*, *::before, *::after { box-sizing: border-box; }

:root {
  --bg: #ffffff;
  --surface: #ffffff;
  --surface-muted: #f1f5f9;
  --line: #dce3ef;
  --text: #0f172a;
  --muted: #64748b;
  --primary: #1457d9;
  --primary-dark: #0f2f6f;
  --success: #16794c;
  --danger: #b42318;
  --warn: #b45309;
  --radius: 12px;
}

html, body { min-height: 100%; background: #fff !important; }
body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
}

.site-header {
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 0 32px;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
}
.brand, .site-header nav { display: flex; align-items: center; gap: 12px; }
.brand { color: var(--text); text-decoration: none; font-weight: 800; font-size: 18px; }
.brand img { width: 38px; height: 38px; border-radius: 10px; }
.site-header nav a { color: var(--muted); text-decoration: none; font-size: 14px; font-weight: 700; }
.site-header nav a:hover { color: var(--primary); }

.auth-shell {
  max-width: 1320px;
  margin: 0 auto;
  padding: 34px 24px 56px;
  background: #fff;
}
.intro-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 28px;
  align-items: end;
  margin-bottom: 22px;
}
.eyebrow, .section-label {
  color: var(--primary);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: .12em;
  text-transform: uppercase;
}
.intro-panel h1 {
  max-width: 760px;
  margin: 10px 0;
  font-size: clamp(28px, 4vw, 48px);
  line-height: 1.05;
  letter-spacing: -0.02em;
}
.intro-panel p { max-width: 720px; color: var(--muted); line-height: 1.7; margin: 0; }
.intro-list {
  min-width: 330px;
  display: grid;
  gap: 10px;
}
.intro-list div {
  display: grid;
  grid-template-columns: 34px 1fr;
  align-items: center;
  gap: 10px;
  padding: 10px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
}
.intro-list strong {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  background: #e8f0ff;
  color: var(--primary);
}
.intro-list span { color: var(--muted); font-size: 13px; font-weight: 700; }

.auth-grid {
  display: grid;
  grid-template-columns: minmax(320px, 420px) minmax(0, 1fr);
  gap: 18px;
  align-items: start;
}
.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: 0 18px 50px rgba(15, 23, 42, .06);
}
.card h2 { margin: 6px 0 8px; font-size: 24px; letter-spacing: -0.01em; }
.card p { color: var(--muted); line-height: 1.6; margin: 0 0 18px; }
.card-copy { max-width: 760px; }

form label {
  display: grid;
  gap: 7px;
  color: #334155;
  font-size: 13px;
  font-weight: 800;
}
input, select, textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--text);
  font: inherit;
  padding: 11px 12px;
  outline: none;
}
textarea { resize: vertical; }
input:focus, select:focus, textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(20, 87, 217, .12);
}
input[readonly], textarea[readonly] {
  background: #e9eef5;
  color: #334155;
  cursor: not-allowed;
}

.form-stack { display: grid; gap: 14px; }
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.wide { grid-column: 1 / -1; }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.three-col { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.form-section {
  display: grid;
  gap: 14px;
  padding: 16px;
  background: var(--surface-muted);
  border: 1px solid var(--line);
  border-radius: 12px;
}
.form-section h3 { margin: 0; font-size: 16px; }
.verification-row {
  display: grid;
  grid-template-columns: auto minmax(150px, 220px) auto;
  align-items: end;
  gap: 12px;
}
.tax-lookup-row {
  display: grid;
  grid-template-columns: minmax(220px, 1fr) auto;
  align-items: start;
  gap: 12px;
}
.tax-lookup-row .secondary-action { margin-top: 23px; }
.section-help { margin: -6px 0 0 !important; font-size: 12px; }
.edit-company-row {
  display: flex;
  align-items: center;
  gap: 9px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}
.edit-company-row input { width: 17px; height: 17px; flex: 0 0 17px; accent-color: var(--primary); }
.edit-company-row:has(input:disabled) { opacity: .6; }
.business-required-contact {
  display: grid;
  gap: 7px;
  padding: 14px;
  border: 1px solid #f5b8b8;
  border-radius: 10px;
  background: #fff4f4;
  color: #8f1d1d;
  font-size: 12px;
}
.business-required-contact[hidden] { display: none; }
.business-required-contact a { color: var(--primary); font-weight: 800; }
.check-row {
  display: flex;
  grid-template-columns: none;
  align-items: flex-start;
  gap: 10px;
  color: var(--muted);
  font-weight: 600;
}
.check-row input { width: 18px; height: 18px; margin-top: 2px; }

