/* ============================================
   DESIGN SYSTEM & GLOBAL STYLES
   Elena Vassiliou — Architectural Portfolio
   ============================================ */

:root {
  /* Colors */
  --color-bg: #f9f9f9;
  --color-bg-alt: #f0eeeb;
  --color-bg-dark: #111111;
  --color-text: #111111;
  --color-text-muted: #666666;
  --color-text-light: #999999;
  --color-white: #ffffff;
  --color-accent: #c5a880;
  --color-accent-dark: #a88b5e;
  --color-accent-light: #e8dcc8;
  --color-border: #e0ddd8;
  --color-overlay: rgba(17, 17, 17, 0.55);

  /* Typography */
  --font-serif: 'Cormorant Garamond', Georgia, serif;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --space-2xl: 6rem;
  --space-3xl: 8rem;

  /* Layout */
  --container-max: 1200px;
  --container-narrow: 900px;
  --header-height: 80px;

  /* Effects */
  --transition: all 0.3s ease;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 8px 30px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.15);
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  font-weight: 400;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

ul {
  list-style: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input,
textarea {
  font-family: inherit;
  font-size: inherit;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: 500;
  line-height: 1.2;
  color: var(--color-text);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  padding: 0.875rem 2rem;
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border: 2px solid transparent;
  transition: var(--transition);
  cursor: pointer;
}

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

.btn--primary:hover {
  background-color: var(--color-accent-dark);
  border-color: var(--color-accent-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn--secondary {
  background-color: var(--color-text);
  color: var(--color-white);
  border-color: var(--color-text);
}

.btn--secondary:hover {
  background-color: transparent;
  color: var(--color-text);
  transform: translateY(-2px);
}

.btn--outline {
  background-color: transparent;
  color: var(--color-white);
  border-color: var(--color-white);
}

.btn--outline:hover {
  background-color: var(--color-white);
  color: var(--color-text);
  transform: translateY(-2px);
}

.btn--full {
  width: 100%;
}

/* Section */
.section {
  padding: var(--space-3xl) 0;
}

.section__header {
  margin-bottom: var(--space-xl);
}

.section__header--center {
  text-align: center;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.section__eyebrow {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-sm);
}

.section__title {
  font-size: clamp(2.25rem, 5vw, 3.5rem);
  margin-bottom: var(--space-sm);
}

.section__desc {
  font-size: 1.0625rem;
  color: var(--color-text-muted);
  line-height: 1.8;
}

/* Page Hero (inner pages) */
.page-hero {
  padding: calc(var(--header-height) + var(--space-2xl)) 0 var(--space-xl);
  background-color: var(--color-bg-alt);
  text-align: center;
}

.page-hero__title {
  font-size: clamp(2.5rem, 6vw, 4rem);
  margin-bottom: var(--space-sm);
}

.page-hero__desc {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  max-width: 560px;
  margin: 0 auto;
}

/* ============================================
   HEADER / NAVIGATION
   ============================================ */

.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  transition: var(--transition);
}

.header--scrolled {
  background-color: rgba(249, 249, 249, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: var(--shadow-sm);
}

.header--dark {
  background-color: transparent;
}

.header--dark.header--scrolled {
  background-color: rgba(17, 17, 17, 0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--color-text);
  transition: var(--transition);
}

.header--dark .logo,
.header--dark .nav__link {
  color: var(--color-white);
}

.header--dark.header--scrolled .logo,
.header--dark.header--scrolled .nav__link {
  color: var(--color-text);
}

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

.logo--footer {
  font-size: 1.375rem;
  color: var(--color-white);
}

.nav {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.nav__list {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.nav__link {
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text);
  position: relative;
  padding: 0.25rem 0;
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 1px;
  background-color: var(--color-accent);
  transition: var(--transition);
}

.nav__link:hover::after,
.nav__link.active::after {
  width: 100%;
}

.nav__link:hover,
.nav__link.active {
  color: var(--color-accent);
}

.header--dark .nav__link:hover,
.header--dark .nav__link.active {
  color: var(--color-accent);
}

.nav__cta {
  padding: 0.625rem 1.5rem;
  font-size: 0.75rem;
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  width: 32px;
  height: 32px;
  z-index: 1001;
}

.hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-text);
  transition: var(--transition);
  transform-origin: center;
}

.header--dark .hamburger span {
  background-color: var(--color-white);
}

.header--dark.header--scrolled .hamburger span {
  background-color: var(--color-text);
}

.hamburger.active span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* ============================================
   HERO SECTION
   ============================================ */

.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero__bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero__overlay {
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(
    135deg,
    rgba(17, 17, 17, 0.75) 0%,
    rgba(17, 17, 17, 0.45) 50%,
    rgba(17, 17, 17, 0.65) 100%
  );
}

.hero__content {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 100vh;
  padding-top: var(--header-height);
  padding-bottom: var(--space-2xl);
}

.hero__eyebrow {
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-md);
}

.hero__title {
  font-size: clamp(2.75rem, 7vw, 5.5rem);
  font-weight: 500;
  color: var(--color-white);
  margin-bottom: var(--space-md);
  max-width: 800px;
}

