/* =========================================================
   ZFT ADVANCEMENTS — Design System & Styles
   Dark-first, professional, minimal
   ========================================================= */

/* --- TOKENS --- */
:root {
  /* Type Scale */
  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.95rem + 0.25vw, 1.125rem);
  --text-lg:   clamp(1.125rem, 1rem    + 0.75vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1.2rem  + 1.25vw, 2.25rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);
  --text-3xl:  clamp(2.5rem,   1rem    + 4vw,    5rem);

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 400ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Content widths */
  --content-default: 1080px;
  --content-narrow: 640px;
  --content-wide: 1280px;

  /* Fonts */
  --font-display: 'Cabinet Grotesk', 'Helvetica Neue', sans-serif;
  --font-body: 'Satoshi', 'Inter', sans-serif;
}

/* --- DARK MODE (default) --- */
:root, [data-theme="dark"] {
  --color-bg:              #0e0e0d;
  --color-surface:         #141413;
  --color-surface-2:       #1a1a18;
  --color-surface-offset:  #1e1e1c;
  --color-surface-dynamic: #252522;
  --color-divider:         #242422;
  --color-border:          #2e2e2b;

  --color-text:            #d4d3d0;
  --color-text-muted:      #787772;
  --color-text-faint:      #4a4947;
  --color-text-inverse:    #0e0e0d;

  /* Accent: cool teal-blue */
  --color-primary:         #4f98a3;
  --color-primary-hover:   #62b0bc;
  --color-primary-active:  #3a7d88;
  --color-primary-glow:    rgba(79, 152, 163, 0.15);

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.4);
  --shadow-lg: 0 16px 40px rgba(0,0,0,0.5);
}

/* --- LIGHT MODE --- */
[data-theme="light"] {
  --color-bg:              #f8f8f6;
  --color-surface:         #ffffff;
  --color-surface-2:       #f3f3f0;
  --color-surface-offset:  #eeeeed;
  --color-surface-dynamic: #e8e8e5;
  --color-divider:         #e2e2de;
  --color-border:          #d8d8d4;

  --color-text:            #1a1a18;
  --color-text-muted:      #6b6b68;
  --color-text-faint:      #a8a8a5;
  --color-text-inverse:    #f8f8f6;

  --color-primary:         #2b7d87;
  --color-primary-hover:   #1f6470;
  --color-primary-active:  #174e57;
  --color-primary-glow:    rgba(43, 125, 135, 0.1);

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg: 0 16px 40px rgba(0,0,0,0.1);
}

/* --- SYSTEM PREFERENCE FALLBACK --- */
@media (prefers-color-scheme: light) {
  :root:not([data-theme]) {
    --color-bg:              #f8f8f6;
    --color-surface:         #ffffff;
    --color-surface-2:       #f3f3f0;
    --color-surface-offset:  #eeeeed;
    --color-surface-dynamic: #e8e8e5;
    --color-divider:         #e2e2de;
    --color-border:          #d8d8d4;
    --color-text:            #1a1a18;
    --color-text-muted:      #6b6b68;
    --color-text-faint:      #a8a8a5;
    --color-text-inverse:    #f8f8f6;
    --color-primary:         #2b7d87;
    --color-primary-hover:   #1f6470;
    --color-primary-active:  #174e57;
    --color-primary-glow:    rgba(43, 125, 135, 0.1);
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
    --shadow-lg: 0 16px 40px rgba(0,0,0,0.1);
  }
}

/* --- BASE RESET --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  -webkit-text-size-adjust: none;
  text-size-adjust: none;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  scroll-padding-top: var(--space-20);
}

body {
  min-height: 100dvh;
  line-height: 1.65;
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  transition: background-color 0.3s ease, color 0.3s ease;
}

img, picture, video, canvas, svg { display: block; max-width: 100%; height: auto; }
ul[role="list"], ol[role="list"] { list-style: none; }
input, button, textarea, select { font: inherit; color: inherit; }
h1, h2, h3, h4, h5, h6 { text-wrap: balance; line-height: 1.15; }
p, li { text-wrap: pretty; }
button { cursor: pointer; background: none; border: none; }

a, button, [role="button"] {
  transition: color var(--transition-interactive),
              background-color var(--transition-interactive),
              border-color var(--transition-interactive),
              opacity var(--transition-interactive),
              box-shadow var(--transition-interactive);
}

