body {
    margin: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: linear-gradient(135deg, #0f172a, #020617);
    color: #f9fafb;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    background: #020617;
    border-radius: 24px;
    padding: 32px 24px 28px;
    max-width: 900px;
    width: 100%;
    box-shadow: 0 24px 60px rgba(15,23,42,0.9);
    border: 1px solid rgba(148,163,184,0.3);
}

h1 {
    margin-top: 0;
    text-align: center;
    margin-bottom: 16px;
    font-size: 2.4rem;
}

.timer {
    font-family: "SF Mono", Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
    font-size: 4rem;
    text-align: center;
    margin: 12px 0 20px;
    color: #22c55e;
    letter-spacing: 0.05em;
}

.big-button {
    display: block;
    margin: 0 auto;
    padding: 18px 32px;
    font-size: 1.1rem;
    border-radius: 999px;
    border: none;
    cursor: pointer;
    background: #ef4444;
    color: #f9fafb;
    font-weight: 600;
    box-shadow: 0 10px 30px rgba(248,113,113,0.5);
    transition: transform 0.08s ease, box-shadow 0.08s ease, background 0.08s ease;
}

.big-button:hover {
    background: #f97373;
    transform: translateY(-1px);
    box-shadow: 0 14px 40px rgba(248,113,113,0.7);
}

.big-button:active {
    transform: translateY(0);
    box-shadow: 0 6px 20px rgba(248,113,113,0.5);
}

.history {
    margin-top: 28px;
}

.history h2 {
    font-size: 1.1rem;
    margin-bottom: 10px;
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

th, td {
    padding: 8px 6px;
    text-align: left;
}

th {
    border-bottom: 1px solid rgba(148,163,184,0.7);
    color: #e5e7eb;
    font-weight: 600;
}

tbody tr:nth-child(even) {
    background: rgba(15,23,42,0.75);
}

tbody tr:nth-child(odd) {
    background: rgba(15,23,42,0.4);
}

tbody tr:hover {
    background: rgba(30,64,175,0.6);
}

.clear-button {
    padding: 8px 16px;
    font-size: 0.85rem;
    border-radius: 999px;
    border: 1px solid rgba(248,250,252,0.2);
    background: transparent;
    color: #f9fafb;
    cursor: pointer;
    opacity: 0.7;
    transition: opacity 0.15s ease, background 0.15s ease;
}

.clear-button:hover {
    opacity: 1;
    background: rgba(248,250,252,0.08);
}