.hero__subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: rgba(255, 255, 255, 0.85);
  max-width: 520px;
  margin-bottom: var(--space-lg);
  line-height: 1.8;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-2xl);
}

.hero__stats {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xl);
  padding-top: var(--space-lg);
  border-top: 1px solid rgba(255, 255, 255, 0.15);
}

.hero__stat {
  display: flex;
  flex-direction: column;
}

.hero__stat-number {
  font-family: var(--font-serif);
  font-size: 2.5rem;
  font-weight: 600;
  color: var(--color-white);
  line-height: 1;
}

.hero__stat-label {
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.6);
  margin-top: var(--space-xs);
}

.hero__scroll {
  position: absolute;
  bottom: var(--space-lg);
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xs);
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.6875rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  transition: var(--transition);
  animation: bounce 2s infinite;
}

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

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
  40% { transform: translateX(-50%) translateY(-8px); }
  60% { transform: translateX(-50%) translateY(-4px); }
}

/* ============================================
   ABOUT SECTION
   ============================================ */

.about {
  background-color: var(--color-white);
}

.about__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2xl);
  align-items: center;
}

.about__image {
  position: relative;
}

.about__image-frame {
  position: relative;
  z-index: 1;
  overflow: hidden;
  aspect-ratio: 4 / 5;
}

.about__image-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: var(--transition);
}

.about__image:hover .about__image-frame img {
  transform: scale(1.03);
}

.about__image-accent {
  position: absolute;
  bottom: -20px;
  right: -20px;
  width: 60%;
  height: 60%;
  border: 2px solid var(--color-accent);
  z-index: 0;
}

.about__lead {
  font-family: var(--font-serif);
  font-size: 1.375rem;
  font-weight: 500;
  line-height: 1.6;
  color: var(--color-text);
  margin-bottom: var(--space-md);
}

.about__content p {
  color: var(--color-text-muted);
  margin-bottom: var(--space-sm);
}

.about__quote {
  margin: var(--space-lg) 0;
  padding-left: var(--space-md);
  border-left: 3px solid var(--color-accent);
}

.about__quote p {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-style: italic;
  color: var(--color-text);
  margin-bottom: var(--space-xs);
}

.about__quote cite {
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  font-style: normal;
  letter-spacing: 0.05em;
  color: var(--color-text-light);
}

/* ============================================
   SERVICES SECTION
   ============================================ */

.services {
  background-color: var(--color-bg);
}

.services__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-md);
}

.service-card {
  background-color: var(--color-white);
  padding: var(--space-lg);
  border: 1px solid var(--color-border);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.service-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
  border-color: transparent;
}

.service-card__icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  color: var(--color-accent);
  margin-bottom: var(--space-md);
  border: 1px solid var(--color-accent-light);
  transition: var(--transition);
}

.service-card:hover .service-card__icon {
  background-color: var(--color-accent);
  color: var(--color-white);
  border-color: var(--color-accent);
}

.service-card__title {
  font-size: 1.375rem;
  margin-bottom: var(--space-sm);
}

.service-card__text {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  line-height: 1.7;
  flex-grow: 1;
  margin-bottom: var(--space-md);
}

.service-card__link {
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-accent);
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
}

.service-card__link i {
  transition: var(--transition);
}

.service-card__link:hover {
  color: var(--color-accent-dark);
}

.service-card__link:hover i {
  transform: translateX(4px);
}

/* ============================================
   FEATURED WORK
   ============================================ */

.featured {
  background-color: var(--color-white);
}

.featured__grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  grid-template-rows: repeat(2, 280px);
  gap: var(--space-md);
}

.featured__item {
  position: relative;
  overflow: hidden;
  display: block;
}

.featured__item--large {
  grid-row: span 2;
}

.featured__item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s ease;
}

.featured__item:hover img {
  transform: scale(1.05);
}

.featured__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(17, 17, 17, 0.7) 0%, transparent 60%);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: var(--space-md);
  transition: var(--transition);
}

.featured__item:hover .featured__overlay {
  background: linear-gradient(to top, rgba(17, 17, 17, 0.85) 0%, rgba(17, 17, 17, 0.2) 100%);
}

.featured__category {
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-xs);
}

.featured__title {
  font-size: 1.5rem;
  color: var(--color-white);
}

.featured__cta {
  text-align: center;
  margin-top: var(--space-xl);
}

/* ============================================
   CONTACT SECTION
   ============================================ */

.contact {
  background-color: var(--color-bg-alt);
}

.contact__grid {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: var(--space-2xl);
  align-items: start;
}

.contact__info {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.contact__info-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-md);
}

.contact__info-icon {
  width: 48px;
  height: 48px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  color: var(--color-accent);
  font-size: 1rem;
  transition: var(--transition);
}

.contact__info-item:hover .contact__info-icon {
  background-color: var(--color-accent);
  color: var(--color-white);
  border-color: var(--color-accent);
}

.contact__info-item h4 {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-light);
  margin-bottom: 0.25rem;
}

.contact__info-item a,
.contact__info-item p {
  font-size: 1rem;
  color: var(--color-text);
}

