:root {
    --bg-color: #020617;
    --card-bg: #0f172a;
    --accent-blue: #38bdf8;
    --text-main: #f8fafc;
    --text-muted: #64748b;
    --border-color: #1e293b;
    --green-accent: #22c55e;
    --red-accent: #ef4444;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, monospace;
    user-select: none;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 16px;
}

.clock-container {
    width: 100%;
    max-width: 500px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

/* Top Toolbar */
.clock-header {
    width: 100%;
    display: flex;
    justify-content: flex-end;
    align-items: center;
}

.icon-btn {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    color: var(--text-main);
    padding: 6px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.85rem;
}

/* Clock Display */
.clock-display {
    width: 100%;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 32px 16px;
    text-align: center;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.date-text {
    font-size: 1rem;
    color: var(--text-muted);
    letter-spacing: 2px;
    text-transform: uppercase;
    margin-bottom: 8px;
}

.time-text {
    font-size: 3.8rem;
    font-weight: bold;
    color: var(--accent-blue);
    letter-spacing: 2px;
    font-variant-numeric: tabular-nums;
}

/* Tracker Panel */
.tracker-panel {
    width: 100%;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.tracker-controls {
    display: flex;
    gap: 10px;
}

.action-btn {
    flex: 1;
    padding: 10px 0;
    border: none;
    border-radius: 6px;
    font-weight: bold;
    font-size: 0.95rem;
    cursor: pointer;
    transition: opacity 0.2s;
}

.action-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.action-btn.start { background: var(--green-accent); color: #020617; }
.action-btn.stop  { background: var(--red-accent); color: #ffffff; }
.action-btn.reset { background: var(--border-color); color: var(--text-main); }

.timestamps-display {
    display: flex;
    justify-content: space-around;
    border-top: 1px solid var(--border-color);
    padding-top: 12px;
}

.stamp-box {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

.stamp-box .label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
}

.stamp-box .value {
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--text-main);
    font-variant-numeric: tabular-nums;
}

/* Footer */
.clock-footer {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.75rem;
}