:root {
  --color-bg-from: #dbe8ff;
  --color-bg-to: #eef4ff;
  --color-bg-orb-1: rgba(57, 99, 235, 0.18);
  --color-bg-orb-2: rgba(14, 165, 233, 0.12);
  --color-surface: rgba(255, 255, 255, 0.72);
  --color-surface-hover: rgba(248, 251, 255, 0.92);
  --color-surface-strong: rgba(255, 255, 255, 0.90);
  --color-border: rgba(86, 103, 135, 0.30);
  --color-border-strong: rgba(54, 71, 104, 0.42);
  --color-ink: #0b1628;
  --color-ink-secondary: #243752;
  --color-ink-muted: #43546f;
  --color-accent: #2857d7;
  --color-accent-hover: #1d46bd;
  --color-accent-text: #173a9b;
  --color-accent-contrast: #f8fbff;
  --color-accent-glow: rgba(40, 87, 215, 0.18);
  --color-good: #116235;
  --color-bad: #a61d18;
  --color-input-bg: rgba(255, 255, 255, 0.70);
  --color-input-hover: rgba(255, 255, 255, 0.92);
  --color-glass-blur: 20px;
  --radius-sm: 10px;
  --radius-lg: 20px;
  --radius-xl: 26px;
  --shadow-elevated: 0 4px 18px rgba(15, 23, 42, 0.12), 0 28px 70px rgba(40, 87, 215, 0.12);
  --font-sans: 'Albert Sans', 'Avenir Next', 'Helvetica Neue', Arial, system-ui, sans-serif;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg-from: #08111f;
    --color-bg-to: #101b31;
    --color-bg-orb-1: rgba(71, 116, 255, 0.20);
    --color-bg-orb-2: rgba(20, 184, 166, 0.10);
    --color-surface: rgba(17, 28, 50, 0.72);
    --color-surface-hover: rgba(29, 44, 72, 0.92);
    --color-surface-strong: rgba(23, 36, 61, 0.92);
    --color-border: rgba(133, 155, 196, 0.32);
    --color-border-strong: rgba(158, 179, 220, 0.48);
    --color-ink: #eef5ff;
    --color-ink-secondary: #c3d4ee;
    --color-ink-muted: #9fb2d0;
    --color-accent: #78a3ff;
    --color-accent-hover: #9bbcff;
    --color-accent-text: #b8cdfd;
    --color-accent-contrast: #071326;
    --color-accent-glow: rgba(120, 163, 255, 0.18);
    --color-good: #7fe6a1;
    --color-bad: #ff9a9a;
    --color-input-bg: rgba(7, 16, 31, 0.62);
    --color-input-hover: rgba(17, 31, 54, 0.86);
    --color-glass-blur: 22px;
    --shadow-elevated: 0 5px 24px rgba(0,0,0,0.38), 0 32px 84px rgba(0,0,0,0.30);
    color-scheme: dark;
  }
}

[data-theme="light"] {
  color-scheme: light;
  --color-bg-from: #dbe8ff;
  --color-bg-to: #eef4ff;
  --color-bg-orb-1: rgba(57, 99, 235, 0.18);
  --color-bg-orb-2: rgba(14, 165, 233, 0.12);
  --color-surface: rgba(255, 255, 255, 0.72);
  --color-surface-hover: rgba(248, 251, 255, 0.92);
  --color-surface-strong: rgba(255, 255, 255, 0.90);
  --color-border: rgba(86, 103, 135, 0.30);
  --color-border-strong: rgba(54, 71, 104, 0.42);
  --color-ink: #0b1628;
  --color-ink-secondary: #243752;
  --color-ink-muted: #43546f;
  --color-accent: #2857d7;
  --color-accent-hover: #1d46bd;
  --color-accent-text: #173a9b;
  --color-accent-contrast: #f8fbff;
  --color-accent-glow: rgba(40, 87, 215, 0.18);
  --color-good: #116235;
  --color-bad: #a61d18;
  --color-input-bg: rgba(255, 255, 255, 0.70);
  --color-input-hover: rgba(255, 255, 255, 0.92);
  --color-glass-blur: 20px;
  --shadow-elevated: 0 4px 18px rgba(15, 23, 42, 0.12), 0 28px 70px rgba(40, 87, 215, 0.12);
}

