* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    background: linear-gradient(160deg, #f3f6fb 0%, #e9f1ff 100%);
    color: #0f172a;
    font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
}

.time-tracker {
    width: min(760px, 92vw);
    margin: 3rem auto;
    background: #ffffff;
    border: 1px solid #dbe6ff;
    border-radius: 18px;
    box-shadow: 0 18px 48px rgba(15, 23, 42, 0.12);
    padding: 1.5rem;
    display: grid;
    gap: 1.25rem;
}

.time-tracker__head h1 {
    margin: 0;
    font-size: 1.6rem;
}

.time-tracker__head p {
    margin: 0.4rem 0 0;
    color: #475569;
}

.time-tracker__profile {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem;
}

.time-tracker__profile label,
.time-tracker__topic {
    display: grid;
    gap: 0.35rem;
}

.time-tracker__profile span,
.time-tracker__topic label {
    font-size: 0.9rem;
    color: #334155;
}

input[type="text"] {
    width: 100%;
    border: 1px solid #cbd5e1;
    border-radius: 10px;
    padding: 0.7rem 0.8rem;
    font-size: 1rem;
    background: #fff;
}

input[type="text"]:focus {
    outline: 2px solid #94a3b8;
    border-color: #64748b;
}

input[type="datetime-local"] {
    width: 100%;
    border: 1px solid #cbd5e1;
    border-radius: 10px;
    padding: 0.7rem 0.8rem;
    font-size: 1rem;
    background: #fff;
}

input[type="datetime-local"]:focus {
    outline: 2px solid #94a3b8;
    border-color: #64748b;
}

.time-tracker__clock {
    background: #0f172a;
    border-radius: 14px;
    padding: 1rem;
    color: #f8fafc;
    display: grid;
    gap: 1rem;
}

.time-tracker__display {
    font-size: clamp(2rem, 8vw, 3rem);
    font-weight: 700;
    text-align: center;
    letter-spacing: 0.08em;
    font-variant-numeric: tabular-nums;
}

.time-tracker__buttons {
    display: flex;
    gap: 0.65rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    border: 0;
    border-radius: 999px;
    padding: 0.65rem 1.2rem;
    font-size: 0.95rem;
    font-weight: 700;
    cursor: pointer;
    color: #fff;
}

.btn:disabled {
    opacity: 0.45;
    cursor: not-allowed;
}

.btn--start {
    background: #15803d;
}

.btn--pause {
    background: #b45309;
}

.btn--stop {
    background: #b91c1c;
}

.btn--manual {
    background: #1d4ed8;
    width: fit-content;
}

.time-tracker__manual,
.time-tracker__recent {
    border: 1px solid #dbe6ff;
    border-radius: 14px;
    padding: 1rem;
    background: #f8fbff;
    display: grid;
    gap: 0.75rem;
}

.time-tracker__manual h2,
.time-tracker__recent h2 {
    margin: 0;
    font-size: 1.05rem;
}

.time-tracker__manual-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem;
}

.time-tracker__manual-grid label {
    display: grid;
    gap: 0.35rem;
}

.time-tracker__manual-grid span {
    font-size: 0.9rem;
    color: #334155;
}

.time-tracker__recent-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    gap: 0.65rem;
}

.time-tracker__recent-item {
    display: grid;
    gap: 0.2rem;
    border: 1px solid #dbe6ff;
    border-radius: 10px;
    background: #fff;
    padding: 0.6rem 0.75rem;
}

.time-tracker__recent-item strong {
    font-size: 0.96rem;
}

.time-tracker__recent-item span {
    font-size: 0.88rem;
    color: #475569;
}

.time-tracker__recent-empty {
    color: #64748b;
    font-size: 0.92rem;
}

.time-tracker__status {
    min-height: 1.3rem;
    margin: 0;
    color: #0f172a;
    font-size: 0.95rem;
}

@media (max-width: 700px) {
    .time-tracker {
        margin: 1rem auto 2.2rem;
        padding: 1rem;
    }

    .time-tracker__profile {
        grid-template-columns: 1fr;
    }

    .time-tracker__manual-grid {
        grid-template-columns: 1fr;
    }
}