
  padding: var(--space-3xl) var(--section-pad) var(--space-xl);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr 1fr auto;
  gap: var(--space-2xl);
  max-width: var(--content-max);
  margin: 0 auto var(--space-2xl);
  padding-bottom: var(--space-xl);
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.footer-grid h4 {
  color: var(--white);
  font-size: 0.9rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-md);
}
.footer-grid ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.footer-grid li {
  margin-bottom: var(--space-sm);
}
.footer-grid a {
  color: var(--mist-light);
}
.footer-grid a:hover {
  color: var(--white);
}
.footer-bottom {
  max-width: var(--content-max);
  margin: 0 auto;
  font-size: 0.85rem;
  text-align: center;
  color: var(--mist);
}
.footer-bottom .disclaimer {
  margin-top: var(--space-md);
  max-width: 56rem;
  margin-left: auto;
  margin-right: auto;
  margin-top: var(--space-md);
}

@media (max-width: 767px) {
  .footer-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
}

/* Full-bleed section with image */
.full-bleed {
  position: relative;
  min-height: 50vh;
  display: flex;
  align-items: center;
  padding: var(--section-pad);
  background: linear-gradient(180deg, rgba(30, 58, 95, 0.7) 0%, rgba(30, 58, 95, 0.85) 100%);
  background-size: cover;
  background-position: center;
  color: var(--white);
}
.full-bleed .bleed-bg {
  position: absolute;
  inset: 0;
  object-fit: cover;
  width: 100%;
  height: 100%;
  z-index: -1;
}
.full-bleed h1 {
  color: var(--white);
  margin-bottom: var(--space-md);
}
.full-bleed p {
  opacity: 0.95;
  max-width: 36rem;
}

/* Two-column content */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: start;
}
@media (max-width: 767px) {
  .two-col {
    grid-template-columns: 1fr;
  }
}

/* Form */
.form-group {
  margin-bottom: var(--space-lg);
}
.form-group label {
  display: block;
  font-weight: 600;
  margin-bottom: var(--space-xs);
  color: var(--slate);
}
.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  font-family: inherit;
  font-size: 1rem;
  border: var(--border);
  border-radius: var(--radius-sm);
  background: var(--white);
  transition: border-color var(--duration) var(--ease), box-shadow var(--duration) var(--ease);
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--lake-mid);
  box-shadow: 0 0 0 3px rgba(45, 90, 135, 0.2);
}
.form-group input.error,
.form-group select.error,
.form-group textarea.error {
  border-color: #c53030;
}
.form-group .error-msg {
  font-size: 0.85rem;
  color: #c53030;
  margin-top: var(--space-xs);
}
.form-group textarea {
  min-height: 120px;
  resize: vertical;
}
.form-success {
  display: none;
  padding: var(--space-xl);
  background: rgba(30, 58, 95, 0.08);
  border-radius: var(--radius-md);
  border: 1px solid var(--lake-light);
  color: var(--slate);
  text-align: center;
}
.form-success.visible {
  display: block;
}

/* Reveal animation (respects reduced motion in script) */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}
.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* What happens next */
.steps-inline {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
  counter-reset: step;
}
.step-box {
  text-align: center;
  padding: var(--space-xl);
}
.step-box::before {
  counter-increment: step;
  content: counter(step);
  display: block;
  width: 40px;
  height: 40px;
  margin: 0 auto var(--space-md);
  border-radius: 50%;
  background: var(--lake-deep);
  color: var(--white);
  line-height: 40px;
  font-weight: 700;
}
.step-box h3 {
  margin-bottom: var(--space-sm);
}
.step-box p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin: 0;
}
@media (max-width: 767px) {
  .steps-inline {
    grid-template-columns: 1fr;
  }
}

/* Package cards */
.package-card {
  background: var(--white);
  border: 2px solid rgba(30, 58, 95, 0.15);
  border-radius: var(--radius-lg);
  padding: var(--space-2xl);
  transition: border-color var(--duration) var(--ease), box-shadow var(--duration) var(--ease);
}
.package-card:hover {
  border-color: var(--lake-mid);
  box-shadow: var(--shadow-md);
}
.package-card h3 {
  margin-bottom: var(--space-sm);
}
.package-card .meta {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: var(--space-md);
}
.package-card ul {
  margin: 0 0 var(--space-lg);
  padding-left: 1.25rem;
  color: var(--text-secondary);
}
.package-card .note {
  font-size: 0.85rem;
  color: var(--mist);
  margin-top: var(--space-md);
}