::selection {
  background: var(--color-primary-glow);
  color: var(--color-text);
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border-width: 0;
}

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

/* --- LAYOUT --- */
.container {
  width: 100%;
  max-width: var(--content-default);
  margin: 0 auto;
  padding: 0 clamp(var(--space-5), 5vw, var(--space-16));
}

.section {
  padding-block: clamp(var(--space-16), 8vw, var(--space-32));
}

/* --- HEADER & NAV --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in srgb, var(--color-bg) 85%, transparent);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-slow), box-shadow var(--transition-slow);
}

.site-header.scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.nav-inner {
  display: flex;
  align-items: center;
  gap: var(--space-8);
  padding: var(--space-5) clamp(var(--space-5), 5vw, var(--space-16));
  max-width: var(--content-wide);
  margin: 0 auto;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: var(--color-text);
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 700;
  letter-spacing: -0.01em;
  flex-shrink: 0;
}

.nav-logo:hover { color: var(--color-primary); }
.logo-mark { color: var(--color-primary); flex-shrink: 0; }

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-8);
  list-style: none;
  margin-left: auto;
}

.nav-links a {
  text-decoration: none;
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  font-weight: 500;
  letter-spacing: 0.01em;
}

.nav-links a:hover { color: var(--color-text); }

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-left: var(--space-4);
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  background: none;
  border: none;
  cursor: pointer;
}

.theme-toggle:hover {
  color: var(--color-text);
  background: var(--color-surface-2);
}

.nav-mobile-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
}

.nav-mobile-toggle:hover { color: var(--color-text); background: var(--color-surface-2); }

.mobile-menu {
  display: none;
  flex-direction: column;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: var(--space-4) clamp(var(--space-5), 5vw, var(--space-16));
  padding-bottom: var(--space-6);
}

.mobile-menu ul { list-style: none; }
.mobile-menu li + li { border-top: 1px solid var(--color-divider); }

.mobile-link {
  display: block;
  padding: var(--space-4) 0;
  text-decoration: none;
  color: var(--color-text);
  font-size: var(--text-base);
  font-weight: 500;
}

.mobile-link:hover { color: var(--color-primary); }

@media (max-width: 720px) {
  .nav-links { display: none; }
  .nav-mobile-toggle { display: flex; }
  .mobile-menu { display: flex; }
  .mobile-menu:not(.is-open) { display: none; }
}

/* --- BUTTONS --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 600;
  font-family: var(--font-body);
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  letter-spacing: 0.01em;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-bg);
  border-color: var(--color-primary);
}

.btn-primary:hover {
  background: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
  color: var(--color-bg);
  box-shadow: 0 0 24px var(--color-primary-glow);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text-muted);
  border-color: var(--color-border);
}

.btn-ghost:hover {
  color: var(--color-text);
  border-color: var(--color-text-muted);
  background: var(--color-surface-2);
}

/* --- HERO --- */
.hero {
  position: relative;
  min-height: 88vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  padding-block: clamp(var(--space-20), 10vw, var(--space-32));
}

.hero-bg-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--color-border) 1px, transparent 1px),
    linear-gradient(90deg, var(--color-border) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: 0.35;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black 40%, transparent 100%);
}

.hero-glow {
  position: absolute;
  top: -20%;
  left: 50%;
  transform: translateX(-50%);
  width: 700px;
  height: 500px;
  background: radial-gradient(ellipse at center, var(--color-primary-glow) 0%, transparent 70%);
  pointer-events: none;
}

