/* ============================================================
   fretmarks — styles.css
   Mobile-first, dark editorial aesthetic
   ============================================================ */

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

/* ============================================================
   CUSTOM PROPERTIES
   ============================================================ */
:root {
  /* Colors */
  --color-bg:           #0f1011;
  --color-surface:      #161819;
  --color-surface-2:    #1c1f21;
  --color-border:       #252829;
  --color-border-faint: #1a1d1f;
  --color-text:         #e2e2e2;
  --color-text-muted:   #737880;
  --color-text-dim:     #3c4048;
  --color-accent: #c6861a;
  --color-accent-dim:   rgba(224, 154, 42, 0.1);
  --color-accent-glow:  rgba(224, 154, 42, 0.22);
  --color-accent-light: #f0ab3a;

  /* Typography */
  --font-display: 'Outfit', sans-serif;
  --font-mono:    'JetBrains Mono', monospace;
  --font-body:    'Plus Jakarta Sans', sans-serif;

  /* Spacing scale */
  --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;

  /* Layout */
  --max-width:  1100px;
  --radius:     6px;
  --radius-lg:  12px;
  --radius-xl:  20px;

  /* Transitions */
  --t:      180ms ease;
  --t-slow: 420ms ease;
}

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

/* ============================================================
   BASE
   ============================================================ */
body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  line-height: 1.1;
  letter-spacing: -0.025em;
  color: var(--color-text);
}

p {
  max-width: 65ch;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--t);
}

strong {
  font-weight: 600;
  color: var(--color-text);
}

/* ============================================================
   LAYOUT
   ============================================================ */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

/* ============================================================
   EYEBROW / SECTION LABEL
   ============================================================ */
.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--color-accent);
  margin-bottom: var(--space-4);
  max-width: none;
}

.section-header {
  margin-bottom: var(--space-12);
}

.section-title {
  font-size: clamp(1.875rem, 4.5vw, 2.75rem);
  font-weight: 700;
}

/* ============================================================
   BUTTONS
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.9375rem;
  cursor: pointer;
  transition: background-color var(--t), border-color var(--t), color var(--t), transform var(--t), box-shadow var(--t);
  white-space: nowrap;
  border: 1.5px solid transparent;
  line-height: 1;
}

.btn--primary {
  background-color: var(--color-accent);
  color: #0e0c08;
  border-color: var(--color-accent);
}

.btn--primary:hover {
  background-color: var(--color-accent-light);
  border-color: var(--color-accent-light);
  transform: translateY(-1px);
  box-shadow: 0 4px 24px var(--color-accent-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);
}

.btn--large {
  padding: 1rem 2.25rem;
  font-size: 1rem;
}

/* ============================================================
   SITE HEADER / NAV
   ============================================================ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(15, 16, 17, 0.82);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--color-border-faint);
  transition: border-color var(--t);
}

.site-header.is-scrolled {
  border-bottom-color: var(--color-border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.nav__logo {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.0625rem;
  color: var(--color-text);
  letter-spacing: -0.02em;
  transition: color var(--t);
}

.nav__logo:hover {
  color: var(--color-accent);
}

.nav__menu {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  list-style: none;
}

.nav__link {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius);
  transition: color var(--t);
}

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

/* CTA variant in nav */
.nav__link--cta {
  background-color: var(--color-accent);
  color: #0e0c08;
  font-weight: 600;
  padding: 0.45rem 1rem;
  border-radius: var(--radius);
  font-size: 0.875rem;
  transition: background-color var(--t), color var(--t), transform var(--t);
}

.nav__link--cta:hover {
  background-color: var(--color-accent-light);
  color: #0e0c08;
  transform: translateY(-1px);
}

/* Hamburger */
.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-2);
  z-index: 101;
}

.nav__toggle-bar {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 2px;
  transition: all var(--t);
}

/* Open state bars */
.nav__toggle[aria-expanded="true"] .nav__toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav__toggle[aria-expanded="true"] .nav__toggle-bar:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.nav__toggle[aria-expanded="true"] .nav__toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  padding-top: calc(64px + var(--space-16));
  padding-bottom: var(--space-24);
  overflow: hidden;
}

/* Subtle ambient glow behind hero */
.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: -10%;
  right: 0;
  height: 70%;
  background: radial-gradient(ellipse at 35% 40%, rgba(224, 154, 42, 0.055) 0%, transparent 68%);
  pointer-events: none;
}

.hero .container {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-12);
  align-items: center;
}

.hero__headline {
  font-size: clamp(3.25rem, 9vw, 5.75rem);
  font-weight: 800;
  margin-bottom: var(--space-6);
  line-height: 1.0;
}

.hero__subhead {
  font-size: clamp(1.0625rem, 2vw, 1.25rem);
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: var(--space-5);
  max-width: 46ch;
  line-height: 1.5;
}

.hero__copy {
  font-size: 1rem;
  color: var(--color-text-muted);
  margin-bottom: var(--space-8);
  max-width: 50ch;
  line-height: 1.75;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  align-items: center;
}

