/* ============================================
   Build My Idea — Landing Page Styles
   ============================================ */

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

:root {
  /* Brand colors — trustworthy yet not boring */
  --color-primary: #7C3AED;        /* vibrant violet */
  --color-primary-dark: #6D28D9;
  --color-primary-light: #A78BFA;
  --color-primary-glow: rgba(124, 58, 237, 0.15);

  --color-bg: #09090B;             /* near-black */
  --color-bg-elevated: #18181B;
  --color-bg-surface: #27272A;

  --color-text: #FAFAFA;
  --color-text-secondary: #A1A1AA;
  --color-text-muted: #71717A;

  --color-border: #3F3F46;
  --color-border-light: #27272A;

  --color-success: #10B981;
  --color-success-bg: rgba(16, 185, 129, 0.1);

  --color-error: #EF4444;
  --color-error-bg: rgba(239, 68, 68, 0.1);

  /* Typography */
  --font: 'Inter', system-ui, -apple-system, sans-serif;

  /* Spacing (4px grid) */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;
  --space-20: 80px;

  /* Radii */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
}

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

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

a {
  color: var(--color-primary-light);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* --- Focus styles --- */
:focus-visible {
  outline: 2px solid var(--color-primary-light);
  outline-offset: 2px;
}

/* --- Nav --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(9, 9, 11, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border-light);
}

.nav-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 var(--space-6);
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--color-text);
  text-decoration: none;
}

.nav-logo:hover {
  text-decoration: none;
  opacity: 0.9;
}

.nav-logo-icon {
  font-size: 1.25rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-6);
}

.nav-link {
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  transition: color 0.2s;
}

.nav-link:hover {
  color: var(--color-text);
  text-decoration: none;
}

.nav-link--cta {
  background: var(--color-primary);
  color: #fff;
  padding: var(--space-2) var(--space-5);
  border-radius: var(--radius-full);
  font-weight: 600;
  transition: background 0.2s;
}

.nav-link--cta:hover {
  background: var(--color-primary-dark);
}

/* --- Hero --- */
.hero {
  position: relative;
  min-height: 92vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(64px + var(--space-16)) var(--space-6) var(--space-16);
  overflow: hidden;
}

.hero-inner {
  max-width: 800px;
  position: relative;
  z-index: 1;
}

.hero-badge {
  display: inline-block;
  padding: var(--space-1) var(--space-4);
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  background: var(--color-bg-elevated);
  color: var(--color-text-secondary);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  margin-bottom: var(--space-8);
}

.hero-headline {
  font-size: clamp(2.25rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-6);
}

.hero-headline--accent {
  background: linear-gradient(135deg, var(--color-primary-light), var(--color-primary));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-sub {
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  color: var(--color-text-secondary);
  max-width: 560px;
  margin: 0 auto var(--space-10);
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: var(--space-4);
  justify-content: center;
  flex-wrap: wrap;
}

.hero-glow {
  position: absolute;
  top: 15%;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 400px;
  background: radial-gradient(ellipse, var(--color-primary-glow), transparent 70%);
  pointer-events: none;
  z-index: 0;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  font-family: var(--font);
  font-weight: 600;
  font-size: 0.9375rem;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.btn--primary {
  background: var(--color-primary);
  color: #fff;
  padding: var(--space-3) var(--space-6);
}

.btn--primary:hover {
  background: var(--color-primary-dark);
  text-decoration: none;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(124, 58, 237, 0.3);
}

.btn--primary:active {
  transform: translateY(0);
}

.btn--ghost {
  background: transparent;
  color: var(--color-text-secondary);
  padding: var(--space-3) var(--space-6);
  border: 1px solid var(--color-border);
}

.btn--ghost:hover {
  border-color: var(--color-text-muted);
  color: var(--color-text);
  text-decoration: none;
}

.btn--lg {
  padding: var(--space-4) var(--space-8);
  font-size: 1rem;
  border-radius: var(--radius-md);
}

.btn--full {
  width: 100%;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none !important;
}

.btn-text {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}

.btn-spinner {
  display: none;
  animation: spin 0.8s linear infinite;
}

.btn--loading .btn-text {
  display: none;
}

.btn--loading .btn-spinner {
  display: inline-flex;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* --- Sections --- */
.section-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.025em;
  margin-bottom: var(--space-3);
}

.section-sub {
  font-size: 1.0625rem;
  color: var(--color-text-secondary);
  max-width: 480px;
  margin: 0 auto var(--space-12);
}

/* --- How it works --- */
.how {
  padding: var(--space-20) var(--space-6);
  border-top: 1px solid var(--color-border-light);
}

.how-inner {
  max-width: 1120px;
  margin: 0 auto;
  text-align: center;
}

.how-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-8);
  text-align: left;
}

.how-step {
  padding: var(--space-8);
  border-radius: var(--radius-lg);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border-light);
  transition: border-color 0.2s;
}

.how-step:hover {
  border-color: var(--color-border);
}

.how-step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  background: var(--color-primary-glow);
  color: var(--color-primary-light);
  font-weight: 700;
  font-size: 0.875rem;
  margin-bottom: var(--space-4);
}

.how-step-title {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: var(--space-2);
}

.how-step-desc {
  color: var(--color-text-secondary);
  font-size: 0.9375rem;
  line-height: 1.6;
}

/* --- Form Section --- */
.form-section {
  padding: var(--space-20) var(--space-6);
  border-top: 1px solid var(--color-border-light);
}