.hero .container { position: relative; z-index: 1; }

.hero-content {
  max-width: 760px;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: var(--space-6);
  padding: var(--space-2) var(--space-4);
  border: 1px solid color-mix(in srgb, var(--color-primary) 30%, transparent);
  border-radius: var(--radius-full);
  background: color-mix(in srgb, var(--color-primary) 8%, transparent);
}

.hero-heading {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1.05;
  color: var(--color-text);
  margin-bottom: var(--space-6);
}

.hero-accent {
  color: var(--color-primary);
  position: relative;
}

.hero-body {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: var(--space-10);
  max-width: 55ch;
  font-weight: 300;
}

.hero-cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  align-items: center;
}

.hero-scroll-indicator {
  position: absolute;
  bottom: var(--space-10);
  left: 50%;
  transform: translateX(-50%);
}

.hero-scroll-indicator span {
  display: block;
  width: 1px;
  height: 48px;
  background: linear-gradient(to bottom, var(--color-primary), transparent);
  margin: 0 auto;
  animation: scroll-line 2s ease-in-out infinite;
}

@keyframes scroll-line {
  0% { opacity: 0; transform: scaleY(0); transform-origin: top; }
  40% { opacity: 1; transform: scaleY(1); transform-origin: top; }
  60% { opacity: 1; transform: scaleY(1); transform-origin: bottom; }
  100% { opacity: 0; transform: scaleY(0); transform-origin: bottom; }
}

/* --- SECTION SHARED --- */
.section-header {
  max-width: 600px;
  margin-bottom: clamp(var(--space-10), 5vw, var(--space-16));
}

.section-label {
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: var(--space-3);
}

.section-title {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 800;
  letter-spacing: -0.025em;
  line-height: 1.1;
  color: var(--color-text);
  margin-bottom: var(--space-4);
}

.section-subtitle {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.7;
  font-weight: 400;
}

/* --- SERVICES --- */
.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
}

@media (max-width: 900px) {
  .services-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 560px) {
  .services-grid { grid-template-columns: 1fr; }
}

.service-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  transition: border-color var(--transition-interactive), box-shadow var(--transition-interactive), transform var(--transition-interactive);
}

.service-card:hover {
  border-color: color-mix(in srgb, var(--color-primary) 40%, var(--color-border));
  box-shadow: 0 8px 32px var(--color-primary-glow);
  transform: translateY(-2px);
}

.service-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: color-mix(in srgb, var(--color-primary) 10%, transparent);
  border: 1px solid color-mix(in srgb, var(--color-primary) 20%, transparent);
  border-radius: var(--radius-md);
  color: var(--color-primary);
  margin-bottom: var(--space-5);
}

.service-title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--color-text);
  margin-bottom: var(--space-3);
}

.service-desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* --- DIVIDER --- */
.section-divider {
  height: 1px;
  background: linear-gradient(to right, transparent, var(--color-border), transparent);
  margin: 0 clamp(var(--space-5), 5vw, var(--space-16));
}

/* --- ABOUT --- */
.about-layout {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: clamp(var(--space-12), 8vw, var(--space-24));
  align-items: start;
}

@media (max-width: 860px) {
  .about-layout { grid-template-columns: 1fr; }
  .about-visual { display: none; }
}

.about-text .section-title {
  margin-bottom: var(--space-6);
}

.about-text p {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.75;
  margin-bottom: var(--space-5);
  max-width: 60ch;
}

.about-meta {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  margin-top: var(--space-8);
  padding-top: var(--space-8);
  border-top: 1px solid var(--color-border);
}

.meta-item {
  display: flex;
  align-items: baseline;
  gap: var(--space-4);
}

.meta-label {
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-faint);
  min-width: 100px;
}

.meta-value {
  font-size: var(--text-sm);
  color: var(--color-text);
  font-weight: 500;
}

/* About visual */
.about-visual {
  position: sticky;
  top: var(--space-20);
}

.about-grid-vis {
  display: grid;
  grid-template-columns: 20px 1fr 20px;
  grid-template-rows: auto auto auto auto;
  gap: var(--space-6);
  align-items: center;
  padding: var(--space-10);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
}

