:root {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    line-height: 1.6;
    color-scheme: light;
    --background: #f4f6f8;
    --surface: #ffffff;
    --text: #172b3a;
    --muted: #425867;
    --border: #dce3e9;
    --input-border: #93a6b5;
    --link: #145d82;
    --primary: #155e83;
    --primary-text: #ffffff;
    --error: #ac2020;
    --focus: #2981ab;
    color: var(--text);
    background: var(--background);
}
.login-screen[data-theme="light"] {
    --background: #f3f3f3;
    --text: #202020;
    --muted: #595959;
    --border: #dddddd;
    --input-border: #858585;
    --link: #a44200;
    --primary: #a44200;
    --focus: #ba4b00;
}
.login-screen[data-theme="dark"] {
    color-scheme: dark;
    --background: #0c0c0c;
    --surface: #191919;
    --text: #f2f2f2;
    --muted: #b8b8b8;
    --border: #363636;
    --input-border: #858585;
    --link: #ff9a45;
    --primary: #ff9a45;
    --primary-text: #191919;
    --error: #ffaaaa;
    --focus: #ff9a45;
}
* { box-sizing: border-box; }
body { margin: 0; }
header { max-width: 1000px; margin: auto; padding: 24px; display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.brand { font-size: 1.4rem; font-weight: 750; text-decoration: none; color: var(--text); }
.brand span { font-size: .9rem; font-weight: 400; color: var(--muted); margin-left: 8px; }
nav { display: flex; gap: 18px; }
a { color: var(--link); text-underline-offset: 3px; }
main { max-width: 600px; margin: 40px auto; padding: 32px; background: var(--surface); border: 1px solid var(--border); border-radius: 14px; box-shadow: 0 8px 30px #00000008; }
h1 { font-size: 1.7rem; line-height: 1.2; margin-top: 0; }
h2 { font-size: 1.15rem; }
p { color: var(--muted); }
label { display: block; font-weight: 600; margin: 20px 0 6px; }
input[type=email], input[type=password] { width: 100%; font: inherit; padding: 10px 12px; border: 1px solid var(--input-border); border-radius: 6px; background: var(--background); color: var(--text); }
button, .button { font: inherit; font-weight: 600; background: var(--primary); color: var(--primary-text); border: 1px solid var(--primary); padding: 10px 20px; border-radius: 6px; cursor: pointer; text-decoration: none; display: inline-block; }
button.secondary { background: var(--surface); color: var(--text); border-color: var(--input-border); }
.actions { display: flex; gap: 12px; align-items: center; margin-top: 24px; flex-wrap: wrap; }
.validation-summary-errors, .field-validation-error { color: var(--error); font-size: .95rem; }
.validation-summary-errors ul { padding-left: 20px; }
input:focus-visible, button:focus-visible, a:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; }
dt { font-weight: 600; margin-top: 12px; }
dd { margin-left: 0; overflow-wrap: anywhere; }
.muted { font-size: .9rem; color: var(--muted); }
.scope-list { padding-left: 22px; }
footer { text-align: center; padding: 20px; color: var(--muted); font-size: .85rem; }
code { overflow-wrap: anywhere; }
.theme-switch { display: flex; justify-content: flex-end; margin-bottom: 20px; }
.theme-switch button { font-size: .85rem; padding: 6px 12px; }
.login-screen main { max-width: 460px; border-top: 3px solid var(--primary); }
.login-screen h1 { margin-bottom: 12px; }
.login-screen .brand { color: var(--primary); }
.login-screen main > p { margin-bottom: 28px; }
.google-login { width: 100%; display: flex; justify-content: center; align-items: center; gap: 10px; background: #fff; border: 1px solid #747775; color: #1f1f1f; font-size: 14px; font-weight: 500; min-height: 44px; padding: 10px 12px; }
.google-login:hover { background: #f2f2f2; }
.google-logo { background: #fff; display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.google-logo img { display: block; }
@media (max-width: 640px) {
    main { margin: 20px 16px; padding: 24px; }
    header { padding: 20px 16px; }
    .brand span { display: block; margin: 0; }
    nav { font-size: .9rem; }
}