/* ===================================
   FANGUYE - Modern Website Styles
   Following genesis-DESIGN.md guidelines
   =================================== */

/* CSS Custom Properties */
:root {
  /* Colors */
  --color-primary: #6366F1;
  --color-primary-hover: #4F46E5;
  --color-secondary: #20970B;
  --color-neutral: #9C9C9C;
  --color-background: #FAFAFA;
  --color-surface: #FFFFFF;
  --color-text-primary: #0A0A0A;
  --color-text-secondary: #6B6B6B;
  --color-border: #E8E8EC;
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-error: #EF4444;
  
  /* Spacing (4px base) */
  --space-4: 4px;
  --space-8: 8px;
  --space-12: 12px;
  --space-16: 16px;
  --space-20: 20px;
  --space-24: 24px;
  --space-32: 32px;
  --space-40: 40px;
  --space-48: 48px;
  --space-64: 64px;
  --space-80: 80px;
  --space-96: 96px;
  
  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-xl: 12px;
  --radius-full: 9999px;
  
  /* Typography */
  --font-display: 'General Sans', sans-serif;
  --font-body: 'DM Sans', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  
  /* Shadows */
  --shadow-card-hover: 0 8px 30px rgba(0, 0, 0, 0.08);
  --shadow-button-hover: 0 4px 12px rgba(99, 102, 241, 0.35);
  --shadow-focus: 0 0 0 3px rgba(99, 102, 241, 0.12);
  --shadow-dropdown: 0 10px 25px rgba(0, 0, 0, 0.1);
  
  /* Transitions */
  --transition-fast: 200ms ease;
  --transition-normal: 300ms ease;
}

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

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

body {
  font-family: var(--font-body);
  background-color: var(--color-background);
  color: var(--color-text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

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

ul, ol {
  list-style: none;
}

/* Container */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-24);
}

/* ===================================
   Navigation
   =================================== */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  height: 56px;
}

.nav__container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-24);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav__logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 24px;
  color: var(--color-text-primary);
  letter-spacing: -0.03em;
}

.nav__logo-text {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav__toggle {
  display: none;
  flex-direction: column;
  gap: var(--space-4);
  padding: var(--space-8);
  cursor: pointer;
}

.nav__toggle-line {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text-primary);
  transition: var(--transition-fast);
}

.nav__menu {
  display: flex;
  align-items: center;
  gap: var(--space-32);
}

.nav__link {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text-primary);
  padding: var(--space-8) var(--space-12);
  border-radius: var(--radius-sm);
  transition: var(--transition-fast);
}

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

.nav__link--active {
  color: var(--color-primary);
  background: rgba(99, 102, 241, 0.08);
}

.nav__link--cta {
  background: var(--color-primary);
  color: white;
  padding: var(--space-8) var(--space-16);
  border-radius: var(--radius-md);
}

.nav__link--cta:hover {
  background: var(--color-primary-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-button-hover);
}

/* Mobile Navigation */
@media (max-width: 768px) {
  .nav__toggle {
    display: flex;
  }
  
  .nav__menu {
    position: fixed;
    top: 56px;
    left: 0;
    right: 0;
    background: var(--color-surface);
    flex-direction: column;
    padding: var(--space-24);
    gap: var(--space-16);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-dropdown);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-normal);
  }
  
  .nav__menu.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  
  .nav__toggle.active .nav__toggle-line:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }
  
  .nav__toggle.active .nav__toggle-line:nth-child(2) {
    opacity: 0;
  }
  
  .nav__toggle.active .nav__toggle-line:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }
}

/* ===================================
   Hero Section
   =================================== */
.hero {
  position: relative;
  padding: var(--space-96) 0;
  overflow: hidden;
}

.hero__background {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: 
    radial-gradient(circle at 20% 50%, rgba(99, 102, 241, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(32, 151, 11, 0.08) 0%, transparent 50%);
  z-index: -1;
}

.hero__content {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.hero__badge {
  display: inline-block;
  padding: var(--space-8) var(--space-16);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 500;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-24);
}

.hero__title {
  font-family: var(--font-display);
  font-size: clamp(36px, 6vw, 60px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-24);
  color: var(--color-text-primary);
}

.hero__highlight {
  color: var(--color-primary);
}

.hero__subtitle {
  font-size: 18px;
  line-height: 1.6;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-40);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero__actions {
  display: flex;
  gap: var(--space-16);
  justify-content: center;
  flex-wrap: wrap;
}

.hero__scroll {
  position: absolute;
  bottom: var(--space-32);
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-8);
  color: var(--color-neutral);
  font-size: 12px;
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translateX(-50%) translateY(0);
  }
  40% {
    transform: translateX(-50%) translateY(-10px);
  }
  60% {
    transform: translateX(-50%) translateY(-5px);
  }
}

@media (max-width: 768px) {
  .hero {
    padding: var(--space-64) 0;
  }
  
  .hero__scroll {
    display: none;
  }
}

/* ===================================
   Buttons
   =================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px var(--space-16);
  font-size: 15px;
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: var(--transition-fast);
  cursor: pointer;
  border: none;
}

