/* =============================================================
   TECRA — Landing page
   Structure:
   1. Design tokens (custom properties)
   2. Base / reset
   3. Layout primitives (.container)
   4. Components (buttons, logo, forms)
   5. Sections (header, hero, about, expertise, contact, footer)
   6. Responsive breakpoints
   ============================================================= */

/* ---------- 1. Design tokens ---------- */
:root {
  /* Brand colors */
  --c-primary: #2647c9;        /* buttons, links, active accents      */
  --c-primary-dark: #1a3299;   /* hover / pressed state               */
  --c-accent: #3a5bc7;         /* helix, highlighted words, eyebrows  */
  --c-navy: #182a55;           /* serif display headings              */
  --c-ink: #2b3556;            /* strong body text                    */
  --c-text: #5b6680;           /* default body text                   */
  --c-muted: #97a0b5;          /* placeholders, captions, numbers     */

  /* Surfaces */
  --c-bg: #ffffff;
  --c-bg-alt: #edf0f6;         /* light grey section background       */
  --c-bg-panel: #eef1f7;
  --c-border: #dde3ef;
  --c-field-border: #d4dbe8;

  /* Typography */
  --ff-serif: "Lora", Georgia, "Times New Roman", serif;
  --ff-sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;

  /* Spacing scale */
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Radii & shadows */
  --radius: 10px;
  --radius-lg: 16px;
  --shadow-card: 0 1px 2px rgba(24, 42, 85, 0.04),
                 0 8px 24px rgba(24, 42, 85, 0.06);
  --shadow-form: 0 20px 60px rgba(24, 42, 85, 0.12);

  /* Layout */
  --container: 1200px;
  --transition: 180ms ease;
}

/* ---------- 2. Base / reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--ff-sans);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img,
svg { display: block; max-width: 100%; }

a { color: inherit; text-decoration: none; }

h1, h2, h3, h4 {
  margin: 0;
  font-family: var(--ff-serif);
  color: var(--c-navy);
  line-height: 1.18;
  font-weight: 600;
}

p { margin: 0; }

ul, ol { margin: 0; padding: 0; list-style: none; }

:focus-visible {
  outline: 2px solid var(--c-primary);
  outline-offset: 3px;
  border-radius: 4px;
}

.text-accent { color: var(--c-accent); }

/* ---------- 3. Layout primitives ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-6);
}

.eyebrow {
  font-family: var(--ff-sans);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--c-accent);
  margin-bottom: var(--space-3);
}

/* ---------- 4. Components ---------- */

/* Logo */
.logo {
  display: inline-flex;
  align-items: flex-start;
  color: var(--c-primary);
}
.logo__word {
  font-family: var(--ff-sans);
  font-weight: 500;
  font-size: 1.7rem;
  letter-spacing: 0.06em;
}
.logo__mark { font-size: 0.7rem; line-height: 1; margin-top: 2px; }
.logo--footer .logo__word { font-size: 1.5rem; }

/* Buttons */
.btn {
  --btn-pad-y: 0.7rem;
  --btn-pad-x: 1.4rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: var(--btn-pad-y) var(--btn-pad-x);
  font-family: var(--ff-sans);
  font-size: 0.92rem;
  font-weight: 500;
  border: 1px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background var(--transition), color var(--transition),
              border-color var(--transition), transform var(--transition);
}
.btn:active { transform: translateY(1px); }
.btn svg { width: 18px; height: 18px; }

.btn--primary {
  background: var(--c-primary);
  color: #fff;
}
.btn--primary:hover { background: var(--c-primary-dark); }

.btn--outline {
  background: transparent;
  color: var(--c-primary);
  border-color: var(--c-primary);
}
.btn--outline:hover { background: var(--c-primary); color: #fff; }

.btn--ghost {
  background: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.7);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.78rem;
}
.btn--ghost:hover { background: rgba(255, 255, 255, 0.14); border-color: #fff; }

.btn--block { width: 100%; padding-block: 0.85rem; }

/* Section heading with centered rule */
.section-head { text-align: center; margin-bottom: var(--space-16); }
.section-head__title { font-size: clamp(1.5rem, 3vw, 2rem); }
.section-head__rule {
  display: block;
  width: 96px;
  height: 2px;
  margin: var(--space-4) auto 0;
  background: var(--c-accent);
}

/* ---------- 5. Sections ---------- */

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--c-bg-alt);
  border-bottom: 1px solid transparent;
}
.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 76px;
}
.nav { display: flex; align-items: center; }
.nav__menu {
  display: flex;
  align-items: center;
  gap: var(--space-8);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--c-ink);
}
.nav__menu a:not(.btn):hover { color: var(--c-primary); }
.nav__cta { margin-left: var(--space-2); }

