/* ============================================================
   Free QR Maker — Design Tokens & Component Styles
   Dark-first aesthetic with green accent (matching original MVP)
   ============================================================ */

/* --- Font loading is in index.html <link> tags --- */

/* --- Type Scale (fluid clamp) --- */
:root {
  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.95rem + 0.25vw, 1.125rem);
  --text-lg:   clamp(1.125rem, 1rem    + 0.75vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1.2rem  + 1.25vw, 2.25rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);

  /* Spacing (4px base) */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Content widths */
  --content-default: 960px;

  /* Font families */
  --font-display: 'General Sans', 'Inter', sans-serif;
  --font-body: 'General Sans', 'Inter', sans-serif;
}

/* --- Dark mode (default) --- */
:root, [data-theme="dark"] {
  --color-bg:             #070b14;
  --color-surface:        #0d1424;
  --color-surface-2:      #131b2e;
  --color-surface-offset: #0a1020;
  --color-border:         #1e2a42;
  --color-border-hover:   #2d3f5e;
  --color-text:           #e2e8f0;
  --color-text-muted:     #94a3b8;
  --color-text-faint:     #64748b;
  --color-primary:        #22c55e;
  --color-primary-hover:  #16a34a;
  --color-primary-active: #15803d;
  --color-primary-glow:   rgba(34, 197, 94, 0.15);
  --color-primary-glow-strong: rgba(34, 197, 94, 0.4);
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.4);
  --shadow-lg: 0 16px 48px rgba(0,0,0,0.5);
}

/* --- Light mode --- */
[data-theme="light"] {
  --color-bg:             #f8fafc;
  --color-surface:        #ffffff;
  --color-surface-2:      #f1f5f9;
  --color-surface-offset: #e2e8f0;
  --color-border:         #cbd5e1;
  --color-border-hover:   #94a3b8;
  --color-text:           #0f172a;
  --color-text-muted:     #475569;
  --color-text-faint:     #94a3b8;
  --color-primary:        #16a34a;
  --color-primary-hover:  #15803d;
  --color-primary-active: #166534;
  --color-primary-glow:   rgba(22, 163, 74, 0.1);
  --color-primary-glow-strong: rgba(22, 163, 74, 0.25);
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg: 0 16px 48px rgba(0,0,0,0.12);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme]) {
    --color-bg:             #f8fafc;
    --color-surface:        #ffffff;
    --color-surface-2:      #f1f5f9;
    --color-surface-offset: #e2e8f0;
    --color-border:         #cbd5e1;
    --color-border-hover:   #94a3b8;
    --color-text:           #0f172a;
    --color-text-muted:     #475569;
    --color-text-faint:     #94a3b8;
    --color-primary:        #16a34a;
    --color-primary-hover:  #15803d;
    --color-primary-active: #166534;
    --color-primary-glow:   rgba(22, 163, 74, 0.1);
    --color-primary-glow-strong: rgba(22, 163, 74, 0.25);
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
    --shadow-lg: 0 16px 48px rgba(0,0,0,0.12);
  }
}

/* ============================================================
   Layout
   ============================================================ */

body {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100dvh;
  padding: var(--space-6);
  background: var(--color-bg);
}

/* Subtle radial glow behind content */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background: radial-gradient(ellipse 80% 50% at 50% 0%, var(--color-primary-glow), transparent 70%);
  pointer-events: none;
  z-index: 0;
}

.page-wrapper {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--content-default);
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
}

/* --- Header / Nav --- */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-2) 0;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--color-text);
}

.logo-link:hover { text-decoration: none; }

.logo-text {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--text-sm);
  letter-spacing: -0.02em;
}

.logo-accent {
  color: var(--color-primary);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: border-color var(--transition-interactive),
              color var(--transition-interactive),
              background var(--transition-interactive);
}

.theme-toggle:hover {
  border-color: var(--color-border-hover);
  color: var(--color-text);
}

/* ============================================================
   Main — Two-column grid
   ============================================================ */

.main-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: var(--space-8);
  align-items: start;
}

@media (max-width: 720px) {
  .main-grid {
    grid-template-columns: 1fr;
  }
}

/* --- Card (shared) --- */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-2xl);
  padding: var(--space-8);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

/* --- Left panel: Input card --- */
.input-card::before {
  content: "";
  position: absolute;
  top: -60%;
  left: -30%;
  width: 160%;
  height: 160%;
  background: radial-gradient(circle at 20% 20%, var(--color-primary-glow), transparent 50%);
  pointer-events: none;
  opacity: 0.6;
}

.input-card .card-inner {
  position: relative;
  z-index: 1;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 500;
  margin-bottom: var(--space-4);
}