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

.btn--primary:hover {
  background: var(--color-primary-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-button-hover);
}

.btn--secondary {
  background: transparent;
  color: var(--color-text-primary);
  border: 1px solid var(--color-border);
}

.btn--secondary:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  transform: translateY(-1px);
}

.btn--full {
  width: 100%;
  padding: var(--space-12) var(--space-24);
}

/* ===================================
   Sections
   =================================== */
.section {
  padding: var(--space-64) 0;
}

@media (min-width: 768px) {
  .section {
    padding: var(--space-80) 0;
  }
}

@media (min-width: 1024px) {
  .section {
    padding: var(--space-96) 0;
  }
}

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

.section__header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto var(--space-48);
}

.section__badge {
  display: inline-block;
  padding: var(--space-8) var(--space-16);
  border-radius: var(--radius-full);
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-16);
}

.section__badge--mobile {
  background: rgba(99, 102, 241, 0.1);
  color: var(--color-primary);
}

.section__badge--moodle {
  background: rgba(32, 151, 11, 0.1);
  color: var(--color-secondary);
}

.section__badge--cursos {
  background: rgba(245, 158, 11, 0.1);
  color: var(--color-warning);
}

.section__badge--epub {
  background: rgba(139, 92, 246, 0.1);
  color: #8B5CF6;
}

.section__badge--contact {
  background: rgba(16, 185, 129, 0.1);
  color: var(--color-success);
}

.section__title {
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 700;
  letter-spacing: -0.04em;
  margin-bottom: var(--space-16);
  color: var(--color-text-primary);
}

.section__subtitle {
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text-secondary);
}

/* ===================================
   Cards
   =================================== */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-24);
}

.grid {
  display: grid;
  gap: var(--space-24);
}

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

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  transition: var(--transition-fast);
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-card-hover);
}

.card--feature {
  padding: var(--space-32);
}

.card__icon {
  width: 64px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-16);
}

.card__icon--android,
.card__icon--ios,
.card__icon--flutter {
  background: rgba(99, 102, 241, 0.1);
  color: var(--color-primary);
}

.card__icon--pwa {
  background: rgba(32, 151, 11, 0.1);
  color: var(--color-secondary);
}

.card__title {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-12);
  color: var(--color-text-primary);
}

.card__description {
  font-size: 14px;
  line-height: 1.6;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-16);
}

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

.card__list li {
  font-size: 14px;
  color: var(--color-text-secondary);
  padding-left: var(--space-20);
  position: relative;
}

.card__list li::before {
  content: '•';
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: 700;
}

.card__image {
  width: 100%;
  height: 200px;
  overflow: hidden;
}

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

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

.card__content {
  padding: var(--space-24);
}

.card--info {
  display: grid;
  grid-template-rows: auto 1fr;
}

.card--showcase {
  display: grid;
  grid-template-rows: auto 1fr;
}

.card__checklist {
  display: flex;
  flex-direction: column;
  gap: var(--space-12);
  margin-top: var(--space-16);
}

.card__checklist li {
  display: flex;
  align-items: center;
  gap: var(--space-12);
  font-size: 14px;
  color: var(--color-text-secondary);
}

.card__checklist li svg {
  color: var(--color-success);
  flex-shrink: 0;
}

.card--service {
  padding: var(--space-32);
  text-align: center;
}

.card--service .card__icon {
  margin: 0 auto var(--space-16);
  color: var(--color-primary);
}

.card__tags {
  display: flex;
  gap: var(--space-8);
  flex-wrap: wrap;
  margin-top: var(--space-16);
}

.chip {
  padding: var(--space-4) var(--space-12);
  background: var(--color-background);
  border-radius: var(--radius-full);
  font-size: 12px;
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border);
}

/* ===================================
   Stats Section
   =================================== */
.stats {
  padding: var(--space-64) 0;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-hover) 100%);
  color: white;
}

.stats__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: var(--space-32);
  text-align: center;
}

.stat__number {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-8);
}

.stat__label {
  font-size: 14px;
  opacity: 0.9;
}

/* ===================================
   Contact Section
   =================================== */
.contact__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-48);
  align-items: start;
}

@media (max-width: 768px) {
  .contact__grid {
    grid-template-columns: 1fr;
  }
}

.contact__info {
  max-width: 500px;
}

.contact__text {
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-32);
}

.contact__details {
  display: flex;
  flex-direction: column;
  gap: var(--space-16);
}

.contact__item {
  display: flex;
  align-items: center;
  gap: var(--space-12);
  color: var(--color-text-secondary);
}

.contact__item svg {
  color: var(--color-primary);
  flex-shrink: 0;
}

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

/* Form Styles */
.contact__form {
  background: var(--color-surface);
  padding: var(--space-32);
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border);
}

.form__group {
  margin-bottom: var(--space-20);
}

.form__label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  margin-bottom: var(--space-8);
  color: var(--color-text-primary);
}

.form__input,
.form__select,
.form__textarea {
  width: 100%;
  padding: var(--space-12) var(--space-16);
  font-family: var(--font-body);
  font-size: 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-background);
  transition: var(--transition-fast);
}

