:root {
  --fundo: #FAFAFA;
  --branco: #FFFFFF;
  --preto: #0A0A0A;
  --cinza-700: #444444;
  --cinza-500: #666666;
  --cinza-400: #999999;
  --cinza-200: #E5E5E5;
  --cinza-100: #F0F0F0;
  --marrom: #5C3A1E;
  --transicao: 0.3s ease;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: 'Inter', sans-serif;
  background: var(--fundo);
  color: var(--preto);
  min-height: 100vh;
  padding: 56px 20px;
  line-height: 1.5;
  font-size: 15px;
}

.container {
  max-width: 780px;
  margin: 0 auto;
}

/* HEADER */
.header {
  margin-bottom: 48px;
}

.header h1 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 52px;
  font-weight: 700;
  letter-spacing: -1.5px;
  line-height: 1.05;
  color: var(--preto);
  margin-bottom: 12px;
}

.header h1 span { color: var(--marrom); }

.header p {
  color: var(--cinza-500);
  font-size: 17px;
  max-width: 520px;
}

/* TABS */
.tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 36px;
  flex-wrap: wrap;
}

.tab {
  padding: 12px 20px;
  background: var(--branco);
  border: 1.5px solid var(--cinza-200);
  border-radius: 10px;
  color: var(--cinza-700);
  font-family: 'Inter', sans-serif;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transicao);
  letter-spacing: 0.2px;
}

.tab:hover {
  border-color: var(--marrom);
  color: var(--marrom);
}

.tab.active {
  background: var(--preto);
  border-color: var(--preto);
  color: var(--branco);
}

/* ABA COMO USAR - DESTAQUE */
.tab.help {
  margin-left: auto;
  background: transparent;
  border: 1.5px dashed var(--cinza-400);
  color: var(--cinza-500);
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
}

.tab.help:hover {
  border-color: var(--marrom);
  color: var(--marrom);
  border-style: solid;
}

.tab.help.active {
  background: var(--marrom);
  border-color: var(--marrom);
  color: var(--branco);
  border-style: solid;
}

/* PANELS */
.panel { display: none; }
.panel.active { display: block; }

/* FORM */
label {
  display: block;
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  font-weight: 500;
  color: var(--cinza-500);
  margin-bottom: 8px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

input[type="text"],
input[type="url"],
textarea {
  width: 100%;
  padding: 16px 18px;
  background: var(--branco);
  border: 1.5px solid var(--cinza-200);
  border-radius: 10px;
  color: var(--preto);
  font-family: 'Inter', sans-serif;
  font-size: 16px;
  margin-bottom: 22px;
  transition: var(--transicao);
}

input:focus, textarea:focus {
  outline: none;
  border-color: var(--marrom);
  box-shadow: 0 0 0 4px rgba(92, 58, 30, 0.08);
}

textarea {
  resize: vertical;
  min-height: 90px;
  font-family: 'Inter', sans-serif;
}

/* LINK PREVIEW */
.link-preview {
  background: var(--preto);
  border-radius: 10px;
  padding: 16px 18px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  color: #B8FFB8;
  word-break: break-all;
  margin-bottom: 28px;
  display: none;
}

.link-preview.show { display: block; }

.link-preview-actions {
  display: flex;
  gap: 8px;
  margin-top: 14px;
}

.link-preview-actions button {
  flex: 1;
  padding: 10px;
  font-size: 12px;
  background: rgba(255, 255, 255, 0.1);
  color: var(--branco);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 6px;
  cursor: pointer;
  font-family: 'JetBrains Mono', monospace;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  font-weight: 500;
  transition: var(--transicao);
}

.link-preview-actions button:hover {
  background: var(--marrom);
  border-color: var(--marrom);
}

/* OPÇÕES */
.advanced {
  margin: 28px 0;
  padding-top: 28px;
  border-top: 1px solid var(--cinza-200);
}

.slider-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 10px;
}

.slider-row label { margin-bottom: 0; }

.slider-row .value {
  font-family: 'JetBrains Mono', monospace;
  font-size: 14px;
  color: var(--marrom);
  font-weight: 600;
}

input[type="range"] {
  width: 100%;
  margin-bottom: 20px;
  accent-color: var(--marrom);
  height: 6px;
}

/* BOTÃO PRINCIPAL */
button.generate {
  width: 100%;
  padding: 20px;
  background: var(--preto);
  color: var(--branco);
  border: none;
  border-radius: 12px;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.5px;
  cursor: pointer;
  transition: var(--transicao);
  margin-top: 8px;
}

button.generate:hover {
  background: var(--marrom);
  transform: translateY(-1px);
}

/* QR PREVIEW */
#qrcode-wrapper {
  margin: 32px auto 24px;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 32px;
  background: var(--branco);
  border: 1.5px solid var(--cinza-200);
  border-radius: 16px;
  min-height: 80px;
  max-width: 100%;
  overflow: hidden;
}

#qrcode img, #qrcode canvas { max-width: 100%; display: block; }

/* DOWNLOAD */
.actions {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin-top: 16px;
}

.actions button {
  padding: 16px;
  background: var(--branco);
  color: var(--cinza-700);
  border: 1.5px solid var(--cinza-200);
  border-radius: 10px;
  font-family: 'Inter', sans-serif;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.3px;
  cursor: pointer;
  transition: var(--transicao);
}

.actions button:hover {
  color: var(--marrom);
  border-color: var(--marrom);
}

/* ABA COMO USAR */
.how-to h3 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 32px;
  color: var(--preto);
  margin-bottom: 16px;
  font-weight: 700;
  letter-spacing: -0.8px;
}

.how-to h3 span { color: var(--marrom); }

.how-to > p {
  color: var(--cinza-500);
  font-size: 16px;
  margin-bottom: 28px;
  line-height: 1.6;
}

.how-to h4 {
  font-family: 'JetBrains Mono', monospace;
  font-size: 14px;
  color: var(--marrom);
  margin: 28px 0 12px;
  font-weight: 700;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.how-to p, .how-to li {
  font-size: 15px;
  color: var(--cinza-700);
  line-height: 1.7;
}

.how-to ol, .how-to ul {
  padding-left: 22px;
  margin-bottom: 10px;
}

.how-to li { margin-bottom: 6px; }

.how-to code {
  background: var(--cinza-100);
  padding: 3px 8px;
  border-radius: 5px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  color: var(--marrom);
}

/* RESPONSIVO */
@media (max-width: 600px) {
  body { padding: 32px 16px; }
  .header h1 { font-size: 38px; letter-spacing: -1px; }
  .header p { font-size: 15px; }
  .tab.help { margin-left: 0; }
  .tabs { gap: 6px; }
  .tab { padding: 10px 14px; font-size: 13px; }
}