.form-inner {
  max-width: 600px;
  margin: 0 auto;
}

.form-header {
  text-align: center;
  margin-bottom: var(--space-12);
}

/* --- Form Groups --- */
.form-group {
  margin-bottom: var(--space-8);
}

.form-group--fieldset {
  border: none;
  padding: 0;
}

.form-row {
  display: flex;
  gap: var(--space-4);
}

.form-group--half {
  flex: 1;
  min-width: 0;
}

.form-label {
  display: block;
  font-size: 0.9375rem;
  font-weight: 600;
  margin-bottom: var(--space-2);
  color: var(--color-text);
}

.form-label--hint {
  display: block;
  font-weight: 400;
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin-top: var(--space-1);
}

.form-textarea {
  width: 100%;
  min-height: 120px;
  padding: var(--space-4);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-family: var(--font);
  font-size: 0.9375rem;
  line-height: 1.6;
  resize: vertical;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.form-textarea::placeholder {
  color: var(--color-text-muted);
}

.form-textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-glow);
}

.form-help {
  display: block;
  margin-top: var(--space-2);
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

/* --- Radio Cards --- */
.form-radios {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-3);
}

.radio-card {
  cursor: pointer;
}

.radio-card input {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.radio-card-visual {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-4) var(--space-3);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-bg-elevated);
  transition: all 0.2s;
  text-align: center;
}

.radio-card:hover .radio-card-visual {
  border-color: var(--color-text-muted);
}

.radio-card input:checked + .radio-card-visual {
  border-color: var(--color-primary);
  background: var(--color-primary-glow);
}

.radio-card input:focus-visible + .radio-card-visual {
  outline: 2px solid var(--color-primary-light);
  outline-offset: 2px;
}

.radio-card-dot {
  width: 18px;
  height: 18px;
  border-radius: var(--radius-full);
  border: 2px solid var(--color-border);
  transition: all 0.2s;
  position: relative;
}

.radio-card input:checked + .radio-card-visual .radio-card-dot {
  border-color: var(--color-primary);
}

.radio-card input:checked + .radio-card-visual .radio-card-dot::after {
  content: '';
  position: absolute;
  top: 3px;
  left: 3px;
  width: 8px;
  height: 8px;
  border-radius: var(--radius-full);
  background: var(--color-primary);
}

.radio-card-text {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color 0.2s;
}

.radio-card input:checked + .radio-card-visual .radio-card-text {
  color: var(--color-text);
}

/* --- Form Actions --- */
.form-actions {
  margin-top: var(--space-8);
}

/* --- Error State --- */
.form-error {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-top: var(--space-6);
  padding: var(--space-4);
  background: var(--color-error-bg);
  border: 1px solid rgba(239, 68, 68, 0.3);
  border-radius: var(--radius-md);
  color: var(--color-error);
  font-size: 0.875rem;
}

.form-error[hidden] {
  display: none;
}

/* --- Inline Field Errors --- */
.form-field-error {
  display: block;
  margin-top: var(--space-2);
  font-size: 0.8125rem;
  color: var(--color-error);
  line-height: 1.4;
}

.form-field-error[hidden] {
  display: none;
}

.form-textarea.form-input--error {
  border-color: var(--color-error);
  box-shadow: 0 0 0 3px var(--color-error-bg);
}

/* --- Success State --- */
.form-success {
  text-align: center;
  padding: var(--space-12) var(--space-6);
}

.form-success[hidden] {
  display: none;
}

.form-success-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 64px;
  height: 64px;
  border-radius: var(--radius-full);
  background: var(--color-success-bg);
  color: var(--color-success);
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: var(--space-6);
}

.form-success-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: var(--space-3);
}

.form-success-text {
  color: var(--color-text-secondary);
  margin-bottom: var(--space-6);
  max-width: 400px;
  margin-left: auto;
  margin-right: auto;
}

/* --- Footer --- */
.footer {
  padding: var(--space-12) var(--space-6);
  border-top: 1px solid var(--color-border-light);
  text-align: center;
}

.footer-inner {
  max-width: 1120px;
  margin: 0 auto;
}

.footer-text {
  margin-bottom: var(--space-3);
}

.footer-link {
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  text-decoration: none;
  transition: color 0.2s;
}

.footer-link:hover {
  color: var(--color-text);
}

.footer-copy {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

/* ============================================
   Responsive
   ============================================ */

/* Tablet */
@media (max-width: 768px) {
  .hero {
    min-height: 80vh;
    padding: calc(64px + var(--space-10)) var(--space-6) var(--space-10);
  }

  .hero-headline {
    font-size: clamp(1.75rem, 7vw, 2.5rem);
  }

  .hero-actions {
    flex-direction: column;
    align-items: center;
  }

  .how-grid {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }

  .how-step {
    padding: var(--space-6);
  }

  .form-radios {
    grid-template-columns: 1fr;
  }
}

/* Mobile */
@media (max-width: 480px) {
  .nav-links .nav-link:not(.nav-link--cta) {
    display: none;
  }

  .hero-headline {
    font-size: 1.75rem;
  }

  .hero-sub {
    font-size: 0.9375rem;
  }

  .section-title {
    font-size: 1.5rem;
  }
}

/* --- Prefers reduced motion --- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }

  html {
    scroll-behavior: auto;
  }
}

/* --- High contrast --- */
@media (forced-colors: active) {
  .radio-card-visual {
    border: 2px solid ButtonText;
  }

  .radio-card input:checked + .radio-card-visual {
    border: 2px solid Highlight;
  }
}