*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
    --bg: hsl(225, 25%, 11%);
    --text: hsl(40, 20%, 86%);
    --text-muted: hsl(30, 12%, 48%);
    --lime: #c8e632;
    --lime-dim: rgba(200, 230, 50, 0.08);
    --divider: hsl(225, 15%, 17%);
}

body {
    font-family: 'Noto Sans TC', sans-serif;
    background: var(--bg);
    background-image: radial-gradient(
        ellipse 80% 50% at 50% 0%,
        hsl(30, 20%, 13%) 0%,
        transparent 70%
    );
    color: var(--text);
    line-height: 1.8;
    -webkit-font-smoothing: antialiased;
    min-height: 100dvh;
}

/* --- Layout --- */

.container {
    max-width: 420px;
    margin: 0 auto;
    padding: 3.5rem 1.5rem 4rem;
}

/* --- Header --- */

header {
    margin-bottom: 4rem;
}

.header-emoji {
    font-size: 2.25rem;
    display: block;
    margin-bottom: 1rem;
}

header h1 {
    font-size: 2.25rem;
    font-weight: 900;
    letter-spacing: 0.06em;
    color: var(--text);
    line-height: 1.2;
}

header h1 span {
    color: var(--lime);
}

header p {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 0.5rem;
    letter-spacing: 0.04em;
}

/* --- Rules --- */

.rules {
    margin-bottom: 4rem;
}

.rule {
    padding: 1.5rem 0;
    border-bottom: 1px solid var(--divider);
}

.rule:first-child {
    padding-top: 0;
}

.rule:last-child {
    border-bottom: none;
}

.rule h3 {
    font-size: 0.9375rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 0.375rem;
}

.rule p {
    font-size: 0.8125rem;
    color: var(--text-muted);
    line-height: 1.8;
}

.rule mark {
    background: none;
    color: var(--lime);
    font-weight: 500;
}

/* --- Checklist --- */

.checklist-header {
    font-size: 0.6875rem;
    font-weight: 500;
    color: var(--text-muted);
    letter-spacing: 0.06em;
    margin-bottom: 1.25rem;
}

.checklist {
    display: flex;
    flex-direction: column;
}

.check-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 0;
    border-bottom: 1px solid var(--divider);
    cursor: pointer;
    -webkit-tap-highlight-color: transparent;
    user-select: none;
    transition: color 0.2s;
}

.check-item:last-child {
    border-bottom: none;
}

.check-item input {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
}

.check-dot {
    width: 1.25rem;
    height: 1.25rem;
    flex-shrink: 0;
    border-radius: 50%;
    border: 2px solid var(--divider);
    transition: border-color 0.2s, background 0.2s;
}

.check-item input:checked ~ .check-dot {
    border-color: var(--lime);
    background: var(--lime);
}

.check-label {
    font-size: 0.9375rem;
    font-weight: 500;
    transition: color 0.25s;
}

.check-item input:checked ~ .check-label {
    color: var(--text-muted);
    text-decoration: line-through;
    text-decoration-color: var(--text-muted);
    text-decoration-thickness: 1px;
}

/* --- Success --- */

.success {
    display: none;
    margin-top: 2rem;
    text-align: center;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--lime);
}

.success.show {
    display: block;
}

/* --- Footer --- */

footer {
    margin-top: 5rem;
    font-size: 0.625rem;
    color: var(--text-muted);
    opacity: 0.4;
    letter-spacing: 0.06em;
}