.form__input:focus,
.form__select:focus,
.form__textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: var(--shadow-focus);
}

.form__textarea {
  resize: vertical;
  min-height: 120px;
}

.form__checkbox {
  margin-bottom: var(--space-20);
  display: flex;
  align-items: flex-start;
  gap: var(--space-12);
}

.form__checkbox input[type="checkbox"] {
  margin-top: var(--space-4);
  width: 20px;
  height: 20px;
  accent-color: var(--color-primary);
  cursor: pointer;
}

.form__checkbox label {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

.form__checkbox a {
  color: var(--color-primary);
  text-decoration: underline;
}

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

/* ===================================
   Footer
   =================================== */
.footer {
  background: var(--color-text-primary);
  color: var(--color-neutral);
  padding: var(--space-64) 0 var(--space-32);
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-48);
  margin-bottom: var(--space-48);
}

@media (max-width: 768px) {
  .footer__grid {
    grid-template-columns: 1fr;
    gap: var(--space-32);
  }
}

.footer__logo {
  font-family: var(--font-display);
  font-size: 24px;
  font-weight: 700;
  color: white;
  display: inline-block;
  margin-bottom: var(--space-16);
}

.footer__description {
  font-size: 14px;
  line-height: 1.6;
  max-width: 300px;
}

.footer__heading {
  font-size: 14px;
  font-weight: 600;
  color: white;
  margin-bottom: var(--space-16);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-12);
}

.footer__list li a {
  font-size: 14px;
  transition: var(--transition-fast);
}

.footer__list li a:hover {
  color: white;
}

.footer__list li {
  font-size: 14px;
}

.footer__legal {
  color: var(--color-neutral);
}

.footer__legal:hover {
  color: white;
}

.footer__bottom {
  padding-top: var(--space-32);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
  font-size: 13px;
}

/* ===================================
   Modal
   =================================== */
.modal {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  max-width: 700px;
  width: 90%;
  max-height: 80vh;
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
  padding: 0;
  overflow: hidden;
}

.modal::backdrop {
  background: rgba(0, 0, 0, 0.5);
}

.modal[open] {
  animation: modalFadeIn 0.3s ease;
}

@keyframes modalFadeIn {
  from {
    opacity: 0;
    transform: translate(-50%, -50%) scale(0.9);
  }
  to {
    opacity: 1;
    transform: translate(-50%, -50%) scale(1);
  }
}

.modal__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-24);
  border-bottom: 1px solid var(--color-border);
}

.modal__header h3 {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 600;
}

.modal__close {
  padding: var(--space-8);
  border-radius: var(--radius-sm);
  transition: var(--transition-fast);
}

.modal__close:hover {
  background: var(--color-background);
}

.modal__body {
  padding: var(--space-24);
  max-height: 60vh;
  overflow-y: auto;
}

.modal__body h4 {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 600;
  margin-bottom: var(--space-16);
}

.modal__body p {
  font-size: 14px;
  line-height: 1.6;
  margin-bottom: var(--space-16);
  color: var(--color-text-secondary);
}

.modal__body ul {
  margin-left: var(--space-20);
  margin-bottom: var(--space-16);
}

.modal__body ul li {
  font-size: 14px;
  line-height: 1.6;
  margin-bottom: var(--space-8);
  color: var(--color-text-secondary);
  list-style: disc;
}

.modal__note {
  font-size: 12px;
  color: var(--color-neutral);
  margin-top: var(--space-24);
  padding-top: var(--space-16);
  border-top: 1px solid var(--color-border);
}

@media (max-width: 768px) {
  .modal {
    width: 95%;
    max-height: 90vh;
  }
  
  .modal__body {
    max-height: 70vh;
  }
}

/* ===================================
   Cookie Banner
   =================================== */
.cookie-banner {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 200;
  background: var(--color-text-primary);
  color: var(--color-neutral);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-16);
  padding: var(--space-16) var(--space-24);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

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

.cookie-banner__text {
  font-size: 14px;
  line-height: 1.5;
}

.cookie-banner__link {
  color: var(--color-primary);
  text-decoration: underline;
  margin-left: var(--space-4);
  cursor: pointer;
}

.cookie-banner__link:hover {
  color: #818CF8;
}

.cookie-banner__btn {
  flex-shrink: 0;
  padding: var(--space-8) var(--space-20);
  background: var(--color-primary);
  color: white;
  font-size: 14px;
  font-weight: 500;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: var(--transition-fast);
}

.cookie-banner__btn:hover {
  background: var(--color-primary-hover);
}

@media (max-width: 768px) {
  .cookie-banner {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-12);
  }

  .cookie-banner__btn {
    width: 100%;
    text-align: center;
  }
}

/* ===================================
   Utilities
   =================================== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* Smooth scroll offset for sticky nav */
section[id] {
  scroll-margin-top: 80px;
}

/* Focus styles for accessibility */
*:focus-visible {
  outline: none;
  box-shadow: var(--shadow-focus);
}