/* =========================
   1. Design tokens
========================= */
:root {

  --bg-color: #F5F5F5;
  --fg-color: #1D3246;
  --fg-scnd-color: #E2E8F0;
  --accent-color: #0055FF;

  --font-sans: "Inter", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", monospace;

  --space-layout: 4rem;
  --space-layout-double: calc(var(--space-layout) * 2);

  --line-base-height: 1.75;
}

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

html {
  font-size: 100%;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--fg-color);
  background-color: var(--bg-color);
  line-height: var(--line-base-height);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

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

:focus-visible {
  outline: 0.1875rem solid var(--accent-color);
  outline-offset: 0.25rem;
  border-radius: 0.25rem;
}

/* =========================
   3. Layout container (Mobile First)
========================= */
.container {
  width: 100%;
  margin: 0 auto;
  padding: var(--space-layout) 1.25rem;
}

/* =========================
   4. Nav
========================= */
.nav {
  display: flex;
  justify-content: center;
  gap: clamp(3rem, 15vw, 4rem);
  margin-bottom: var(--space-layout);
}

.nav__link {
  font-size: 1rem;
  font-weight: 700;
  color: var(--fg-color);
  padding-bottom: 0.25rem;
  border-bottom: 0.125rem solid var(--fg-scnd-color);
  transition: all 0.2s ease, color 0.2s ease;
}

.nav__link--active {
  border-bottom: 0.125rem solid var(--accent-color);
}

.nav__link:hover {
  color: var(--accent-color);
  border-bottom-color: var(--accent-color);
}

/* =========================
   5. Header
========================= */
.header {
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 1.875rem;
}

.header__wrap {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.header__title {
  margin: 0;
  color: var(--accent-color);
  font-weight: 900;
  text-transform: uppercase;
  line-height: 1;
  letter-spacing: -0.02em;
  font-size: clamp(3rem, 13.5vw, 5.5rem);
  white-space: nowrap;
}

.header__subtitle {
  margin: 0 auto;
  color: var(--accent-color);
  font-weight: 900;
  line-height: 1.3;
  max-width: 26rem;
  font-size: clamp(1.375rem, 5vw, 2rem);
}

.header__address {
  font-style: normal;
  font-size: 0.875rem;
  color: var(--fg-color);
  opacity: 0.8;
}

/* =========================
   6. Divider
========================= */
.divider {
  border: none;
  height: 2px;
  background-color: var(--fg-scnd-color);
  width: 100%;
  max-width: 18rem;
  margin: var(--space-layout) auto;
}

/* =========================
   7. Main content (About)
========================= */
.about {
  display: flex;
  flex-direction: column;
  gap: var(--space-layout);
}

.about__paragraph {
  margin: 0;
  font-size: 1rem;
  opacity: 0.9;
}

.manifesto {
  margin: 0;
  padding: 0;
  text-align: center;
}

.manifesto__paragraph {
  margin: 0;
  font-size: 1.125rem;
  font-weight: 400;
  opacity: 0.9;
}

/* =========================
   8. Skills
========================= */
.skills {
  display: flex;
  flex-direction: column;
  gap: var(--space-layout);
}

.skills__title {
  margin: 0;
  text-align: center;
  color: var(--accent-color);
  font-size: clamp(1.25rem, 5vw, 1.75rem);
  font-weight: 800;
}

.skill {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.skill__title {
  margin: 0;
  font-size: 1.125rem;
  font-weight: 800;
}

.skill__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.skill__item {
  font-size: 1rem;
  line-height: var(--line-base-height);
}

.skill__name {
  font-weight: 800;
}

.skill__desc {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  opacity: 0.8;
}

/* =========================
   9. CTA (Mobile First)
========================= */
.cta {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-layout);
  text-align: center;
}

.cta__link {
  font-weight: 800;
  font-size: 1.125rem;
  padding-bottom: 0.25rem;
  border-bottom: 0.125rem solid var(--fg-scnd-color);
  transition: border-color 0.2s ease, color 0.2s ease;
}

.cta__link:hover {
  border-bottom-color: var(--accent-color);
  color: var(--accent-color);
}

/* =========================
   10. Footer
========================= */
.footer {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
  margin-top: var(--space-layout-double);
}

.footer__links {
  display: flex;
  gap: var(--space-layout);
}

.footer__link {
  font-weight: 700;
  font-size: 1rem;
  padding-bottom: 0.25rem;
  border-bottom: 0.125rem solid var(--fg-scnd-color);
  transition: border-color 0.2s ease, color 0.2s ease;
}

.footer__link:hover {
  border-bottom-color: var(--accent-color);
  color: var(--accent-color);
}

.footer__copyrights {
  margin: 0;
  font-size: 0.875rem;
  font-weight: 700;
}

/* =========================
   11. Filters (Projects)
========================= */
.filters {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
  margin-bottom: var(--space-layout);
}

.filters__label {
  margin: 0;
  font-size: 1.125rem;
  font-weight: 400;
}

.filters__group {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  justify-content: center;
  gap: clamp(0.75rem, 3vw, 1.5rem);
  width: 100%;
}

.filters__btn {
  background-color: transparent;
  border: 0.125rem solid var(--fg-color);
  color: var(--fg-color);
  font-family: var(--font-mono);
  font-size: clamp(0.875rem, 2.5vw, 1rem);
  padding: 0.5rem 1rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.filters__btn--active {
  color: var(--accent-color);
  border-color: var(--accent-color);
}