.nav__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  background: none;
  border: 0;
  cursor: pointer;
}
.nav__toggle span {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--c-ink);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

/* Hero */
.hero {
  position: relative;
  color: #fff;
  background: linear-gradient(120deg, #1c2f63 0%, #24449e 55%, #2c63c4 100%);
  background: linear-gradient(rgba(20,33,74,.45), rgba(20,33,74,.45)),
              url("Hero.png") center/cover;
  background-size: cover;
  background-position: center;
}
.hero__inner { padding-block: clamp(3.5rem, 9vw, 7rem); }
.hero__card {
  max-width: 540px;
  padding: var(--space-8);
  background: rgba(38, 71, 201, 0.42);
  backdrop-filter: blur(2px);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius);
}
.hero__title {
  color: #fff;
  font-size: clamp(1.9rem, 4.5vw, 2.9rem);
  font-weight: 700;
  margin-bottom: var(--space-4);
}
.hero__text {
  font-size: 0.95rem;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: var(--space-6);
}

/* About */
.about { position: relative; background: var(--c-bg); overflow: hidden; }
.about__inner {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  min-height: 42rem;       /* taller, more spacious section */
  align-content: center;
  padding-block: clamp(3.5rem, 8vw, 6.5rem);
}
/* Full-bleed horizontal helix, centered behind the content (matches the
   reference). The canvas is drawn and rotated in 3D by main.js. */
.about__helix {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 100vw;            /* span the full viewport, beyond the container */
  height: 100%;
  transform: translate(-50%, -50%);
  pointer-events: none;
  z-index: 0;
}
.about__helix-canvas {
  display: block;
  width: 100%;
  height: 100%;
  opacity: 0.9;
}

.about__content {
  position: relative;
  z-index: 1;
  max-width: 520px;
  margin-left: auto;
  text-align: right;
}
.about__title {
  font-size: clamp(1.5rem, 3.2vw, 2.1rem);
  margin-bottom: var(--space-4);
}
.about__text {
  color: var(--c-text);
  margin-bottom: var(--space-6);
  font-size: 0.95rem;
}

/* Expertise */
.expertise { background: var(--c-bg-alt); padding-block: clamp(3.5rem, 8vw, 6rem); }
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}
.card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: var(--space-8) var(--space-6) var(--space-12);
  background: var(--c-bg);
  border: 1px solid var(--c-border);
  border-top: 3px solid var(--c-accent);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  transition: transform var(--transition), box-shadow var(--transition);
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(24, 42, 85, 0.12);
}
.card__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  margin-bottom: var(--space-6);
  color: var(--c-primary);
  background: rgba(38, 71, 201, 0.08);
  border-radius: var(--radius);
}
.card__icon svg { width: 22px; height: 22px; }
.card__title {
  color: var(--c-primary);
  font-family: var(--ff-serif);
  font-size: 1.12rem;
  font-weight: 600;
  margin-bottom: var(--space-3);
}
.card__text { font-size: 0.92rem; color: var(--c-text); }
.card__number {
  position: absolute;
  right: var(--space-6);
  bottom: var(--space-4);
  font-family: var(--ff-sans);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--c-muted);
}

/* Contact */
.contact { background: var(--c-bg-alt); padding-bottom: clamp(3.5rem, 8vw, 6rem); }
.contact__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: stretch;
  gap: 0;
}
.contact__panel {
  position: relative;
  display: flex;
  align-items: flex-end;
  min-height: 360px;
  padding: var(--space-12);
  color: #fff;
  border-radius: var(--radius-lg) 0 0 var(--radius-lg);
  background: linear-gradient(135deg, rgba(28,47,99,.55), rgba(42,85,194,.55)),
              url("Contact.png") center/cover;
  background-size: cover;
  background-position: center;
}
.contact__panel-title {
  color: #fff;
  font-size: clamp(1.4rem, 2.6vw, 1.9rem);
  margin-bottom: var(--space-3);
}
.contact__panel-text {
  font-size: 0.92rem;
  color: rgba(255, 255, 255, 0.9);
  max-width: 38ch;
}

.contact__card {
  position: relative;
  padding: var(--space-12);
  background: var(--c-bg);
  border: 1px solid var(--c-border);
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
  box-shadow: var(--shadow-form);
}
.contact__chip {
  display: block;
  width: 120px;
  height: 14px;
  border-radius: 6px;
  background: var(--c-primary);
  margin-bottom: var(--space-6);
}
.contact__title { font-size: 1.5rem; margin-bottom: var(--space-3); }
.contact__subtitle {
  font-size: 0.9rem;
  color: var(--c-text);
  margin-bottom: var(--space-8);
}

