/* ================================================
   Kairos Landing — Design System v2
   Dark-mode-first, orange accent, premium minimal
   ================================================ */

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

:root {
  /* Accent — Kairos Orange */
  --orange-500: #FF6B2B;
  --orange-400: #FF8F5C;
  --orange-300: #FFB899;
  --orange-100: #FFF4EE;
  --orange-900: #CC4400;

  /* Dark Mode (Primary) */
  --dark-bg: #0F0F0F;
  --dark-surface: #1A1A1A;
  --dark-elevated: #242424;
  --dark-border: #2E2E2E;
  --dark-text-1: #EDEDEF;
  --dark-text-2: #A3A3A3;
  --dark-text-3: #737373;

  /* Light Mode */
  --light-bg: #FAFAFA;
  --light-surface: #FFFFFF;
  --light-border: #E8E8E8;
  --light-subtle: #F5F5F3;
  --light-text-1: #171717;
  --light-text-2: #737373;
  --light-text-3: #A3A3A3;

  /* Semantic */
  --success: #22C55E;
  --error: #EF4444;

  /* System */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow-md: 0 1px 3px rgba(0,0,0,0.06), 0 8px 24px rgba(0,0,0,0.04);
  --shadow-lg: 0 2px 8px rgba(0,0,0,0.08), 0 12px 32px rgba(0,0,0,0.06);
  --transition: 150ms ease;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--dark-text-1);
  background: var(--dark-bg);
}

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

.desktop-only {
  display: none;
}

/* --- Nav --- */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(15, 15, 15, 0.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--dark-border);
}

.nav-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--dark-text-1);
  text-decoration: none;
  letter-spacing: -0.02em;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  font-family: inherit;
  font-size: 0.9375rem;
  font-weight: 500;
  color: #FFFFFF;
  background: var(--orange-500);
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
  text-decoration: none;
  white-space: nowrap;
}

.btn:hover {
  background: var(--orange-400);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(255, 107, 43, 0.25);
}

.btn:active {
  transform: translateY(0);
  box-shadow: none;
}

.btn-sm {
  padding: 8px 16px;
  font-size: 0.875rem;
}

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

.btn-ghost:hover {
  background: var(--dark-elevated);
  box-shadow: none;
}

/* --- Hero --- */
.hero {
  padding: 96px 0 80px;
  background: var(--dark-bg);
  text-align: center;
}

.hero-eyebrow {
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--orange-500);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 20px;
}

.hero-title {
  font-size: 2.5rem;
  font-weight: 600;
  line-height: 1.12;
  letter-spacing: -0.03em;
  color: var(--dark-text-1);
  margin-bottom: 20px;
}

.hero-sub {
  font-size: 1.0625rem;
  color: var(--dark-text-2);
  max-width: 520px;
  margin: 0 auto 40px;
  line-height: 1.7;
}

/* --- Waitlist Form --- */
.waitlist-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-width: 420px;
  margin: 0 auto;
}

.phone-input-wrap {
  display: flex;
  align-items: center;
  width: 100%;
  background: var(--dark-surface);
  border: 1px solid var(--dark-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.phone-input-wrap:focus-within {
  border-color: var(--orange-500);
  box-shadow: 0 0 0 3px rgba(255, 107, 43, 0.15);
}

.phone-prefix {
  padding: 12px 0 12px 16px;
  font-family: inherit;
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--dark-text-3);
  white-space: nowrap;
  user-select: none;
}

.waitlist-form input[type="tel"] {
  flex: 1;
  width: 100%;
  padding: 12px 16px 12px 8px;
  font-family: inherit;
  font-size: 0.9375rem;
  color: var(--dark-text-1);
  background: transparent;
  border: none;
  outline: none;
}

.waitlist-form input[type="tel"]::placeholder {
  color: var(--dark-text-3);
}

.form-msg {
  font-size: 0.875rem;
  text-align: center;
  min-height: 1.4em;
  margin-top: 4px;
}