.contact__info-item a:hover {
  color: var(--color-accent);
}

/* Contact Form */
.contact__form {
  background-color: var(--color-white);
  padding: var(--space-xl);
  border: 1px solid var(--color-border);
}

.form-group {
  position: relative;
  margin-bottom: var(--space-lg);
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 1rem 0 0.5rem;
  font-size: 1rem;
  color: var(--color-text);
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--color-border);
  outline: none;
  transition: var(--transition);
  resize: vertical;
}

.form-group input:focus,
.form-group textarea:focus {
  border-bottom-color: var(--color-accent);
}

.form-group label {
  position: absolute;
  top: 1rem;
  left: 0;
  font-size: 0.9375rem;
  color: var(--color-text-light);
  pointer-events: none;
  transition: var(--transition);
}

.form-group input:focus ~ label,
.form-group input:not(:placeholder-shown) ~ label,
.form-group textarea:focus ~ label,
.form-group textarea:not(:placeholder-shown) ~ label {
  top: -0.25rem;
  font-size: 0.75rem;
  color: var(--color-accent);
  letter-spacing: 0.05em;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: transparent;
}

.form-group--textarea textarea {
  min-height: 120px;
}

.form-error {
  display: block;
  font-size: 0.75rem;
  color: #c0392b;
  margin-top: 0.25rem;
  min-height: 1rem;
}

.form-group input.error,
.form-group textarea.error {
  border-bottom-color: #c0392b;
}

.form-success {
  display: none;
  align-items: center;
  gap: var(--space-sm);
  margin-top: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  background-color: #eaf7ee;
  color: #1e7e34;
  font-size: 0.9375rem;
}

.form-success.visible {
  display: flex;
}

.form-success i {
  font-size: 1.25rem;
}

/* ============================================
   FOOTER
   ============================================ */

.footer {
  background-color: var(--color-bg-dark);
  color: rgba(255, 255, 255, 0.7);
  padding-top: var(--space-xl);
}

.footer__inner {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: var(--space-lg);
  padding-bottom: var(--space-xl);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer__tagline {
  font-size: 0.875rem;
  margin-top: var(--space-xs);
  color: rgba(255, 255, 255, 0.5);
}

.footer__nav {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.footer__nav a {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.7);
  transition: var(--transition);
}

.footer__nav a:hover {
  color: var(--color-accent);
  padding-left: 4px;
}

.footer__social {
  display: flex;
  gap: var(--space-sm);
  justify-content: flex-end;
}

.footer__social a {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: rgba(255, 255, 255, 0.7);
  font-size: 1rem;
  transition: var(--transition);
}

.footer__social a:hover {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-white);
  transform: translateY(-3px);
}

.footer__bottom {
  padding: var(--space-md) 0;
  text-align: center;
}

.footer__bottom p {
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.4);
}

/* ============================================
   SCROLL REVEAL ANIMATIONS
   ============================================ */

.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal--delay {
  transition-delay: 0.15s;
}

.reveal--delay-2 {
  transition-delay: 0.3s;
}

.reveal--delay-3 {
  transition-delay: 0.45s;
}

/* ============================================
   RESPONSIVE
   ============================================ */

@media (max-width: 1024px) {
  .services__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .featured__grid {
    grid-template-columns: 1fr 1fr;
    grid-template-rows: 300px 250px;
  }

  .featured__item--large {
    grid-row: span 1;
    grid-column: span 2;
  }

  .about__grid {
    gap: var(--space-xl);
  }

  .contact__grid {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 70px;
    --space-3xl: 5rem;
  }

  .hamburger {
    display: flex;
  }

  .nav {
    position: fixed;
    top: 0;
    right: -100%;
    width: min(320px, 85vw);
    height: 100vh;
    background-color: var(--color-white);
    flex-direction: column;
    align-items: flex-start;
    padding: calc(var(--header-height) + var(--space-lg)) var(--space-lg) var(--space-lg);
    box-shadow: var(--shadow-lg);
    transition: right 0.4s ease;
    z-index: 999;
  }

  .nav.open {
    right: 0;
  }

  .nav__list {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-md);
    width: 100%;
  }

  .nav__link {
    font-size: 1rem;
  }

  .nav__cta {
    width: 100%;
    margin-top: var(--space-md);
  }

  .about__grid {
    grid-template-columns: 1fr;
  }

  .about__image {
    max-width: 400px;
    margin: 0 auto;
  }

  .services__grid {
    grid-template-columns: 1fr;
  }

  .featured__grid {
    grid-template-columns: 1fr;
    grid-template-rows: auto;
  }

  .featured__item--large {
    grid-column: span 1;
  }

  .featured__item {
    height: 280px;
  }

  .hero__stats {
    gap: var(--space-lg);
  }

  .footer__inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .footer__nav {
    align-items: center;
  }

  .footer__social {
    justify-content: center;
  }

  .contact__form {
    padding: var(--space-lg);
  }
}

@media (max-width: 480px) {
  .hero__actions {
    flex-direction: column;
  }

  .hero__actions .btn {
    width: 100%;
    text-align: center;
  }

  .hero__stat-number {
    font-size: 2rem;
  }
}