/* ============================================================
   CHART FRAME (hero visualization)
   ============================================================ */
.chart-frame {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  position: relative;
}

/* subtle inner glow on chart */
.chart-frame::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  background: radial-gradient(ellipse at 80% 20%, rgba(224, 154, 42, 0.06) 0%, transparent 60%);
  pointer-events: none;
}

.chart-frame__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-4);
}

.chart-frame__label {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-muted);
}

.chart-frame__badge {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 700;
  color: var(--color-accent);
  background: var(--color-accent-dim);
  padding: 2px 8px;
  border-radius: 3px;
  letter-spacing: 0.05em;
}

.bpm-chart {
  width: 100%;
  height: auto;
  display: block;
}

/* SVG text styles (applied via class, referenced in SVG) */
.chart-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 9px;
  fill: #5a6070;
}

.chart-label--accent {
  fill: #e09a2a;
  font-weight: 700;
}

.chart-frame__footer {
  display: flex;
  gap: var(--space-6);
  margin-top: var(--space-4);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border-faint);
}

.chart-frame__stat {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--color-text-muted);
}

.chart-frame__stat-value {
  color: var(--color-text);
  font-weight: 700;
}

/* ============================================================
   PROBLEM SECTION
   ============================================================ */
.problem {
  padding: var(--space-24) 0;
  border-top: 1px solid var(--color-border-faint);
}

.problem__inner {
  max-width: 780px;
}

.problem__heading {
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 800;
  margin-bottom: var(--space-8);
  line-height: 1.08;
}

.problem__copy {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.problem__copy p {
  font-size: clamp(1rem, 1.5vw, 1.0625rem);
  color: var(--color-text-muted);
  line-height: 1.8;
  max-width: 62ch;
}

/* ============================================================
   FEATURES / HOW IT WORKS
   ============================================================ */
.features {
  padding: var(--space-24) 0;
  border-top: 1px solid var(--color-border-faint);
}

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

.feature-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  transition: border-color var(--t), background-color var(--t);
}

.feature-card:hover {
  border-color: rgba(224, 154, 42, 0.45);
  background-color: var(--color-surface-2);
}

.feature-card__icon {
  width: 44px;
  height: 44px;
  background: var(--color-accent-dim);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-accent);
  margin-bottom: var(--space-5);
  flex-shrink: 0;
}

.feature-card__title {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-3);
  line-height: 1.25;
  letter-spacing: -0.02em;
}

.feature-card__body {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  line-height: 1.75;
  max-width: 42ch;
}

/* ============================================================
   CREDIBILITY
   ============================================================ */
.credibility {
  padding: var(--space-24) 0;
  border-top: 1px solid var(--color-border-faint);
}

.credibility__inner {
  max-width: 600px;
}

.credibility__quote {
  margin: var(--space-6) 0 var(--space-4);
  padding-left: var(--space-6);
  border-left: 3px solid var(--color-accent);
}

.credibility__quote p {
  font-size: clamp(1.125rem, 2vw, 1.375rem);
  font-style: italic;
  color: var(--color-text);
  line-height: 1.6;
  max-width: 48ch;
}

.credibility__byline {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  max-width: none;
}

/* ============================================================
   TECHNIQUE CATEGORIES
   ============================================================ */
.techniques {
  padding: var(--space-24) 0;
  border-top: 1px solid var(--color-border-faint);
}

.techniques__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3);
}

.technique-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  display: flex;
  align-items: center;
  gap: var(--space-4);
  transition: border-color var(--t), background-color var(--t);
}

.technique-card:hover {
  border-color: rgba(224, 154, 42, 0.45);
  background-color: var(--color-surface-2);
}

.technique-card__icon {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  background: var(--color-accent-dim);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-accent);
}

.technique-card__name {
  font-family: var(--font-body);
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.015em;
  line-height: 1.2;
}

/* ============================================================
   BOTTOM CTA
   ============================================================ */
.cta-bottom {
  position: relative;
  padding: var(--space-24) 0;
  border-top: 1px solid var(--color-border-faint);
  overflow: hidden;
}

/* Ambient glow centered */
.cta-bottom::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 50% 60%, rgba(224, 154, 42, 0.06) 0%, transparent 65%);
  pointer-events: none;
}

.cta-bottom__inner {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 580px;
  margin: 0 auto;
}

.cta-bottom__heading {
  font-size: clamp(2.5rem, 7vw, 4.25rem);
  font-weight: 800;
  margin-bottom: var(--space-8);
  line-height: 1.04;
}

.cta-bottom__sub {
  margin-top: var(--space-5);
  font-size: 0.875rem;
  color: var(--color-text-muted);
  line-height: 1.65;
  max-width: 44ch;
  margin-left: auto;
  margin-right: auto;
}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  padding: var(--space-12) 0;
  border-top: 1px solid var(--color-border);
}

.footer__inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
  margin-bottom: var(--space-8);
}

.footer__logo {
  font-family: var(--font-mono);
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.02em;
  display: inline-block;
  margin-bottom: var(--space-2);
  transition: color var(--t);
}

