:root {
    --stelia-accent: #1a73e8;
    --stelia-accent-dark: #1557b0;
    --stelia-danger: #d93025;
    --stelia-bg: #f0f2f5;
    --stelia-surface: #ffffff;
    --stelia-border: #e3e6ea;
    --stelia-text: #202124;
    --stelia-muted: #5f6368;
}

* {
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    background: var(--stelia-bg);
    color: var(--stelia-text);
}

.container,
#auth-container,
#chat-container,
#storage-container,
#billing-section,
main {
    max-width: 1000px;
    margin: 40px auto;
    padding: 24px;
    background: var(--stelia-surface);
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

h1,
h2,
h3 {
    color: var(--stelia-accent);
    margin-top: 0;
}

h1 {
    font-size: 26px;
}

h2 {
    font-size: 20px;
}

.header-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
    margin-bottom: 20px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--stelia-border);
}

.nav-links {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
}

.nav-links a {
    color: var(--stelia-accent);
    text-decoration: none;
    font-weight: 500;
    font-size: 14px;
}

.nav-links a:hover {
    text-decoration: underline;
}

.nav-links a.active {
    color: var(--stelia-text);
    font-weight: 700;
}

input,
select,
textarea {
    padding: 10px 12px;
    border: 1px solid #ccd1d7;
    border-radius: 6px;
    font-size: 15px;
    font-family: inherit;
    color: inherit;
    background: var(--stelia-surface);
}

button {
    padding: 10px 20px;
    background: var(--stelia-accent);
    color: #fff;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 15px;
    font-weight: 600;
    font-family: inherit;
    transition: background 0.2s ease;
}

button:hover {
    background: var(--stelia-accent-dark);
}

button:disabled {
    background: #c3c8ce;
    cursor: not-allowed;
}

button.danger {
    background: var(--stelia-danger);
}

button.danger:hover {
    background: #a50e0e;
}

.error {
    color: var(--stelia-danger);
    background: #fce8e6;
    padding: 10px 12px;
    border-radius: 6px;
    margin-bottom: 15px;
}

.hint {
    font-size: 12px;
    color: var(--stelia-muted);
    font-weight: 400;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}

th,
td {
    text-align: left;
    padding: 12px;
    border-bottom: 1px solid var(--stelia-border);
}

th {
    background: #f8f9fa;
    color: var(--stelia-accent);
}

pre {
    white-space: pre-wrap;
    overflow-wrap: anywhere;
    font: 13px/1.5 ui-monospace, SFMono-Regular, Menlo, monospace;
    background: #f8f9fa;
    border: 1px solid var(--stelia-border);
    border-radius: 6px;
    padding: 12px;
}

@media (max-width: 640px) {
    .container,
    #auth-container,
    #chat-container,
    #storage-container,
    main {
        margin: 16px;
        padding: 16px;
    }
}