.primary-action, .secondary-action {
  min-height: 44px;
  border-radius: 10px;
  border: 0;
  cursor: pointer;
  font-weight: 800;
  padding: 0 18px;
}
.primary-action { background: var(--primary); color: #fff; }
.primary-action:hover { background: var(--primary-dark); }
.secondary-action { border: 1px solid var(--line); background: #fff; color: var(--primary-dark); }
.secondary-action:hover { border-color: var(--primary); color: var(--primary); }
.primary-action:disabled, .secondary-action:disabled { opacity: .55; cursor: wait; }
.text-action {
  margin-top: 14px;
  border: 0;
  background: transparent;
  color: var(--primary);
  cursor: pointer;
  font-weight: 800;
  padding: 0;
}
.text-action:hover { text-decoration: underline; }

.reset-box {
  margin-top: 16px;
  display: grid;
  gap: 12px;
  padding: 16px;
  background: var(--surface-muted);
  border: 1px solid var(--line);
  border-radius: 12px;
}
.reset-box[hidden] { display: none; }
.reset-box strong { font-size: 15px; }
.reset-box p { margin: 0; font-size: 13px; }

.field-hint {
  min-height: 16px;
  color: var(--warn);
  font-size: 12px;
  font-weight: 700;
}
.status {
  margin: 0;
  padding: 11px 12px;
  border-radius: 10px;
  background: #fef3c7;
  color: var(--warn);
  font-size: 13px;
  font-weight: 800;
}
.status.success { background: #dcfce7; color: var(--success); }
.status.error { background: #fee2e2; color: var(--danger); }

.form-actions { display: flex; justify-content: flex-end; }

/* Sade hesap ekranı */
.auth-shell { max-width: 1180px; padding-top: 46px; }
.intro-panel { display: block; max-width: 720px; margin: 0 auto 30px; text-align: center; }
.intro-panel h1 { margin: 10px auto; max-width: 680px; font-size: clamp(30px,4vw,44px); }
.intro-panel p { margin: 0 auto; }
.auth-grid { grid-template-columns: repeat(2,minmax(0,1fr)); gap: 24px; align-items: start; }
.card { padding: 30px; }
.login-card,.register-card { min-height: 390px; }
.account-benefits { display: grid; gap: 12px; margin: 22px 0 26px; padding: 0; list-style: none; }
.account-benefits li { position: relative; padding-left: 26px; color: var(--muted); font-size: 14px; font-weight: 650; }
.account-benefits li::before { content: "✓"; position: absolute; left: 0; color: var(--success); font-weight: 900; }
.register-toggle { width: 100%; }
.registration-content { margin-top: 24px; padding-top: 24px; border-top: 1px solid var(--line); }
.registration-content[hidden] { display: none !important; }
.register-card:has(.registration-content:not([hidden])) { grid-column: 1/-1; }
.register-card:has(.registration-content:not([hidden])) .account-benefits { display: none; }
@media(max-width:850px){.auth-grid{grid-template-columns:1fr}.login-card,.register-card{min-height:0}.register-card:has(.registration-content:not([hidden])){grid-column:auto}}

@media (max-width: 1020px) {
  .intro-panel, .auth-grid { grid-template-columns: 1fr; }
  .intro-list { min-width: 0; }
}

@media (max-width: 720px) {
  .site-header { height: auto; align-items: flex-start; padding: 16px; flex-direction: column; }
  .auth-shell { padding: 22px 14px 36px; }
  .card { padding: 18px; }
  .form-grid, .two-col, .three-col, .verification-row, .tax-lookup-row { grid-template-columns: 1fr; }
  .tax-lookup-row .secondary-action { margin-top: 0; }
  .form-actions { justify-content: stretch; }
  .form-actions .primary-action { width: 100%; }
}