/* ============================
   ProjectProof Landing Page
   Mobile-first responsive CSS
   ============================ */

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

:root {
  --primary: #1F3D87;
  --primary-dark: #152B61;
  --accent: #3B82F6;
  --accent-light: #60A5FA;
  --text: #1E293B;
  --text-light: #64748B;
  --text-lighter: #94A3B8;
  --bg: #FFFFFF;
  --bg-off: #F8FAFC;
  --bg-dark: #0F172A;
  --border: #E2E8F0;
  --success: #10B981;
  --radius: 12px;
  --radius-sm: 8px;
  --radius-lg: 20px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
  --shadow-lg: 0 20px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.1);
  --shadow-xl: 0 25px 50px -12px rgba(0,0,0,0.25);
  --transition: 0.3s ease;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

ul {
  list-style: none;
}

/* --- Container --- */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* --- Typography --- */
.section-title {
  font-size: 2rem;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
  color: var(--text);
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--text-light);
  max-width: 640px;
  margin: 0 auto 48px;
  line-height: 1.7;
}

.text-accent {
  color: var(--accent);
}

.hide-mobile {
  display: none;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
  text-decoration: none;
}

.btn-sm {
  padding: 8px 18px;
  font-size: 0.875rem;
}

.btn-lg {
  padding: 16px 32px;
  font-size: 1.0625rem;
  border-radius: var(--radius);
}

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

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

.btn-accent {
  background: var(--accent);
  color: #fff;
}

.btn-accent:hover {
  background: #2563EB;
  transform: translateY(-1px);
  box-shadow: var(--shadow);
}

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

.btn-outline:hover {
  border-color: var(--primary);
  background: var(--bg-off);
}

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

.btn-white:hover {
  background: var(--bg-off);
  transform: translateY(-1px);
  box-shadow: var(--shadow);
}

.btn-block {
  width: 100%;
}

.store-btn {
  min-width: 160px;
}

.store-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

/* --- Animations --- */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.nav.scrolled {
  border-bottom-color: var(--border);
  box-shadow: var(--shadow-sm);
}

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

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--primary);
  letter-spacing: -0.02em;
}

.nav-logo-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: var(--primary);
  color: #fff;
  border-radius: 10px;
  font-size: 1.125rem;
  font-weight: 800;
}

.nav-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  background: none;
  border: none;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: all var(--transition);
}

.nav-toggle.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

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

.nav-toggle.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.nav-links {
  display: none;
  position: absolute;
  top: 64px;
  left: 0;
  right: 0;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  padding: 16px 20px;
  box-shadow: var(--shadow);
}

.nav-links.open {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.nav-links a {
  padding: 10px 0;
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-light);
  transition: color var(--transition);
}

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

.nav-links .btn {
  margin-top: 8px;
  text-align: center;
}

/* --- Hero --- */
.hero {
  padding: 100px 0 60px;
  background: linear-gradient(180deg, var(--bg-off) 0%, var(--bg) 100%);
  overflow: hidden;
}

.hero-content {
  display: flex;
  flex-direction: column;
  gap: 48px;
}

.hero-title {
  font-size: 2.5rem;
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--text);
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--text-light);
  line-height: 1.7;
  margin-top: 16px;
  max-width: 520px;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.hero-note {
  margin-top: 12px;
  font-size: 0.875rem;
  color: var(--text-lighter);
}

/* Phone mockup */
.hero-mockup {
  display: flex;
  justify-content: center;
}

.phone-frame {
  width: 280px;
  padding: 12px;
  background: var(--text);
  border-radius: 36px;
  box-shadow: var(--shadow-xl);
  position: relative;
}

.phone-frame::before {
  content: '';
  position: absolute;
  top: 12px;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 24px;
  background: var(--bg-dark);
  border-radius: 12px;
  z-index: 2;
}

.phone-screen {
  background: var(--bg);
  border-radius: 26px;
  overflow: hidden;
  position: relative;
}

.mock-header {
  background: var(--primary);
  padding: 36px 16px 14px;
}

.mock-status-bar {
  height: 4px;
}

.mock-app-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.mock-title {
  color: #fff;
  font-weight: 700;
  font-size: 0.9375rem;
}

.mock-date {
  color: rgba(255,255,255,0.7);
  font-size: 0.8125rem;
}

.mock-body {
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.mock-capture {
  background: var(--bg-off);
  border-radius: var(--radius-sm);
  padding: 10px;
  border: 1px solid var(--border);
}

.mock-photo {
  height: 48px;
  background: linear-gradient(135deg, #CBD5E1 0%, #94A3B8 100%);
  border-radius: 6px;
  margin-bottom: 8px;
}

.mock-photo-2 {
  background: linear-gradient(135deg, #A5B4FC 0%, #818CF8 100%);
}

