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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background-color: #f8fafc;
    color: #334155;
    min-height: 100vh;
    padding: 20px;
    line-height: 1.6;
}

.container {
    max-width: 640px;
    margin: 0 auto;
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    overflow: hidden;
}

header {
    text-align: center;
    background: #f1f5f9;
    padding: 32px 24px;
    border-bottom: 1px solid #e2e8f0;
}

header h1 {
    font-size: 1.875rem;
    font-weight: 600;
    color: #1e293b;
    letter-spacing: -0.025em;
}

.card {
    padding: 32px;
    border-bottom: 1px solid #e2e8f0;
}

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

.card h2 {
    color: #1e293b;
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.form-group label {
    font-weight: 500;
    color: #334155;
    font-size: 0.875rem;
}

.form-group input {
    padding: 12px 16px;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
    background: #f8fafc;
}

.form-group input:focus {
    outline: none;
    border-color: #94a3b8;
    box-shadow: 0 0 0 3px rgba(148, 163, 184, 0.1);
}

.status-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.timer-display {
    font-size: 2rem;
    font-weight: 600;
    color: #1e293b;
    font-family: monospace;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: #e2e8f0;
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: #3b82f6;
    width: 0%;
    transition: width 0.3s ease;
}

.controls {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
}

.btn-primary, .btn-secondary, .btn-danger {
    padding: 12px 24px;
    border: none;
    border-radius: 6px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    text-align: center;
}

.btn-primary {
    background: #3b82f6;
    color: white;
}

.btn-primary:hover {
    background: #2563eb;
}

.btn-secondary {
    background: #64748b;
    color: white;
}

.btn-secondary:hover {
    background: #475569;
}

.btn-danger {
    background: #ef4444;
    color: white;
    padding: 12px 24px;
    font-weight: 500;
}

.btn-danger:hover {
    background: #dc2626;
}

.hint {
    font-size: 0.875rem;
    color: #64748b;
    margin-top: 4px;
}

footer {
    text-align: center;
    padding: 24px;
    color: #64748b;
    font-size: 0.875rem;
    background: #f1f5f9;
}

.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 12px 20px;
    border-radius: 6px;
    color: white;
    font-size: 0.875rem;
    transform: translateX(200%);
    transition: transform 0.3s ease;
    z-index: 1000;
    max-width: 300px;
    word-wrap: break-word;
}

.notification.success {
    background: #22c55e;
}

.notification.error {
    background: #ef4444;
}

.notification.show {
    transform: translateX(0);
}