.grid-node {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--color-surface-dynamic);
  border: 1px solid var(--color-border);
}

.grid-node.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  box-shadow: 0 0 12px var(--color-primary-glow);
  animation: pulse-node 3s ease-in-out infinite;
}

.grid-node.active-2 {
  background: color-mix(in srgb, var(--color-primary) 60%, transparent);
  border-color: var(--color-primary);
  box-shadow: 0 0 8px var(--color-primary-glow);
  animation: pulse-node 3s ease-in-out infinite 1.5s;
}

.grid-node.small {
  width: 12px;
  height: 12px;
  background: var(--color-surface-dynamic);
}

@keyframes pulse-node {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.7; transform: scale(1.1); }
}

.grid-line {
  height: 2px;
  background: linear-gradient(to right, var(--color-primary), color-mix(in srgb, var(--color-primary) 30%, transparent));
  border-radius: 1px;
  grid-column: 1 / -1;
}

.grid-line.v {
  width: 2px;
  height: 40px;
  background: linear-gradient(to bottom, var(--color-border), transparent);
  border-radius: 1px;
  grid-column: 2;
}

.grid-line.h { grid-column: 2; }
.grid-line.h2 {
  height: 1px;
  background: var(--color-border);
  grid-column: 2;
}

.grid-spacer { grid-column: 2; height: var(--space-4); }

/* --- CONTACT --- */
.contact-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(var(--space-12), 8vw, var(--space-24));
  align-items: start;
}

@media (max-width: 740px) {
  .contact-layout { grid-template-columns: 1fr; }
}

.contact-text .section-title { margin-bottom: var(--space-5); }

.contact-text p {
  color: var(--color-text-muted);
  line-height: 1.75;
  margin-bottom: var(--space-8);
  max-width: 50ch;
}

.contact-email {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-primary);
  font-weight: 600;
  font-size: var(--text-base);
  text-decoration: none;
  border-bottom: 1px solid color-mix(in srgb, var(--color-primary) 30%, transparent);
  padding-bottom: 2px;
}

.contact-email:hover {
  color: var(--color-primary-hover);
  border-bottom-color: var(--color-primary-hover);
}

.contact-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  overflow: hidden;
}

.contact-card-inner {
  padding: var(--space-8);
}

.contact-card-row {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-5) 0;
  border-bottom: 1px solid var(--color-divider);
}

.contact-card-row:last-child { border-bottom: none; }

.card-label {
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-faint);
}

.card-value {
  font-size: var(--text-sm);
  color: var(--color-text);
  font-weight: 500;
}

/* --- FOOTER --- */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding-block: clamp(var(--space-12), 5vw, var(--space-20));
  margin-top: auto;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-10);
  margin-bottom: var(--space-10);
  flex-wrap: wrap;
}

.footer-brand { max-width: 280px; }

.footer-logo {
  margin-bottom: var(--space-3);
  font-size: var(--text-sm);
}

.footer-tagline {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  line-height: 1.5;
}

.footer-nav {
  display: flex;
  gap: var(--space-12);
}

.footer-nav ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer-nav a {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
}

.footer-nav a:hover { color: var(--color-text); }

.footer-bottom {
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-divider);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.footer-bottom p {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

.footer-legal { max-width: none; }

@media (max-width: 600px) {
  .footer-inner { flex-direction: column; }
  .footer-nav { flex-direction: column; gap: var(--space-6); }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
}

/* --- FADE-UP ANIMATION --- */
.fade-up {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger service cards */
.service-card:nth-child(1) { transition-delay: 0ms; }
.service-card:nth-child(2) { transition-delay: 60ms; }
.service-card:nth-child(3) { transition-delay: 120ms; }
.service-card:nth-child(4) { transition-delay: 180ms; }
.service-card:nth-child(5) { transition-delay: 240ms; }
.service-card:nth-child(6) { transition-delay: 300ms; }