[data-theme="dark"] {
  color-scheme: dark;
  --color-bg-from: #08111f;
  --color-bg-to: #101b31;
  --color-bg-orb-1: rgba(71, 116, 255, 0.20);
  --color-bg-orb-2: rgba(20, 184, 166, 0.10);
  --color-surface: rgba(17, 28, 50, 0.72);
  --color-surface-hover: rgba(29, 44, 72, 0.92);
  --color-surface-strong: rgba(23, 36, 61, 0.92);
  --color-border: rgba(133, 155, 196, 0.32);
  --color-border-strong: rgba(158, 179, 220, 0.48);
  --color-ink: #eef5ff;
  --color-ink-secondary: #c3d4ee;
  --color-ink-muted: #9fb2d0;
  --color-accent: #78a3ff;
  --color-accent-hover: #9bbcff;
  --color-accent-text: #b8cdfd;
  --color-accent-contrast: #071326;
  --color-accent-glow: rgba(120, 163, 255, 0.18);
  --color-good: #7fe6a1;
  --color-bad: #ff9a9a;
  --color-input-bg: rgba(7, 16, 31, 0.62);
  --color-input-hover: rgba(17, 31, 54, 0.86);
  --color-glass-blur: 22px;
  --shadow-elevated: 0 5px 24px rgba(0,0,0,0.38), 0 32px 84px rgba(0,0,0,0.30);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
[hidden] { display: none !important; }
html { width: 100%; overflow-x: hidden; scrollbar-gutter: stable; }
body {
  min-height: 100vh;
  overflow-x: hidden;
  color: var(--color-ink);
  background:
    radial-gradient(circle at 7% -8%, var(--color-bg-orb-1), transparent 34%),
    radial-gradient(circle at 95% 6%, var(--color-bg-orb-2), transparent 30%),
    linear-gradient(135deg, var(--color-bg-from), var(--color-bg-to));
  background-attachment: fixed;
  font: 400 16px/1.6 var(--font-sans);
  -webkit-font-smoothing: antialiased;
}
button:focus-visible,
input:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}
.retwitter-mark {
  display: block;
  flex-shrink: 0;
  filter: drop-shadow(0 10px 20px var(--color-accent-glow));
}
.login-brand-mark { width: 46px; height: 46px; }
.login-page {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 20px;
}
.login-shell { display: block; width: min(100%, 420px); }
.login-card {
  position: relative;
  width: 100%;
  max-width: 420px;
  padding: 34px 30px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  background: var(--color-surface);
  box-shadow: var(--shadow-elevated);
  backdrop-filter: blur(var(--color-glass-blur));
  -webkit-backdrop-filter: blur(var(--color-glass-blur));
}
.login-brand { display: flex; align-items: center; gap: 14px; margin-bottom: 24px; }
.login-card h1 { margin-bottom: 2px; font-size: 22px; font-weight: 600; }
.login-card label {
  display: flex;
  flex-direction: column;
  gap: 5px;
  margin-bottom: 14px;
  color: var(--color-ink-muted);
  font-size: 12px;
  font-weight: 500;
}
.login-card input {
  width: 100%;
  min-height: 40px;
  padding: 12px 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-input-bg);
  color: var(--color-ink);
  font: 400 13px/1.4 var(--font-sans);
  transition: border-color 0.15s var(--ease-out), box-shadow 0.15s var(--ease-out), background 0.15s var(--ease-out);
}
.login-card input:hover { border-color: var(--color-border-strong); background: var(--color-input-hover); }
.login-card input:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-glow);
}
.login-card input::placeholder { color: var(--color-ink-muted); }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  width: 100%;
  min-height: 40px;
  margin-top: 6px;
  padding: 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface-strong);
  color: var(--color-ink-secondary);
  box-shadow: 0 1px 0 rgba(255,255,255,0.35) inset;
  cursor: pointer;
  font: 600 14px/1.2 var(--font-sans);
  transition: background 0.15s var(--ease-out), color 0.15s var(--ease-out), border-color 0.15s var(--ease-out), opacity 0.15s var(--ease-out), transform 0.15s var(--ease-out);
}
.btn-primary {
  border-color: var(--color-accent);
  background: var(--color-accent);
  color: var(--color-accent-contrast);
  box-shadow: 0 10px 24px var(--color-accent-glow);
}
.btn:not(:disabled):active { transform: scale(0.97); transition-duration: 0.1s; }
.btn:disabled { opacity: 0.45; cursor: not-allowed; }
.login-tabs {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 3px;
  margin-bottom: 20px;
  padding: 3px;
  border-radius: var(--radius-sm);
  background: var(--color-input-bg);
}
.login-tab {
  width: 100%;
  min-width: 0;
  padding: 8px 6px;
  border: 0;
  border-radius: calc(var(--radius-sm) - 2px);
  background: transparent;
  color: var(--color-ink-muted);
  cursor: pointer;
  font: 600 12px/1.15 var(--font-sans);
  letter-spacing: -0.01em;
  white-space: normal;
  transition: color 0.2s var(--ease-out), background 0.2s var(--ease-out), box-shadow 0.2s var(--ease-out);
}
.login-tab.active {
  background: var(--color-surface);
  color: var(--color-accent-text);
  box-shadow: 0 1px 3px rgba(0,0,0,0.08);
}
.login-section { animation: loginFadeIn 0.25s var(--ease-out); }
.login-hint {
  margin-bottom: 16px;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  background: var(--color-accent-glow);
  color: var(--color-accent-text);
  font-size: 12px;
  line-height: 1.5;
}
.login-sub-form { margin-top: 18px; padding-top: 18px; border-top: 1px solid var(--color-border); }
.message { min-height: 20px; margin-top: 8px; font-size: 13px; }
.message.error { color: var(--color-bad); font-weight: 700; }
.message.ok { color: var(--color-good); font-weight: 700; }

@keyframes loginFadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 480px) {
  .login-page {
    padding:
      max(12px, env(safe-area-inset-top))
      max(12px, env(safe-area-inset-right))
      max(12px, env(safe-area-inset-bottom))
      max(12px, env(safe-area-inset-left));
  }
  .login-shell { max-width: 100%; }
  .login-card { padding: 24px 16px; border-radius: var(--radius-lg); }
  .login-tabs {
    grid-template-columns: 1fr;
    gap: 6px;
    padding: 6px;
    border: 1px solid var(--color-border);
  }
  .login-tab { min-height: 42px; background: var(--color-surface-strong); font-size: 13px; }
}

@media (pointer: coarse) {
  .btn,
  .login-tab,
  .login-card input { min-height: 44px; }
  .login-card input { font-size: 16px; }
}

@media (hover: hover) and (pointer: fine) {
  .btn:not(.btn-primary):not(:disabled):hover {
    border-color: var(--color-border-strong);
    background: var(--color-surface-hover);
  }
  .btn-primary:not(:disabled):hover {
    border-color: var(--color-accent-hover);
    background: var(--color-accent-hover);
  }
  .login-tab:hover { color: var(--color-ink); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.001ms !important;
  }
}