:root {
    --color-primary: #006783;
    --color-primary-strong: #004d63;
    --color-primary-light: #bce9ff;
    --color-surface: #fbfcfe;
    --color-surface-soft: #eef5f8;
    --color-on-surface: #191c1e;
    --color-muted: #40484c;
    --color-border: #dce4e9;
    --color-error: #ba1a1a;
    --color-ring: rgba(0, 103, 131, 0.25);
    --shadow-soft: 0 10px 30px rgba(25, 28, 30, 0.08);
    --radius-md: 14px;
    --radius-lg: 22px;
}

@media (prefers-color-scheme: dark) {
    :root {
        --color-primary: #63d3ff;
        --color-primary-strong: #3db5e5;
        --color-primary-light: #004d63;
        --color-surface: #191c1e;
        --color-surface-soft: #1d2529;
        --color-on-surface: #e1e2e4;
        --color-muted: #c0c8cd;
        --color-border: #40484c;
        --color-ring: rgba(99, 211, 255, 0.28);
        --shadow-soft: 0 14px 36px rgba(0, 0, 0, 0.35);
    }
}

* {
    box-sizing: border-box;
}

body {
    font-family: "IBM Plex Sans", "Segoe UI", sans-serif;
    background:
        linear-gradient(180deg, rgba(251, 252, 254, 0.6) 0%, rgba(251, 252, 254, 0.68) 100%),
        url("/static/images/bg-light.jpg") center / cover no-repeat;
    color: var(--color-on-surface);
    margin: 0;
    padding: 2rem 1rem;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    display: flex;
    align-items: flex-start;
    justify-content: center;
}

@media (prefers-color-scheme: dark) {
    body {
        background:
            linear-gradient(180deg, rgba(25, 28, 30, 0.72) 0%, rgba(25, 28, 30, 0.8) 100%),
            url("/static/images/bg-dark.jpg") center / cover no-repeat;
    }
}

h1, h2, h3, h4 {
    font-family: "Space Grotesk", "IBM Plex Sans", sans-serif;
    letter-spacing: -0.02em;
}

.container {
    width: 100%;
    max-width: 640px;
    margin-top: 2rem;
    padding: 2rem;
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-soft);
    border: 1px solid var(--color-border);
}

h1 {
    color: var(--color-on-surface);
    font-size: 2rem;
    margin: 0 0 0.5rem 0;
    text-align: center;
}

p.description {
    color: var(--color-muted);
    margin: 0 0 1.75rem 0;
    font-size: 0.9375rem;
    text-align: center;
}

.section {
    padding: 1.25rem;
    border-radius: var(--radius-md);
    background: var(--color-surface-soft);
    border: 1px solid var(--color-border);
    margin-bottom: 1.25rem;
}

.section h2 {
    color: var(--color-on-surface);
    font-size: 0.9375rem;
    font-weight: 600;
    margin: 0 0 0.875rem 0;
}

.form-group {
    margin-bottom: 1rem;
}

label {
    display: block;
    margin-bottom: 0.375rem;
    color: var(--color-muted);
    font-size: 0.875rem;
    font-weight: 500;
}

input {
    width: 100%;
    padding: 0.625rem 0.875rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 1rem;
    background: var(--color-surface);
    color: var(--color-on-surface);
    font-family: "IBM Plex Sans", sans-serif;
    transition: border-color 160ms ease, box-shadow 160ms ease;
}

input:focus {
    border-color: var(--color-primary);
    outline: none;
    box-shadow: 0 0 0 3px var(--color-ring);
}

button,
.primary-btn,
.secondary-btn {
    display: block;
    width: 100%;
    margin: 0.5rem auto;
    padding: 0.625rem 1.5rem;
    border: none;
    border-radius: var(--radius-md);
    font-size: 0.9375rem;
    font-weight: 500;
    cursor: pointer;
    text-align: center;
    text-decoration: none;
    transition: background 160ms ease, color 160ms ease, box-shadow 160ms ease;
    font-family: "IBM Plex Sans", sans-serif;
}

.primary-btn {
    background: var(--color-primary);
    width: 100%;
    color: #fff;
    box-shadow: 0 1px 4px rgba(0, 103, 131, 0.2);
    margin-bottom: 1rem;
}

.primary-btn:hover {
    background: var(--color-primary-strong);
    box-shadow: 0 2px 8px rgba(0, 103, 131, 0.3);
    color: #fff;
}

.secondary-btn {
    background: transparent;
    color: var(--color-primary);
    border: 1px solid var(--color-border);
}

.secondary-btn:hover {
    background: var(--color-primary-light);
    border-color: var(--color-primary);
    color: var(--color-primary-strong);
}

.error {
    color: var(--color-error);
    font-size: 0.875rem;
    margin-top: 0.5rem;
    padding: 0.5rem 0.75rem;
    background: rgba(186, 26, 26, 0.08);
    border-radius: 8px;
    border: 1px solid rgba(186, 26, 26, 0.2);
    display: none;
}

.back-link {
    display: block;
    text-align: center;
    margin-top: 1rem;
}

.back-link::before {
    content: '← ';
}

:focus-visible {
    outline: 3px solid var(--color-ring);
    outline-offset: 2px;
}

::selection {
    background: rgba(0, 103, 131, 0.2);
}