:root {
  --ink: #0a0a0a;
  --ink2: #3a3a3a;
  --ink3: #888;
  --paper: #faf9f7;
  --paper2: #f2f0ec;
  --paper3: #e8e5e0;
  --accent: #1a6bff;
  --accent-dim: rgba(26,107,255,0.07);
  --red: #dc2626;
  --border: rgba(0,0,0,0.08);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg: 0 20px 60px rgba(0,0,0,0.12);
  --r-sm: 6px;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body {
  background: var(--paper);
  color: var(--ink);
  font-family: 'Geist', sans-serif;
  font-size: 15px;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* NAV */
nav {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 40px; height: 56px;
  border-bottom: 1px solid var(--border);
}
.nav-logo { font-family: 'Geist Mono', monospace; font-size: 17px; font-weight: 500; color: var(--ink); text-decoration: none; }
.nav-logo span { color: var(--accent); }

/* MAIN */
.auth-page {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 48px 24px;
}

.auth-split {
  display: flex;
  width: 100%;
  max-width: 900px;
  gap: 0;
  border-radius: 20px;
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-lg);
}

/* LEFT PANEL */
.auth-left {
  width: 340px;
  flex-shrink: 0;
  background: var(--ink);
  color: #fff;
  padding: 48px 40px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.al-logo {
  font-family: 'Geist Mono', monospace;
  font-size: 18px;
  font-weight: 500;
  margin-bottom: 40px;
  text-decoration: none;
  color: #fff;
}
.al-logo span { color: #7ba8ff; }

.al-title {
  font-family: 'Instrument Serif', serif;
  font-size: 34px;
  font-weight: 400;
  line-height: 1.15;
  margin-bottom: 12px;
}
.al-title em { font-style: italic; color: #7ba8ff; }

.al-desc {
  font-size: 14px;
  color: rgba(255,255,255,.5);
  line-height: 1.65;
}

.al-features { list-style: none; }
.al-features li {
  display: flex; align-items: center; gap: 10px;
  font-size: 13px;
  color: rgba(255,255,255,.6);
  margin-bottom: 10px;
}
.al-features li::before {
  content: '✓';
  width: 20px; height: 20px;
  border-radius: 50%;
  background: rgba(255,255,255,.1);
  display: flex; align-items: center; justify-content: center;
  font-size: 11px;
  color: #7ba8ff;
  flex-shrink: 0;
}

/* RIGHT PANEL */
.auth-right {
  flex: 1;
  background: #fff;
  padding: 48px 44px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.ar-header { margin-bottom: 32px; }
.ar-title { font-size: 24px; font-weight: 600; color: var(--ink); margin-bottom: 4px; }
.ar-sub { font-size: 14px; color: var(--ink3); }
.ar-sub a { color: var(--accent); text-decoration: none; font-weight: 500; }
.ar-sub a:hover { text-decoration: underline; }

.form-group { margin-bottom: 16px; }
.form-label { display: block; font-size: 13px; font-weight: 500; color: var(--ink2); margin-bottom: 6px; }
.form-input {
  width: 100%; padding: 11px 14px;
  border: 1px solid var(--paper3); border-radius: var(--r-sm);
  font-family: 'Geist', sans-serif; font-size: 14px; color: var(--ink);
  outline: none; transition: border-color .15s, box-shadow .15s;
  background: #fff;
}
.form-input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-dim); }
.form-input.error { border-color: var(--red); }

.form-error {
  font-size: 12px; color: var(--red); margin-top: 4px;
  display: none;
}
.form-error.show { display: block; }

.form-check-row {
  margin-bottom: 8px;
}
.form-check-label {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  cursor: pointer;
  font-size: 14px;
  color: var(--ink2);
  line-height: 1.45;
}
.form-check-input {
  width: 18px;
  height: 18px;
  margin-top: 2px;
  flex-shrink: 0;
  accent-color: var(--accent);
  cursor: pointer;
}
.form-check-hint {
  font-size: 12px;
  color: var(--ink3);
  margin: 8px 0 0 28px;
  line-height: 1.45;
}

.btn-submit {
  width: 100%;
  background: var(--ink); color: #fff;
  border: none; border-radius: var(--r-sm);
  padding: 12px;
  font-family: 'Geist', sans-serif;
  font-size: 15px; font-weight: 500;
  cursor: pointer;
  transition: all .15s;
  margin-top: 8px;
}
.btn-submit:hover { background: var(--ink2); transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn-submit:active { transform: translateY(0); }

@media (max-width: 700px) {
  .auth-split { flex-direction: column; border-radius: 14px; }
  .auth-left { width: 100%; padding: 32px 28px; }
  .auth-right { padding: 32px 28px; }
  .al-title { font-size: 26px; }
  nav { padding: 0 20px; }
}