/* ===== GOOGLE FONTS ===== */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

/* ===== VARIABLES CSS ===== */
:root {
  --header-height: 4rem;

  /* Colors */
  --primary-color: #2563eb;
  --primary-color-dark: #1d4ed8;
  --secondary-color: #16a34a;
  --secondary-color-dark: #15803d;
  --text-color: #334155;
  --text-color-light: #64748b;
  --white-color: #ffffff;
  --gray-color: #f8fafc;
  --gray-color-dark: #e2e8f0;
  --border-color: #e2e8f0;
  --shadow-color: rgba(0, 0, 0, 0.1);

  /* Typography */
  --body-font: 'Inter', sans-serif;
  --biggest-font-size: 3rem;
  --h1-font-size: 2.25rem;
  --h2-font-size: 1.875rem;
  --h3-font-size: 1.5rem;
  --normal-font-size: 1rem;
  --small-font-size: 0.875rem;
  --smaller-font-size: 0.75rem;

  /* Font weight */
  --font-light: 300;
  --font-normal: 400;
  --font-medium: 500;
  --font-semi-bold: 600;
  --font-bold: 700;

  /* Spacing */
  --mb-0-25: 0.25rem;
  --mb-0-5: 0.5rem;
  --mb-0-75: 0.75rem;
  --mb-1: 1rem;
  --mb-1-25: 1.25rem;
  --mb-1-5: 1.5rem;
  --mb-2: 2rem;
  --mb-2-5: 2.5rem;
  --mb-3: 3rem;

  /* Z-index */
  --z-tooltip: 10;
  --z-fixed: 100;
  --z-modal: 1000;
}

/* ===== BASE ===== */
* {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--body-font);
  font-size: var(--normal-font-size);
  background-color: var(--white-color);
  color: var(--text-color);
  line-height: 1.6;
}

h1, h2, h3, h4 {
  color: var(--text-color);
  font-weight: var(--font-semi-bold);
  line-height: 1.2;
}

ul {
  list-style: none;
}

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

img {
  max-width: 100%;
  height: auto;
}

button {
  cursor: pointer;
  border: none;
  outline: none;
}

/* ===== REUSABLE CSS CLASSES ===== */
.container {
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 1rem;
  padding-right: 1rem;
}

.section {
  padding: 4rem 0;
}

.section--gray {
  background-color: var(--gray-color);
}

.section__title {
  font-size: var(--h2-font-size);
  color: var(--text-color);
  text-align: center;
  margin-bottom: var(--mb-3);
  position: relative;
}

.section__title::after {
  content: '';
  position: absolute;
  width: 80px;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  border-radius: 2px;
}

/* ===== HEADER ===== */
.header {
  width: 100%;
  position: fixed;
  top: 0;
  left: 0;
  z-index: var(--z-fixed);
  background-color: var(--white-color);
  box-shadow: 0 2px 20px var(--shadow-color);
  transition: all 0.3s ease;
}

.nav {
  height: var(--header-height);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav__brand h2 {
  color: var(--primary-color);
  font-weight: var(--font-bold);
  font-size: var(--h3-font-size);
}

.nav__list {
  display: flex;
  gap: 2rem;
}

.nav__link {
  color: var(--text-color);
  font-weight: var(--font-medium);
  transition: color 0.3s ease;
  position: relative;
}

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

.nav__link::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -5px;
  left: 0;
  background: var(--primary-color);
  transition: width 0.3s ease;
}

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

.nav__toggle {
  display: none;
  color: var(--text-color);
  font-size: 1.25rem;
  cursor: pointer;
}

/* ===== HERO SECTION ===== */
.hero {
  padding-top: calc(var(--header-height) + 2rem);
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
  color: var(--white-color);
  min-height: 100vh;
  display: flex;
  align-items: center;
}

.hero__container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.hero__title {
  font-size: var(--biggest-font-size);
  font-weight: var(--font-bold);
  margin-bottom: var(--mb-1);
}

.hero__description {
  font-size: var(--h3-font-size);
  font-weight: var(--font-light);
  margin-bottom: var(--mb-2-5);
  opacity: 0.9;
}

.hero__button {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background-color: var(--white-color);
  color: var(--primary-color);
  padding: 1rem 2rem;
  border-radius: 50px;
  font-weight: var(--font-semi-bold);
  transition: all 0.3s ease;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.hero__button:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 48px rgba(0, 0, 0, 0.15);
}

.hero__image {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero__icon {
  font-size: 8rem;
  opacity: 0.8;
}

/* ===== BENEFITS SECTION ===== */
.benefits__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}

.benefit__card {
  background: var(--white-color);
  padding: 2rem;
  border-radius: 16px;
  text-align: center;
  box-shadow: 0 8px 32px var(--shadow-color);
  transition: all 0.3s ease;
  border: 1px solid var(--border-color);
}