.form-msg.success {
  color: var(--success);
}

.form-msg.error {
  color: var(--error);
}

/* --- Sections --- */
.section {
  padding: 80px 0;
}

.section-label {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--orange-500);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  text-align: center;
  margin-bottom: 12px;
}

.section-title {
  font-size: 1.75rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  text-align: center;
  margin-bottom: 48px;
  color: var(--dark-text-1);
}

/* --- Countdown --- */
.countdown {
  background: var(--dark-surface);
  border-top: 1px solid var(--dark-border);
  border-bottom: 1px solid var(--dark-border);
  padding: 32px 0;
}

.countdown-inner {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
}

.countdown-label {
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--dark-text-3);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.countdown-timer {
  display: flex;
  gap: 20px;
}

.countdown-unit {
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.countdown-value {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--orange-500);
  font-variant-numeric: tabular-nums;
  min-width: 2ch;
  text-align: right;
}

.countdown-desc {
  font-size: 0.75rem;
  font-weight: 400;
  color: var(--dark-text-3);
}

/* --- Problem --- */
.problem {
  background: var(--dark-bg);
  border-top: 1px solid var(--dark-border);
}

.problem-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
  max-width: 640px;
  margin: 0 auto;
}

.problem-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  padding: 20px 24px;
  background: var(--dark-surface);
  border: 1px solid var(--dark-border);
  border-radius: var(--radius-md);
}

.problem-number {
  flex-shrink: 0;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--orange-500);
  padding-top: 2px;
  font-variant-numeric: tabular-nums;
}

.problem-item p {
  font-size: 1rem;
  color: var(--dark-text-2);
  line-height: 1.65;
}

/* --- Features / Cards --- */
.features {
  background: var(--dark-surface);
  border-top: 1px solid var(--dark-border);
  border-bottom: 1px solid var(--dark-border);
}

.cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.card {
  background: var(--dark-elevated);
  border: 1px solid var(--dark-border);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  transition: border-color var(--transition), transform var(--transition);
}

.card:hover {
  border-color: var(--dark-text-3);
  transform: translateY(-2px);
}

.card-number {
  font-size: 0.6875rem;
  font-weight: 600;
  color: var(--orange-500);
  letter-spacing: 0.05em;
  margin-bottom: 12px;
  font-variant-numeric: tabular-nums;
}

.card h3 {
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--dark-text-1);
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.card p {
  font-size: 0.9375rem;
  color: var(--dark-text-2);
  line-height: 1.65;
}

/* --- Stat --- */
.stat {
  background: var(--dark-bg);
  padding: 80px 0;
  border-top: 1px solid var(--dark-border);
}

.stat-block {
  text-align: center;
  background: var(--dark-surface);
  border: 1px solid var(--dark-border);
  border-radius: var(--radius-lg);
  padding: 48px 32px;
  max-width: 600px;
  margin: 0 auto;
}

.stat-number {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--dark-text-1);
  letter-spacing: -0.02em;
  line-height: 1.3;
}

.stat-number .accent {
  color: var(--orange-500);
}

.stat-equals {
  font-size: 2rem;
  font-weight: 300;
  color: var(--dark-text-3);
  margin: 16px 0;
}

.stat-source {
  font-size: 0.8125rem;
  color: var(--dark-text-3);
  margin-top: 24px;
  line-height: 1.5;
}

.stat-link {
  display: inline-block;
  margin-top: 16px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--orange-500);
  text-decoration: none;
  transition: color var(--transition);
}

.stat-link:hover {
  color: var(--orange-400);
}

/* --- CTA --- */
.cta {
  background: var(--dark-surface);
  border-top: 1px solid var(--dark-border);
  padding: 96px 0;
  text-align: center;
}

.cta-sub {
  font-size: 1rem;
  color: var(--dark-text-2);
  max-width: 480px;
  margin: -20px auto 40px;
  line-height: 1.7;
}