@media (hover: hover) {
.filters__btn:hover {
    color: var(--accent-color);
    border-color: var(--accent-color);
  }
}

/* =========================
   12. Projects List
========================= */
.projects {
  display: flex;
  flex-direction: column;
  gap: var(--space-layout);
}

.project {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.project__header {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.project__title {
  margin: 0;
  width: fit-content;
}

.project__link {
  color: var(--fg-color);
  font-weight: 800;
  font-size: clamp(1.375rem, 4vw, 1.75rem);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding-bottom: 0.25rem;
  border-bottom: 0.125rem solid var(--fg-scnd-color);
  transition: all 0.2s ease;
}

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

.project__link::after {
  content: "↗";
  font-family: var(--font-sans);
  font-size: 1em;
  font-weight: 800;
  margin-left: 0.15rem;
  transition: transform 0.2s ease;
}

.project__link:hover::after {
  transform: translate(0.15rem, -0.15rem);
}

.project__tech-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  row-gap: 0.5rem;
}

.project__tech-item {
  font-family: var(--font-mono);
  font-size: 1rem;
  display: flex;
  align-items: center;
}

.project__tech-item:not(:last-child)::after {
  content: "■";
  font-size: 0.4rem;
  color: var(--fg-scnd-color);
  margin: 0 0.75rem;
}

.project__content {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.project__detail {
  margin: 0;
  font-size: clamp(0.9375rem, 2vw, 1rem);
  line-height: var(--line-base-height);
}

.project__label {
  font-weight: 800;
}

/* =========================
   13. Desktop Enhancements
========================= */
@media (min-width: 48rem) {
  .container {
    max-width: 48rem;
    padding: calc(var(--space-layout) * 1.5) 1.5rem;
  }

  .manifesto__paragraph {
    font-size: 1.25rem;
  }

  .cta {
    flex-direction: row;
    justify-content: center;
    gap: var(--space-layout);
  }

  .footer {
    flex-direction: row;
    justify-content: center;
    gap: var(--space-layout-double);
  }

  .footer__links {
    gap: var(--space-layout);
  }

  .filters {
    flex-direction: row;
    justify-content: flex-start;
    align-items: center;
    gap: 2rem;
  }

  .filters__label {
    margin-bottom: 0;
  }

  .filters__group {
    justify-content: flex-start;
  }
}

/* =========================
   14. Contact (Mobile First)
========================= */

.contact {
  display: flex;
  flex-direction: column;
  gap: clamp(2rem, 6vw, var(--space-layout));
}

.contact__email {
  display: block;
  text-align: center;
  font-weight: 800;
  font-size: clamp(1rem, 4vw, 1.25rem);
  color: var(--fg-color);
  padding-bottom: 0.25rem;
  width: fit-content;
  margin: 0 auto;
  border-bottom: 0.125rem solid var(--fg-scnd-color);
  transition: border-color 0.2s ease, color 0.2s ease;
}

.contact__email:hover {
  color: var(--accent-color);
  border-bottom-color: var(--accent-color);
}

/* =========================
   15. Form (Mobile First)
========================= */

.form {
  display: flex;
  flex-direction: column;
  gap: clamp(1.5rem, 4vw, 2rem);
}

.form__group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.form__label {
  font-size: 0.875rem;
  font-weight: 400;
  color: var(--fg-color);
  opacity: 0.8;
}

.form__control {
  appearance: none;
  -webkit-appearance: none;
  width: 100%;
  padding: 0.625rem 0.75rem;
  font-family: var(--font-sans);
  font-size: clamp(0.9375rem, 2.5vw, 1rem);
  color: var(--fg-color);
  background-color: transparent;
  border: 2px solid var(--fg-color);
  border-radius: 0;
  line-height: var(--line-base-height);
  transition: border-color 0.2s ease;
}

.form__control:focus {
  outline: none;
  border-color: var(--accent-color);
}

.form__control--textarea {
  min-height: clamp(11.25rem, 30vw, 13.75rem);
  resize: vertical;
}

.form__actions {
  display: flex;
  justify-content: flex-end;
}

.form__btn {
  appearance: none;
  -webkit-appearance: none;
  background-color: transparent;
  border: 2px solid var(--fg-color);
  color: var(--fg-color);
  font-family: var(--font-sans);
  font-size: clamp(0.875rem, 2.5vw, 1rem);
  font-weight: 700;
  padding: 0.5rem 1rem;
  cursor: pointer;
  transition: color 0.2s ease, border-color 0.2s ease;
}

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

.form__btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

/* =========================
   16. Success Message  
========================= */
.success-send {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: clamp(1rem, 4vw, 1.5rem);
}
.success-send__title {
  margin: 0;
  color: var(--accent-color);
  font-size: clamp(1.375rem, 4vw, 1.75rem);
  font-weight: 800;
}

.success-send__paragraph {
  margin: 0;
  font-size: 1rem;
  opacity: 0.9;
}

.success-send__link {
  font-weight: 800;
  font-size: clamp(0.875rem, 2.5vw, 1rem);
  padding-bottom: 0.25rem;
  border-bottom: 0.125rem solid var(--fg-scnd-color);
  transition: border-color 0.2s ease, color 0.2s ease;
}

.success-send__link:hover {
  border-bottom-color: var(--accent-color);
  color: var(--accent-color);
}