.mock-voice {
  height: 32px;
  background: linear-gradient(90deg,
    var(--accent) 0%, var(--accent) 8%,
    transparent 8%, transparent 12%,
    var(--accent) 12%, var(--accent) 16%,
    transparent 16%, transparent 20%,
    var(--accent) 20%, var(--accent) 32%,
    transparent 32%, transparent 36%,
    var(--accent) 36%, var(--accent) 40%,
    transparent 40%, transparent 44%,
    var(--accent) 44%, var(--accent) 56%,
    transparent 56%, transparent 60%,
    var(--accent) 60%, var(--accent) 64%,
    transparent 64%, transparent 68%,
    var(--accent) 68%, var(--accent) 76%,
    transparent 76%, transparent 80%,
    var(--accent) 80%, var(--accent) 84%,
    transparent 84%, transparent 88%,
    var(--accent) 88%, var(--accent) 92%,
    transparent 92%
  );
  opacity: 0.3;
  border-radius: 6px;
  margin-bottom: 8px;
}

.mock-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 4px;
}

.mock-time {
  font-size: 0.6875rem;
  color: var(--text-lighter);
  font-weight: 500;
}

.mock-tag {
  font-size: 0.625rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--primary);
  background: rgba(31, 61, 135, 0.08);
  padding: 2px 6px;
  border-radius: 4px;
}

.tag-voice {
  color: var(--accent);
  background: rgba(59, 130, 246, 0.08);
}

.mock-desc {
  font-size: 0.75rem;
  color: var(--text);
  line-height: 1.4;
}

.mock-fab {
  position: absolute;
  bottom: 14px;
  right: 14px;
  width: 44px;
  height: 44px;
  background: var(--accent);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 300;
  box-shadow: var(--shadow-lg);
}

/* --- Problem --- */
.problem {
  padding: 80px 0;
  background: var(--bg);
  text-align: center;
}

.problem-grid {
  display: grid;
  gap: 24px;
  margin: 40px 0;
}

.problem-card {
  padding: 32px 24px;
  background: var(--bg-off);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  text-align: left;
}

.problem-icon {
  font-size: 2rem;
  margin-bottom: 16px;
}

.problem-card h3 {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text);
}

.problem-card p {
  font-size: 0.9375rem;
  color: var(--text-light);
  line-height: 1.6;
}

.problem-cta {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--primary);
  margin-top: 8px;
}

/* --- Features --- */
.features {
  padding: 80px 0;
  background: var(--bg-off);
  text-align: center;
}

.features-grid {
  display: grid;
  gap: 24px;
}

.feature-card {
  padding: 32px 24px;
  background: var(--bg);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  text-align: left;
  transition: transform var(--transition), box-shadow var(--transition);
}

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

.feature-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(59, 130, 246, 0.08);
  color: var(--accent);
  border-radius: var(--radius-sm);
  margin-bottom: 16px;
}

.feature-icon svg {
  width: 28px;
  height: 28px;
}

.feature-card h3 {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text);
}

.feature-card p {
  font-size: 0.9375rem;
  color: var(--text-light);
  line-height: 1.6;
}

/* --- How It Works --- */
.how-it-works {
  padding: 80px 0;
  background: var(--bg);
  text-align: center;
}

.steps {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0;
  margin-top: 48px;
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}

.step {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  text-align: left;
  width: 100%;
}

.step-number {
  flex-shrink: 0;
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--primary);
  color: #fff;
  font-size: 1.25rem;
  font-weight: 800;
  border-radius: 50%;
}

.step-content h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 6px;
  margin-top: 2px;
}

.step-content p {
  font-size: 0.9375rem;
  color: var(--text-light);
  line-height: 1.6;
}

.step-connector {
  width: 2px;
  height: 32px;
  background: var(--border);
  margin-left: 25px;
}

/* --- Pricing --- */
.pricing {
  padding: 80px 0;
  background: var(--bg-off);
  text-align: center;
}

.pricing-grid {
  display: grid;
  gap: 24px;
  max-width: 800px;
  margin: 0 auto;
}

.pricing-card {
  padding: 32px 24px;
  background: var(--bg);
  border-radius: var(--radius-lg);
  border: 2px solid var(--border);
  text-align: left;
  position: relative;
}

.pricing-card-pro {
  border-color: var(--accent);
  box-shadow: var(--shadow-lg);
}

.pricing-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent);
  color: #fff;
  font-size: 0.8125rem;
  font-weight: 700;
  padding: 4px 20px;
  border-radius: 20px;
  white-space: nowrap;
}

.pricing-header {
  margin-bottom: 24px;
}

.pricing-header h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
}

.pricing-price {
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.price-amount {
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--text);
  letter-spacing: -0.02em;
}

.price-period {
  font-size: 1rem;
  color: var(--text-light);
}

.pricing-features {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 28px;
}

.pricing-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9375rem;
  color: var(--text);
}