/* Forms */
.form { display: flex; flex-direction: column; gap: var(--space-4); }
.form__row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
}
.field { display: flex; flex-direction: column; gap: var(--space-2); }
.field label {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--c-ink);
}
.field input,
.field select,
.field textarea {
  width: 100%;
  padding: 0.7rem 0.85rem;
  font-family: inherit;
  font-size: 0.92rem;
  color: var(--c-ink);
  background: var(--c-bg);
  border: 1px solid var(--c-field-border);
  border-radius: var(--radius);
  transition: border-color var(--transition), box-shadow var(--transition);
}
.field textarea { resize: vertical; min-height: 84px; }
.field input::placeholder,
.field textarea::placeholder { color: var(--c-muted); }
.field input:focus,
.field select:focus,
.field textarea:focus {
  outline: none;
  border-color: var(--c-primary);
  box-shadow: 0 0 0 3px rgba(38, 71, 201, 0.12);
}
.field__error {
  display: block;
  margin-top: 0.4rem;
  font-size: 0.8rem;
  color: #cf2b2b;
  min-height: 1.25rem;
}
.field--error input,
.field--error select,
.field--error textarea {
  border-color: #cf2b2b;
}
.field--error input:focus,
.field--error select:focus,
.field--error textarea:focus {
  box-shadow: 0 0 0 3px rgba(207, 43, 43, 0.16);
}
.field select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='14' height='14' viewBox='0 0 24 24' fill='none' stroke='%2397a0b5' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.85rem center;
  padding-right: 2.2rem;
}

/* Footer */
.site-footer {
  background: var(--c-bg);
  border-top: 4px solid var(--c-primary);
}
.site-footer__inner {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: var(--space-12);
  padding-block: var(--space-16) var(--space-8);
}
.site-footer__desc {
  max-width: 36ch;
  margin-top: var(--space-4);
  font-size: 0.85rem;
  color: var(--c-text);
}
.site-footer__contact h4 {
  font-family: var(--ff-sans);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--c-ink);
  margin-bottom: var(--space-2);
}
.site-footer__contact a:hover { color: var(--c-primary); }

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding-block: var(--space-6);
  border-top: 1px solid var(--c-border);
}
.site-footer__copy { font-size: 0.8rem; color: var(--c-muted); }
.site-footer__links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-6);
  font-size: 0.82rem;
  color: var(--c-text);
}
.site-footer__links a:hover { color: var(--c-primary); }

/* ---------- 6. Responsive ---------- */
@media (max-width: 900px) {
  .cards { grid-template-columns: 1fr; max-width: 520px; margin-inline: auto; }

  .contact__inner { grid-template-columns: 1fr; }
  .contact__panel { border-radius: var(--radius-lg) var(--radius-lg) 0 0; min-height: 260px; }
  .contact__card { border-radius: 0 0 var(--radius-lg) var(--radius-lg); }

  .about__content { max-width: none; text-align: left; }
  .about__helix {
    top: 45%;
    width: 120vw;
  }
  .about__helix-canvas { opacity: 0.5; }
  .about__inner { min-height: clamp(30rem, 60vw, 38rem); }
}

@media (max-width: 720px) {
  /* Mobile navigation */
  .nav__toggle { display: flex; }
  .nav__menu {
    position: absolute;
    inset: 76px 0 auto 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--space-4) var(--space-6) var(--space-8);
    background: var(--c-bg-alt);
    border-bottom: 1px solid var(--c-border);
    box-shadow: var(--shadow-card);
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition), transform var(--transition),
                visibility var(--transition);
  }
  .nav__menu li { padding-block: var(--space-2); }
  .nav__cta { margin: var(--space-3) 0 0; }
  .nav__cta .btn { width: 100%; }
  .nav[data-open="true"] .nav__menu {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .site-footer__inner { grid-template-columns: 1fr; gap: var(--space-8); }
  .site-footer__bottom { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 480px) {
  .form__row { grid-template-columns: 1fr; }
  .contact__card,
  .contact__panel { padding: var(--space-8); }
  .about__inner { min-height: clamp(24rem, 70vw, 30rem); padding-block: clamp(3rem, 8vw, 5rem); }
  .about__helix { top: 50%; }
  .about__helix-canvas { opacity: 0.65; }
}

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