/* ==========================================================================
   Spool Official Website Stylesheet
   Design Philosophy: Apple Human Interface inspired, native, clean, responsive
   ========================================================================== */

:root {
  --primary-color: #0071e3;
  --primary-hover: #0077ed;
  --primary-light: rgba(0, 113, 227, 0.1);
  --accent-color: #30d158;
  --text-main: #1d1d1f;
  --text-secondary: #6e6e73;
  --text-tertiary: #86868b;
  --bg-main: #ffffff;
  --bg-secondary: #f5f5f7;
  --bg-card: rgba(255, 255, 255, 0.85);
  --border-color: rgba(0, 0, 0, 0.08);
  --border-subtle: rgba(0, 0, 0, 0.04);
  --nav-bg: rgba(255, 255, 255, 0.8);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.12);
  --font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --code-font: "SF Mono", Menlo, Monaco, Consolas, "Courier New", monospace;
  --max-width: 1120px;
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 10px;
  --transition-fast: 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --primary-color: #2997ff;
    --primary-hover: #47a3ff;
    --primary-light: rgba(41, 151, 255, 0.15);
    --accent-color: #32d74b;
    --text-main: #f5f5f7;
    --text-secondary: #a1a1a6;
    --text-tertiary: #6e6e73;
    --bg-main: #000000;
    --bg-secondary: #161617;
    --bg-card: rgba(28, 28, 30, 0.85);
    --border-color: rgba(255, 255, 255, 0.12);
    --border-subtle: rgba(255, 255, 255, 0.06);
    --nav-bg: rgba(0, 0, 0, 0.75);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.6);
  }
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.55;
  letter-spacing: -0.015em;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

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

/* Header & Navigation */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--nav-bg);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border-color);
  transition: all var(--transition-fast);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 600;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}

.brand-icon {
  width: 34px;
  height: 34px;
  border-radius: 8.5px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
  object-fit: cover;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav-link {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  font-weight: 450;
  position: relative;
  padding: 6px 0;
}

.nav-link:hover, .nav-link.active {
  color: var(--text-main);
}

.nav-cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  font-size: 0.875rem;
  font-weight: 550;
  color: #ffffff !important;
  background-color: var(--primary-color);
  border-radius: 980px;
  transition: transform var(--transition-fast), background-color var(--transition-fast);
}

.nav-cta-btn:hover {
  background-color: var(--primary-hover);
  transform: scale(1.02);
}

/* Mobile Menu Button */
.mobile-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  color: var(--text-main);
}

/* Hero Section */
.hero-section {
  padding: 96px 0 64px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: 980px;
  background-color: var(--primary-light);
  color: var(--primary-color);
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero-title {
  font-size: clamp(2.5rem, 5.5vw, 4.25rem);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.035em;
  margin-bottom: 20px;
  max-width: 860px;
  margin-left: auto;
  margin-right: auto;
}

.hero-subtitle {
  font-size: clamp(1.125rem, 2.2vw, 1.375rem);
  color: var(--text-secondary);
  max-width: 680px;
  margin: 0 auto 36px;
  line-height: 1.45;
}

.hero-actions {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 16px;
  margin-bottom: 56px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 980px;
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all var(--transition-fast);
}

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

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(0, 113, 227, 0.28);
}

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

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

/* Interactive Simulator / Live Demo */
.simulator-wrapper {
  max-width: 820px;
  margin: 0 auto;
  padding: 24px;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  backdrop-filter: blur(20px);
  text-align: left;
}

.simulator-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-subtle);
}

.simulator-title {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-tertiary);
  display: flex;
  align-items: center;
  gap: 6px;
}

.simulator-title::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--accent-color);
}

.preset-selector {
  display: flex;
  gap: 6px;
  background-color: var(--bg-secondary);
  padding: 3px;
  border-radius: 980px;
}

.preset-btn {
  background: none;
  border: none;
  padding: 4px 12px;
  font-size: 0.8125rem;
  font-weight: 550;
  color: var(--text-secondary);
  border-radius: 980px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.preset-btn.active {
  background-color: var(--bg-main);
  color: var(--text-main);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.1);
}

