:root {
    --color-bg: #f6f8fc;
    --color-surface: #ffffff;
    --color-border: #e3e6ea;
    --color-text: #202124;
    --color-text-muted: #5f6368;
    --color-text-faint: #80868b;
    --color-accent: #3452d9;
    --color-accent-hover: #2a41b3;
    --color-accent-bg: #eef1fd;
    --color-danger: #c5221f;
    --color-star: #e8a33d;

    --space-1: 4px;
    --space-2: 8px;
    --space-3: 16px;
    --space-4: 24px;
    --space-5: 32px;

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;

    --shadow-modal: 0 8px 28px rgba(32, 33, 36, 0.28);

    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: #131314;
        --color-surface: #1e1f20;
        --color-border: #3c3f43;
        --color-text: #e8eaed;
        --color-text-muted: #9aa0a6;
        --color-text-faint: #80868b;
        --color-accent: #7b93ff;
        --color-accent-hover: #97aaff;
        --color-accent-bg: #232a4d;
        --color-danger: #f2897f;
        --color-star: #f2c063;
        --shadow-modal: 0 8px 28px rgba(0, 0, 0, 0.55);
    }
}

* {
    box-sizing: border-box;
}

html, body {
    height: 100%;
}

body {
    margin: 0;
    background: var(--color-bg);
    color: var(--color-text);
    font-family: var(--font-family);
    font-size: 14px;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

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

button {
    font-family: inherit;
    font-size: inherit;
    cursor: pointer;
}

input, textarea {
    font-family: inherit;
    font-size: inherit;
    color: inherit;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-1);
    border: none;
    border-radius: var(--radius-md);
    padding: 10px 20px;
    font-weight: 500;
    background: var(--color-surface);
    color: var(--color-text);
    border: 1px solid var(--color-border);
    transition: background-color 0.15s ease, box-shadow 0.15s ease;
}

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

.btn-primary {
    background: var(--color-accent);
    color: #fff;
    border-color: transparent;
}

.btn-primary:hover {
    background: var(--color-accent-hover);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: default;
}

.btn-icon {
    width: 36px;
    height: 36px;
    padding: 0;
    border: none;
    background: transparent;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-muted);
}

.btn-icon:hover {
    background: var(--color-bg);
}