.eyebrow-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-glow-strong);
}

.hero-heading {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: var(--space-3);
  color: var(--color-text);
}

.hero-sub {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-6);
  max-width: 36ch;
  line-height: 1.5;
}

/* --- Form elements --- */
.form-label {
  display: block;
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-faint);
  margin-bottom: var(--space-2);
}

.input-row {
  display: flex;
  gap: var(--space-3);
  margin-bottom: var(--space-3);
}

.input-field {
  flex: 1;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border);
  background: var(--color-surface-2);
  color: var(--color-text);
  font-size: var(--text-sm);
  outline: none;
  transition: border-color var(--transition-interactive),
              box-shadow var(--transition-interactive),
              background var(--transition-interactive);
}

.input-field::placeholder {
  color: var(--color-text-faint);
}

.input-field:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-glow);
  background: var(--color-surface);
}

/* --- Buttons --- */
.btn {
  border: none;
  cursor: pointer;
  border-radius: var(--radius-full);
  padding: var(--space-3) var(--space-5);
  font-size: var(--text-sm);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  white-space: nowrap;
  transition: transform 100ms ease,
              box-shadow var(--transition-interactive),
              background var(--transition-interactive),
              border-color var(--transition-interactive),
              color var(--transition-interactive);
}

.btn:active {
  transform: translateY(1px) scale(0.98);
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary), #4ade80);
  color: #022c22;
  box-shadow: 0 8px 32px var(--color-primary-glow-strong);
}

.btn-primary:hover {
  box-shadow: 0 12px 40px var(--color-primary-glow-strong);
  filter: brightness(1.05);
}

.btn-ghost {
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
}

.btn-ghost:hover {
  border-color: var(--color-border-hover);
  color: var(--color-text);
}

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

.btn-ghost:disabled:hover {
  border-color: var(--color-border);
  color: var(--color-text-muted);
}

/* --- Helper chip --- */
.helper {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin-bottom: var(--space-5);
}

.helper-chip {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
}

.helper-icon {
  width: 16px;
  height: 16px;
  border-radius: var(--radius-sm);
  background: var(--color-primary-glow-strong);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 10px;
  color: var(--color-primary);
}

/* --- Action row --- */
.actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-top: var(--space-1);
}

/* --- Tip --- */
.tip {
  margin-top: var(--space-4);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  line-height: 1.5;
}

.tip strong {
  color: var(--color-text);
  font-weight: 600;
}

/* ============================================================
   Right panel: Preview card
   ============================================================ */

.preview-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-5);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-2xl);
  padding: var(--space-6);
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

.preview-card::before {
  content: "";
  position: absolute;
  top: -40%;
  left: 10%;
  width: 80%;
  height: 80%;
  background: radial-gradient(circle, var(--color-primary-glow), transparent 60%);
  pointer-events: none;
  opacity: 0.5;
}

.preview-header {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  position: relative;
  z-index: 1;
}

.chip {
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  font-weight: 500;
}

/* --- QR code container --- */
.qr-wrapper {
  width: 220px;
  height: 220px;
  padding: var(--space-4);
  border-radius: var(--radius-2xl);
  background: linear-gradient(135deg, var(--color-primary-glow), var(--color-surface-2));
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  z-index: 1;
}

.qr-canvas {
  width: 188px;
  height: 188px;
  background: #ffffff;
  border-radius: var(--radius-xl);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.qr-canvas canvas,
.qr-canvas img {
  width: 100% !important;
  height: 100% !important;
}

/* --- Empty state --- */
.empty-state {
  text-align: center;
  color: var(--color-text-faint);
  font-size: var(--text-xs);
  padding: 0 var(--space-4);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
}

.empty-dots {
  display: flex;
  gap: 4px;
}

.empty-dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--color-text-faint);
  opacity: 0.5;
}

/* --- Footer pills --- */
.preview-footer {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  position: relative;
  z-index: 1;
}

.pill-row {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.pill {
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  background: var(--color-surface-2);
  font-size: var(--text-xs);
  white-space: nowrap;
}

/* ============================================================
   Site footer
   ============================================================ */

.site-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) 0;
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

.site-footer a {
  color: var(--color-text-faint);
  text-decoration: none;
  transition: color var(--transition-interactive);
}

.site-footer a:hover {
  color: var(--color-text-muted);
}

/* ============================================================
   Mobile adjustments
   ============================================================ */

@media (max-width: 720px) {
  body {
    padding: var(--space-4);
  }

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

  .hero-heading {
    font-size: var(--text-xl);
  }

  .input-row {
    flex-direction: column;
  }

  .preview-footer {
    flex-direction: column;
    gap: var(--space-2);
    align-items: flex-start;
  }

  .site-footer {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
}