.benefit__card:hover {
  transform: translateY(-8px);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.15);
}

.benefit__icon {
  width: 80px;
  height: 80px;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--mb-1);
}

.benefit__icon i {
  font-size: 2rem;
  color: var(--white-color);
}

.benefit__title {
  font-size: var(--h3-font-size);
  margin-bottom: var(--mb-0-75);
  color: var(--text-color);
}

.benefit__description {
  color: var(--text-color-light);
  line-height: 1.6;
}

/* ===== OBLIGATIONS SECTION ===== */
.obligations__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-bottom: var(--mb-3);
}

.obligation__card {
  background: var(--white-color);
  padding: 2rem;
  border-radius: 16px;
  box-shadow: 0 8px 32px var(--shadow-color);
  border-left: 4px solid var(--primary-color);
}

.obligation__title {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: var(--mb-1-5);
  color: var(--primary-color);
}

.obligation__title i {
  font-size: 1.5rem;
}

.obligation__list {
  space-y: 0.5rem;
}

.obligation__list li {
  padding: 0.5rem 0;
  padding-left: 1.5rem;
  position: relative;
  color: var(--text-color-light);
}

.obligation__list li::before {
  content: '•';
  color: var(--secondary-color);
  position: absolute;
  left: 0;
  font-weight: var(--font-bold);
}

.warning__box {
  background: linear-gradient(135deg, #fef3c7, #fde68a);
  border: 1px solid #f59e0b;
  border-radius: 12px;
  padding: 1.5rem;
  text-align: center;
}

.warning__title {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  color: #92400e;
  margin-bottom: var(--mb-0-75);
}

.warning__title i {
  color: #f59e0b;
}

/* ===== DOCUMENTS SECTION ===== */
.documents__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-bottom: var(--mb-3);
}

.document__category {
  background: var(--white-color);
  padding: 2rem;
  border-radius: 16px;
  box-shadow: 0 8px 32px var(--shadow-color);
  border-top: 4px solid var(--secondary-color);
}

.document__title {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: var(--mb-1-5);
  color: var(--secondary-color);
}

.document__title i {
  font-size: 1.5rem;
}

.document__list li {
  padding: 0.5rem 0;
  padding-left: 1.5rem;
  position: relative;
  color: var(--text-color-light);
}

.document__list li::before {
  content: '✓';
  color: var(--secondary-color);
  position: absolute;
  left: 0;
  font-weight: var(--font-bold);
}

.tip__box {
  background: linear-gradient(135deg, #dbeafe, #bfdbfe);
  border: 1px solid var(--primary-color);
  border-radius: 12px;
  padding: 1.5rem;
}

.tip__title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--primary-color);
  margin-bottom: var(--mb-0-75);
}

.tip__title i {
  color: #fbbf24;
}

/* ===== TAX SECTION ===== */
.tax__content {
  display: grid;
  gap: 3rem;
}

.tax__table {
  background: var(--white-color);
  padding: 2rem;
  border-radius: 16px;
  box-shadow: 0 8px 32px var(--shadow-color);
}

.tax__subtitle {
  color: var(--primary-color);
  margin-bottom: var(--mb-1-5);
  text-align: center;
}

.table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1rem;
}

.table th,
.table td {
  padding: 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.table th {
  background-color: var(--gray-color);
  font-weight: var(--font-semi-bold);
  color: var(--text-color);
}

.table td {
  color: var(--text-color-light);
}

.table tr:hover {
  background-color: var(--gray-color);
}

.tax__info {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.info__card {
  background: var(--white-color);
  padding: 2rem;
  border-radius: 16px;
  box-shadow: 0 8px 32px var(--shadow-color);
}

.info__title {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--primary-color);
  margin-bottom: var(--mb-1-5);
}

.info__title i {
  font-size: 1.5rem;
}

.info__list li,
.info__steps li {
  padding: 0.5rem 0;
  color: var(--text-color-light);
}

.info__steps {
  counter-reset: step-counter;
}

.info__steps li {
  counter-increment: step-counter;
  padding-left: 2rem;
  position: relative;
}

.info__steps li::before {
  content: counter(step-counter);
  position: absolute;
  left: 0;
  top: 0.5rem;
  background: var(--primary-color);
  color: var(--white-color);
  width: 1.5rem;
  height: 1.5rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--small-font-size);
  font-weight: var(--font-bold);
}

/* ===== ERRORS SECTION ===== */
.errors__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin-bottom: var(--mb-3);
}

.error__card {
  background: var(--white-color);
  padding: 2rem;
  border-radius: 16px;
  box-shadow: 0 8px 32px var(--shadow-color);
  text-align: center;
  transition: all 0.3s ease;
}