.check {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  color: var(--success);
}

/* Comparison */
.pricing-comparison {
  margin-top: 56px;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.comparison-inner {
  background: var(--bg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  overflow: hidden;
}

.comparison-title {
  font-size: 1.125rem;
  font-weight: 700;
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
  text-align: left;
}

.comparison-table {
  padding: 0 24px;
}

.comparison-row {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 12px;
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.875rem;
  align-items: center;
}

.comparison-row:last-child {
  border-bottom: none;
}

.comparison-header-row {
  font-weight: 700;
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-light);
}

.comparison-highlight {
  color: var(--accent);
  font-weight: 700;
}

.comparison-row small {
  display: block;
  font-size: 0.75rem;
  color: var(--text-lighter);
}

/* --- CTA --- */
.cta {
  padding: 80px 0;
  background: var(--primary);
  text-align: center;
}

.cta-content h2 {
  font-size: 2rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 12px;
}

.cta-content p {
  font-size: 1.125rem;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: 32px;
}

.cta-buttons {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
}

.cta-note {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.6);
  margin-top: 16px;
}

/* --- Footer --- */
.footer {
  padding: 60px 0 32px;
  background: var(--bg-dark);
  color: rgba(255, 255, 255, 0.7);
}

.footer-grid {
  display: grid;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand {
  max-width: 320px;
}

.footer-brand .nav-logo {
  color: #fff;
  margin-bottom: 12px;
}

.footer-brand .nav-logo-icon {
  background: var(--accent);
}

.footer-brand p {
  font-size: 0.875rem;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.5);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links h4 {
  font-size: 0.875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: rgba(255, 255, 255, 0.4);
  margin-bottom: 4px;
}

.footer-links a {
  font-size: 0.9375rem;
  color: rgba(255, 255, 255, 0.7);
  transition: color var(--transition);
}

.footer-links a:hover {
  color: #fff;
}

.footer-bottom {
  padding-top: 32px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
}

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

/* ============================
   Responsive — Tablet (640px+)
   ============================ */
@media (min-width: 640px) {
  .container {
    padding: 0 32px;
  }

  .section-title {
    font-size: 2.5rem;
  }

  .hide-mobile {
    display: inline;
  }

  .hero-title {
    font-size: 3rem;
  }

  .problem-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1fr;
  }

  .cta-content h2 {
    font-size: 2.5rem;
  }
}

/* ============================
   Responsive — Desktop (1024px+)
   ============================ */
@media (min-width: 1024px) {
  .section-title {
    font-size: 2.75rem;
  }

  /* Nav */
  .nav-toggle {
    display: none;
  }

  .nav-links {
    display: flex !important;
    position: static;
    background: none;
    border: none;
    padding: 0;
    box-shadow: none;
    flex-direction: row;
    align-items: center;
    gap: 32px;
  }

  .nav-links a {
    padding: 0;
    font-size: 0.9375rem;
  }

  .nav-links .btn {
    margin-top: 0;
  }

  /* Hero */
  .hero {
    padding: 120px 0 80px;
  }

  .hero-content {
    flex-direction: row;
    align-items: center;
    gap: 80px;
  }

  .hero-text {
    flex: 1;
  }

  .hero-title {
    font-size: 3.5rem;
  }

  .hero-mockup {
    flex-shrink: 0;
  }

  .phone-frame {
    width: 320px;
  }

  /* Problem */
  .problem {
    padding: 100px 0;
  }

  /* Features */
  .features {
    padding: 100px 0;
  }

  .features-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
  }

  /* How It Works */
  .how-it-works {
    padding: 100px 0;
  }

  .steps {
    flex-direction: row;
    max-width: 100%;
    gap: 0;
    align-items: flex-start;
  }

  .step {
    flex-direction: column;
    align-items: center;
    text-align: center;
    flex: 1;
  }

  .step-number {
    margin-bottom: 20px;
  }

  .step-connector {
    width: 100%;
    height: 2px;
    margin-left: 0;
    margin-top: 26px;
    flex-shrink: 1;
    max-width: 120px;
  }

  /* Pricing */
  .pricing {
    padding: 100px 0;
  }

  /* CTA */
  .cta {
    padding: 100px 0;
  }

  .cta-content h2 {
    font-size: 3rem;
  }

  /* Footer */
  .footer {
    padding: 80px 0 40px;
  }
}

/* ============================
   Responsive — Large (1280px+)
   ============================ */
@media (min-width: 1280px) {
  .hero-title {
    font-size: 4rem;
  }

  .section-title {
    font-size: 3rem;
  }
}

/* ============================
   Reduced Motion
   ============================ */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .fade-in {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .feature-card:hover {
    transform: none;
  }

  .btn:hover {
    transform: none;
  }
}