/* --- Footer --- */
.footer {
  padding: 24px 0;
  text-align: center;
  font-size: 0.8125rem;
  color: var(--dark-text-3);
  background: var(--dark-bg);
  border-top: 1px solid var(--dark-border);
}

/* --- Follow-up Overlay --- */
.followup-overlay {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  opacity: 0;
  visibility: hidden;
  transition: opacity 300ms ease, visibility 300ms ease;
}

.followup-overlay.active {
  opacity: 1;
  visibility: visible;
}

.followup-panel {
  position: relative;
  width: 92%;
  max-width: 440px;
  max-height: 90vh;
  overflow-y: auto;
  background: var(--dark-surface);
  border: 1px solid var(--dark-border);
  border-radius: var(--radius-lg);
  padding: 36px 28px 28px;
  transform: translateY(24px);
  transition: transform 300ms ease;
}

.followup-overlay.active .followup-panel {
  transform: translateY(0);
}

.followup-close {
  position: absolute;
  top: 12px;
  right: 16px;
  background: none;
  border: none;
  color: var(--dark-text-3);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 4px 8px;
  line-height: 1;
  transition: color var(--transition);
}

.followup-close:hover {
  color: var(--dark-text-1);
}

.followup-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--dark-text-1);
  letter-spacing: -0.01em;
  margin-bottom: 6px;
  padding-right: 24px;
}

.followup-sub {
  font-size: 0.875rem;
  color: var(--dark-text-3);
  margin-bottom: 24px;
  line-height: 1.5;
}

#followup-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

#followup-form input[type="text"],
#followup-form select {
  width: 100%;
  padding: 12px 16px;
  font-family: inherit;
  font-size: 0.9375rem;
  color: var(--dark-text-1);
  background: var(--dark-elevated);
  border: 1px solid var(--dark-border);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
  -webkit-appearance: none;
  appearance: none;
}

#followup-form select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%23737373' stroke-width='1.5' fill='none'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 36px;
}

/* Placeholder-style for unselected selects */
#followup-form select:invalid,
#followup-form select option[value=""][disabled] {
  color: var(--dark-text-3);
}

#followup-form select option {
  background: var(--dark-elevated);
  color: var(--dark-text-1);
}

#followup-form input[type="text"]::placeholder {
  color: var(--dark-text-3);
}

#followup-form input[type="text"]:focus,
#followup-form select:focus {
  border-color: var(--orange-500);
  box-shadow: 0 0 0 3px rgba(255, 107, 43, 0.15);
}

#followup-form .btn {
  margin-top: 4px;
  width: 100%;
}

.followup-skip {
  display: block;
  width: 100%;
  margin-top: 12px;
  padding: 10px;
  background: none;
  border: none;
  color: var(--dark-text-3);
  font-family: inherit;
  font-size: 0.875rem;
  cursor: pointer;
  transition: color var(--transition);
}

.followup-skip:hover {
  color: var(--dark-text-2);
}

/* ================================================
   Responsive
   ================================================ */
@media (min-width: 640px) {
  .desktop-only {
    display: inline;
  }

  .hero {
    padding: 120px 0 96px;
  }

  .hero-title {
    font-size: 3.25rem;
  }

  .waitlist-form {
    flex-direction: row;
  }

  .waitlist-form .btn {
    flex-shrink: 0;
  }

  .section-title {
    font-size: 2rem;
  }

  .cards {
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
  }

  .stat-number {
    font-size: 1.75rem;
  }
}

@media (min-width: 1024px) {
  .hero-title {
    font-size: 3.75rem;
  }

  .hero-sub {
    font-size: 1.125rem;
  }

  .section {
    padding: 96px 0;
  }

  .stat {
    padding: 96px 0;
  }

  .stat-block {
    padding: 56px 48px;
  }

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

  .cta {
    padding: 120px 0;
  }
}

/* --- Reduced motion --- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition-duration: 0ms !important;
    animation-duration: 0ms !important;
  }

  html {
    scroll-behavior: auto;
  }
}