.sim-input-area {
  margin-bottom: 18px;
}

.sim-textarea {
  width: 100%;
  min-height: 88px;
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  background-color: var(--bg-secondary);
  color: var(--text-main);
  font-family: inherit;
  font-size: 0.9375rem;
  resize: vertical;
  line-height: 1.45;
}

.sim-textarea:focus {
  outline: none;
  border-color: var(--primary-color);
}

.sim-quick-actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 8px;
}

.sim-char-counter {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
}

/* Virtual Keyboard Rendering */
.virtual-keyboard-card {
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  padding: 16px;
  border: 1px solid var(--border-color);
}

.vk-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.vk-brand {
  font-weight: 600;
  font-size: 0.9375rem;
  display: flex;
  align-items: center;
  gap: 6px;
}

.vk-progress-badge {
  font-size: 0.8125rem;
  font-weight: 600;
  padding: 2px 8px;
  background-color: var(--primary-light);
  color: var(--primary-color);
  border-radius: 980px;
}

.vk-progress-bar-container {
  width: 100%;
  height: 5px;
  background-color: var(--border-color);
  border-radius: 980px;
  overflow: hidden;
  margin-bottom: 14px;
}

.vk-progress-bar {
  height: 100%;
  background-color: var(--primary-color);
  border-radius: 980px;
  transition: width var(--transition-normal);
  width: 33.3%;
}

.vk-card-preview {
  background-color: var(--bg-main);
  border-radius: var(--radius-sm);
  padding: 14px;
  min-height: 90px;
  border: 1px solid var(--border-subtle);
  margin-bottom: 14px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.vk-segment-text {
  font-size: 0.9375rem;
  color: var(--text-main);
  white-space: pre-wrap;
  word-break: break-word;
  line-height: 1.45;
}

.vk-card-meta {
  display: flex;
  justify-content: flex-end;
  margin-top: 10px;
  font-size: 0.75rem;
  color: var(--text-tertiary);
  font-family: var(--code-font);
}

.vk-controls {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 10px;
  align-items: center;
}

.vk-nav-btns {
  display: flex;
  gap: 6px;
}

.vk-btn-icon {
  width: 42px;
  height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background-color: var(--bg-main);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

.vk-btn-icon:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.vk-btn-icon:hover:not(:disabled) {
  background-color: var(--bg-secondary);
}

.vk-btn-insert {
  background-color: var(--primary-color);
  color: #ffffff;
  border: none;
  font-size: 0.9375rem;
  font-weight: 600;
  padding: 10px 24px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  transition: background-color var(--transition-fast), transform 0.1s;
}

.vk-btn-insert:hover {
  background-color: var(--primary-hover);
}

.vk-btn-insert:active {
  transform: scale(0.97);
}

.vk-btn-split {
  background-color: var(--bg-main);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  font-size: 0.875rem;
  font-weight: 550;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  text-align: center;
  transition: background-color var(--transition-fast);
}

.vk-btn-split:hover {
  background-color: var(--bg-secondary);
}

/* Section Header */
.section {
  padding: 96px 0;
  position: relative;
}

.section-light {
  background-color: var(--bg-secondary);
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 56px;
}

.section-tag {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--primary-color);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(2rem, 3.8vw, 3rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
}

.section-desc {
  font-size: 1.125rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Feature Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.feature-icon-wrapper {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  background-color: var(--primary-light);
  color: var(--primary-color);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  font-size: 1.5rem;
}

.feature-heading {
  font-size: 1.25rem;
  font-weight: 650;
  margin-bottom: 10px;
  letter-spacing: -0.02em;
}

.feature-text {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.55;
  flex-grow: 1;
}

/* Steps Section */
.steps-container {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-top: 40px;
}

.step-card {
  position: relative;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
}

.step-number {
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1;
  color: var(--primary-color);
  opacity: 0.3;
  margin-bottom: 16px;
  font-feature-settings: "tnum";
}

