:root {
    --bg: #0f172a;
    --panel: #1e293b;
    --panel-2: #334155;
    --text: #e2e8f0;
    --muted: #94a3b8;
    --accent: #38bdf8;
    --accent-strong: #0ea5e9;
    --danger: #ef4444;
    --success: #22c55e;
    --radius: 12px;
}

* {
    box-sizing: border-box;
}

html, body {
    margin: 0;
    padding: 0;
    height: 100%;
    background: linear-gradient(160deg, #0f172a 0%, #1e293b 100%);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    -webkit-font-smoothing: antialiased;
}

body {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
}

.container {
    width: 100%;
    max-width: 480px;
    background: var(--panel);
    border-radius: var(--radius);
    padding: 32px 28px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
}

h1 {
    margin: 0 0 24px;
    font-weight: 600;
    font-size: 22px;
    text-align: center;
    letter-spacing: 0.5px;
    color: var(--muted);
    text-transform: uppercase;
}

.display {
    font-variant-numeric: tabular-nums;
    font-feature-settings: "tnum";
    font-size: 88px;
    font-weight: 200;
    text-align: center;
    line-height: 1;
    margin-bottom: 16px;
    letter-spacing: -2px;
    transition: color 0.2s ease;
}

.display.alert {
    color: var(--danger);
}

.display.done {
    color: var(--success);
}

.progress {
    height: 6px;
    background: var(--panel-2);
    border-radius: 999px;
    overflow: hidden;
    margin-bottom: 12px;
}

.progress-bar {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--accent), var(--accent-strong));
    transition: width 0.2s linear;
}

.status {
    text-align: center;
    color: var(--muted);
    margin-bottom: 24px;
    font-size: 14px;
    min-height: 1.2em;
}

.settings {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    margin-bottom: 20px;
}

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

.field label {
    font-size: 12px;
    color: var(--muted);
    margin-bottom: 6px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.field input {
    background: var(--panel-2);
    border: 1px solid transparent;
    border-radius: 8px;
    color: var(--text);
    padding: 10px 12px;
    font-size: 16px;
    font-variant-numeric: tabular-nums;
    transition: border-color 0.15s ease;
    width: 100%;
}

.field input:focus {
    outline: none;
    border-color: var(--accent);
}

.field input:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.counter {
    text-align: center;
    color: var(--muted);
    font-size: 14px;
    margin-bottom: 20px;
    font-variant-numeric: tabular-nums;
}

.controls {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
}

.btn {
    background: var(--panel-2);
    color: var(--text);
    border: none;
    border-radius: 8px;
    padding: 12px 16px;
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.15s ease, transform 0.05s ease;
}

.btn:hover:not(:disabled) {
    background: #475569;
}

.btn:active:not(:disabled) {
    transform: translateY(1px);
}

.btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.btn-primary {
    background: var(--accent-strong);
    color: #0b1220;
    font-weight: 600;
}

.btn-primary:hover:not(:disabled) {
    background: var(--accent);
}

.btn-ghost {
    background: transparent;
    border: 1px solid var(--panel-2);
    color: var(--muted);
}

.btn-ghost:hover:not(:disabled) {
    background: var(--panel-2);
    color: var(--text);
}

.hint {
    margin-top: 18px;
    font-size: 12px;
    color: var(--muted);
    text-align: center;
    line-height: 1.5;
}

@media (max-width: 420px) {
    .display {
        font-size: 64px;
    }
    .container {
        padding: 24px 18px;
    }
    .controls {
        grid-template-columns: 1fr;
    }
}