.footer__logo:hover {
  color: var(--color-accent);
}

.footer__tagline {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  max-width: none;
}

.footer__nav ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4) var(--space-6);
}

.footer__nav a {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  transition: color var(--t);
}

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

.footer__social {
  display: flex;
  gap: var(--space-2);
}

.social-link {
  width: 36px;
  height: 36px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  transition: color var(--t), border-color var(--t), background-color var(--t);
}

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

.footer__bottom {
  border-top: 1px solid var(--color-border-faint);
  padding-top: var(--space-6);
}

.footer__bottom p {
  font-size: 0.8125rem;
  color: var(--color-text-dim);
  max-width: none;
}

/* ============================================================
   SCROLL ANIMATIONS
   ============================================================ */
.fade-up {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}

.fade-up.is-visible {
  opacity: 1;
  transform: none;
}

/* Stagger delays for grid children */
.feature-card:nth-child(2).fade-up  { transition-delay: 0.1s; }
.feature-card:nth-child(3).fade-up  { transition-delay: 0.2s; }

.technique-card:nth-child(2).fade-up { transition-delay: 0.05s; }
.technique-card:nth-child(3).fade-up { transition-delay: 0.1s; }
.technique-card:nth-child(4).fade-up { transition-delay: 0.15s; }
.technique-card:nth-child(5).fade-up { transition-delay: 0.2s; }
.technique-card:nth-child(6).fade-up { transition-delay: 0.25s; }

/* ============================================================
   RESPONSIVE — TABLET (600px+)
   ============================================================ */
@media (min-width: 600px) {
  .techniques__grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ============================================================
   RESPONSIVE — DESKTOP (900px+)
   ============================================================ */
@media (min-width: 900px) {
  .hero .container {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-16);
  }

  .features__grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .footer__inner {
    flex-direction: row;
    justify-content: space-between;
    align-items: flex-start;
  }
}

/* ============================================================
   RESPONSIVE — MOBILE NAV (below 640px)
   ============================================================ */
@media (max-width: 639px) {
  .nav__toggle {
    display: flex;
  }

  .nav__menu {
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--space-3) 0;
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: transform var(--t), opacity var(--t), visibility var(--t);
    z-index: 99;
  }

  .nav__menu.is-open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav__menu li {
    width: 100%;
  }

  .nav__link {
    display: block;
    padding: var(--space-4) var(--space-6);
    border-radius: 0;
    font-size: 1rem;
    border-bottom: 1px solid var(--color-border-faint);
    color: var(--color-text-muted);
  }

  .nav__link--cta {
    margin: var(--space-3) var(--space-6);
    display: flex;
    justify-content: center;
    padding: 0.75rem;
    border-radius: var(--radius);
    border-bottom: none;
    background-color: var(--color-accent);
    color: #0e0c08;
  }

  .hero__actions {
    flex-direction: column;
    align-items: flex-start;
  }

  .hero__actions .btn {
    width: 100%;
    justify-content: center;
  }
}

/* ============================================================
   COOKIE CONSENT BANNER
   ============================================================ */
.cookie-banner {
  position: fixed;
  bottom: var(--space-6);
  left: 50%;
  transform: translateX(-50%);
  width: calc(100% - var(--space-8));
  max-width: 680px;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.5);
  z-index: 9999;
  animation: cookie-slide-up 0.3s ease;
}

.cookie-banner[hidden] {
  display: none;
}

@keyframes cookie-slide-up {
  from { opacity: 0; transform: translateX(-50%) translateY(12px); }
  to   { opacity: 1; transform: translateX(-50%) translateY(0); }
}

.cookie-banner__inner {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  padding: var(--space-5) var(--space-6);
}

.cookie-banner__text {
  flex: 1;
  min-width: 0;
}

.cookie-banner__title {
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-1);
}

.cookie-banner__desc {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  line-height: 1.5;
}

.cookie-banner__link {
  color: var(--color-accent-light);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.cookie-banner__actions {
  display: flex;
  gap: var(--space-3);
  flex-shrink: 0;
}

.cookie-banner__btn {
  font-size: 0.8rem;
  padding: 0.45rem 1rem;
  border-radius: var(--radius);
  font-family: var(--font-display);
  font-weight: 700;
  cursor: pointer;
  border: 1px solid transparent;
  white-space: nowrap;
}

.cookie-banner__btn--reject {
  background: transparent;
  border-color: var(--color-border);
  color: var(--color-text-muted);
}

.cookie-banner__btn--reject:hover {
  border-color: var(--color-text-muted);
  color: var(--color-text);
}

.cookie-banner__btn--accept {
  background: var(--color-accent);
  color: #0e0c08;
  border-color: var(--color-accent);
}

.cookie-banner__btn--accept:hover {
  background: var(--color-accent-light);
  border-color: var(--color-accent-light);
}

@media (max-width: 540px) {
  .cookie-banner__inner {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-4);
    padding: var(--space-5);
  }

  .cookie-banner__actions {
    width: 100%;
  }

  .cookie-banner__btn {
    flex: 1;
    text-align: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  .cookie-banner {
    animation: none;
  }
}