.step-title {
  font-size: 1.25rem;
  font-weight: 650;
  margin-bottom: 8px;
}

.step-desc {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Privacy Callout Banner */
.privacy-callout {
  background: linear-gradient(135deg, rgba(0, 113, 227, 0.08) 0%, rgba(48, 209, 88, 0.08) 100%);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  margin: 64px 0 0;
}

.privacy-content h3 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.privacy-content p {
  color: var(--text-secondary);
  font-size: 1rem;
  max-width: 620px;
  line-height: 1.55;
}

/* FAQ Accordion */
.faq-list {
  max-width: 760px;
  margin: 0 auto;
}

.faq-item {
  border-bottom: 1px solid var(--border-color);
}

.faq-question {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 22px 0;
  background: none;
  border: none;
  font-family: inherit;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-main);
  text-align: left;
  cursor: pointer;
  transition: color var(--transition-fast);
}

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

.faq-chevron {
  width: 20px;
  height: 20px;
  transition: transform var(--transition-normal);
  color: var(--text-tertiary);
  flex-shrink: 0;
}

.faq-item.active .faq-chevron {
  transform: rotate(180deg);
  color: var(--primary-color);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-normal), opacity var(--transition-normal);
  opacity: 0;
}

.faq-item.active .faq-answer {
  max-height: 400px;
  opacity: 1;
  padding-bottom: 24px;
}

.faq-answer p {
  font-size: 0.98rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Footer */
.site-footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 64px 0 36px;
  color: var(--text-secondary);
  font-size: 0.875rem;
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}

.footer-brand h4 {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 8px;
}

.footer-brand p {
  line-height: 1.5;
  max-width: 320px;
}

.footer-col h5 {
  font-size: 0.8125rem;
  font-weight: 650;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-main);
  margin-bottom: 16px;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 10px;
}

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

.footer-bottom {
  padding-top: 28px;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

/* Privacy Page Specifics */
.legal-container {
  max-width: 780px;
  margin: 48px auto 96px;
  padding: 0 24px;
}

.legal-header {
  margin-bottom: 40px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
}

.legal-badge {
  display: inline-block;
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--primary-color);
  letter-spacing: 0.05em;
  margin-bottom: 8px;
}

.legal-title {
  font-size: clamp(2rem, 4vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 8px;
}

.legal-updated {
  font-size: 0.875rem;
  color: var(--text-tertiary);
}

.legal-body {
  line-height: 1.7;
  color: var(--text-main);
}

.legal-body h2 {
  font-size: 1.375rem;
  font-weight: 650;
  margin: 36px 0 12px;
  letter-spacing: -0.02em;
}

.legal-body p {
  margin-bottom: 16px;
  color: var(--text-secondary);
}

.legal-body ul {
  margin-bottom: 20px;
  padding-left: 24px;
  color: var(--text-secondary);
}

.legal-body li {
  margin-bottom: 8px;
}

.highlight-box {
  background-color: var(--bg-secondary);
  border-left: 4px solid var(--primary-color);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 16px 20px;
  margin: 24px 0;
}

.highlight-box p {
  margin-bottom: 0;
  color: var(--text-main);
  font-weight: 500;
}

/* Responsive Breakpoints */
@media (max-width: 960px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .steps-container {
    grid-template-columns: 1fr;
  }
  .privacy-callout {
    flex-direction: column;
    text-align: center;
  }
}

@media (max-width: 720px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    width: 100%;
    background-color: var(--bg-main);
    border-bottom: 1px solid var(--border-color);
    flex-direction: column;
    padding: 20px 24px;
    gap: 16px;
    box-shadow: var(--shadow-md);
  }

  .nav-links.show {
    display: flex;
  }

  .mobile-toggle {
    display: block;
  }

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

  .footer-top {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .hero-section {
    padding: 60px 0 40px;
  }

  .vk-controls {
    grid-template-columns: 1fr;
    gap: 12px;
  }
}