:root {
    --color-bg: #f2f4f7;
    --color-surface: #ffffff;
    --color-primary: #2c3e50;
    --color-primary-dark: #1c2833;
    --color-accent: #2980b9;
    --color-accent-dark: #1f618d;
    --color-border: #e1e5ea;
    --color-text: #2c3e50;
    --color-text-muted: #6b7785;
    --color-error: #c0392b;
    --color-error-bg: #fdecea;
    --color-notice: #2c3e50;
    --color-notice-bg: #eaf2f8;
    --radius: 12px;
}

* {
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif;
    background: var(--color-bg);
    color: var(--color-text);
    margin: 0;
    padding: 0;
    min-height: 100vh;
}

.app-header {
    background: var(--color-primary);
    color: #fff;
    padding: 20px 16px;
    text-align: center;
}

.app-header h1 {
    margin: 0;
    font-size: 1.3rem;
    font-weight: 600;
}

.app-content {
    max-width: 480px;
    margin: 24px auto 48px;
    background: var(--color-surface);
    border-radius: var(--radius);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.06);
    padding: 24px 20px;
}

@media (max-width: 520px) {
    .app-content {
        margin: 0;
        border-radius: 0;
        box-shadow: none;
        min-height: calc(100vh - 76px);
    }
}

h2 {
    font-size: 1.05rem;
    margin: 24px 0 12px;
    padding-bottom: 6px;
    border-bottom: 1px solid var(--color-border);
    color: var(--color-primary);
}

h2:first-child {
    margin-top: 0;
}

p {
    line-height: 1.6;
}

a {
    color: var(--color-accent);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
    color: var(--color-accent-dark);
}

code {
    background: var(--color-bg);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.9em;
}

hr {
    border: none;
    border-top: 1px solid var(--color-border);
    margin: 24px 0;
}

.error, .notice {
    padding: 10px 14px;
    border-radius: 8px;
    margin-bottom: 16px;
    font-size: 0.95rem;
}

.error {
    color: var(--color-error);
    background: var(--color-error-bg);
}

.notice {
    color: var(--color-notice);
    background: var(--color-notice-bg);
}

ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

ul li {
    padding: 12px 14px;
    border: 1px solid var(--color-border);
    border-radius: 8px;
    margin-bottom: 8px;
}

form {
    margin-bottom: 16px;
}

label {
    display: block;
    margin-top: 14px;
    font-size: 0.9rem;
    color: var(--color-text-muted);
}

input[type=text], input[type=email], input[type=password], select {
    width: 100%;
    padding: 11px 12px;
    box-sizing: border-box;
    margin-top: 6px;
    border: 1px solid var(--color-border);
    border-radius: 10px;
    font-size: 1rem;
    background: var(--color-surface);
    color: var(--color-text);
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(41, 128, 185, 0.15);
}

select {
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    background-image:
        linear-gradient(45deg, transparent 50%, var(--color-text-muted) 50%),
        linear-gradient(135deg, var(--color-text-muted) 50%, transparent 50%);
    background-position: calc(100% - 20px) center, calc(100% - 15px) center;
    background-size: 5px 5px, 5px 5px;
    background-repeat: no-repeat;
    padding-right: 36px;
}

button, input[type=submit] {
    -webkit-appearance: none;
    appearance: none;
    margin-top: 20px;
    padding: 13px 20px;
    border: none;
    border-radius: 10px;
    background: linear-gradient(135deg, var(--color-accent), var(--color-accent-dark));
    color: #fff;
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: 0.01em;
    cursor: pointer;
    width: 100%;
    box-shadow: 0 3px 8px rgba(41, 128, 185, 0.3);
    transition: transform 0.12s ease, box-shadow 0.12s ease, filter 0.12s ease;
}

button:hover, input[type=submit]:hover {
    filter: brightness(1.06);
    box-shadow: 0 5px 12px rgba(41, 128, 185, 0.4);
    transform: translateY(-1px);
}

button:active, input[type=submit]:active {
    transform: translateY(0);
    box-shadow: 0 2px 4px rgba(41, 128, 185, 0.35);
}

button:focus-visible, input[type=submit]:focus-visible {
    outline: 2px solid var(--color-accent-dark);
    outline-offset: 2px;
}

.btn-secondary {
    display: inline-block;
    margin-top: 14px;
    padding: 10px 18px;
    border-radius: 10px;
    background: var(--color-bg);
    color: var(--color-text);
    border: 1px solid var(--color-border);
    text-decoration: none;
    font-weight: 500;
    transition: background 0.15s ease, border-color 0.15s ease;
}

.btn-secondary:hover {
    background: #e8ebef;
    border-color: var(--color-accent);
    text-decoration: none;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 8px;
    font-size: 0.9rem;
}

table th, table td {
    padding: 8px 6px;
    border-bottom: 1px solid var(--color-border);
    text-align: left;
}

table th {
    color: var(--color-text-muted);
    font-weight: 600;
}

.nav-links {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin: 8px 0 16px;
}

.nav-links a {
    display: inline-block;
    padding: 10px 16px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: 10px;
    font-weight: 500;
    transition: background 0.15s ease, border-color 0.15s ease;
}

.nav-links a:hover {
    background: #e8ebef;
    border-color: var(--color-accent);
    text-decoration: none;
}