.error__card:hover {
  transform: translateY(-5px);
}

.error__icon {
  margin-bottom: var(--mb-1);
}

.error__icon i {
  font-size: 3rem;
  color: #ef4444;
}

.error__title {
  color: var(--text-color);
  margin-bottom: var(--mb-0-75);
}

.error__description {
  color: var(--text-color-light);
  margin-bottom: var(--mb-1);
}

.error__solution {
  background: var(--gray-color);
  padding: 1rem;
  border-radius: 8px;
  text-align: left;
  color: var(--text-color-light);
  font-size: var(--small-font-size);
}

.error__solution strong {
  color: var(--primary-color);
}

.tips__box {
  background: linear-gradient(135deg, #d1fae5, #a7f3d0);
  border: 1px solid var(--secondary-color);
  border-radius: 16px;
  padding: 2rem;
}

.tips__title {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--secondary-color);
  margin-bottom: var(--mb-1-5);
  text-align: center;
  justify-content: center;
}

.tips__title i {
  color: #fbbf24;
}

.tips__list {
  display: grid;
  gap: 1rem;
}

.tip__item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.75rem;
  background: var(--white-color);
  border-radius: 8px;
  box-shadow: 0 2px 8px var(--shadow-color);
}

.tip__item i {
  color: var(--secondary-color);
  font-size: 1.25rem;
  flex-shrink: 0;
}

.tip__item span {
  color: var(--text-color-light);
}

/* ===== FOOTER ===== */
.footer {
  background: linear-gradient(135deg, var(--text-color) 0%, #1e293b 100%);
  color: var(--white-color);
  padding: 3rem 0 1rem;
}

.footer__content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin-bottom: var(--mb-2);
}

.footer__title {
  color: var(--white-color);
  margin-bottom: var(--mb-1);
}

.footer__description {
  color: #cbd5e1;
  margin-bottom: var(--mb-1-5);
  line-height: 1.6;
}

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

.contact__item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: #cbd5e1;
}

.contact__item i {
  color: var(--primary-color);
  font-size: 1.25rem;
}

.footer__subtitle {
  color: var(--white-color);
  margin-bottom: var(--mb-1);
}

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

.footer__link {
  color: #cbd5e1;
  transition: color 0.3s ease;
}

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

.footer__bottom {
  border-top: 1px solid #475569;
  padding-top: var(--mb-1);
  text-align: center;
  color: #94a3b8;
}

/* ===== RESPONSIVE DESIGN ===== */
@media screen and (max-width: 968px) {
  :root {
    --biggest-font-size: 2.5rem;
    --h1-font-size: 2rem;
    --h2-font-size: 1.5rem;
    --h3-font-size: 1.25rem;
  }
  
  .container {
    margin-left: var(--mb-1);
    margin-right: var(--mb-1);
  }
  
  .nav__menu {
    position: fixed;
    top: var(--header-height);
    left: -100%;
    width: 100%;
    height: calc(100vh - var(--header-height));
    background-color: var(--white-color);
    padding: 2rem 1rem;
    transition: left 0.3s ease;
    box-shadow: 0 2px 20px var(--shadow-color);
  }
  
  .nav__menu.show-menu {
    left: 0;
  }
  
  .nav__list {
    flex-direction: column;
    gap: 1.5rem;
  }
  
  .nav__link {
    font-size: var(--h3-font-size);
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
  }
  
  .nav__toggle {
    display: block;
  }
  
  .hero__container {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 2rem;
  }
  
  .hero__icon {
    font-size: 5rem;
  }
  
  .benefits__grid,
  .obligations__grid,
  .documents__grid,
  .errors__grid {
    grid-template-columns: 1fr;
  }
  
  .tax__info {
    grid-template-columns: 1fr;
  }
  
  .table {
    font-size: var(--small-font-size);
  }
  
  .table th,
  .table td {
    padding: 0.5rem;
  }
  
  .footer__content {
    grid-template-columns: 1fr;
    text-align: center;
  }
}

@media screen and (max-width: 576px) {
  .hero {
    padding-top: calc(var(--header-height) + 1rem);
  }
  
  .section {
    padding: 2rem 0;
  }
  
  .hero__title {
    font-size: var(--h1-font-size);
  }
  
  .hero__description {
    font-size: var(--normal-font-size);
  }
  
  .benefit__card,
  .obligation__card,
  .document__category,
  .info__card,
  .error__card {
    padding: 1.5rem;
  }
  
  .tips__box,
  .warning__box,
  .tip__box {
    padding: 1rem;
  }
}

/* ===== SCROLL ANIMATIONS ===== */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.6s ease;
}

.animate-on-scroll.animated {
  opacity: 1;
  transform: translateY(0);
}

/* ===== CUSTOM SCROLLBAR ===== */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--gray-color);
}

::-webkit-scrollbar-thumb {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(135deg, var(--primary-color-dark), var(--secondary-color-dark));
}